pre-hospital and retrieval medicine update

Pre-hospital update has moved

2011-06-04T04:01:00.000-07:00

Please visit the RESUS.ME site for updates in pre-hospital care as well as other aspects of resuscitation medicine

Plasma:red cell transfusion ratio in trauma

2010-02-12T17:53:00.002-08:00

In major trauma patients who require blood transfusion, fresh frozen plasma (FFP) to packed red blood cell (RBC) ratios of up to 1:1 have been associated with reduced mortality in retrospective studies, which may be in part due to survival bias (some patients die before they can be given as much FFP as the survivors).

To eliminate this bias, Australian researchers reviewed 331 trauma patients receiving at least 5 units of red cells in the first 4 hours, with a median Injury Severity Score of 36. When deaths in the first 24 hours were excluded, FFP:RBC ratio had no association with mortality. They conclude that prospective randomised controlled trials are needed.

Fresh frozen plasma (FFP) use during massive blood transfusion in trauma resuscitation
Injury. 2010 Jan;41(1):35-9

Self-extrication with a collar on

2010-02-12T17:53:00.001-08:00

Using a sophisticated infrared six camera motion capture system, investigators demonstrated decreased cervical spine movement when collared volunteers self-extricated from a mock smashed up Toyota Corolla, when compared with extrication by paramedics using a backboard.

The authors conclude that in ambulatory subjects who do not complain of back pain, the least motion of the cervical spine may occur when the subject is allowed to exit the car in a c-collar without backboard immobilisation.

Cervical spine motion during extrication: a pilot study
West J Emerg Med. 2009 May;10(2):74-8

Full text article

Standard medication kit for prehospital and retrieval physicians

2010-02-09T19:59:00.001-08:00

A very comprehensive (hence the title of the paper) review of medications required for pre-hospital & retrieval medicine missions was undertaken, resulting in recommendations. While the casemix seen by various services may be influenced by local geography or tasking restrictions, the list provides an excellent standard from which locally appropriate modifications can be made.

Defining a standard medication kit for prehospital and retrieval physicians: a comprehensive review.
Emerg Med J. 2010 Jan;27(1):62-71

Self-extrication with a collar on

2010-02-09T19:58:00.001-08:00

Cervical spine motion during extrication: a pilot study
West J Emerg Med. 2009 May;10(2):74-8

Full text article

Best way to insert NG tube in intubated patients

2010-02-04T22:42:00.001-08:00

A randomised controlled trial on 200 anaesthetised, tracheally intubated adults compared four methods of nasogastric tube placement, looking at success rates, time to insertion, and complications.

The four groups were: control, using a ureteral guidewire as stylet, a slit endotracheal tube as an introducer, and head flexion with lateral neck pressure. All intervention groups were more successful than the control group. The time necessary to insert the NG tube was significantly longer in the slit endotracheal tube group, which also had the highest bleeding rate. Complications were fewest in the flexion group.

Nasogastric tube insertion using different techniques in anesthetized patients: a prospective, randomized study
Anesth Analg. 2009 Sep;109(3):832-5

Heliox in COPD exacerbation

2010-02-04T22:41:00.002-08:00

A 65:35 helium-oxygen mix was compared with 35% oxygen in air in patients with COPD exacerbations requiring non-invasive ventilation. In this RCT there was no difference in intubation rates between the heliox or air/oxygen groups.

A multicenter, randomized trial of noninvasive ventilation with helium-oxygen mixture in exacerbations of chronic obstructive lung disease
Crit Care Med. 2010 Jan;38(1):145-51

Surviving Sepsis Campaign guideline adherence and mortality

2010-02-04T22:41:00.001-08:00

Data from 15,022 subjects at 165 sites at which the Surviving Sepsis Campaign (SSC) 6 hour and 24 hour care guideline bundles were introduced were submitted from 2005 to early 2008. As adherence to the guidelines increased (18.4 to 26.1%), hospital mortality decreased (37 to 30.8%). The study was partly funded by manufacturers of some of the monitoring and therapeutic components of the SSC guidelines.

The Surviving Sepsis Campaign: Results of an international guideline- based performance improvement program targeting severe sepsis
Crit Care Med. 2010 Feb;38(2):367-74

An insightful editorial points out several methodological weaknesses in this study, as well as the interesting point that the guidelines published in 2004 drew on evidence published predominantly between 2000 and 2003, and subsequent research has called a number of components into question. Examples are:

The Corticosteroid Therapy of Septic Shock (CORTICUS) study did not confirm that low-dose corticosteroids were beneficial
the Normoglycaemia in Intensive Care Evaluation and Survival Using Glucose Algorithm Regulation (NICE- SUGAR) study reported that targeting tight glycemic control may be harmful
Early goal-directed therapy is the subject of no less than three ongoing clinical trials supported by national research funding agencies
and the effect of drotrecogin alfa (activated) is being re-examined in both industry-sponsored and investigator-initiated trials.

While scientific skepticism is healthy, there is no doubt at least that in part due to the efforts of the SSC more clinicians than ever are aware of the importance of timely aggressive management of severe sepsis / septic shock.

The Surviving Sepsis Campaign: robust evaluation and high-quality primary research is still neede
Crit Care Med. 2010 Feb;38(2):683-4

Differentiating arteries from veins

2010-02-04T22:40:00.002-08:00

In a letter to Critical Care Medicine, ultrasound legend Michael Blaivas reminds readers that during ultrasound-guided central venous catheterisation, an additional technique for differentiating the common carotid artery from the internal jugular vein: pulse-wave doppler.

Blaivas states: “The left panel shows a classic arterial tracing from the common carotid artery with a normal velocity. The right panel shows the vessel of choice on the same patient: the right internal jugular vein. The image shows a slightly chaotic venous tracing from the jugular. This a common appearance and is markedly different from the waveform of the carotid.”

Posterior vessel wall penetration by needles during internal jugular vein central catheter placement using ultrasound guidance: is that a real danger? Author’s Reply.
Crit Care Med. 2010 Feb;38(2):736-7

Therapeutic hypothermia with simple measures

2010-02-04T22:40:00.001-08:00

Thirty-eight post-cardiac arrest patients were effectively cooled to the target temperature range of 32-34 celsius using intravenous cold saline and ice packs to groin, axillae, and neck. The ice packs were frozen 250 ml saline bags wrapped in pillow cases. If shivering occurred muscle relaxation with rocuronium was used until the target temperature was reached. Interestingly, rebound hyperthermia occurred in 8/34 patients.

Although a small study, these data reassure those of us who induce therapeutic hypothermia without the use of dedicated cooling equipment.

Cold saline infusion and ice packs alone are effective in inducing and
maintaining therapeutic hypothermia after cardiac arrest
Resuscitation 2010;81:15–19

External jugular vein a tricky one

2010-02-04T22:39:00.007-08:00

Emergency medicine residents and paramedics cannulated patients who were anaesthetised. The external jugular vein (EJV) took longer to cannulate and had a higher failure rate than an antecubital vein. More than a quarter of the paramedics and a third of the doctors failed to cannulate the EJV.
Is external jugular vein cannulation feasible in emergency care? A randomised study in open heart surgery patients
Resuscitation. 2009 Dec;80(12):1361-4

IO in OI

2010-02-04T22:39:00.005-08:00

A case report describes three failed attempts to flush or secure an intraosseous needle placed using the EZ-IO drill during cardiac arrest of an adult patient subsequently noted to have osteogenesis imperfecta (OI) type III. While not listed as a contraindication to EZ-IO use by the manufacturer, one should consider that OI may result in procedural failure.

Intraosseous access in osteogenesis imperfecta (IO in OI)

HEMS paramedic intubation success

2010-02-04T22:39:00.003-08:00

All medical out of hospital cardiac arrests attended by the Warwickshire and Northamptonshire Air Ambulance (WNAA) over a 64-month period were reviewed. There were no significant differences in self-reported intubation failure rate, morbidity or clinical outcome between doctor-led and paramedic-led cases. The authors conclude that experienced paramedics regularly operating with physicians have a low tracheal intubation failure rate at out of hospital cardiac arrests, whether practicing independently or as part of a doctor-led team, and that this is likely due to increased and regular clinical exposure.

Can experienced paramedics perform tracheal intubation at cardiac arrests? Five years experience of a regional air ambulance service in the UK
Resuscitation. 2009 Dec;80(12):1342-5

DC shock? I want my blankie!

2010-02-04T22:39:00.001-08:00

A blanket made of nonconducting material was used to allow CPR to continue during defibrillation of arrested swine. Coronary perfusion pressure was maintained when the blanket was used

but fell when there was a hands-off interruption for defibrillation. Also, the defibrillation threshold was significantly lower when the blanket was used. A good idea, although even the authors point out that “Thus far, medical literature has not reported any rescuer or bystander serious injury from receiving an inadvertent shock while in direct or indirect contact with a patient while performing CPR“

The resuscitation blanket: A useful tool for “hands-on” defibrillation
Resuscitation. 2010 Feb;81(2):230-23

Precordial thump

2010-02-04T22:38:00.003-08:00

The precordial thump is recommended for witnessed and monitored ventricular fibrillation/ventricular tachycardia (VF/VT) cardiac arrest when a defibrillator is not immediately available.

Haman et al investigated the precordial thump in patients in whom VT or VF was initiated during an electrophysiological study, applying a single thump after initiation of ventricular arrhythmia in 155 patients. This terminated the tachycardia in two (1.3%) patients.

Pellis et al investigated the precordial thump as an initial measure by paramedics in 144 patients in out-of-hospital cardiac arrest, irrespective of the initial rhythm. Three patients had return of spontaneous circulation and two were discharged alive.

Precordial thump efficacy in termination of induced ventricular arrhythmias
Resuscitation 2009;80:14–6

Utility of pre-cordial thump for treatment of out of hospital cardiac arrest: a prospective study
Resuscitation 2009;80:17–23

Naloxone in cardiac arrest

2010-02-04T22:38:00.001-08:00

Previous case reports and animal studies have suggested a possible role for naloxone in cardiac arrest even in the absence of opioid overdose.

Possible mechanisms include reducing the myocardial depressant effect of endogenous opioids, stimulating catecholamine release, and providing antiarryhthmic effects through an effect on cardiomyocyte ion channels.

A retrospective review of 32,544 out of hospital cardiac arrests over 5 years revealed 36 to have received pre-hospital naloxone. Of these, only one survived to hospital discharge, who tested positive for opiates in a urine toxicology screen in the emergency department.

No need to change the guidelines yet then.

Naloxone in cardiac arrest with suspected opioid overdoses
Resuscitation. 2010 Jan;81(1):42-6

Thoracostomy in blunt traumatic arrest

2010-01-16T14:30:00.001-08:00

37 patients with blunt traumatic cardiac arrest underwent attempted resuscitation by a HEMS crew over a four year period. Chest decompression was performed in 18 cases (17 thoracostomy, one needle decompression). The procedure revealed evidence of chest injury in 10 cases (pneumothorax, haemothorax, massive air leak) and resulted in return of circulation and survival to hospital in four cases. All four cases died of associated major head injury, although one became a heart beating organ donor. Only half of the cases found to have pneumothorax demonstrated clinical signs of one prior to chest decompression.
The authors state: ‘Relying on clinical signs of the thorax alone will not identify all patients with these injuries, and our data support extending the practice into all patients with a suitable mechanism of injury together with external evidence of chest injury.’
Chest decompression during the resuscitation of patients in prehospital traumatic cardiac arrest
Emerg Med J. 2009 Oct;26(10):738-40

Not such a B.I.G. success in the field?

2010-01-16T14:24:00.002-08:00

Success rates with the bone injection gun were 71% (10 out of 14) in children <16 years and 73% (19 out of 26) in adults. Less encouraging data than that seen with the EZ-IO device, and consistent with the experience of some other services.

Prehospital Intraosseus Access With the Bone Injection Gun by a Helicopter-Transported Emergency Medical Team
J Trauma. 2009 Jun;66(6):1739-41

Ballistic penetrating neck injury and the risk of immobilisation

2010-01-16T14:24:00.001-08:00

British military physicians reported the outcomes of patients sustaining penetrating neck injury from the Iraq and Afghanistan conflicts. Three quarters were injured in explosions, one quarter from gunshots.

Of 90 patients, only 1 of the 56 survivors to reach a surgical facility sustained an unstable cervical spine injury that required surgical stabilisation. This patient later died as result of a co-existing head injury. The authors conclude that penetrating ballistic trauma to the neck is associated with a high mortality rate, and their data suggest that it is very unlikely that penetrating ballistic trauma to the neck will result in an unstable cervical spine in survivors. In a hazardous environment the risk/benefit ratio of mandatory spinal immobilisation is unfavourable and may place medical teams at prolonged risk, and cervical collars may hide potential life-threatening conditions.

Learning the lessons from conflict: Pre-hospital cervical spine stabilisation following ballistic neck trauma
Injury. 2009 Dec;40(12):1342-5

Prehospital Hypocapnia and Poor Outcome After Severe Traumatic Brain Injury

2010-01-16T14:23:00.000-08:00

Patients admitted to a level 1 trauma centre with traumatic brain injury whose end-tidal CO2 was kept with the Brain Trauma Foundation recommended limits of 30-35 mmHg (3.9-4.6 kPa) had a lower mortality than those whose CO2 was outside this range. The group in which the target was not achieved had a greater injury severity, which may have contribute to the difficulty in optimising ETCO2.

Prehospital Hypocapnia and Poor Outcome After Severe Traumatic Brain Injury
J Trauma. 2009 Jun;66(6):1577-82

No benefit from drugs in pre-hospital cardiac arrest

2010-01-16T14:22:00.000-08:00

A Norwegian randomised controlled trial over five years compared out-of-hospital nontraumatic cardiac arrest outcomes between ACLS protocols with and without access to intravenous drugs (epinephrine/adrenaline, atropine, amiodarone).

Patients randomised to the drug group had a higher rate of hospital admission with return of spontaneous circulation, but there was no significant difference in survival to discharge, survival with favourable neurological outcome, or one year survival.

Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest
JAMA. 2009 Nov 25;302(20):2222-9

Is cervical spine protection always necessary following penetrating neck injury?

2010-01-16T14:21:00.000-08:00

This short cut review in the Best Bets format attempted to answer the question: “is cervical spine protection always necessary following penetrating neck injury?”

From the available evidence they draw the following conclusions:

In stab wounds to the neck (with or without neurological deficit) an unstable spinal injury is very unlikely and c-spine immobilisation is not needed
In gunshot wounds the value of cspine immobilisation is limited: for gunshot wounds without neurological deficit no immobilisation is required, while in cases of gunshot wounds with neurological deficit, or where the diagnosis cannot be made (ie, altered mental status), a collar or sandbag is advised once ABCs are stable, with close observation and intermittent removal to inspect and reassess.
In the rare event of penetrating injury with combined blunt force trauma, a collar or sandbag is advised if possible, once ABCs are stable, with intermittent removal to reassess.

Emerg Med J. 2009 Dec;26(12):883-7

Full text at BestBets.org

Spinal imaging and immobilisation may be unnecessary in many GSW patients

2010-01-16T14:19:00.000-08:00

A retrospective review of 4204 patients sustaining gunshot wounds (GSW) to the head, neck or torso examined the incidence of spinal cord injury and bony spinal column injury required operative spinal intervention. None of the patients demonstrated spinal instability requiring operative intervention, and only 2/327 (0.6%) required any form of operative intervention for decompression. The authors concluded that spinal instability following GSW with spine injury is very rare, and that routine spinal imaging and immobilisation is unwarranted in examinable patients without symptoms consistent with spinal injury following GSW to the head, neck or torso.
The role of routine spinal imaging and immobilisation in asymptomatic patients after gunshot wounds
Injury. 2009 Aug;40(8):860-3

Effect on noradrenaline on tissue oxygen delivery

2009-12-20T20:49:00.000-08:00

Some persist in thinking and teaching that the ‘vasopressor’ noradrenaline (norepinephrine) increases mean arterial pressure (MAP) simply by increasing systemic vascular resistance, leading to concerns that it may increase blood pressure at the expense of tissue perfusion. This assertion is contested by many, who now have further support from this study.

In 16 patients with septic shock, various measures of peripheral perfusion were recorded while the dose of noradrenaline was increased to achieve target MAPs. The use of noradrenaline to achieve incremental targets for MAP was associated with increases in global oxygen delivery, cutaneous microvascular flow, and tissue oxygenation in patients with established septic shock; there were no associated changes in the preexisting abnormalities of sublingual microvascular flow. The authors state that these findings suggest that in patients with septic shock, improvements in global hemodynamics and tissue oxygen delivery can be achieved with noradrenaline, without exacerbating microcirculatory flow abnormalities.

The effect of increasing doses of norepinephrine on tissue oxygenation and microvascular flow in patients with septic shock
Crit Care Med. 2009 Jun;37(6):1961-6

Cuffed tracheal tubes for children

2009-12-07T13:34:00.004-08:00

In a prospective randomised controlled multi-centre trial, cuffed tracheal tubes were compared with uncuffed tubes in 2246 children aged from birth to five years undergoing general anaesthesia. There was no significant difference in post-extubation stridor but the need for tube exchange was 2.1% in the cuffed and 30.8% in the uncuffed groups (P<0.0001).

From the resuscitation point of view, there remain few if any arguments for using an uncuffed tube.

Prospective randomized controlled multi-centre trial of cuffed or uncuffed endotracheal tubes in small children

Br J Anaesth. 2009 Dec;103(6):867-73

First Aid for Burns

2009-12-07T13:34:00.003-08:00

A review of burn first aid treatments highlights the paucity of evidence on which to make firm recommendations. The authors recommend using cold running tap water (between 2 and 15 degrees C) and to avoid ice or alternative therapies. The optimum duration of first aid application and the delay after the injury for which first aid can still be effective are two areas of research which need further exploration.

A review of first aid treatments for burn injuries
Burns. 2009 Sep;35(6):768-75

Physicians didn’t improve outcome from nontraumatic cardiac arrest

2009-12-07T13:34:00.001-08:00

A Norwegian study retrospectively compared outcomes from non-traumatic cardiac arrest between ambulances staffed by physicians (PMA) and non-physician ambulances (non-PMA). There were no differences in any of the clinical outcome measures used in this study of 977 patients, in which 13% (PMA) and 11% (non-PMA) survived to hospital discharge.

Out-of hospital advanced life support with or without a physician: Effects on quality of CPR and outcome
Resuscitation. 2009 Nov;80(11):1248-52

Fluids for cooling post cardiac arrest

2009-12-07T13:33:00.001-08:00

Large volume cold fluid resuscitation after return of spontaneous circulation can contribute to effective cooling but does it impair cardiac or respiratory function? A retrospective review of 52 resuscitated cardiac arrest patients suggests that the infusion of large volumes of cold fluid does not cause a further significant reduction in respiratory function beyond that normally seen after cardiac arrest despite significantly reduced LV function.

Effects of large volume, ice-cold intravenous fluid infusion on respiratory function in cardiac arrest survivors
Resuscitation. 2009 Nov;80(11):1223-8

In the same issue of Resuscitation, a prospective study of cardiac arrest survivors in positive fluid balance from cold fluid cooling showed frequent evidence of hypovolaemia as determined by serial ultrasound assessment.

An accompanying editorial suggests this may be due to the systemic inflammatory response syndrome that follows successful cardiac arrest resuscitation; large volumes are tolerated well and myocardial dysfunction should not lead to restriction of fluids after cardiac arrest.

Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors
Resuscitation. 2009 Nov;80(11):1234-9

Pre-hospital intubation for head injury: ?no benefit

2009-12-07T13:32:00.000-08:00

A systematic review of pre-hospital intubation for head injured patients failed to show evidence of benefit of tracheal intubation or invasive ventilation. The authors acknowledge the lack of methodological quality in the studies reviewed and the predominance of US paramedic-delivered intubations without the use of anaesthetic drugs.

Pre-hospital tracheal intubation in patients with traumatic brain injury: systematic review of current evidence
Br J Anaesth. 2009 Sep;103(3):371-86

Pre-hospital intubation ’success’ at a US centre

2009-12-07T13:31:00.000-08:00

Of 203 patients attending a US Level 1 trauma centre who had pre-hospital airway management, 25 (12%) had unrecognised oesophageal intubations.

Patients were treated in the field by fire rescue personnel of various municipalities and with different experience levels. Patients transported by air were significantly more likely to be successfully intubated than those transported by ground, perhaps due to both increased experience and the use by air crews of succinylcholine. The authors in their discussion contrast these results with those of European studies which report higher success rates with pre-hospital systems that employ emergency physicians and anaesthetists.

Prehospital intubations and mortality: a level 1 trauma center perspective
Anesth Analg. 2009 Aug;109(2):489-93

Vehicle Rollover

2009-12-07T13:29:00.000-08:00

Vehicle rollover as an indicator of mechanism of injury was investigated in a study examining accident databases and the medical literature. Only 2.4% of crashes involved rollovers but they accounted for one third of occupant deaths.

Some facts on vehicle rollover from the article:

Rollover is defined as a vehicle overturned by at least one quarter turn (at least onto its side).
Some rollovers involve many quarter turns and the final resting position may be on the vehicle’s side, roof, or back on its wheels.
Factors that cause a vehicle to roll over include trajectory (i.e., turning vs. straight), vehicle type, and speed (precrash velocity may be the most predictive factor)

The importance of vehicle rollover as a field triage criterion
J Trauma. 2009 Aug;67(2):350-7

Paramedics apply cervical spine rule successfully

2009-10-28T15:38:00.001-07:00

The Canadian C-Spine rule – a decision instrument designed to clinically rule out important cervical spine injuries in alert patients – was successfully and safely applied by Canadian paramedics in a study of 1949 patients. Any misinterpretation erred on the side of safety.
This important work could ultimately result in less stress, discomfort, and wasting of ambulance resources and time for this large subgroup of pre-hospital patients.

The Out-of-Hospital Validation of the Canadian C-Spine Rule by Paramedics
Ann Emerg Med. 2009 Nov;54(5):663-671

emergence with ketamine overstated

2009-10-28T15:32:00.001-07:00

A prospective study of 746 children sedated in the emergency department with iv or im ketamine revealed 2.1% may have experienced ‘emergence delirium’ although the authors concede this was difficult to define. In contrast, 291 (38%) reported pleasant altered perceptions. Follow up revealed at least one nightmare in the following weeks in 3.4% of patients, which may be well under the rate reported in the normal unsedated paediatric population.

What is the nature of the emergence phenomenon when using intravenous or intramuscular ketamine for paediatric procedural sedation?
Emerg Med Australas. 2009 Aug;21(4):315-22

Ambulance transport induces stress

2009-10-28T15:30:00.000-07:00

Plasma levels of adrenaline and noradrenaline increased signficantly in patients with acute coronary syndrome during ambulance transportation – a finding in keeping with studies on normal volunteers. I wonder how much more of an effect helicopter retrieval might have?

Emergency ambulance transport induces stress in patients with acute coronary syndrome
Emerg Med J. 2009 Jul;26(7):524-8.

Ketamine lowered ICP in brain-injured kids

2009-10-28T15:24:00.000-07:00

Ventilated children between the ages of 1 and 16 with traumatic brain injury and elevated intracranial pressure (ICP) were given ketamine and effect on cerebral perfusion pressure (CPP) and ICP was measured. Ketamine decreased ICP while maintaining blood pressure and CPP. These results refute the notion that ketamine increases ICP. The authors conclude: “Ketamine is a safe and effective drug for patients with traumatic brain injury and intracranial hypertension, and it can possibly be used safely in trauma emergency situations”
Effectiveness of ketamine in decreasing intracranial pressure in children with intracranial hypertension
J Neurosurg Pediatr. 2009 Jul;4(1):40-6 (Full text)

Etomidate versus ketamine for rapid sequence intubation

2009-10-03T20:18:00.000-07:00

Finally a well designed blinded randomised controlled trial on this subject. 0.3 mg/kg etomidate was compared with 2mg/kg ketamine for RSI in 655 patients requiring emergency intubation in the pre-hospital, emergency department, or intensive care unit environments. No difference was observed in intubation conditions or the primary endpoint of maximum SOFA score in the first three days, although the etomidate group had a higher rate of adrenal insufficiency as defined by response to an ACTH test.

Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: a multicentre randomised controlled trial.
Lancet. 2009 Jul 25;374(9686):293-300

Clinical Update July 2009 CME Questions

2009-09-12T13:23:00.000-07:00

Answer True or False to the following questions. Answers at the bottom of the July 2009 Update.

1) In refractory septic shock there is no clear evidence that steroids reduce mortality.

2) Noradrenaline (norepinephrine) may cause cerebral vasodilation by reducing minute ventilation

3) Intravenous morphine provides more effective analgesia to children than nebulised fentanyl

4) Paediatric non-femoral central venous catheter tips should be sited at the level of the carina

5) Following fibrinolysis for ST-elevation myocardial infarction, transferring the patient for urgent percutaneous coronary intervention (PCI) within six hours may improve outcome compared with delayed cardiac catheterisation.

July 2009

2009-09-12T12:29:00.000-07:00

A Systematic Review of Corticosteroids in the Treatment of Severe Sepsis and Septic Shock in Adults

This thorough review confirms that steroids have no clear benefit on mortality in severe sepsis / septic shock. Looking at prolonged courses of low dose steroids, there may be a beneficial effect but this did not reach statistical significance.

JAMA. 2009 Jun 10;301(22):2362-75

http://www.ncbi.nlm.nih.gov/pubmed/1950938 3

Evaluation of emergency medicine trainees’ ability to use transport equipment

47 senior emergency medicine trainees from three Australian hospitals were tested three pieces of transport equipment from their own EDs: portable ventilator, infusion pump, and monitor-defibrillator. They didn’t do as well as you’d want....how would you fare?

Emerg Med Australas. 2009 Jun;21(3):170-7

http://www.ncbi.nlm.nih.gov/pubmed/19527275

Investigating pressure bandaging for snakebite in a simulated setting: Bandage type, training and the effect of transport

Previous work showed that systemic spread of venom from a snakebite to the limb could be prevented or delayed by complete immobilisation of the limb in combination with a pressure bandage of 55-70 mmHg or 40-70 mmHg in the lower and upper limbs, respectively. An assessment of the public’s and health care professionals’ ability to apply this ‘Aussie wrap’ revealed elasticised bandages to be far more likely than crepe bandages to achieve appropriate pressures, even after training, and a 30 minute ambulance ride further rendered the pressures achieved by crepe bandages inadequate.

Emerg Med Australas. 2009 Jun;21(3):184-90

http://www.ncbi.nlm.nih.gov/pubmed/19527277

Is cerebral oxygenation negatively affected by infusion of norepinephrine in healthy subjects?

An interesting study on nine healthy volunteers demonstrated noradrenaline infusions to increase MAP without increasing cardiac output (by increasing systemic vascular resistance). Measures of cerebral (frontal lobe) oxygenation, jugular venous saturation, and mean flow velocity in the middle cerebral artery all reduced with increasing doses of noradrenaline. The authors conclude that doses greater than 0.1 mcg/kg/min may reduce cerebral oxygenation. However increases in noradrenaline lowered paCO2 (through increases pulmonary ventilation) and it is unknown whether this was the major contributor to reduced oxygenation. It is also hard to ascertain the relevance to patients receiving noradrenaline, who unlike the healthy volunteers are not driven to supranormal blood pressures. In the meantime we will continue to attempt to optimise cerebral perfusion pressure using vasoactive drugs, but should be mindful that gross estimates of CPP may not tell us what we’re doing to cerebral oxygenation.

Br J Anaesth. 2009 Jun;102(6):800-5

http://www.ncbi.nlm.nih.gov/pubmed/19376788

Measuring the performance of an inter-hospital transport service

“There is currently no consensus on how the performance of an interhospital transport service can be measured” say the busy Children’s Acute Transport Service (CATS) in London, who classify their indicators under headings of safety, speed, efficiency, and satisfaction. They include a number of useful outcome measurements (such as unplanned subsequent transfers, and need for urgent intensive care interventions at the receiving hospital) that should stimulate other retrieval services - adult and paediatric - to look out how they measure their own performance. Nice paper, proving once again that paediatricians are not just little doctors.

Arch Dis Child. 2009 Jun;94(6):414-6

http://www.ncbi.nlm.nih.gov/pubmed/19174393

Nebulized fentanyl versus intravenous morphine in children with suspected limb fractures in the emergency department: a randomized controlled trial

In an nutshell: you can nebulise fentanyl in a dose of 4 mcg/kg for kids of 4 years of age and over and get pain relief equivalent to i.v. morphine 0.1 mg/kg

Emerg Med Australas. 2009 Jun;21(3):203-9

http://www.ncbi.nlm.nih.gov/pubmed/1952728 0

Practical anatomic landmarks for determining the insertion depth of central venous catheter in paediatric patients

The level of the carina is usually chosen as the target depth for internal jugular vein catheters in children to avoid catheter tip perforation of the right atrium or intrapericardial SVC. This level can now be estimate

d using external landmarks following this study of 90 children under 5 years of age. Ready? Right....

Find the sticky-out bit of the medial head of the right clavicle (point A in diagram) and measure its distance to a point halfway towards the internipple line (B). Add this to the distance between the insertion point of the catheter in the neck (I) and the medial head of the right clavicle (A again) and subtract 0.5. This gives you the catheter tip insertion distance in cm. It doesn’t apply to left sided or subclavian lines, but it seems useful for paediatric RIJV lines.

Br J Anaesth. 2009 Jun;102(6):820-3

http://www.ncbi.nlm.nih.gov/pubmed/19380312

Routine Early Angioplasty after Fibrinolysis for Acute Myocardial Infarction

Oh dear......A randomised controlled trial of 1059 patients who were thrombolysed for STEMI in centres without access to percutaneous coronary intervention (PCI) compared ‘standard’ timing of PCI (median time from randomisation to catheterisation 32 hrs) with urgent transfer and PCI (within 6 hours -actual median time from thrombolysis to ballooon inflation 3.9 hrs). The composite end point of death, reinfarction, heart failure, cardiogenic shock or recurrent ischaemia at 30 days was reduced in the intervention group from 17.2 to 11% (NNT = 16). The authors suggest that previous studies not showing such a benefit pre-dated modern stents and antiplatelet therapies. The study was not powered to detect differences in the individual components of the composite end point. It will be interesting to see if cardiologists consider this a bandwagon to jump upon, in which case let ambulance retrieval services beware!

N Engl J Med. 2009 Jun 25;360(26):2705-18

http://www.ncbi.nlm.nih.gov/pubmed/19553646

Use of a stylet for insertion of a Classic LMA

The most common problem in inserting the LMA classic is difficulty in passing it through the posterior pharynx, a problem made worse by a loss of curvature produced by repeated autoclaving. A stylet can be used to create a bend at two points: near the junction of the mask and the tube, and at the middle of the tube. The mask can then be inserted against the hard palate and swung inward. Care must be taken to avoid protruding the stylet beyond the aperture bar.

Resuscitation. 2009 Aug;80(8):964

http://www.ncbi.nlm.nih.gov/pubmed/19523741

Answers to July CME Questions:

1) T 2) F 3) F 4) T 5) T

Clinical Update June 2009 CME Questions

2009-07-29T17:02:00.000-07:00

Answer True or False to the following questions. Answers at the bottom of the June 2009 Update.

1) Intraosseous fluid infusion rates are similar between humeral and tibial insertion sites.

2) Urban populations have a lower threshold for calling an emergency ambulance than rural populations

3) ACLS guidelines for ventilation are easier to achieve with larger self-inflating bags

4) ACLS guidelines for defibrillation are harder to achieve if the team must be formed during the resuscitation

5) The use of a pressure bag halves the rate of intraosseous saline infusion

June 2009

2009-07-29T17:00:00.000-07:00

Trauma scissors vs the Rescue Hook, exposing a simulated patient: a pilot study

American military investigators compared traditional trauma scissors with the ‘rescue hook’ (a hooked knife with the cutting edge on the inside of the hook) in rapidly removing the clothes from a simulated casualty. An army desert combat uniform and boots were removed more quickly with the rescue hook, which was favoured by the combat medics employed in the study. We don’t have data on how it would work on denim, leather, or belts, but it looks pretty good. I just want to know if it’ll go through a sternum before I trade in my trauma scissors.

J Emerg Med. 2009 Apr;36(3):232-5

http://www.ncbi.nlm.nih.gov/pubmed/18155382

Prehospital airway management on rescue helicopters in the United Kingdom

26 of 27 identified UK rescue helicopter bases responded to a questionnaire sent by German anaesthesiologists on the airway equipment they carried. The take home message is that there were some important gaps: not all carried equipment for establishing a surgical airway and not all had a means of capnometry. Pull your socks up guys the Germans are watching.

Anaesthesia. 2009 Jun;64(6):625-31

http://www.ncbi.nlm.nih.gov/pubmed/19453316

An observational, prospective study comparing tibial and humeral intraosseous access using the EZ-IO

Emergency physicians at Singapore General Hospital found flow rates to be similar when comparing the tibia with the humerus as sites for adult IO access. The EZ-IO had a very high insertion success rate. It took about 12 minutes to infuse a litre of saline, which drops to about 6 minutes if a pressure bag is used.

Am J Emerg Med. 2009 Jan;27(1):8-15

http://www.ncbi.nlm.nih.gov/pubmed/19041528

Use of non-invasive ventilation to wean critically ill adults off invasive ventilation: meta-analysis and systematic review

The growing evidence base in support of liberating patients from invasive mechanical ventilation by means of non-invasive weaning is summarised in this systematic review of 12 randomised trials. Non-invasive weaning was associated with decreased mortality, ventilator associated pneumonia, length of stay in intensive care and hospital, total duration of mechanical ventilation, and duration of invasive ventilation. It should be noted that most of the trials exclusively enrolled patients with exacerbation of chronic obstructive pulmonary disease; benefits in other types of ventilated patients remain to be firmly proven.

BMJ. 2009 May 21;338:b157

http://www.ncbi.nlm.nih.gov/pubmed/19460803

Aeromedical retrieval for critical clinical conditions: 12 years of experience with the Royal Flying Doctor Service, Queensland, Australia

Over twelve years in Queensland the RFDS undertook over 72000 fixed wing retrievals, including

over 4000 critically ill patients. Trauma was the commonest diagnostic category. There were only 90 primary retrievals, from locations without healthcare facilities - less than one per month on average. This fascinating service covers vast distances, low population density, and a high number of indigenous people.

J Emerg Med. 2009 May;36(4):363-8

http://www.ncbi.nlm.nih.gov/pubmed/18814993

Does ambulance use differ between geographic areas? A survey of ambulance use in sparsely and densely populated areas

A lower use of emergency department health care services by rural residents as compared with urban residents has previously been described. This Swedish study examined the use of ambulance services in relation to geography, showing that patients from sparsely populated areas were sicker. required more treatment, and were assessed as not needing prehospital care less than half as often as their urban counterparts (16% vs 39%). Take home message is that population density is related to inappropriate use of ambulance services.

Am J Emerg Med. 2009 Feb;27(2):202-11

http://www.ncbi.nlm.nih.gov/pubmed/19371529

Hands-on time during cardiopulmonary resuscitation is affected by the process of teambuilding: a prospective randomised simulator-based trial

During simulated cardiac arrest resuscitations, a comparision was made between those run by teams that had had time to form before the arrest, and those that had to be assembled ad hoc after the arrest occurred. 99 teams of three doctors, including GPs and hospital physicians were studied. ACLS algorithms were less closely followed in the ad hoc formed teams, with more delays to therapies such as defibrillation. Analysis of voice recordings revealed the ad hoc teams to make fewer leadership utterances (eg. ‘we should defibrillate’ or ‘the next countershock will be 360J’) and more reflective utterances (eg. ‘what should we do next?’). The authors suggest that team building is therefore to be regarded as an additional task imposed on teams formed ad hoc during CPR that may substantially impact on outcome. No surprise to those of us who banned ‘cardiac arrest teams’ from our emergency department resuscitation rooms many years ago!

BMC Emerg Med. 2009 Feb 14;9:3

http://www.ncbi.nlm.nih.gov/pubmed/19216796

Full text at http://www.biomedcentral.com/1471-227X/9/3

Is the prevalence of deliberate penetrating trauma increasing in London? Experiences of an urban pre-hospital trauma service

The physician-led pre-hospital service London HEMS examined its penetrating trauma caseload between 1991 and 2006. Overall, stabbings rose annually by 23.2% and shootings by 11.0%.

Injury. 2009 May;40(5):560-3

http://www.ncbi.nlm.nih.gov/pubmed/19232594

Prehospital management of severe traumatic brain injury

A review of current practice and evidence base of this important topic can be found at

BMJ. 2009 May 19;338:b1683

http://www.ncbi.nlm.nih.gov/pubmed/19454738

Full text http://www.bmj.com/cgi/content/full/338/may19_1/b1683

Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation

A comparison between two sizes of self-inflating resuscitation bags revealed improved adherence to resuscitation guidelines with the smaller bag. Student paramedics were more likely to produce suboptimal tidal volumes and ventilation rates with a 1500ml bag than a 1000ml bag during simulated ventilation of an artificial lung model.

BMC Emerg Med. 2009 Feb 20;9:4

http://www.ncbi.nlm.nih.gov/pubmed/19228432

Full text at http://www.biomedcentral.com/1471-227X/9/4

Answers to June CME Questions:

1) T 2) T 3) F 4) T 5) F

May 2009 Clinical Update CME Questions

2009-07-07T12:53:00.000-07:00

Answer True or False to the following:

1. Ketamine when used as an induction agent for rapid sequence induction lowers ICP

2. Firm broad inguinal compression in an infant increases the diameter of the femoral vein for catheterisation

3. Doubling the radius of an intravenous cannula in a vein increases the flow rate by a factor of sixteen

4. Obesity is an independent risk factor for impossible bag-mask ventilation

5. Movement of a tracheal tube from the centre to the corner of the mouth at the same fixed insertion length risks endobronchial migration of the tube tip

May 2009

2009-07-07T12:44:00.000-07:00

A comparison of three cervical immobilization devices
A novel, rigid cervical collar was compared with more commonly used one and two piece devices. It permitted less neck movement in normal volunteers in the seated and supine positions, although there was still some movement without manual immobilisation. The authors conclude: ‘the XCollar may provide an acceptable alternative to manual cervical stabilization in situations where the number of patients exceeds the number of EMS providers available to provide care'.

Now if only we had some evidence that collars improved outcome anyway...

Prehosp Emerg Care. 2009 Apr-Jun;13(2):256-60

http://www.ncbi.nlm.nih.gov/pubmed/19291567

Anaesthesia in haemodynamically compromised emergency patients: does ketamine represent the best choice of induction agent?

Yes! And this article does a great job of attempting to convince those that still don’t believe it. An excerpt:Despite widespread avoidance of ketamine by clinicians following (actual or potential) brain injury, this stance does not withstand scrutiny and we would argue that ketamine is a rational choice for use in patients with brain injury, especially where haemodynamic compromise (e.g. polytrauma) is present or likely. C’mon everybody else, catch up here - you know it makes sense.

Anaesthesia. 2009 May;64(5):532-9

http://www.ncbi.nlm.nih.gov/pubmed/19413824

Analysis of the retrieval times of a centralised transport service, New South Wales, Australia

A key first step in quality improvement is knowing what you’re doing now. Newborn and Paediatric retrieval times for over 17000 missions were broken down into components such as initial response, stabilisation, and handover times. These data might provide a benchmark for other services.

Arch Dis Child. 2009 Apr;94(4):282-6

http://www.ncbi.nlm.nih.gov/pubmed/18927147

Does a Higher Positive End Expiratory Pressure Decrease Mortality in Acute Respiratory Distress Syndrome?

This systematic review and meta-analysis makes the following points: (1) while most benefit is likely to be produced when it is used as part of a protective ventilation strategy (including low tidal volumes and limited plateau pressure) high PEEP may have an independent beneficial effect; (2) studies of ALI/ARDS are dogged by the heterogeneous nature of the disease and the spectrum of severity included; (3) the nonsignificant trend towards a greater incidence of barotrauma in high-PEEP patients is outweighed by the benefits, although evidence is limited by the lack of a standard definition for barotrauma.

Take home message: the sicker the patient (in terms of oxygenation), the more likely high PEEP (as defined by >10 cmH₂O or 1-2 cmH₂O above the lower inflection point) will be beneficial, through the prevention of atelectasis, recruitment of already collapsed alveolar units, and avoiding the cyclical opening/collapse of alveoli.

Anesthesiology. 2009 May;110(5):1098-105

http://www.ncbi.nlm.nih.gov/pubmed/19352160

Effects of reverse Trendelenburg position and inguinal compression on femoral vein cross-sectional area in infants and young children

Ultrasound demonstrated an increase in femoral vein diameter in infants and children when a head up-leg down position was adopted. This was increased further when inguinal compression was performed by applying compression 1–2 cm above the inguinal ligament with three ﬁngers as ﬁrmly and as broadly as possible at the point of arterial pulsation. A top tip for optimising success in paediatric femoral vein catheterisation.

Anaesthesia. 2009 Apr;64(4):399-402

http://www.ncbi.nlm.nih.gov/pubmed/19317705

Fluid Flow Through Intravenous Cannulae in a Clinical Model

Published flow rates for cannulae are derived from a test in which fluid runs through a perfectly straight cannula into an open receptacle. Laminar flow is expected in such a model in which the Hagen-Poisseuille formula tells us that flow is proportional to the fourth power of the radius. In this study manufacturers’ published flow rates were compared with an artifical vein model. Hartmann’s flowed faster than Gelofusine. For all cannulas flow was less than the manufacturers’ published rates. Although the radius was the biggest determinant of flow rate, the fourth power could not be used, suggesting a mixture of laminar and turbulent flow. The addition of pressurised infusions increased the flow rate with increasing pressure. Although the vein model used has limitations, and many other factors may influence flow rate in the clinical setting, the authors’ conclusions are helpful:

While the effect of radius is less than commonly believed, it is still important. However, clinicians should be aware of the limitations of increasing radius and use other strategies to increase flow when needed. These could include use of pressure, choice of fluid to be infused, and using multiple cannulae in parallel.

Anesth Analg. 2009 Apr;108(4):1198-202

http://www.ncbi.nlm.nih.gov/pubmed/19299786

Prediction and Outcomes of Impossible Mask Ventilation - A Review of 50,000 Anesthetics

Of 53,041 attempts at mask ventilation, 77 cases of impossible mask ventilation (0.15%) were observed. Neck radiation changes, male sex, sleep apnea, Mallampati III or IV, and presence of beard were identiﬁed as independent predictors. Nineteen impossible mask ventilation patients (25%) also demonstrated difﬁcult intubation, with 15 being intubated successfully. Impossible mask ventilation is an infrequent airway event that is associated with difﬁcult intubation. Neck radiation changes represented the most signiﬁcant clinical predictor of impossible mask ventilation. Risk factors for impossible mask ventilation have not previously been described and you read it here first!

Anesthesiology. 2009 Apr;110(4):891-7

http://www.ncbi.nlm.nih.gov/pubmed/19293691

Focused emergency echocardiography: lifesaving tool for a 14-year-old girl suffering out-of-hospital pulseless electrical activity arrest because of cardiac tamponade

A post-operative pericardial effusion following VSD repair caused a PEA cardiac arrest, during which a pre-hospital physician identified tamponade on portable ultrasound and successfully performed pericardiocentesis. The patient made a full recovery.

Eur J Emerg Med. 2009 Apr;16(2):103-5

http://www.ncbi.nlm.nih.gov/pubmed/19218856

Tracheal tube ﬁxation: the effect on depth of insertion of midline ﬁxation compared to the angle of the mouth

This elegant study from India showed that movement of a tracheal tube from the middle to the corner of the mouth while fixed at the same insertion length results in migration of the tube tip towards the carina, an average of 1.34 cm in females and 1.36 cm in males. This is because the lip is lower at the angle of the mouth, and the tracheal tube slipped off the tongue into the paraglossal area on lateral movement, thereby taking a shorter course. This resulted in a significant risk of endobronchial intubation, particular in females. The authors recommend that the depth of insertion when ﬁxing the tube at the angle of the mouth should be adjusted, and should not be the same as those recommended for midline ﬁxation. When securing the tracheal tube at the angle of the mouth, the depth of insertion should be reduced by an average of 1.35 cm. It is recommended that the tube should be moved to its ﬁnal position of ﬁxation while the laryngoscope is still in place and the distal insertion mark still in view and the depth of insertion noted.

Anaesthesia. 2009 Apr;64(4):383-6

http://www.ncbi.nlm.nih.gov/pubmed/19317702

Answers to May CME Questions:

1) F 2) T 3) F 4) F 5)T

April 2009 Clinical Update CME Questions

2009-06-12T02:41:00.001-07:00

Answer True or False:

Pre-hospital blood pressure measured invasively via an arterial line produces significantly different systolic and diastolic readings from non-invasive measurement

Compartment intrusion may be ignored as a relevant factor when taking the history in children with trauma due to motor vehicle collison.

A tourniquet will not effectively control arterial bleeding if placed below the elbow or knee

Obesity does not protect against severe traumatic brain injury in frontal impact motor vehicle collisions

The ETCO₂ of ventilated trauma patients may grossly underestimate the arterial CO₂ levels.

April 2009

2009-06-12T02:37:00.001-07:00

Eﬀect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study

German trauma patients are more likely to survive if they have a whole body CT rather than selective scans. Or that’s what this paper would have you believe IF you’re happy with the retrospective comparison, multivariate adjustments, and potential confounders. Still, if it helps you get your radiologists to play ball, the reference is...

Lancet. 2009 Apr 25;373(9673):1455-61

http://www.ncbi.nlm.nih.gov/pubmed/19321199

Invasive arterial blood pressure monitoring in an out-of-hospital setting: an observational study

Arterial lines in the field? You’ve got to be nuts, or.....French! Yep, the SAMU boys and girls put in 94 arterial lines in pre-hospital cases over two years, and found big differences between invasive and non-invasive arterial pressures in systolic and diastolic pressures. What about mean pressures though, which we’d expect to be more closely correlated? They didn’t say. An interesting paper, but I don’t think I can use it.

Emerg Med J. 2009 Mar;26(3):210-2

http://www.ncbi.nlm.nih.gov/pubmed/19234017

Introduction to the ‘‘space-control theory of paramedic scene management’’

Paramedics practice practise ‘‘in the street’’ and perform in ‘‘a context rife with chaotic, dangerous, and often uncontrollable elements with which hospital-based practitioners need not contend’ We knew that, but what isn’t known is how more experienced or expert paramedics differ from novices in scene management. This qualitative study involving interviews of 24 paramedics describes the ‘space control theory’ - how paramedics establish control over their immediate workspace to effectively deliver patient care. It’s not big on detail, but at least this paper documents for hospital-based ambulance medical advisors that there is more to paramedicine than purely clinical factors , which is why insistence on hospital-derived clinical treatment algorithms might sometimes be inappropriate in the field. I’ve emailed the author for more details.

Emerg Med J. 2009 Mar;26(3):213-6

http://www.ncbi.nlm.nih.gov/pubmed/19234018

Passenger Compartment Intrusion as a Predictor of Significant Injury for Children in Motor Vehicle Crashes

The presence and degree of compartment intrusion (from crash investigation data) was correlated with the likelihood of serious injury in 880 children from age 0-15 years, and odds for presence of serious injury increased for each centimetre of compartment intrusion.

J Trauma. 2009 Feb;66(2):504-7

http://www.ncbi.nlm.nih.gov/pubmed/19204529

Sodium lactate versus mannitol in the treatment of intracranial hypertensive episodes in severe traumatic brain-injured patients

Lactate may be an important metabolic substrate for injured brain and sodium lactate may have beneficial effects on cerebral oedema and cerebral blood flow. Sodium lactate was compared with 20% mannitol in severely brain injured patients with cranial hypertension in a randomised controlled trial. Sodium lactate was more likely to lower ICP, and to have a sustained effect on ICP. A nonsignificant improvement in one year outcome was seen with sodium lactate, although the study was not powered for this endpoint. These promising findings should prompt a larger multicentre study.

Intensive Care Med. 2009 Mar;35(3):471-9

http://www.ncbi.nlm.nih.gov/pubmed/18807008

The Relationship of Blood Product Ratio to Mortality: Survival Benefit or Survival Bias?

Haemostatic resuscitation of trauma patients, using high ratios of fresh frozen plasma (FFP) to packed red cells (PRBC), is growing in popularity as a result of military experience. Few data support the practice in civilian trauma. It is possible that some of the demonstrated mortality benefit is a result of survival bias: it takes time to obtain FFP, by which time severely injured patients may be dead. Therefore, those that receive large ratios of FFP:PRBC must have survived long enough to receive it. In other words FFP doesn’t lead to survival, but survival leads to FFP. Some evidence in favour of this explanation is provided on a study of 134 patients in the Journal of Trauma. Reanalysing data to correct for survival bias made an apparently significant survival benefit from high FFP:PRBC ratios go away. An interesting paper, although unlikely to dissuade us from paying attention to coagulopathy in trauma. I suspect the debate on optimal blood product resuscitation will be around for a while.

J Trauma. 2009 Feb;66(2):358-62

http://www.ncbi.nlm.nih.gov/pubmed/19204508

The Utility of Early End-Tidal Capnography in Monitoring Ventilation Status After Severe Injury

In 180 intubated trauma patients in the ED, there was little correlation between arterial carbon dioxide tension (PaCO₂) and end-tidal carbon dioxide levels (ETCO₂) (R² = 0.277). In fact, in those patients ventilated to the ‘normal range’ of 35-40 mmHg (4.6-5.2 kPa), PaCO₂ was over 50 mmHg 30% of the time. Slightly reassuring that in isolated brain injury the correlation was better (r² = 0.52)

J Trauma. 2009 Jan;66(1):26-31

http://www.ncbi.nlm.nih.gov/pubmed/19131802

Tourniquets Revisited

A volunteer study showed that tourniquets were just as effective at occluding distal blood flow measured by doppler signal when placed below the elbow or knee compared with above those joints. A makeshift windlass tourniquet, a rubber tube tourniquet, and a blood pressure cuff were all effective. Digital ‘pressure point control’ failed to maintain control of brachial or femoral artery flow.

J Trauma. 2009 Mar;66(3):672-5

http://www.ncbi.nlm.nih.gov/pubmed/19276736

Traumatic Brain Injury After Frontal Crashes: Relationship With Body Mass Index

In adult patients injured in front impact motor vehicle collisions, the outcomes of obese patients with a Body Mass Index greater than 30 kg/m2 was compared with those less than 30 kg/m2. Obese patients were more likely to suffer a severe head injury from a frontal collision.

J Trauma. 2009 Mar;66(3):727-9

http://www.ncbi.nlm.nih.gov/pubmed/19276745

Answers to April CME Questions:

1) T 2)F 3) F 4) T 5)T

March 2009 Clinical Update CME Questions

2009-05-02T07:23:00.000-07:00

Answer True or False:

1. In pre-hospital care, the greatest survival benefit from physician-based services has been demonstrated in paediatric medical emergencies.

2. Digital rectal examination is not always necessary in the secondary survey examination of trauma patients.

3. Standard iv catheters are often too short to effectively decompress a tension pneumothorax

4. High flow oxygen may cause harm when routinely administered to patients with uncomplicated acute myocardial infarction

5. Numerous studies document serious injury to rescuers caused by electric shocks from defibrillators

March 2009

2009-05-02T01:33:00.000-07:00

Ventilator-associated tracheobronchitis: the impact of targeted antibiotic therapy on patient outcomes

Chest. 2009 Feb;135(2):521-8

http://www.ncbi.nlm.nih.gov/pubmed/18812452

Ventilator associated pneumonia (VAP) is a well recognised complication of ICU care, but colonisation and infection further up the respiratory tract may be a risk factor for VAP that is worth identifying and treating. Ventilator-associated tracheobronchitis (VAT) has similar diagnostic criteria to VAP, but without the radiographic infiltrates.

A systematic review of controlled studies: do physicians increase survival with prehospital treatment?

Scand J Trauma Resusc Emerg Med. 2009 Mar 5;17(1):12

http://www.ncbi.nlm.nih.gov/pubmed/19265550

This systematic review by Scandinavian authors examined controlled studies comparing physician with non-physician treatment in pre-hospital care. Fourteen of the 26 studies identified demonstrated significantly improved survival in the intervention (physician-treated) group. Most survival benefit has been demonstrated in trauma and cardiac arrest, reflecting the fact that these two areas are the most studied. The authors rightly remind us of the paucity of pre-hospital controlled studies of sufficient quality and strength.

Full text available at http://www.sjtrem.com/content/pdf/1757-7241-17-12.pdf

Comparison of use of the Airtraq with direct laryngoscopy by paramedics in the simulated airway.

Prehosp Emerg Care. 2009 Jan-Mar;13(1):75-80

http://www.ncbi.nlm.nih.gov/pubmed/19145529

Paramedics intubated simulated patients positioned supine on the floor by direct laryngoscopy (DL) and by using the Airtraq device. Ventilation was achieved more quickly with the Airtraq in a difficult airway scenario (tongue oedema), and after a short training period the Airtraq was faster at intubating a ‘normal’ airway.

A prospective study of the time to evacuate acute subdural and extradural haematomas.

Anaesthesia. 2009 Mar;64(3):277-81

http://www.ncbi.nlm.nih.gov/pubmed/19302640

Further evidence from the UK shows that patients with acute traumatic brain injury suffer delays in the neurosurgical evacuation of intracranial haematomas which are increased from an average of 3.7 hours to 5.4 hours if they have to undergo interhospital transfer. Coordinated regional trauma systems please!

Bispectral index monitoring in helicopter emergency medical services patients

Prehosp Emerg Care. 2009 Apr-Jun;13(2):193-7

http://www.ncbi.nlm.nih.gov/pubmed/19291556

Bispectral index monitoring (BIS) was applied to 57 intubated patients transported by a Helcopter Emergency Medical Service (HEMS), demonstrating (1) that the patients were adequately sedated, (2) BIS works in helicopters, and (3) there is enormous scope for publishing work related to the retrieval environment - anything is of interest!

Early packed red blood cell transfusion and acute respiratory distress syndrome after trauma.

Anesthesiology. 2009 Feb;110(2):351-60

http://www.ncbi.nlm.nih.gov/pubmed/19164959

Blood transfusion in trauma is a risk factor for acute respiratory distress syndrome (ARDS). An analysis of 14070 patients in a trauma database showed that 521 (4.6%) developed ARDS. Logisitc regression analysis demonstrated that, independent of injury type, injury severity, or pneumonia, (1) early PRBCs transfusion of more than 5 units during the ﬁrst 24 h of hospital admission predicted ARDS and (2) each unit of PRBCs transfused early after admission increased the risk of ARDS by 6%.

Is external defibrillation an electric threat for bystanders?

Resuscitation. 2009 Apr;80(4):395-401

http://www.ncbi.nlm.nih.gov/pubmed/19211180

No rescuer or bystander has ever been seriously harmed by receiving an inadvertent shock while in direct or indirect contact with a patient during deﬁbrillation. New evidence suggests that it might even be electrically safe for the rescuer to continue chest compressions during deﬁbrillation if self-adhesive deﬁbrillation electrodes are used and examination gloves are worn. This paper reviews the existing evidence, but warns more deﬁnite data are needed to make absolutely sure that there is no risk before deﬁbrillation safety recommendations are changed.

Routine use of oxygen in the treatment of myocardial infarction: systematic review

Heart. 2009 Mar;95(3):198-202

http://www.ncbi.nlm.nih.gov/pubmed/18708420

Hyperoxia may reduce coronary artery blood flow, increase systemic vascular resistance, and decrease cardiac output. This paper argues that if the baseline arterial oxygen saturations are >90%, high concentration oxygen does not increase oxygen transport, as the reductions in cardiac output are in excess of the increase in oxygen content. The balance of the limited evidence that exists suggests that the routine use of oxygen in uncomplicated MI (no failure or shock) may increase infarct size and possibly increase the risk of mortality, owing to its haemodynamic effects, including a reduction in coronary blood flow.

Needle thoracostomy for tension pneumothorax: failure predicted by chest computed tomography

Prehosp Emerg Care. 2009 Jan-Mar;13(1):14-7

http://www.ncbi.nlm.nih.gov/pubmed/19145519

This CT study of 110 trauma patients showed: ‘the standard 4.4-cm angiocatheter is likely to be unsuccessful in 50% (95% conﬁdence interval = 40.7–59.3%) of trauma patients on the basis of body habitus. In light of its low predicted success, the standard method for treatment of tension pneumothorax by prehospital personnel deserves further consideration’. Consistent with several other Ultrasound and CT-based studies published on the same subject then.

Performance of endotracheal intubation and rescue techniques by emergency services personnel in an air medical service

Prehosp Emerg Care. 2009 Jan-Mar;13(1):44-9

http://www.ncbi.nlm.nih.gov/pubmed/19145523

In contrast to literature showing high intubation failure rates by ground paramedics, a review over eight years of 369 intubations by flight paramedics and nurses showed successful tracheal intubation in 92.1% cases. Of the 369 intubation encounters, rapid sequence medications were given in 345. The authors ascribe their success to both initial training and mandatory ongoing practice and demonstration of competencies.

Should the digital rectal examination be a part of the trauma secondary survey?

Ann Emerg Med. 2009 Feb;53(2):208-12

http://www.ncbi.nlm.nih.gov/pubmed/19177638

A comprehensive review of the literature, the findings of which showed ‘compelling’ consistency: digital rectal examination (DRE) as a screening test had sensitivities ranging from 0% to 50%, had consistently high false-positive and false-negative rates, and did not improve the predictive value of the other components of a typical trauma examination.

Based on case reports of five patients, the authors suggest DRE may be of value during trauma evaluation in the following settings: (1) patients with evidence of penetrating trauma in the vicinity of the rectum, (2) cases in which the presence of neurologic injury is neither completely supported nor refuted by the clinical ﬁndings, and (3) before pharmacologic paralysis. A selective approach is therefore recommended. Some good news for your patients if this will persuade you to discard another piece of longstanding dogma perpetuated in basic trauma teaching.

Answers to March CME Questions:

1) F 2) T 3) T 4) T 5)F

February 2009 Clinical Update CME Questions

2009-02-27T21:53:00.000-08:00

Answer True or False:

1. The addition of a physician to a HEMS crew prolongs scene times due to the increased number and sophistication of interventions provided

2. Rural Australian HEMS services usually take less than 30 minutes from dispatch to arriving on scene.

3. Infants receiving alprostadil infusions for congenital cardiac lesions should be intubated prior to transport because of the risk of apnoea.

4. Like midazolam and propofol, dexmedetomidine is a GABA-agonist.

5. Benzodiazepine administration helps reduce the risk of delirium in ICU patients.

February 2009

2009-02-27T21:48:00.000-08:00

London HEMS doctors describe their use of ketamine for pre-hospital analgesia and sedation in 1030 retrospectively reviewed cases, concluding its prehospital use is safe.

Emerg Med J. 2009 Jan;26(1):62-4
http://www.ncbi.nlm.nih.gov/pubmed/19104109?dopt=Abstract

171 rural Australian HEMS missions were retrospectively analysed. Some of the data contrast starkly with the more limelight-occupying urban services: average time from dispatch to scene was 48 minutes, average scene time was 50 mins, and average total distance flown was 160 nautical miles (297 km!) - the longest reported in the literature. There was no difference in injury severity between physician-staffed and paramedic-staffed missions, and no difference in mortality. When transport times for distances less than 50km from the hospital were compared, road responses were significantly faster than helicopter dispatch, whereas helicopter use created significant time savings at distances over 100km. The authors suggest that in the absence of special circumstances, a helicopter response within 100 km from base does not improve time to definitive care. They also recommend caution in mandating physician staffing of HEMS, particularly in environments with a limited pool of critical care doctors.
Emerg Med Australas. 2008 Dec;20(6):494-9
http://www.ncbi.nlm.nih.gov/pubmed/19125828

Careflight Queensland report a 9 month series of intubations by their doctor-paramedic HEMS teams who performed 39 intubations (and assisted hospital doctors in an additonal 4), of which less than half were pre-hospital. There was one failed intubation, successfully ventilated with a laryngeal mask airway.
Emerg Med J. 2009 Jan;26(1):65-9
http://www.ncbi.nlm.nih.gov/pubmed/19104110

Two English HEMS services covering the same geographical area, one physican / paramedic crewed and one double paramedic crewed, were compared. There were no differences in scene times. As well as predictably providing more rapid sequence induction, nerve blocks, and ketamine use, the physician-paramedic team discharged more people at scene and were more likely to cease resuscitation attempts in GCS 3 patients.
Emerg Med J. 2009 Feb;26(2):128-34
http://www.ncbi.nlm.nih.gov/pubmed/19164630

The risk of apnoea in neonates requiring prostaglandin E1 infusions for duct-dependent congenital heart disease is well described and often results in the recommendation to intubate prior to transfer. An American study of 202 transported infants on PGE1 shows a higher rate of transport-related complications in those that had been intubated. None of the 73 (36%) unintubated patients required intubation for apneoa during transport. These data are in keeping with a previous Australian study of 300 infants receiving PGE1 in which only 2 of 78 unintubated patients experienced apnoea.
Pediatrics. 2009 Jan;123(1):e25-30
http://www.ncbi.nlm.nih.gov/pubmed/19064611?dopt=Abstract

An industry-sponsored double-blind randomised controlled trial comparing midazolam with the central alpha-2 agonist dexmedetomidine showed the newer drug to provide similar levels of sedation with less delirium and a shorter time to extubation. It was associated with more episodes of bradycardia not requiring intervention.
This new sedative drug, related to clonidine, provides some analgesia and anxiolysis, and is noted for its lack of respiratory depression. An accompanying editorial points out the known association between benzodiazepines and delirium, and asks whether a comparison with propofol would have shown the same improved outcomes.
JAMA. 2009 Feb 4;301(5):542-4
http://www.ncbi.nlm.nih.gov/pubmed/19188334?dopt=Abstract

Answers to February CME Questions:

1) F 2) F 3) F 4) F 5)F

January 2009 Clinical Update CME Questions

2009-02-16T19:57:00.000-08:00

Answer true or false

1. Axillary temperature measurements are more accurate than tympanic measurements in adults

2. Oral temperature readings are approximately 0.5 degree lower than axillary

3. Length-based estimates of children’s weights are more accurate than age-based estimates

4. The administration of CPAP in the pre-hospital environment does not require a dedicated NIV ventilator

5. Central venous oxygen saturation of 70% is not a reliable goal in resuscitated septic shock patients in ICU

6. Passive leg raising as a predictor of fluid responsiveness is best done on a supine patient

7. Oral decontamination of ICU patients is almost as effective as selective decontamination of the digestive tract (SDD) with a number needed to treat (NNT) of approxmately 35

8. Risk of death increases sharply when pre-hospital systolic blood pressure is less than 90 mmHg when compared with less than 100 mmHg

9. Standard Operating Procedures for trauma care are useful in the field, but there is no evidence to support their use in the emergency department

10. A large difference in pCO2 between central venous and arterial blood may indicate global tissue hypoperfusion

January 2009

2009-02-16T19:38:00.000-08:00

A review of 1954 out-of-hospital tracheal intubation (ETI) attempts by EMS crews revealed 444 (22.7%) patients experienced one or more ETI errors, including tube misplacement or dislodgement in 61 (3%), multiple ETI attempts in 62 (3%) and failed ETI in 359 (15%). Pneumonitis was associated with failed ETI (n=20, 19%; univariable OR 2.54; 95% CI 1.24-5.25). The authors conclude that out-of-hospital ETI errors are not associated with mortality, but failed out-of-hospital ETI increases the odds of pneumonitis.
http://www.ncbi.nlm.nih.gov/pubmed/18952357?ordinalpos=20&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

A prospective observational study of paediatric patients requiring pre-hospital intubation attended by a helicopter medical team (HMT) included 95 children with a GCS of 3-4. Fifty-four received bag-mask support by EMS paramedics until the HMT arrived and intubated them (survival 63%), and 41 were intubated by EMS paramedics. Of these, ‘correction of tube/ventilation’ was required in 37% and the survival was 5%. The authors conclude that bag-mask support should be the technique of choice by EMS paramedics, as the rate of complications of tracheal intubation in this patient group is unacceptably high. Hard to comment as I only have access to the abstract but one wonders if the EMS-intubation group were sicker patients requiring more aggressive early control of airway and breathing.

http://www.ncbi.nlm.nih.gov/pubmed/18684547?ordinalpos=31&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

A nurse-based pre-hospital care system in Holland describes its experience with pre-hospital CPAP for acute cardiogenic pulmonary oedema. It appears that the simple Boussignac apparatus is straightforward to apply in the ambulance environment. Arguments about lack of outcome studies aside, if it’s necessary to undertake an interhospital transfer of a patient established on CPAP then this might be a relatively straightforward means of doing so.

http://www.ncbi.nlm.nih.gov/pubmed/19164632?dopt=Abstract

http://www.vitaid.com/canada/boussignac/index.html

The introduction of Standard Operating Procedures for trauma management into a German emergency department resulted in quicker resuscitation, shorter time in the ED, and shortened time to definitive diagnosis in polytrauma patients. Nice to see some evidence to support SOP use in critical medical settings, not least because there are still clinicians out there who fail to see their value.
http://www.ncbi.nlm.nih.gov/pubmed/19078832

In septic shock, a central venous oxygen saturation of 70% has been proposed as a target for early (ED-phase) goal-directed haemodynamic resuscitation, indicating adequate oxygen delivery to tissues. However later in the disease course (ICU-phase) disturbances in microcirculation or mitochondrial function may inhibit peripheral oxygen uptake, resulting in a healthy looking ScvO2 value in spite of evidence of inadequate tissue oxygenation (eg. rising lactate). ScvO2 targets are therefore of limited use in the ICU phase. French investigators hypothesised that an increased arterial-central venous CO2 difference [P(cv-a)CO2] may serve as a global index of tissue hypoperfusion when the ScvO2 goal of 70% has been reached in resuscitated septic shock patients. Using a P(cv-a)CO2 cut off of 6 mmHg, there was a significant difference between low and high ‘gap’ patients for cardiac index, lactate clearance, and improvement in SOFA score, but not for ScvO2. The authors conclude that in ICU-resuscitated septic shock patients, ScvO2 may be insufficient to guide therapy, and that when a target of 70% is reached, the presence of P(cv-a)CO2 > 6 mmHg may be a useful tool to identify patients who remain inadequately resuscitated.
http://www.ncbi.nlm.nih.gov/pubmed/18607565

A controlled crossover study cluster randomised among 13 Dutch ICUs examined both selective decontanimation of the digestive tract (SDD) and of the oral cavity (SOD) on 28 day mortality. The mortality rate associated with standard care
was 27.5% at day 28; the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. Concerns over the selection of multi-drug resistant organisms contribute to a lack of uptake of SDD; this study showing similar benefit of SOD which does not require the administration of systemic antibiotics, an so is more likely to be practice-changing.
http://www.ncbi.nlm.nih.gov/pubmed/19118302

A randomised prospective comparison study of 345 adult ED attenders with and without fever showed no difference in the reliability of temperature measurement by tympanic, oral, and axillary readings. Tympanic temperatures were not affected by otitis or by cerumen impaction. Although not statistically significant, tympanic readings were 0.15 degrees higher than oral, which the authors suggest may be advantageous in the elderly, in whom a single temperature reading of 37.8 degrees is a predictor of infection. Axillary temperatures were 0.27 degrees lower than oral.
http://www.ncbi.nlm.nih.gov/pubmed/19078836

The response of pulse-contour derived cardiac index to passive leg raising by 45 degrees predicts fluid responsiveness in patients with circulatory failure. French investigators demonstrated that performing this manoeuvre starting from a semi-recumbent, as opposed to a supine, position detected a greater number of patients with fluid responsiveness, thought to be due to recruitment of the splanchnic venous reservoir. In their study performing the manoeuvre from the supine position missed 15 of 35 fluid responsive patients. The recommend commencing with the patient in the semi-recumbent position, and simultaneous elevating the legs to 45 degrees while transferring the trunk from a semi-recumbent to a horizontal position.
http://www.ncbi.nlm.nih.gov/pubmed/18795254

A retrospective analysis of 16 365 patients from a Level I trauma center registry examined patient outcomes for several levels of pre-hospital systolic blood pressure. PSBP strongly correlated with systolic blood pressure obtained in the emergency department. The risk of death increased sharply when PSBP dropped less than 110 mmHg, which the authors suggest should become the cut-off for triage to a trauma centre.

http://www.ncbi.nlm.nih.gov/sites/entrez?db=PubMed&cmd=retrieve&dopt=Abstract&list_uids=19077604

Further evidence that the APLS formula (2 x (age +4)) underestimates a child’s weight is provided by a prospective study of 544 kids in Britain, in which the formula was compared with length-based and age-based estimates from growth chart reference data. While length-based estimates of weight were the most accurate, the authors concede that the practical difficulties of measuring a child during a resuscitation mean that the ready availability of age-based reference tables or charts in critical care areas is the best option, and more accurate than the APLS formula.
http://www.ncbi.nlm.nih.gov/pubmed/19104098?dopt=Abstract

December 2008 Clinical Update CME Questions

2009-02-04T04:54:00.001-08:00

1. What is the effect on survival of administering pre-hospital thrombolytics to patients in cardiac arrest?
2. What percentage of patients who receive thrombolytics from massive PE will suffer fatal or intracranial haemorrhage?
3. What is the role of hypertonic saline in the management of severe hyperkalaemia?
4. What effect does sodium bicarbonate have on serum potassium levels in patients with renal failure?
5. What dose of salbutamol should be nebulised in severe life-threatening hyperkalaemia?

December 2008

2009-02-04T04:52:00.000-08:00

Seasons Greetings! Some delicacies from this month’s literature to add to your Christmas fayre:

Some have theorised that giving thrombolytics during cardiac arrest might result in survivors in those with a thrombotic aetiology, such as MI or PE. An RCT from 10 European countries on 1050 patients may have put that idea to rest: tenecteplase and placebo had the same survival outcomes when given to out-of-hospital arrest patients prior to transport to hospital, although a seven times greater incidence (2.7% vs 0.4%) of intracranial haemorrhage in the tenecteplase group.
http://www.ncbi.nlm.nih.gov/pubmed/19092151

Speaking of pulmonary embolism, a review of the disease reminds us that a meta-analysis of 5 RCTs of thrombolysis in patients with PE and arterial hypotension or shock reduces death or recurrent PE from 19% to 9.4% compared with heparin alone (NNT = 10). The benefit is less clear in those with evidence of RV dysfunction but who are normotensive; the need for further therapeutic interventions is reduced but mortality rates are unaffected. The risk of intracranial or fatal haemorrhage from thrombolysis in PE is 1.8%.
http://www.ncbi.nlm.nih.gov/pubmed/19109575?ordinalpos=1&itool=Entrez...

A review of hyperkalaemia and its treatment contains some useful pearls: calcium gluconate is preferred to calcium chloride because of the latter's tendency to cause tissue necrosis if extravasation occurs; hypertonic saline may reverse the ECG changes of hyperkalaemia, particularly in the presence of hyponatraemia; 10mg nebulised salbutamol lowers serum potassium by about 0.6 mmol/l, whereas 20mg lowers it by about 1.0 mmol/l - however up to 40% of patients are resistant to the hypokalaemic effects of salbutamol, for unknown reasons; the effects of insulin/dextrose are additive to those of salbutamol; sodium bicarbonate does not reduce potassium in dialysis-dependent kidney failure. Read the full article for more detailed discussion
http://www.ncbi.nlm.nih.gov/pubmed/18936701

Cardiologists have described a new ECG sign of acute proximal left anterior descending coronary artery occlusion: instead of the signature ST segment elevation, the ST segment showed a 1-3 mm upsloping ST segment depression at the J-point in V1-V6 that continued into tall, positive, symmetrical T waves. In most patients there was also a 1-2 mm St elevation in AVR. These changes were seen in 30 of 1532 (2.0%) of anterior AMI patients. A recognition of this pattern is essential for ensuring these patients receive early reperfusion therapy.
http://www.ncbi.nlm.nih.gov/pubmed/18987380

November 2008 Clinical Update CME Questions

2009-02-04T04:51:00.000-08:00

1. What effect does obesity have on outcome from critical illness?
2. List one or more ventilator measurements that might predict post-extubation laryngeal oedema
3. If you put the Zoll NIBP cuff on a patient's ankle at a primary due to limited access, how would you expect the reading to correlate with a brachial BP (if at all)?
4. List three reasons why outcome in severe burns has improved over the last few decades
5. What is the VITRIS trial, and where is it being conducted?
6. What is the evidence in the civilian population to support or refute the military 1:1:1 transfusion strategy in massive traumatic haemorrhage?
7. Which part of the body is most likely to be injured by the deployment of a steering wheel airbag

November 2008

2009-02-04T04:29:00.001-08:00

Here’s the latest update of literature relevant to what we do. Don’t get stressed if you don’t get round to reading all the original articles - reading the regular summaries should soothe your conscience and remove any nagging worries that you might be missing something big out there.

Let me know if these updates could be done in a more helpful way - feedback much appreciated

Critical care and retrieval
We all assume obese patients do badly on intensive care, but body fat may confer a survival advantage in critical illness. A study and editorial in Intensive Care Medicine add to the ‘large body’ of literature showing the optimal BMI for surviving critical illness is probably much higher than normally assumed, as adipocytes perform a number of protective functions including an immunomodulatory role.
http://www.ncbi.nlm.nih.gov/pubmed/18670754

A meta-analysis of six RCTs tells us that prophylactic administration of steroids in multidose regimens before planned extubation reduces the incidence of laryngeal oedema after extubation and the consequent reintubation rate in adults, with few adverse events. The accompanying editorial suggests a prudent approach might be to limit use to those patients at greatest risk of post-extubation stridor. Risk factors include female sex, short stature, trauma, and prolonged intubation. Laryngeal oedema may be predicted by deflating the cuff and demonstrating a leak of <18% ahref="http://www.bmj.com/cgi/content/abstract/337/oct20_1/a1841">

http://www.bmj.com/cgi/content/abstract/337/oct20_1/a1841

Pre-hospital Care and Trauma

For those of you following the etomidate story, a small nonblinded RCT in trauma patients comparing etomidate with fentanyl/midazalom is the first study to couple adverse clinical endpoints with depressed adrenocortical function. Not an issue in Australia of course, but there are enough Americans and Brits for this to give the willies to. http://www.ncbi.nlm.nih.gov/pubmed/18784570

So you're at a primary where a patient is trapped under a bus and just the legs are sticking out. Tempted to attach the Zoll to the lower limbs for Sats and BP? In normal subjects the mean NIBP at the calf or ankle is very similar to that at the arm, whereas the systolic will be a bit off. Now your obs chart needn't look incomplete even if your patient does. http://www3.interscience.wiley.com/journal/121509623/abstract

Ever been taught a simple way of predicting mortality from burns based on age and total body surface area burned (BSAB)? Examples include if age + BSAB > 75, there is a >50% probability of death. Well now there's a complicated one but it has a catchy acronym: The FLAMES score (Fatality by Longevity, APACHE II score, Measured Extent of burn, and Sex) was derived and (retrospectively) validated. The authors argue that a new more accurate predictive tool is needed because burns mortality has improved over the last few decades as a result of better management of burn shock, use of more effective topical antimicrobials, better systemic antibiotics, organization of regional burn units, earlier excision, and alternative measures for wound closure. Clearly this is tool for hospital use, catches on remember you heard it here first.
http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=pubmed&dopt=...

More info this month on detection of intracranial hypertension by sonographic optic nerve sheath diameter measurement, this time in patients undergoing ICP monitoring. The take home messages: optic nerve sheath diameter correlates better than optic nerve diameter with ICP, and a small ONSD probably means ICP isn't raised. I'm not selling this very well am I?
http://icmjournal.esicm.org/journals/abstract.html?v=34&j=134&i=11&a=...

A nice example of an international collaborative pre-hospital research trial is VITRIS (Vasopressin In refractory TRaumatic HemorrhagIc Shock), being studied by a network of 40 EMS helicopters in Austria, Germany, Switzerland, The Netherlands. The rationale? To maintain coronary and cerebral perfusion pressures and minimise subdiaphragmatic bleeding in patients who would otherwise bleed out and arrest before getting to a hospital trauma team. This thinking is supported by successful animal studies, all further explained in the uploaded article.

Trial homepage: http://www.vitris.at/frameset.htm

Further data to support a liberal FFP and Platelet transfusion strategy in trauma is supplied by Vanderbilt University Medical Centre where they retrospectively evaluated their 'Trauma Exsanguination Protocol' (only in America... ). 30 day mortality was significantly better with FFP:RBC ratios > 2:3 and Plt:RBC ratios > 1:5. Nice to have civilian data to compare with the controversial and scarely achievable military 1:1:1 recommendations.

http://www.ncbi.nlm.nih.gov/pubmed/18469638

There’s another couple of papers to add to the pre-hospital intubation pile (thanks to Mark Newcombe for these). The first paper shows that air medical teams find it harder to effect advanced airway interventions inside the aircraft compared with on scene, and the second takes an interesting look at the effect of out of hospital intubation (OOH-ETI) on outcome when related to distance from hospital . At all distances OOH-ETI was associated with worse outcomes unless patients were transported by helicopter. Take home message? Intubation bad, helicopters good - or perhaps the RSI delivered by experienced helicopter teams provides a survival benefit in salvageable patients (as opposed to patients dead enough to be intubated without drugs). Take a look for yourself and see if you can make sense of it!
First paper: http://www.ncbi.nlm.nih.gov/pubmed/18924006

Second paper: http://www.ncbi.nlm.nih.gov/pubmed/18924009

You attend a motor vehicle collision and the driver’s airbag has deployed. Which part of the body is most likely to be injured by the airbag and its housing? The answer is the upper limbs , particularly forearm fractures. The risk is maximised when the forearm crosses the middle of the steering wheel, for example the left forearm when turning right. As pre-hospital specialists, you can sleep soundly at night smugly reassured that no-one else knows this sort of thing.

http://www.ncbi.nlm.nih.gov/pubmed/18784588

And on the horizon....
A supplement to November’s Critical Care Medicine contains a glimpse of what might be to come in the field of cardiopulmonary resuscitation: animal studies demonstrate the possible benefit of head cooling during CPR, infusion of bone marrow stem cells to facilitate neurological repair post-resuscitation, and replacing conventional chest compressions with electrical stimulation of thoracic cage musculature. Perhaps the most likely of the proposed interventions to reach clinical practice in the shorter term is the impedence threshold device, which appears to contribute to improved outcomes in both piglets and humans, although it has been around for a few years now without catching on.
http://www.ccmjournal.com/pt/re/ccm/toc.00003246-200811001-00000.htm;...

October 2008

2009-02-04T03:53:00.000-08:00

Recent gems from the literature that we could use or should know about:

Pre-hospital Care and Trauma
There have been recent concerns expressed about the possibility of FAST scanning by our retrieval team prolonging scene times, but what about on board the helicopter in flight? Can it be done? Would the results be accurate? Looks like our counterparts in South Australia have answered the question
http://www.ncbi.nlm.nih.gov/pubmed/18339389
If anyone has full text online access to the journal Injury, please let me in!

A dilemma we sometimes face: big trauma mechanism, but the patient seems fine. Do we immobilise? Do we give oxygen? Do we take to a
trauma centre? Well here’s some Australian evidence that supports what we’ve known inside all along: mechanism alone does not usefully
predict major injury in patients whose physiology and physical exam are normal
http://www.ncbi.nlm.nih.gov/pubmed/18674759

Identifying raised ICP using ultrasound of the eyes: This technique has been known about for a while but the evidence base hasn’t been strong. A recent Indian study adds further weight to the conclusions of this year’s BestBet on the topic: that there is a correlation between raised ICP and an optic nerve sheath diameter greater than 5mm. Likely to change our practice in pre-hospital and retrieval work? You decide!
Optic nerve ultrasound http://www.ncbi.nlm.nih.gov/pubmed/18325519
BestBet http://www.bestbets.org/bets/bet.php?id=1641

Cardiovascuar Critical Care
AHA/ACC guidelines for STEMI - implications for emergency medicine practice. This helpful summary provides a useful update as well as guidance for when particular procedures and drugs are indicated. Could be useful for retrieval practice, for example in assessing the appropriateness of a request to transfer a patient for rescue PCI.

http://www.ncbi.nlm.nih.gov/pubmed/18519158

Heart failure therapy - out with the old, in with the new: Morphine’s role in acute heart failure has been questioned for a while now. This article from New Zealand summarises what’s known. Take home message: don’t use it as a heart failure treatment - it doesn’t work and could be harmful.

http://www.ncbi.nlm.nih.gov/pubmed/18973635

What about CPAP/BiPAP? We know that works right? The most solid evidence to date - a multicentre RCT - says nope! Outcomes are the same as ‘medical’ therapy, other than a small difference in patient-reported dyspnoea. Nice to know we don’t need to transport heart failure patients on NIV now - fix ‘em medically or intubate them.
http://www.ncbi.nlm.nih.gov/pubmed/18614781

So gimme something that works for heart failure!! Okay, but you’re not going to like it......Ultrafiltration seems to work better than diuretics, with a lasting benificial effect on the hormonal components of heart failure. A bit fiddly at the moment because it requires a similar set up to haemofiltration (central access, ICU nurses, a haemofilter). From a retrieval point of view let’s hope it doesn’t catch on Australia until the newer peripheral access devices become available.
http://www.ncbi.nlm.nih.gov/pubmed/18787444?dopt=Abstract

On the subject of central venous access, there are some things that will improve your chances of hitting the femoral vein : reverse Trendenlberg position, Valsalva maneouvre, or pushing on the abdomen in the RUQ. Combining them improves things further.
http://www.ncbi.nlm.nih.gov/pubmed/18632187

And finally...

Want a useful update on evidence-based management of GI bleeding? This one is brand new and fits in your pocket - from the Scottish Intercollegiate Guidelines Network (SIGN)
http://www.sign.ac.uk/pdf/qrg105.pdf

That’s it for now....enjoy!!

September 2008

2009-02-04T03:46:00.000-08:00

Hearts and Minds
Some interesting stuff in the literature in the last few months, from high quality RCTs that may change your practice to review articles that can bring you up to date on the latest management of common emergencies:

HEARTS
Are you happy with the diagnostic criteria for MI? What about relative benefits of thrombolysis vs PCI? Have you heard of the newer alternatives to heparin: the DTIs and Factor Xa inhibitors? Check out the Lancet review of Myocardial Infarction

http://www.ncbi.nlm.nih.gov/pubmed/18707987

Extracorporeal Life Support (ECLS) vs convential CPR? Wouldn't that be nice!
http://www.ncbi.nlm.nih.gov/pubmed/18603291

Hard to imagine how this evidence could be applied locally, but for interest here’s an article on the pre-hospital administration of GP 2b-3a antagonists for STEMI:
http://www.ncbi.nlm.nih.gov/pubmed/18707985?ordinalpos=1&itool=Entrez...

This has to be the best paper of the season: the CAT study by Sydney’s own John Myburgh comparing noradrenaline vs adrenaline in 280 critically ill patients requiring vasopressors. What do you think the difference in outcome was?
http://www.ncbi.nlm.nih.gov/pubmed/18654759

MINDS
Review of therapeutic hypothermia for neuroprotection - what it works for, and the dos and don'ts. Recommended reading for FACEM and FJFICM candidates - this is a favourite topic for exams at moment
http://www.ncbi.nlm.nih.gov/pubmed/18539227

Thrombolysis for stroke - up to 4.5 hours now, although that’s not an excuse to dawdle (if you’re a believer).
http://content.nejm.org/cgi/content/short/359/13/1317

Want to waste money and time? Then give rFVIIa for intracerebral haemorrhage! Hemostatic therapy with rFVIIa reduced growth of the hematoma but did not improve survival or functional outcome after intracerebral hemorrhage.
http://content.nejm.org/cgi/content/short/358/20/2127

More soon!