(1016) Phenobarbital Facilitates Weaning of Fentanyl, Dexmedetomidine, and Midazolam: A Case Series

Introduction: Phenobarbital (Pb) is a barbiturate anxiolytic and sedative known for treating seizure disorders and alcohol withdrawal. While limited data describe benefits of Pb for benzodiazepine withdrawal, there is a paucity of evidence for Pb to facilitate the weaning and withdrawal of opioids and central alpha agonists.
Tapering of sedation can be challenging in ICU patients. Dose reduction may result in tachypnea, tachycardia, hypertension, and agitation. With a mean half-life of 72 hours, Pb allows for a gradual taper of sedation as it is eliminated. We describe the successful use of Pb to facilitate the weaning and withdrawal of fentanyl, dexmedetomidine, and midazolam in three ICU patients.

Description: Case 1 – A 66-year-old woman with pulmonary fibrosis and chronic respiratory failure requiring tracheostomy was transferred from a long-term acute care hospital for hypoxia due to ventilator-associated pneumonia. She was sedated on a fentanyl infusion which was continued from her prior facility. After resolution of pneumonia, she had difficulty weaning off fentanyl due to agitation. She was started on Pb 65 mg PO TID on day 10 of hospitalization which allowed weaning off fentanyl on day 11. Pb was tapered over the following three days then discontinued.
Case 2 – A 66-year-old man with duodenal adenocarcinoma was admitted for pancreaticoduodenectomy. He developed ventilator-associated pneumonia post-operatively. He was sedated with dexmedetomidine but repeatedly developed agitation when weaning was attempted. On day 29 of hospitalization PO Pb was added, leading to discontinuation of dexmedetomidine on day 30. Pb was tapered then discontinued over the following three days.
Case 3 – A 32-year-old man was admitted for multifocal pneumonia. He was intubated due to persistent hypoxia despite maximal non-invasive support. He developed ARDS requiring prone positioning and steroid therapy. He was sedated with midazolam due to side effects from other sedative options. He had difficulty weaning off midazolam due to agitation. Pb 65 mg PO BID was added on day 9, which allowed for midazolam to be discontinued and the patient to be extubated on day 11. Pb was discontinued the following day.

Discussion: Further investigation is necessary to fully define the role of Pb in the withdrawal of ICU sedation.