EFFECTS OF A NIGHTTIME OPIOID INFUSION WITH PCA THERAPY ON PATIENT COMFORT AND ANALGESIC REQUIREMENTS AFTER ABDOMINAL HYSTERECTOMY

Since pain during the early postoperative period can disrupt a patient's normal sleep pattern, we investigated the influence of a nighttime "basal" infusion of morphine on patient comfort, ability to sleep at night, restfulness, and analgesic requirements following elective abdominal hysterectomy. One hundred fifty-six adult women were randomly assigned to receive either patient-controlled analgesia (PCA) alone or PCA supplemented with a nighttime infusion of morphine 1.0 mg . h-1. The infusion was started in the postanesthesia care unit and continued until the morning after surgery. Subsequently, the infusion was used only during the nighttime hours (10 PM-8 AM). Patients in both treatment groups were able to self-administer supplemental bolus doses of morphine, 2 mg intravenously, as needed during the 72-h study period. The use of a nighttime morphine infusion did not significantly improve the patient's ability to sleep or to rest comfortably at night. Only 8% and 7% of patients in the control and infusion groups, respectively, found it inconvenient to self-administer bolus doses at night. In addition, the number of patient demands and supplemental bolus doses, opioid usage, and recovery parameters were similar in the two treatment groups. The use of a basal infusion resulted in six programming errors, and three patients required discontinuation of the infusion because of hemoglobin oxygen desaturation (i.e., Sp(O2) < 85% for > 5 min). We concluded that the routine use of a continuous nighttime opioid infusion in combination with a standard PCA regimen failed to improve the management of postoperative pain, sleep patterns, or recovery profiles compared to PCA alone after abdominal hysterectomy.