Advanced Life Support for Out-of-Hospital Chest Pain: The OPALS Study^†

Abstract

Context: As many as 14% of patients transported by ambulance with chest pain die prior to hospital discharge. To date, no high-quality controlled trials have revealed that prehospital advanced life support interventions affect survival for these patients. Objective: The Ontario Prehospital Advanced Life Support (OPALS) Study assessed the effect of adding an advance life support service to an existing basic life support emergency medical service program, on the rate of mortality and morbidity for patients with out-of-hospital chest pain. Design: Controlled clinical trial comparing survival for 9 months before and 9 after instituting an advanced life support program. Setting: Thirteen urban and suburban Ontario communities (populations ranging from 30,000 to 750,000; total, 2.5 million). Patients: All adult patients with a primary complaint of chest pain and transported by paramedics to the emergency department. Intervention: Paramedics were trained in standard advanced life support, which includes endotracheal intubation, intravenous furosemide and morphine, oral ASA, and sublingual NTG. Emergency medical services within each community had to meet predefined criteria in order to qualify for the advanced life support phase. Main Outcome Measure: Survival to hospital discharge. Results: Overall, 12,168 patients were enrolled in either the basic life support phase (N = 5,788) or the advanced life support phase (N = 6,380). The rate of mortality significantly decreased from 4.3% in the basic life support phase to 3.2% in the advanced life support phase (absolute change 1.1, 95% CI 0.4-1.8, P = 0.0013). We also demonstrated a decrease in mortality for the subgroup of patients with a discharge diagnosis of myocardial infarction (13.1 percent vs 8.2 percent, P = 0.002). Conclusions: The addition of a prehospital advanced life support program to an existing basic life support emergency medical service was associated with a significant decrease in the mortality rate among patients complaining of chest pain. Future research should clarify the most effective interventions and target specific populations.

Disclosure Statement

The authors report no conflicts of interest.

Acknowledgments

We thank the OPALS Study Group investigators from the following base hospital programs:

We thank the other members of the OPALS Study Coordinating Center, Tammy Beaudoin (Research Coordinator), David Brisson (Research Coordinator), Irene Harris (Administrative Secretary), and My-Linh Tran (Database Coordinator). We thank Cathy Francis of the Ministry of Health and Long –Term Care for her support, contributing staff members from our network of Ontario Base Hospitals, and the many primary care and advanced care paramedics who participated in the OPALS Study.

We thank Angela Marcantonio and Marie-Joe Nemnom from the Ottawa Hospital Research Institute for their help with the manuscript.

Additional information

Funding

This study has been funded by peer-reviewed grants from the Emergency Health Services Branch of the Ontario Ministry of Health and Long-Term Care and the Canadian Health Services Research Foundation.