Category Archives: PHARM

Prehospital and Retrieval Medicine

Paramedics control space

Paramedics practice ‘‘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.

Introduction to the ‘‘space-control theory of paramedic scene management’’
Emerg Med J. 2009 Mar;26(3):213-6

Pre-hospital arterial lines

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

Air medical intubation success

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.

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

Chest needle too short

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.

Needle thoracostomy for tension pneumothorax: failure predicted by chest computed tomography
Prehosp Emerg Care. 2009 Jan-Mar;13(1):14-7

Is defib danger overstated

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.

Is external defibrillation an electric threat for bystanders?
Resuscitation. 2009 Apr;80(4):395-401

BIS+HEMS

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!

Bispectral index monitoring in helicopter emergency medical services patients
Prehosp Emerg Care. 2009 Apr-Jun;13(2):193-7

Delays to neurosurgery

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!

A prospective study of the time to evacuate acute subdural and extradural haematomas.
Anaesthesia. 2009 Mar;64(3):277-81

Airtraq use by paramedics

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.

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

Physicians in pre-hospital care

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.

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

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

 

oxygen for myocardial infarction – harmful?

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.

Routine use of oxygen in the treatment of myocardial infarction: systematic review
Heart. 2009 Mar;95(3):198-202