Objectives: This study was designed to assess the benefits and complications associated with the use of intrathecal morphine (ITM) in patients undergoing coronary artery bypass surgery (CABG).
Design: This was a retrospective chart review.
Setting: The study was performed in a single hospital that is affiliated with a university medical school.
Participants: The charts of all patients who presented for CABG in a 12-month period were reviewed.
Interventions: All patients entered into the study had received ITM (0.03 mg/kg) at induction of anesthesia.
Measurements and main results: Complete data were available for 152 patients (86%). Median duration of ventilation postoperatively was 12 hours, and median duration of stay in the ICU was 72 hours. All patients received additional postoperative opioid analgesia, many by the epidural route. Fifteen percent developed respiratory complications, and the incidence of respiratory depression was 1.9%. Thirty-five percent required inotropic support; 17% percent were treated for hypertension; and 49% received antiarrhythmic therapy. The re-infarction rate was 2.6%, and 3% developed cardiac tamponade. Three patients developed neurologic complications unrelated to lumbar puncture. There were no in-hospital deaths.
Conclusions: ITM is safe and provides effective pain relief after cardiac surgery. The high incidence of respiratory depression confirms the need for close observation of these patients postoperatively.