Post-Naloxone Observation of ED Patients is Focus of Study

According to the rule developed in 2000 by St. Paul’s Hospital in Vancouver, British Columbia, Canada, one hour was set as the standard length for observation of patients after naloxone treatment before discharge, as long as their vital signs meet specific criteria and they are ambulatory.

However, the rule was never externally validated or assessed in light of the changes that have occurred in recent years with opioid use disorder.

That changed when the Jacobs School of Medicine and Biomedical Sciences researchers conducted the current study, published Dec. 28 in Academic Emergency Medicine.

“The landscape of opioid use disorder has changed dramatically,” says Brian Clemency, DO, associate professor of emergency medicine and lead author on the paper.

Two decades ago, he explains, doctors, nurses and paramedics almost exclusively administered naloxone intravenously.

Today, the medication is far more widely available, including to members of the public, and is often given in the form of a nasal spray. In addition, the use of heroin and synthetic opioids, such as fentanyl and carfentanil, has increased tremendously.

“Recommendations for patient observation after naloxone administration are inconsistent,” says Clemency, an attending physician specializing in emergency medicine at Erie County Medical Center (ECMC) and a physician with UBMD Emergency Medicine. “Patients can be observed for six or more hours or they can be immediately discharged with no further evaluation.”

“The question is, which of these patients needs to be watched longer?” he asks.

“Right now, there isn’t a really good rule. This has wide-ranging negative implications for emergency care and opioid use disorder treatment,” he adds.

“It is our hope that these findings will lead to a reduction in practice variation and allow for better use of resources in the ED, while ensuring patient safety.”

To determine if the one-hour early discharge rule is valid, given the changes in opioid use disorder, Clemency and his colleagues launched an ambitious study at Buffalo’s ECMC, a busy, urban teaching hospital affiliated with the Jacobs School.

Patients who arrived at the medical center by ambulance after receiving naloxone for suspected opioid overdose had to be enrolled and evaluated within 30 to 40 minutes of arrival.

One hour after receiving naloxone in the community, patients’ vital signs were evaluated, ranging from body temperature and heart rate to blood pressure and the blood oxygen level.

A total of 538 patients were included in the study. Patients were typically observed for at least four hours before being discharged.

Patients were tracked through their hospitalization for any adverse events. Medical examiner records were then reviewed for subsequent fatalities.

The study’s authors reported that most adverse events seen in patients with normal examinations after receiving naloxone were minor and unlikely to be life-threatening.

“This one-hour evaluation rule is a way to predict which patients will have adverse outcomes after they overdose on opiates,” Clemency says. “The rule is simple to follow and can be used by health care providers with varying levels of training and experience.”

“We anticipate this study will lead to nationally standardized recommendations for the observation of patients following the administration of naloxone for suspected opioid overdose,” he adds.

Co-authors from the Jacobs School are:

• Michael Cheung, a third-year medical student
• Michael A. Manka Jr., MD, clinical associate professor of emergency medicine
• Nicholas Pokoj, a third-year medical student
• Evan Shaw, a third-year medical student

Co-authors from UB’s School of Public Health and Health Professions are:

• David P. Hostler III, PhD, professor and chair of exercise and nutrition sciences and clinical professor of emergency medicine 
• Heather A. Lindstrom, PhD, research assistant professor of epidemiology and environmental health
• Han Yu, MBBS, PhD, research assistant professor of biostatics

Other co-authors are from ECMC and the Upstate New York Poison Center.