[Combination of morphine with low-dose naloxone for intravenous patient-controlled analgesia].
OBJECTIVE
To compare the analgesic effect and side effects of morphine for intravenous patient-controlled analgesia (PCA) with or without low-dose naloxone after abdominal surgery.


METHODS
Fifty-nine ASA I - II patients undergoing elective abdominal surgery were randomly divided into two groups: group morphine received postoperative PCA with 0.4 mg/ml morphine (a 1 mg bolus with a 5 min lockout), group naloxone received morphine 0.4 mg/ml with 6 microg/kg naloxone. Blood pressure, heart rate, respiratory rate, and pulse oxygen saturation were monitored. Visual analogue scale (VAS), nausea/vomiting, pruritus, sedation and consumption of morphine were recorded for 24 hours.


RESULTS
VAS had no difference between group morphine and group naloxone, but group naloxone had significantly lower VAS for pain at rest or movement (beyond 4-8 h), and the incidence of nausea/vomiting significantly decreased in group naloxone (P < 0.05). No differences existed in pruritus, sedation, respiratory rate, and hemodynamic parameters between these two groups. The 24 hours postoperative morphine consumption was (36.6 +/- 13.5) mg in group naloxone and (43.7 +/- 14.6) mg in group morphine (P < 0.05).


CONCLUSIONS
For morphine PCA, morphine with 6 microg/kg naloxone is effective in preventing some PCA morphinerelated side effects. Naloxone not only reduces postoperative morphine requirements but also improves the analgesic effect.
Zhao
Li-yun
LY
Department of Anesthesiology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. zhaopux@yahoo.com
Ye
Tie-hu
TH
Zhang
Yin-zhong
YZ
Zhao
Hong
H
D000005:Abdomen / Q000601:surgery; D000328:Adult; D016058:Analgesia, Patient-Controlled / Q000379:methods; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D009270:Naloxone / Q000008:administration & dosage* / Q000009:adverse effects; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000009:adverse effects; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000188:drug therapy* / Q000517:prevention & control
D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009270:Naloxone; D009020:Morphine