Plasma:red cell transfusion ratio in trauma

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

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

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

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

Best way to insert NG tube in intubated patients

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

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

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

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

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

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

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

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!

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

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

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