Researchers from the London Helicopter Emergency Medical Service describe the success of pre-hospital laryngoscopy according to the grade and specialty of the HEMS physician…
There is conflicting evidence concerning the role and safety of prehospital intubation, and which providers should deliver it. Success rates for physician-performed rapid sequence induction are reported to be 97-100%, with limited evidence of improved survival in some patient groups. However, there is also evidence that prehospital intubation and ventilation can do harm. Prospective data were recorded on the success of intubation, the quality of the laryngeal view obtained and the number of attempts at intubation. These data were then analysed by the grade of intubating doctor and whether the intubating doctor had a background in anaesthesia or emergency medicine. All groups had a similar success rate after two attempts at intubation. Doctors with a background in anaesthesia and consultant emergency physicians had a significantly better first-pass intubation rate than emergency medicine trainees. The quality of laryngeal view was significantly better in doctors with an anaesthetics background.
Success in physician prehospital rapid sequence intubation: what is the effect of base speciality and length of anaesthetic training? Emerg Med J. 2011 Mar;28(3):225-9
The SAMU (Service d’aide médicale urgente) guys have had a run of interesting pre-hospital publications lately. In this study, one of their ultrasound-wielding physicians travelled in a car to meet comatose head injured patients in a large semi-rural territory area with up to a 120–160-min transport time to a hospital with emergency neurosurgical capability. Pre-hospital transcranial Doppler was done, the results of which appear to have influenced treatment decisions, including the pre-hospital administration of noradrenaline (norepinephrine). I think this study has answered the ‘can it be done?’ question, but further work is needed to determine whether it really makes a difference to outcome.
Background: Investigation of the feasibility and usefulness of pre-hospital transcranial Doppler (TCD) to guide early goal-directed therapy following severe traumatic brain injury (TBI). Methods: Prospective, observational study of 18 severe TBI patients during pre-hospital medical care. TCD was performed to estimate cerebral perfusion in the field and upon arrival at the Level 1 trauma centre. Specific therapy (mannitol, noradrenaline) aimed at improving cerebral perfusion was initiated if the initial TCD was abnormal (defined by a pulsatility index >1.4 and low diastolic velocity). Results: Nine patients had a normal initial TCD and nine an abnormal one, without a significant difference between groups in terms of the Glasgow Coma Scale or the mean arterial pressure. Among patients with an abnormal TCD, four presented with an initial areactive bilateral mydriasis. Therapy normalized TCD in five patients, with reversal of the initial mydriasis in two cases. Among these five patients for whom TCD was corrected, only two died within the first 48 h. All four patients for whom the TCD could not be corrected during transport died within 48 h. Only patients with an initial abnormal TCD required emergent neurosurgery (3/9). Mortality at 48 h was significantly higher for patients with an initial abnormal TCD. Conclusions: Our preliminary study suggests that TCD could be used in pre-hospital care to detect patients whose cerebral perfusion may be impaired.
Background Every day throughout the UK, ambulance services seek medical assistance in providing critically ill or injured patients with pre-hospital care. Objective To identify the current availability and utilisation of physician-based pre-hospital critical care capability across England, Wales and Northern Ireland. Design A postal and telephone survey was undertaken between April and December 2009 of all 13 regional NHS ambulance services, 17 air ambulance charities, 34 organisations affiliated to the British Association for Immediate Care and 215 type 1 emergency departments in England, Wales and Northern Ireland. The survey focused on the availability and use of physician-based pre-hospital critical care support. Results The response rate was 100%. Although nine NHS ambulance services recorded physician attendance at 6155 incidents, few could quantify doctor availability and utilisation. All but one of the British Association for Immediate Care organisations deployed ‘only when available’ and only 45% of active doctors could provide critical care support. Eleven air ambulance services (65%) operated with a doctor but only 5 (29%) operated 7 days a week. Fifty-nine EDs (27%) had a pre-hospital team but only 5 (2%) had 24 h deployable critical care capability and none were used regularly. Conclusion There is wide geographical and diurnal variability in availability and utilisation of physician-based pre-hospital critical care support. Only London ambulance service has access to NHS-commissioned 24 h physician-based pre-hospital critical care support. Throughout the rest of the UK, extensive use is made of volunteer doctors and charity sector providers of varying availability and capability.
A Swiss study examined the on site triage decision making of pre-hospital emergency physicians. Dispatch of the physicians was coordinated by trained nurses or paramedics.
OBJECTIVE: Accurate identification of major trauma patients in the prehospital setting positively affects survival and resource utilization. Triage algorithms using predictive criteria of injury severity have been identified in paramedic-based prehospital systems. Our rescue system is based on prehospital paramedics and emergency physicians. The aim of this study was to evaluate the accuracy of the prehospital triage performed by physicians and to identify the predictive factors leading to errors of triage. METHODS: Retrospective study of trauma patients triaged by physicians. Prehospital triage was analyzed using criteria defining major trauma victims (MTVs, Injury Severity Score >15, admission to ICU, need for immediate surgery and death within 48 h). Adequate triage was defined as MTVs oriented to the trauma centre or non-MTV (NMTV) oriented to regional hospitals. RESULTS: One thousand six hundred and eighti-five patients (blunt trauma 96%) were included (558 MTV and 1127 NMTV). Triage was adequate in 1455 patients (86.4%). Overtriage occurred in 171 cases (10.1%) and undertriage in 59 cases (3.5%). Sensitivity and specificity was 90 and 85%, respectively, whereas positive predictive value and negative predictive value were 75 and 94%, respectively. Using logistic regression analysis, significant (P<0.05) predictors of undertriage were head or thorax injuries (odds ratio >2.5). Predictors of overtriage were paediatric age group, pedestrian or 2 wheel-vehicle road traffic accidents (odds ratio >2.0). CONCLUSION: Physicians using clinical judgement provide effective prehospital triage of trauma patients. Only a few factors predicting errors in triage process were identified in this study.
A Czech study demonstrated effective pre-hospital therapeutic cooling of post-cardiac arrest patients using fairly modest amounts of intravenous saline at 4°C: the administration of 12.6 ± 6.4 mL/kg (1,032 ± 546 mL) of 4°C normal saline led to a tympanic temperature decrease of 1.4 ± 0.8°C (from 36.2 ± 1.5 to 34.7 ± 1.4°C; P < 0.001) in 42.8 ± 19.6 minutes. No ice packs were applied.
Before other emergency medical services adopt this, it should be noted that all these patients were managed in the field by emergency physicians who administered sedatives and neuromuscular blockers. It’s a European thing. Pre-hospital cooling of patients following cardiac arrest is effective using even low volumes of cold saline Critical Care 2010, 14:R231 Full text
A contribution has been made to the literature supporting physician intervention in some pre-hospital trauma patients, in the form of the FIRST study: French Intensive care Recorded in Severe Trauma. Not exactly the class 1 evidence we’d (well, I’d) like to see, but a prospective study from France comparing outcomes in patients treated by routine pre-hospital providers with those managed in the field by emergency physicians working for SMUR (Service Mobile d’Urgences et de Réanimation). Primary outcome was 30-day mortality. Only patients admitted to an ICU were included, and researchers were not blinded to which group (SMUR vs nonSMUR) patients belonged. A large group of SMUR patients (2513) was compared with a much smaller (190) nonSMUR group.
Patients were sicker in the SMUR group (lower GCS and SpO2, higher Injury Severity Score, higher frequency of abnormal pupils). Unadjusted mortality was not significantly different but when adjustment for ISS and physiological status was made (I don’t really understand how this was done), SMUR care was significantly associated with a reduced risk of 30-day mortality (OR: 0.55, 95% CI: 0.32-0.94, p = 0.03).
Lots of interesting points in this study, most of which ask more questions that they answer. The French pre-hospital physicians have an aggressive approach to trauma resuscitation, doing rapid sequence intubation in more than a half of their patients and even starting catecholamine infusions as a fluid-sparing strategy in shocked patients. The full text link is worth a read for those interested in this area of medicine. Medical pre-hospital management reduces mortality in severe blunt trauma: a prospective epidemiological study Critical Care 2011, 15:R34 Full text as provisional PDF
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]
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]
Being human, I suffer from confirmation bias: I’ve become aware that I’m always on the look out for studies that show benefit from physician-provided pre-hospital care and therefore it’s possible I miss the ones that show no benefit. Of course, no ‘level 1’ evidence is out there yet. This study isn’t hugely impressive, but worth adding to the list. After adjusting for injury severity, trauma patients treated on scene by Dutch physicians had no difference in mortality compared with those that received standard care. In the subgroup analysis for patients with severe traumatic brain injury, the mortality rate with physician involvement was lower than that without, but was not statistically significant. On scene times averaged 2.7 minutes longer in the physician group although factors that might have contributed to this, such as entrapment or on scene interventions, were not recorded.
A major limitation in study design is that patients who died while under care at the scene or during transport were excluded from the analysis. The on scene time in these patients could have been prolonged by medical interventions in the field possibly contributing to the adverse outcome.
Take home message? More evidence needed. The Association of Mobile Medical Team Involvement on On-Scene Times and Mortality in Trauma Patients J Trauma. 2010 Sep;69(3):589-94
More junior pre-hospital doctors took longer on scene than their senior colleagues according to a German study, although patient clinical factors were the main determinant of scene time. The majority of cases were non-trauma presentations Duration of mission time in prehospital emergency medicine: effects of emergency severity and physicians level of education Emerg Med J 2010;27:398-403