Outcomes after cardiac arrest better with basic vs. advanced life support

Among patients with out-of-hospital cardiac arrest, those who received basic life support had better survival and less chance of poor neurological functioning compared with those who received advanced life support, according to results of an observational cohort study.

Although most patients with out-of-hospital cardiac arrest in the United States are treated with advanced life support, there is little supporting evidence for its efficacy compared with basic life support, researchers wrote in the study background.

Providers of basic life support use simple devices such as bag valve masks and automated external defibrillators, whereas providers of advanced life support use more sophisticated interventions such as endotracheal intubation, IV fluid and drug delivery and semiautomatic defibrillation, and therefore the latter spend more time at the site of the cardiac arrest, the researchers wrote.

Prachi Sanghavi, BS, and colleagues analyzed a nationally representative sample of traditional Medicare beneficiaries from nonrural counties who experienced out-of-hospital cardiac arrest from 2009 to Oct. 2, 2011. All had advanced life support (n=31,292) or basic life support (n=1,643) services billed to Medicare.

The researchers used propensity score methods to compare the effects of advanced life support and basic life support. The primary outcomes were survival to hospital discharge, to 30 days and to 90 days. Secondary outcomes included neurological performance and medical spending. Patients were classified has having poor neurological performance if they were identified as having anoxic brain injury, coma, persistent vegetative state or brain death. Total medical spending for each patient was computed for up to 1 year after cardiac arrest or death, whichever was earlier.

Survival differences

Sanghavi, of the Interfaculty Initiative in Health Policy at Harvard University, and colleagues found that after propensity adjustment, compared with advanced life support, patients who received basic life support had higher survival to hospital discharge (13.1% vs. 9.2%; percentage point difference, 4; 95% CI, 2.3-5.7), 30-day survival (9.6% vs. 6.2%; percentage point difference, 3.4; 95% CI, 1.9-4.8) and 90-day survival (8% vs. 5.4%; percentage point difference, 2.6; 95% CI, 1.2-4).

In addition, 21.8% of patients who received basic life support had poor neurological functioning while hospitalized vs. 44.8% of those receiving advanced life support (percentage point difference, 23; 95% CI, 18.6-27.4).

Mean medical spending was higher in those receiving basic life support in part because of longer survival ($11,875 vs. $9,097; difference, $2,778; 95% CI, 582-4,973), and incremental medical spending per additional survivor to 1 year for basic life support relative to advanced life support was $154,333, according to the researchers.

Among possible explanations for the results are that prehospital endotracheal intubation entails risks that may lead to worse outcomes compared with bag valve mask ventilation, limited evidence of the benefits of IV drug delivery in out-of-hospital cardiac arrest, and possible delays in hospital care associated with advanced life support in the field, the researchers wrote.

Evidence not there

In a related editorial, Michael Callaham, MD, from the department of emergency medicine at the University of California, San Francisco, wrote that advanced life support procedures “are distracting, taking extra time and interrupting critical and effective [basic life support] measures.”

Most advanced life support procedures have their basis in case reports from the early 1960s, and their efficacy has not been demonstrated in better-quality studies conducted between the 1990s and the present, Callaham wrote. “Most [advanced life support] interventions are ‘advanced’ chiefly in our expectations, not in evidence-based efficacy,” and for now the focus should be on basic interventions proven to work, such as bystander cardiopulmonary resuscitation, quick-response and high-quality early CPR, and early defibrillation, he wrote.

For more information:

Callaham M. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2014.6590.

Sanghavi P. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2014.5420.

Disclosure: Some researchers were supported by the NIH, the National Science Foundation and the Agency for Healthcare Research and Quality. One researcher reports financial ties with Aetna. Callaham reports no relevant financial disclosures.