The Emergency Medical Retrieval Service (EMRS) provides an aeromedical retrieval service to remote and rural communities in Scotland. They examined 300 retrievals over a five year period and showed a correlation between amount of critical care interventions required and total time on scene (defined as the total length of time between the aircraft landing and taking off from the scene, this includes access to patient, transfer to the helicopter and packaging for flight departure). Median scene time for both medical and trauma patients was 60 minutes.
The authors remind us that critical care secondary retrieval from rural healthcare facilities has many similarities to prehospital care (primary retrieval), and therefore consideration of scene times is of interest.
On-scene times and critical care interventions for an aeromedical retrieval service
Emerg Med J. 2010 Aug 19. [Epub ahead of print]
Tag Archives: EMS
Ketamine for HEMS intubation in Canada
Ketamine was used by clinical staff from the The Shock Trauma Air Rescue Society (STARS) in Alberta to facilitate intubation in both the pre-hospital & in-hospital setting (with a neuromuscular blocker in only three quarters of cases). Changes in vital signs were small despite the severity of illness in the study population.
A prospective review of the use of ketamine to facilitate endotracheal intubation in the helicopter emergency medical services (HEMS) setting
Emerg Med J. 2010 Oct 6. [Epub ahead of print]
Scene times & penetrating trauma
An observational cohort study of penetrating trauma patients treated by the Mobile Emergency Care Unit in Copenhagen, Denmark over a seven-and-a-half year period sought to determine the effect of on-scene time on 30-day mortality.
In this setting, in cases of penetrating trauma to the chest, or abdomen, a Mobile Emergency Care Unit (MECU) and Basic Life Support unit are dispatched simultaneously, and rendezvous at the site of the incident. The MECU is staffed with consultants in anaesthesiology, intensive care and emergency medicine, as well as a specially trained ALS provider.
The physician manning the MECU administers medication and is able to perform procedures such as intubation, thoracocentesis, pleural drainage, intravenous and intraosseous access for fluid resuscitation. Although some patients were in cardiac arrest due to penetrating torso trauma (9 patients received chest compressions, and all were dead at 30 follow up), thoracotomy was not listed as a skill provided.
Of the 467 patients registered, 442 (94.6%) were identified at the 30-day follow-up, of whom 40 (9%) were dead. A higher mortality was found among patients treated on-scene for more than 20 min (p<0.0001), although on-scene time was not a significant predictor of 30-day mortality in the multivariate analysis; OR 3.71, 95% CI 0.66 to 20.70 (p<0.14). The number of procedures was significantly correlated to a higher mortality in the multivariate analysis.
The authors conclude that on-scene time might be important in penetrating trauma, and ALS procedures should not delay transport to definite care at the hospital. However their adjusted Odds Ratio for on scene time >20 minutes as a predictor of 30 day mortality was 3.71 with very wide 95% confidence intervals (0.66 to 20.70) and there were several weaknesses and confounding factors in the study which the authors acknowledge.
The only real information this study provides appears to be on the idiosyncrasies of the Copenhagen pre-hospital care system. Looking at their list of procedures and their practice of chest compressions in cardiac arrest due to penetrating trauma, it is very hard to ascertain what, if any, advantage their physicians offer over trained paramedics. As the authors point out: “Currently, strict guidelines are not practiced. Hence, the decision to treat by a ‘scoop and run’ or a ‘stay and play’ approach is at the discretion of the physician”
On-scene time and outcome after penetrating trauma: an observational study
Emerg Med J. 2010 Oct 9. [Epub ahead of print]
Pre-hospital RSI by different specialties
This aim of the study was to evaluate the tracheal intubation success rate of doctors drawn from different clinical specialities performing rapid sequence intubation (RSI) in the pre-hospital environment operating on the Warwickshire and Northamptonshire Air Ambulance. Over a 5-year period, RSI was performed in 200 cases (3.1/month).
Failure to intubate was declared if >2 successive attempts were required to achieve intubation or an ETT could not be placed correctly necessitating the use of an alternate airway. Successful intubation occurred in 194 cases, giving a failure rate of 3% (6 cases, 95% CI 0.6 to 5.3%). While no difference in failure rate was observed between emergency department (ED) staff and anaesthetists (2.73% (3/110, 95% CI 0 to 5.7%) vs 0% (0/55, 95% CI 0 to 0%); p=0.55), a significant difference was found when non-ED, non- anaesthetic staff (GP and surgical) were compared to anaesthetists (10.34% (3/29, 95% CI 0 to 21.4%) vs 0%; p=0.04). There was no significant difference associated with seniority of practitioner (p=0.65). The authors conclude that non-anaesthetic practitioners have a higher tracheal intubation failure rate during pre-hospital RSI, which may reflect a lack of training opportunities.
The small numbers of ‘failure’ rates, combined with the definition of failure in this study, make it hard to draw generalisations. Of note is that the paper lists the outcomes of the six patients who met the failed intubation definition, all of whom appear to have had their airway satisfactorily maintained by the RSI practitioner, three by eventual tracheal intubation, one by LMA, and two by surgical airway. More data are needed before whole specialties are judged on the performance of a small group of doctors.
Should non-anaesthetists perform pre-hospital rapid sequence induction? an observational study
Emerg Med J. 2010 Jul 26. [Epub ahead of print]
Compression-only CPR vs standard CPR
Two studies comparing compression-only CPR with conventional CPR:
BACKGROUND: The role of rescue breathing in cardiopulmonary resuscitation (CPR) performed by a layperson is uncertain. We hypothesized that the dispatcher instructions to bystanders to provide chest compression alone would result in improved survival as compared with instructions to provide chest compression plus rescue breathing.
METHODS: We conducted a multicenter, randomized trial of dispatcher instructions to bystanders for performing CPR. The patients were persons 18 years of age or older with out-of-hospital cardiac arrest for whom dispatchers initiated CPR instruction to bystanders. Patients were randomly assigned to receive chest compression alone or chest compression plus rescue breathing. The primary outcome was survival to hospital discharge. Secondary outcomes included a favorable neurologic outcome at discharge.
RESULTS: Of the 1941 patients who met the inclusion criteria, 981 were randomly assigned to receive chest compression alone and 960 to receive chest compression plus rescue breathing. We observed no significant difference between the two groups in the proportion of patients who survived to hospital discharge (12.5% with chest compression alone and 11.0% with chest compression plus rescue breathing, P=0.31) or in the proportion who survived with a favorable neurologic outcome in the two sites that assessed this secondary outcome (14.4% and 11.5%, respectively; P=0.13). Prespecified subgroup analyses showed a trend toward a higher proportion of patients surviving to hospital discharge with chest compression alone as compared with chest compression plus rescue breathing for patients with a cardiac cause of arrest (15.5% vs. 12.3%, P=0.09) and for those with shockable rhythms (31.9% vs. 25.7%, P=0.09).
CONCLUSIONS: Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups. The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing. (Funded in part by the Laerdal Foundation for Acute Medicine and the Medic One Foundation; ClinicalTrials.gov number, NCT00219687.)
CPR with chest compression alone or with rescue breathing
N Engl J Med. 2010 Jul 29;363(5):423-3
BACKGROUND: Emergency medical dispatchers give instructions on how to perform cardiopulmonary resuscitation (CPR) over the telephone to callers requesting help for a patient with suspected cardiac arrest, before the arrival of emergency medical services (EMS) personnel. A previous study indicated that instructions to perform CPR consisting of only chest compression result in a treatment efficacy that is similar or even superior to that associated with instructions given to perform standard CPR, which consists of both compression and ventilation. That study, however, was not powered to assess a possible difference in survival. The aim of this prospective, randomized study was to evaluate the possible superiority of compression-only CPR over standard CPR with respect to survival.
METHODS: Patients with suspected, witnessed, out-of-hospital cardiac arrest were randomly assigned to undergo either compression-only CPR or standard CPR. The primary end point was 30-day survival.
RESULTS: Data for the primary analysis were collected from February 2005 through January 2009 for a total of 1276 patients. Of these, 620 patients had been assigned to receive compression-only CPR and 656 patients had been assigned to receive standard CPR. The rate of 30-day survival was similar in the two groups: 8.7% (54 of 620 patients) in the group receiving compression-only CPR and 7.0% (46 of 656 patients) in the group receiving standard CPR (absolute difference for compression-only vs. standard CPR, 1.7 percentage points; 95% confidence interval, -1.2 to 4.6; P=0.29).
CONCLUSIONS: This prospective, randomized study showed no significant difference with respect to survival at 30 days between instructions given by an emergency medical dispatcher, before the arrival of EMS personnel, for compression-only CPR and instructions for standard CPR in patients with suspected, witnessed, out-of-hospital cardiac arrest. (Funded by the Swedish Heart–Lung Foundation and others; Karolinska Clinical Trial Registration number, CT20080012.)
Compression-Only CPR or Standard CPR in Out-of-Hospital Cardiac Arrest
N Engl J Med. 2010 Jul 29;363(5):434-42
Is cervical spine protection always necessary following penetrating neck injury?
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
Pre-hospital intubation 'success' at a US centre
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
Prehospital management of severe traumatic brain injury
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
Population density & use of ambulance services
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
72000 retrievals by Flying Doctors
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.
Aeromedical retrieval for critical clinical conditions: 12 years of experience with the Royal Flying Doctor Service, Queensland, Australia
J Emerg Med. 2009 May;36(4):363-8
http://www.ncbi.nlm.nih.gov/pubmed/18814993