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
Posts
