Patients in cardiac arrest may be better off riding to the hospital in an ambulance without advanced life support services. A new study finds that cardiac patients who received advanced care from paramedics had lower survival rates and worse clinical outcomes at substantially higher costs.
Emergency physicians who reviewed the study say the findings offer important insights but also caution that additional research is needed to validate the findings. They say some unstudied variables may confound the results.
Cardiac arrest is the abrupt loss of heart function caused by a short circuit in the heart's electrical system. Immediate cardiopulmonary resuscitation (CPR) is needed until defibrillation—generally administered by emergency medical providers—is available to issue an electric shock that can reestablish normal heart rhythms. The overall survival rate in 2013 for a patient who experienced cardiac arrest outside of a hospital was only about 9.5% if CPR was not immediately provided at the scene, according to estimates from the American Heart Association.
A study released Monday in JAMA Internal Medicine compared the differences in outcomes between patients experiencing cardiac arrest who rode to the hospital in an advanced ambulance with specially trained paramedics, and patients who received care in a basic ambulance with a medical technician. The authors say the study calls into question a widespread assumption that advanced life support improves cardiac outcomes.
“Our study suggests basic life support saves more lives than advanced life support, and therefore, the principles of basic life support should be a priority for treating and transporting out-of-hospital cardiac arrest patients,” said Prachi Sanghavi, a doctoral student of evaluative science and statistics in Harvard's health policy program, and lead author of the study.
Researchers found, for example, that the survival rate at hospital discharge for patients who had received basic life support was 13.1%, compared with 9.2% among patients who received advanced life-support services. At 90 days after discharge, the survival rate was 8% for patients who had received basic services in the ambulance and 5.4% for the advanced care group.
Neurological functioning was markedly better among patients admitted to the hospital who had received basic services in the ambulance. Incremental medical spending for cardiac arrest survivors one year after their hospital visit was $52,442 less among those who had received basic life support, the study found.
Emergency medical technicians use more basic technologies such as bag valve masks and automated external defibrillators to assist cardiac arrest patients, noted the Harvard University team of health policy and economics researchers. Those technicians undergo less training than a paramedic, and are not generally allowed to provide advanced treatments.
Paramedics, on the other hand, are specially trained to use sophisticated, invasive interventions, including endotracheal intubation, IV-fluid and drug delivery and semi-automatic defibrillation. However, these services can lead to additional risks, such as aspiration of gastric contents, aggravation of existing injuries and interference with chest compressions, the study authors said.
Researchers used Medicare billing data to look retrospectively at patients who experienced out-of-hospital cardiac arrest between Jan. 1, 2009, and Oct. 2, 2011, and for whom advanced or basic life support ambulance services were billed. There were 31,292 billings for advanced life support and 1,643 for basic life support analyzed during the study's timeframe.
Though the findings raise questions about the value of advanced life support, at least one emergency physician who reviewed the results said additional research is needed to understand the link between the emergency services provided and their outcomes. Claims that basic cardiac arrest care saves more lives than advanced care might be an overstatement, according to Dr. Terry Fairbanks, an associate professor of emergency medicine at Georgetown University.
“This certainly does not demonstrate that advanced life support is harmful,” Fairbanks told Modern Healthcare. “I think the question we really need to examine is what it is about the addition of advanced life support that impacts outcomes.”
The study excluded cardiac-arrest patients who might have most benefitted from advanced care, such as those who died en route to the hospital, and patients in rural areas with particularly long transport times, he said. Advanced services are also vital for treating other life-threatening conditions such as seizures and diabetic reactions.
“It would be premature to abandon the use of advanced life support, even if this study is validated in the future,” Fairbanks said. He also serves as director of the National Center for Human Factors in Healthcare, which address safety issues associated with the deployment of new technology. “Overstating the implication of a study like this can be dangerous. Further study will be necessary to determine if this retrospective study actually predicts outcomes,” Fairbanks said.
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