Evaluation of the side effects of intravenous patient controlled analgesia after spine surgery

BACKGROUND: We have adopted intrravenous patient controlled analgesia (IV-PCA) for spine surgery. We could not find reports about detailed examinations of the side effects of IV-PCA using morphine after spine surgery, so we investigated retrospectively side effects in cases using morphine IV-PCA. METHODS: Eighty-five patients underwent IV-PCA after spine surgery. The contents of PCA pump were morphine 20 mg (= 2 ml), droperidol 2 mg (= 0.8 ml), and saline 77 ml. We fixed continuous infusion at 2 ml x hr(-1), bolus infusion at 2 ml x hr(-1), and lockout time at 15 minutes. Respiration time, SpO2, blood pressure, pulse rate, nausea and vomiting, and VAS were monitored while IV-PCA was in use. When severe side effects were noticed, IV-PCA was discontinued by physician in charge. We judged discontinuation of IV-PCA as occurrence of severe side effects. RESULTS: IV-PCA was discontinued in seven patients. The causes of discontinuation were nausea and vomiting, hypotension, and bradycardia. Nausea and vomiting was the most common cause and found mostly in women. CONCLUSIONS: Because IV-PCA was discontinuated in 8.2% of patients, it was thought that its management depending on patients' personal state was necessary to utilize IV-PCA as a method of postoperative analgesia.