Narcotic and benzodiazepine use after withdrawal of life support: association with time to death?

OBJECTIVE: To determine whether the dose of narcotics and benzodiazepines is associated with length of time from mechanical ventilation withdrawal to death in the setting of withdrawal of life-sustaining treatment in the ICU.
DESIGN: Retrospective chart review.
SETTING: University-affiliated, level I trauma center. PATIENTS: Consecutive critically ill patients who had mechanical ventilation withdrawn and subsequently died in the ICU during two study time periods.
RESULTS: There were 75 eligible patients with a mean age of 59 years. The primary ICU admission diagnoses included intracranial hemorrhage (37%), trauma (27%), acute respiratory failure (27%), and acute renal failure (20%). Patients died during a median of 35 min (range, 1 to 890 min) after ventilator withdrawal. On average, 16.2 mg/h opiates in morphine equivalents and 7.5 mg/h benzodiazepine in lorazepam equivalents were administered during the time period starting 1 h before ventilator withdrawal and ending at death. There was no statistically significant relationship between the average hourly narcotic and benzodiazepine use during the 1-h period prior to ventilator withdrawal until death, and the time from ventilator withdrawal to death. The restriction of medication assessment in the last 2 h of life showed an inverse association between the use of benzodiazepines and time to death. For every 1 mg/h increase in benzodiazepine use, time to death was increased by 13 min (p = 0.015). There was no relationship between narcotic dose and time to death during the last 2 h of life (p = 0.11).
CONCLUSIONS: We found no evidence that the use of narcotics or benzodiazepines to treat discomfort after the withdrawal of life support hastens death in critically ill patients at our center. Clinicians should strive to control patient symptoms in this setting and should document the rationale for escalating drug doses.