Does Pre-Hospital ALS Saves Lives in Trauma?
Search Strategy: While reading Emergency Physicians Monthly, you note an interesting ALS debate. Recognizing that the research being discussed is a Canadian study, you first search EMBASE (the European equivalent of PUBMED) using the combined search terms “advanced life support” and “trauma” (limit English, human, and 2000-2009) yielding 112 citations including the 2008 OPALS findings. Next, you turn to PUBMED using the same search terms and limits with 32 citations identified but nothing more of relevance so you select “related articles” for the OPALS study. This strategy identifies a number of studies including a Cochrane Review on the topic (which is where you probably should have started for a question of therapy)
Medic 10 has responded to a high speed MVC with one death at the scene and a critically ill patient with ETA 5 minutes. The patient is moaning, tachycardic, and breathing rapidly, but high ambient noise levels mean that EMS cannot obtain a blood pressure.
The trauma team is gowned, gloved, and ready and waiting… And waiting… And waiting… Dr. Buchman is pacing. 15 minutes later, Medic 10 rolls in with patient in tow. A combitube is in place, 20-gauge IV line in one arm, 16-gauge hanging out of the other with blood running down the patient’s arm.
After listening to their report, you ask them what took so long since they were supposedly on their way. They report attempting intubation twice and (using capnography) realized that they failed. Ultimately, they intubated with the combitube. In addition, they know that they are supposed to start 2 IV’s: one blew and the other fell out en route.
As CPR is beginning, you wonder if the patient would have had a better chance if the crew just practiced “scoop and run” instead of “stay and play”. You remember to ask Dr. Levine what the heck his crews are doing on scene for so long. He answers that his protocols limit scene time to 10-minutes and that paramedics to be up to date with procedures in the field. Unfortunately, he can’t produce any supporting evidence, so Dr. Carpenter assigns him the May journal club.
Population: Pre-hospital trauma patients
Intervention: Pre-hospital Advanced Life Support interventions (definitive airway, intravenous access)
Comparison: “Scoop and run” pre-hospital care
Outcome: Survival to hospital discharge, functional outcomes, hospital length-of-stay, aspiration complications
First years: Emergency intubation for acutely ill and injured patients, Cochrane Database of Systematic Reviews 2008; Issue 2: Art No. CD001429. DOI: 10.1002/14651858.CD001429.pub2 (http://pmid.us/18425873)
Article 1: Emergency intubation for acutely ill and injured patients. Cochrane Database of Systematic Reviews 2008; Issue 2, Art No. CD001429
Article 2: The OPALS Major Trauma Study: impact of advanced life-support on survival and morbidity, CMAJ 2008; 178:1141-1152
Article 3: A Controlled Trial of Pre-hospital Advanced Life Support in Trauma Annals of Emergency Medicine 1988;17:582-588
Article 4: The Impact of rapid sequence intubation on trauma patient mortality in attempted prehospital intubation, JEM 2009 (in press)
The Succinct Answer
Currently there is insufficient high-quality data available to comment on the efficacy of emergency ETI by paramedics in the pre-hospital setting. Although prompt airway management with ETI is advocated as life-saving, current trials do not constitute definitive evidence. Thus, large high-quality randomized trials comparing ETI efficacy to basic maneuvers in urban out-of-hospital trauma patients are needed to refine current practice. In the meantime, pre-hospital definitive airway interventions should not take priority over rapid transfer to definitive trauma center care. Looking at the best-evidence available:
- Multi-center Ontario based before/after controlled observational trial demonstrating no survival benefit associated with ALS-trained pre-hospital EMS for adult trauma victims in urban environments transferred to a trauma center within 8-hours of their injury. In fact, among severely head injured patients (GCS < 9) ALS-care and pre-hospital intubation independently increase mortality when adjusted for age and injury severity. Before expanding or continuing ALS related training and spending for urban EMS systems, effective and safe components of this pre-hospital care must be demonstrated. In the meantime, ALS crews should avoid pre-hospital intubations and IV attempts in lieu of an expedited scoop and run philosophy to minimize time to definitive trauma center care.
- Retrospective analysis of Oregon trauma registry suggests that propensity score balanced cohort of consecutive adult trauma patients requiring pre-hospital airway intervention by experienced paramedics offers no survival benefit for RSI vs. non-RSI. However, point estimates consistently favor RSI and approach significance for the subset with GCS ≤ 8. In lieu of a randomized controlled trial to demonstrate a more bias free answer, EMS airway training with medications (RSI) should focus on subsets most likely to benefit (GCS ≤ 8).
- Among children, paramedic non-RSI ETI vs. bag-valve-mask (BVM) in 830 children <13 years old (71% non-traumatic cardiac arrest, 13% respiratory arrest, 8% status epilepticus) with 57% EMS ETI success rate demonstrated no survival (26% vs. 30%; OR 0.82, 95% CI 0.61 – 1.11) or neurological outcome advantages (good outcome 23% vs. 20%; OR 0.87, 95% CI 0.62 – 1.22).