Early Postdischarge Mortality After Phenobarbital Treatment for Alcohol Withdrawal in the Emergency Department

Phenobarbital (PB) use in the emergency department (ED) for alcohol withdrawal syndrome (AWS) management is rapidly increasing; however, short-term post-discharge safety has not been well characterized. Understanding early post-discharge mortality following ED care is critical to evaluating treatment safety. The objective of this study was to evaluate early post-discharge mortality among discharged ED patients with AWS who received PB using comprehensive, state-level mortality data.

This is a retrospective, observational study of adults (age ≥ 18) who received PB for AWS in the ED and were discharged from 11 hospital-based EDs within a large, integrated health system between 2022-2025. The primary outcome was death within three days of the index ED encounter, ascertained through deterministic linkage with state public health mortality records. Secondary outcomes included ED revisits and hospital readmissions within 7 and 30 days of discharge. Demographic characteristics and PB dosing were extracted via an analytics data report from the shared electronic health record. Descriptive statistics were used to characterize the cohort.

A total of 537 ED encounters met inclusion criteria. The median patient age was 38 years (IQR 15), and approximately 76% were male. The median total PB dose administrated in the ED was 260mg (IQR 130), corresponding to a median weight-based dose of 3.2 mg/kg (IQR 2.0). Notably, 20 encounters received ≥8 mg/kg of PB during the ED visit. No patients died within three days of the index ED encounter. ED revisits occurred in 16.4% within 7 days and 34.3% within 30 days. Hospital readmissions occurred in 12.7% within 7 days and 17.7% within 30 days of discharge.

No deaths occurred within three days of the index encounter among patients with AWS treated with PB and discharged from the ED, including among a clinically important subset who received high-dose PB (≥8 mg/kg). To our knowledge, this represents the largest cohort to date evaluating short-term post–ED discharge outcomes after PB treatment for AWS. While ED revisits and readmissions were common, the absence of early post-discharge mortality provides reassurance regarding the short-term safety of ED PB treatment for alcohol withdrawal, including at higher doses, and highlights the need for prospective evaluation of optimal dosing and discharge criteria.