Characteristics of Patients Experiencing Opioid Overdose and Eligibility for Prehospital Treatment with Buprenorphine

Objectives: Opioids kill tens of thousands of patients each year. While only a fraction of people with opioid use disorder (OUD) have accessed treatment in the last year, 30% of people who died from an overdose had an Emergency Medical Services (EMS) encounter within a year of their death. Prehospital buprenorphine represents an important emerging OUD treatment, yet limited data describe barriers to this treatment. Our objectives were to quantify the number of patients encountered by EMS who were eligible for prehospital buprenorphine, and to examine characteristics of patients who did or did not receive treatment.

Methods: In this retrospective observational study, we analyzed EMS patient records from Contra Costa County, CA, where paramedics were trained to identify patients experiencing opioid withdrawal and administer buprenorphine. Patient records were selected for review based on "buprenorphine patient triggers," which were keywords within the charts that identified patients with potential overdose or symptoms that could indicate withdrawal or naloxone administration. We describe proportion of eligible patients and the characteristics of those who did and did not receive prehospital buprenorphine.

Results: We reviewed 1,159 records from September 2020 to July 2022. Of included patients, 984 (85%) were not eligible for buprenorphine. Nearly half (482, 49%,) of patients ineligible for buprenorphine fell into 2 primary categories: 331 (33%) had altered mental status (326 of 331 received naloxone), and 151 (15%) had no active withdrawal symptoms documented. Additional exclusions included other intoxicants, severe medical illness, or the patient denied having an OUD. Of those eligible for buprenorphine, 67 (38%) received buprenorphine. Of the 108 patients who did not receive buprenorphine, 69 (64%) had protocol deviation, 24 (22%) declined treatment, and 15 (14%) were in a non-enabled zone. Of all buprenorphine administrations, 19 (28%) were post-opioid overdose and 48 (72%) were for abstinence withdrawal.

Conclusions: One-in-three EMS patients with suspected opioid use disorder were ineligible for treatment with buprenorphine due to altered mental status. The second largest group consisted of patients who were eligible but not offered buprenorphine, highlighting potential gaps in paramedic training, logistical challenges in field administrations, and other factors that warrant further exploration.