Adding an advanced life support capability to emergency medical services increases the chances of survival for people in respiratory distress, according to a Canadian report in this week’s New England Journal of Medicine.

Approximately 2 million people with respiratory distress are transported by ambulance to hospitals in the United States each year, the report indicates. Up to 18% of these patients will die before leaving the hospital. Whether prehospital advanced life support is beneficial has been unclear.

Ian G. Stiell, department of emergency medicine, University of Ottawa, Ontario, and colleagues assessed the outcomes of more than 8,000 patients with respiratory distress who were treated before or after a program was implemented to provide advanced life support to patients before they were brought to the hospital.

During the earlier phase, none of the patients received advanced life support before reaching the hospital; during the second phase, support was provided to 56%of patients.

With the implementation of prehospital advanced life support, overall mortality rates fell from 14.3% to 12.4%, Stiell and his associates report.

The findings indicate that advanced life support in the out-of-hospital setting "significantly reduced mortality for patients with shortness of breath," the team concludes. Nonetheless, they add, "The benefit of an advanced-life-support program must be balanced against the relatively high cost of its implementation."