Advanced Ambulance Life Support Increases Mortality

Patients have a better chance of survival if they are transported by a basic ambulance than by an advanced life support (ALS) ambulance, according to a new study.

Researchers at the University of Chicago (IL, USA) and Harvard Medical School (Boston, MA, USA) conducted a study to compare survival outcomes following ALS or basic life support (BLS) triage in out-of-hospital medical emergencies. The observational study involved nearly 400,000 patients nationwide between 2006 and 2011 who suffered major trauma, stroke, acute myocardial infarction (AMI), or respiratory failure. The main outcome was neurologic functioning and survival to 30 days, 90 days, one year, and two years.

The results showed that for trauma patients, survival was 6.1% higher for those transported by a BLS ambulance than those who were transported by an ALS one; patients with critical major trauma had a 12.5% greater chance of surviving for 90 days if transported by BLS. Patients with AMI were 5.9% more likely to survive and patients with stroke had a 4.3% greater chance of surviving for 90 days, when transported by a BLS ambulance. There was no survival difference between BLS and ALS ambulances for patients with respiratory failure. The study was published in the October 13, 2015, issue of Annals of Internal Medicine.

“We studied conditions that were representative of the major causes of death where we thought we were most likely to see a benefit from the kinds of services that ALS provides,” said lead author Prachi Sanghavi, PhD, of the University of Chicago, and a research fellow in health care policy at Harvard Medical School. “But we found that basic life support patients were more likely to survive. They were also more likely to have better outcomes on measures such as neurological functioning.”

ALS ambulances, staffed by paramedics, are equipped to perform more invasive procedures than BLS ambulances, which are staffed by emergency medical technicians. A patient in respiratory distress, for example, might be intubated by an ALS crew; a BLS crew in the same situation would use a bag-mask respirator. The researchers said they suspect that ALS transport may delay hospital care, since the ALS approach (known as “stay and play”) takes longer to deliver patients to the hospital than the BLS “scoop and run” methodology.

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University of Chicago
Harvard Medical School