(927) Multisite Experience With a Phenobarbital Protocol for Alcohol Withdrawal

Introduction: Phenobarbital has regained popularity for treatment of alcohol withdrawal, but available literature reflects wide variations in dosing regimens. Single-site descriptions exist, but few studies describe the multisite use of a phenobarbital protocol for the management of acute alcohol withdrawal in the ICU.

Methods: A retrospective cohort analysis of phenobarbital order set use in six ICUs in a single health system was performed. The protocol included a 230 mg IV initial dose, with an accelerated daily taper and as-needed doses for symptom control. The primary outcome was to describe the adoption of the order set for first- or second-line therapy. Secondary outcomes included protocol; the need for additional doses; the incidence of vasopressor initiation; and the incidence of respiratory depression, defined as any subsequent escalation in support.

Results: Phenobarbital was initiated for 39 patients over a 6-month period in 2022. The population included predominantly surgical non-trauma and trauma patients. On average, phenobarbital was utilized as second-line therapy, for an average 4 days and a total dose exposure of 1043 mg (91 mg/kg). Ten patients (26%) received an off-protocol initial 10 mg/kg load. The other most commonly used agents were dexmedetomidine (n=22) and benzodiazepines (21).. Seven patients (18%) received escalating, additional phenobarbital doses. Ten were intubated prior to phenobarbital; two of the 29 (6%) remaining non-intubated patients required escalated respiratory support following phenobarbital; both placed on nasal cannula,and neither required intubation. Two of 39 patients (5%) required vasopressor initiation following phenobarbital, both were also on dexmedetomidine and propofol. Of patients who received a 10 mg/kg load, one experienced hemodynamic instability and none experienced respiratory compromise, although 4/ 10 were intubated prior to phenobarbital.

Conclusions: A multisite phenobarbital protocol was well tolerated amongst a diverse surgical ICU population. No significant hemodynamic compromise or respiratory depression occurred. A substantial proportion of patients required additional doses beyond the protocol, indicating an opportunity to optimize the recommended dosing schedule, specifically with addition of a weight-based load into the protocol.