Comparison between epidural infusion of fentanyl/bupivacaine and morphine/bupivacaine after orthopaedic surgery.
OBJECTIVE
To compare epidural infusions of bupivacaine-fentanyl and bupivacaine-morphine mixtures for postoperative pain relief after total hip replacement.


METHODS
In a prospective, randomized, double-blind study, 30 ASA physical status I-II patients undergoing total hip replacement were studied. Anaesthesia was provided by combined general/epidural anaesthesia without epidural opioids. Postoperative epidural analgesia was by continuous infusion of bupivacaine 0.125% (4 ml.hr-1) with either 0.05 mg.ml-1 morphine (morphine, n = 15) or 0.005 mg.ml-1 fentanyl (fentanyl, n = 15). Visual analogue pain scale (VAS), sedation (four-point scale), respiratory rate, pulse oximetry, rescue analgesics and supplemental oxygen were recorded by a blind observer at 1, 3, 6, 9, 12 and 24 hr after surgery.


RESULTS
No differences in pain relief, sedation, or non-respiratory side effects were observed between the two groups. Rescue analgesics were required in three patients in the fentanyl group (20%) and in two receiving morphine (13.3%) (P:NS). Two patients in the fentanyl group and three in the morphine group required oxygen due to SpO2 < 90% (P:NS). Both opioid/bupivacaine mixtures decreased haemoglobin oxygen saturation compared with preoperative values. The mean +/- SD SpO2 values measured at 3, 6, 12 and 24 hr were 94.4 +/- 1, 92.6 +/- 0.9, 92 +/- 0.8, and 92.8 +/- 1 in the morphine group, 95.3 +/- 0.5, 95 +/- 0.5, 94.6 +/- 1.2, and 95.6 +/- 1 in the fentanyl group (P < 0.05).


CONCLUSIONS
Continuous epidural infusion of bupivacaine-morphine or bupivacaine-fentanyl mixtures provided similar pain relief. Patients receiving morphine showed a more marked decrease in SpO2 than those receiving fentanyl. However, the average SpO2 remained > 90% in both groups.
Berti
M
M
Department of Anaesthesiology and Intensive Care, University of Milan, IRCCS H. San Raffaele, Italy.
Fanelli
G
G
Casati
A
A
Lugani
D
D
Aldegheri
G
G
Torri
G
G
D015360:Analgesia, Epidural; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use*; D000767:Anesthesia, Epidural; D000768:Anesthesia, General; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D019644:Arthroplasty, Replacement, Hip; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D003243:Consciousness / Q000187:drug effects; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control*; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D004338:Drug Combinations; D006454:Hemoglobins; D009020:Morphine; D010100:Oxygen; D005283:Fentanyl; D002045:Bupivacaine