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
Category Archives: PHARM
Prehospital and Retrieval Medicine
EZ-IO outperformed B.I.G
A small randomised trial of adult emergency department patients showed faster insertion and higher success rates with the EZ-IO compared with the Bone Injection Gun (B.I.G). This is in keeping with my own experience and that of several services I have worked for.
Comparison of two intraosseous access devices in adult patients under resuscitation in the emergency department: A prospective, randomized study
Resuscitation. 2010 Aug;81(8):994-9
Scene time not linked to outcome in large cohort
Okay – I admit to loving this paper, partly because it blows away the dogma of short scene times and ‘scoop & run’, and the oft-quoted but obnoxious assertion that the only pre-hospital fluid of benefit is gasoline.
A massive database of 3656 sick trauma patients (SBP < 90, 10>resp rate>29, GCS≤12, or advanced airway intervention), transported by 146 EMS agencies to 51 hospitals, was analysed to identify any association between mortality and emergency medical services (EMS) timings (activation, response, on-scene, transport, and total time). Overall mortality in this group was 22%.
There was no significant association between time and mortality for any EMS interval: activation (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.95 to 1.05), response (OR 1.00; 95% CI 9.97 to 1.04), on-scene (OR 1.00; 95% CI 0.99 to 1.01), transport (OR 1.00; 95% CI 0.98 to 1.01), or total EMS time (OR 1.00; 95% CI 0.99 to 1.01).
The authors state: “In this study, we were unable to support the contention that shorter out-of-hospital times… improve survival among injured adults with field-based physiologic abnormality… Our findings are consistent with those of previous studies that similarly have failed to demonstrate a relationship between out-of-hospital time and outcome using different patient populations, trauma and EMS systems, regions, data sources, and confounders”
Emergency Medical Services Intervals and Survival in Trauma: Assessment of the “Golden Hour” in a North American Prospective Cohort
Ann Emerg Med. 2010 Mar;55(3):235-246
Increased mortality with non-trauma centre care
A trauma database was analysed to see if patients who were transported from the field to a non-trauma centre (NTC) and subsequently sent on to a trauma centre (TC) for definitive care fared worse than similar patients who were transferred directly to the TC.
There were 1,112 patients of whom 318 (29%) were initially triaged to a NTC. After adjusting for confounders, this was associated with an increase in prehospital crystalloids (4.2 L vs. 1.4 L, p < 0.05) and a 12-fold increase in blood transfusions (60% vs. 5%, p < 0.001). Age, injury severity score, Acute Physiology and Chronic Health Evaluation II score, and time from injury to TC arrival were independent predictors of mortality. The odds of death were 3.8 times greater (95% CI, 1.6–9.0) when patients were initially triaged to a nontrauma facility.
The authors conclude: triaging severely injured patients to hospitals that are incapable of providing definitive care is associated with increased mortality. Attempts at initial stabilization at an NTC may be harmful. These findings are consistent with a need for continued expansion of regional trauma systems.
Scoop and Run to the Trauma Center or Stay and Play at the Local Hospital: Hospital Transfer’s Effect on Mortality
Journal of Trauma-Injury Infection & Critical Care September 2010;69(3):595-601
Peripheral vasoactive infusions
It is often recommended that vasoactive agents are infused via central lines because of the risk of infiltration and tissue injury. The Children’s Hospital Boston transport team describe transport of 73 infants and children who were treated during interhospital transport with vasoactive medications via a peripheral intravenous line.
Median transport time was only 38 minutes (range 3[!!]-216) and median age was 1 (birth to 19) .
Dopamine monotherapy was given in 66 patients, adrenaline (epinephrine) monotherapy in 2, dobutamine plus phenylephrine in 1, dopamine and epinephrine in 3, and dopamine, dobutamine, and epinephrine in 1 patient.
In this retrospective study no patients developed infiltration or other complications related to peripheral vasoactive agents during interfacility transport. Eleven of the 73 patients, however, did develop infiltrates related to vasoactive infusion after arrival at the accepting institution; all infiltrates involved only minimal blanching and/or erythema, and all resolved without significant intervention and caused no lasting tissue injury. The risk of infiltration rose with increasing medication dose and duration of use.
Interesting that noradrenaline (norepinephrine) wasn’t used. This study is interesting but the overwhelming predominance of dopamine makes it hard to extrapolate this to European or Australasian practice.
The Use of Vasoactive Agents Via Peripheral Intravenous Access During Transport of Critically Ill Infants and Children
Pediatr Emerg Care. 2010 Aug;26(8):563-6
rFVIIa did not reduce trauma mortality
An industry sponsored placebo-controlled multicentre randomised controlled trial has shown no mortality reduction from recombinant activated Factor VII (rFVIIa) in patients with trauma.
rFVIIa acts physiologically by enhancing clot formation in the presence of tissue factor expressed on injured or ischemic vascular subendothelium. It also acts pharmacologically, binding directly to activated platelets, increasing thrombin burst, and promoting the formation of a stable hemostatic plug.
Blunt and/or penetrating trauma patients aged 18 years to 70 years were eligible if they had continuing torso and/or proximal lower extremity bleeding after receiving 4 units of RBCs despite standard hemostatic interventions. There was no 30 day mortality reduction, although fewer blood products were transfused from dosing to 24 hours in the rFVIIa group.
No significant difference was seen in the safety profile of rFVIIa compared with placebo.
The CONTROL trial was terminated early (573 of 1502 patients) after an interim analysis suggested a high likelihood of futility in demonstrating the primary endpoint in the blunt trauma population.
Results of the CONTROL Trial: Efficacy and Safety of Recombinant Activated Factor VII in the Management of Refractory Traumatic Hemorrhage
Journal of Trauma-Injury Infection & Critical Care September 2010 69(3):489-500
Paediatric Tube Cuff Pressures
A paediatric critical care transport service encountered elevated tracheal tube cuff pressures (>30 cmH20) in 41% of 60 consecutive care studied, and over 60 cmH20 in 30%. This measurement was taken on arrival at the bedside, not in flight.
Cuffed tubes are good, but we need to keep an eye on the pressures.
This is in keeping with the results of an adult study previously blogged on this site.
Endotracheal Tube Cuff Pressures in Pediatric Patients Intubated Before Aeromedical Transport
Pediatr Emerg Care. 2010 May;26(5):361-3
Alternative toothless mask position
An alternative position for holding the facemask when bag-mask ventilating edentulous patients is described and evaluated. 49 patients with inadequate seal and air leak during two-hand positive-pressure ventilation had significantly improved ventilation as measured by reduced air leak and increased expiratory volume when the caudal end of the mask was repositioned above the lower lip while maintaining neck extension.
Face mask ventilation in edentulous patients: a comparison of mandibular groove and lower lip placement
Anesthesiology. 2010 May;112(5):1190-3
Taming the Ketamine Tiger
A paper of great interest for those of us who spend a lot of time teaching the use of ketamine describes its history from initial synthesis in the early 1960s. Ketamine pioneer Edward F. Domino, M.D describes how it was first given to humans in 1964: ‘Our findings were remarkable! The overall incidence of side effects was about one out of three volunteers. Frank emergence delirium was minimal. Most of our subjects described strange experiences like a feeling of floating in outer space and having no feeling in their arms or legs.‘
Domino goes on to list interesting anecdotes in ketamine’s history, like how his wife came up with the term ‘dissociative anaesthetic’ and how physicians and their partners experimenting with ketamine in the 1970s tried communicating with dolphins, fell in love, and froze to death in a forest. The pharmacology of ketamine is described along with its effects on pain and even depression.
Taming the ketamine tiger.
Anesthesiology. 2010 Sep;113(3):678-84 Free Full Text
Unexpected survivors after pre-hospital intubation
Data on patients with moderate to severe traumatic brain injury from the San Diego Trauma Registry were analysed using modified TRISS methodology to determine predicted survival, from which an observed-predicted survival differential (OPSD) was calculated. The mean OPSD was calculated as the primary outcome for the following comparisons: intubated versus nonintubated, air versus ground transport, eucapnia (PCO2 30–50 mm Hg) versus noneucapnia, and hypoxemia (PO<90 mm Hg) versus nonhypoxemia. Of note in this region is that ground EMS staff intubate without drugs, whereas air medical services use rapid sequence intubation with suxamethonium plus either etomidate or midazolam.
The rationale behind this methodology was to eliminate the possible selection bias present in previous studies linking pre-hospital intubation with mortality (sicker patients are able to be intubated without drugs).
A total of 9,018 TBI patients had complete data to allow calculation of probability of survival using TRISS. A total of 16.7% of patients were intubated in the field; 49.6% of these were transported by air medical providers. Patients undergoing prehospital intubation, transported by ground, with arrival eucapnia, and without arrival hypoxemia had higher mean OPSD values.
Intubated patients were more likely to be “unexpected survivors” and live to hospital discharge despite low predicted survival values; patients transported by air medical personnel had higher OPSD values and had a higher proportion of unexpected survivors. No statistically significant differences were observed between air- and ground-transported patients with regard to arrival PCO2 values arrival PO2 values.
Prehospital Airway and Ventilation Management: A Trauma Score and Injury Severity Score-Based Analysis
J Trauma. 2010 Aug;69(2):294-301