Patients who had cardiac arrest at home or elsewhere outside of a hospital had greater survival to hospital discharge and to 90 days beyond if they received basic life support (BLS) vs. advanced life support (ALS) from ambulance personnel, according to a report published online by JAMA Internal Medicine.
Emergency medical services (EMS) respond to an estimated 380,000 cardiac arrests that happen annually out of the hospital. ALS providers, or paramedics, are trained to use sophisticated, invasive interventions (such as intubation - the placement of a breathing tube) to treat cardiac arrest before the patient arrives at the hospital. BLS providers, or emergency medical technicians, use simpler devices such as bag valve masks (hand-operated mask that helps breathe for the patient) and automated external defibrillators. Consequently, ALS paramedics tend to spend more time at the location of a cardiac arrest than BLS personnel.
Prachi Sanghavi, B.S., of Harvard University, Boston, and colleagues used data from a nationally representative sample of Medicare beneficiaries from nonrural counties in the United States who had out-of-hospital cardiac arrest between January 2009 and October 2011 for whom ALS or BLS ambulance services were charged to Medicare. There were 31,292 ALS cases and 1,643 BLS cases. Researchers primarily examined patient survival to hospital discharge, to 30 days and to 90 days.
The results show survival to hospital discharge was greater among patients receiving BLS (13.1 percent vs. 9.2 percent for ALS) and so was survival to 90 days postdischarge (8.0 percent vs. 5.4 percent for ALS). Rates of poorer neurological functioning were lower for hospitalized patients who received BLS (21.8 percent vs. 44.8 percent with poor neurological function for ALS). Results suggest the difference in survival between ALS and BLS is explained by higher mortality in the first few days after cardiac arrest for patients who received ALS.
"Our study calls into question the widespread assumption that advanced prehospital care improves outcomes of out-of-hospital cardiac arrest relative to care following the principles of BLS, including rapid transport and basic interventions such as effective chest compressions, bag valve mask ventilation and automated external defibrillation. It is crucial to evaluate BLS and ALS use in other diagnosis groups and setting and to investigate the clinical mechanisms behind our results to identify the most effective prehospital care strategies for saving lives and improving quality of life conditional on survival," the study concludes.
Source: The JAMA Network Journals