The use of flumazenil for benzodiazepine associated respiratory depression in postanesthesia recovery: risks and outcomes

BACKGROUND AND OBJECTIVES: The primary aim was to determine risk factors for flumazenil administration during postanesthesia recovery. A secondary aim was to describe outcomes among patients who received flumazenil. METHODS: Patients admitted to the postanesthesia recovery room at a large, academic, tertiary care facility after surgery under general anesthesia from January 1, 2010, to April 30, 2015, were identified and matched to 2 controls each, by age, sex, and surgical procedure. Flumazenil was administered in the recovery phase immediately after general anesthesia, according to the clinical judgment of the anesthesiologist. Demographic, procedural, and outcome data were extracted from the electronic health record. Conditional logistic regression, accounting for the 1:2 matched-set case-control study designs, was used to assess characteristics associated with flumazenil use. RESULTS: The incidence of flumazenil administration in the postanesthesia care unit was 9.9 per 10,000 (95% CI, 8.4–11.6) general anesthetics. History of obstructive sleep apnea (Odds Ratio [OR] = 2.27; 95% CI 1.02–5.09), longer anesthesia (OR = 1.13; 95% CI 1.03–1.24 per 30 minutes), use of total intravenous anesthesia (OR = 6.09; 95% CI 2.60–14.25), and use of benzodiazepines (OR = 8.17; 95% CI 3.71–17.99) were associated with risk for flumazenil administration. Among patients who received midazolam, cases treated with flumazenil received a higher median (interquartile range) dose than controls: 3.5 mg (2.0–4.0 mg) vs. 2.0 mg (2.0–2.0 mg), respectively (p < 0.001). Flumazenil use was correlated with a higher rate of unanticipated noninvasive positive pressure ventilation, longer postanesthesia care unit stay, and increased rate of intensive care unit admissions. CONCLUSIONS: Patients who required flumazenil postoperatively had received a higher dosage of benzodiazepines and utilized more postoperative health care resources. More conservative perioperative use of benzodiazepines may improve postoperative recovery and use of health care resources.