Acetaminophen as an adjunct to morphine by patient-controlled analgesia in the management of acute postoperative pain.
Opioids play a fundamental role in the management of postoperative pain, but their use is associated with a number of side effects, including nausea and vomiting, sedation, and respiratory depression. Co-administration of a nonopioid has been proposed as a method of reducing opioid intake and minimizing side effects. Sixty-one ASA physical status I and II patients were enrolled in a double-blind, randomized, placebo-controlled, parallel study to investigate the effect of a combination of acetaminophen and morphine after open reduction and internal fixation of acute limb fractures. Patients were randomized to receive either oral acetaminophen (1 g every 4 h) or placebo as an adjuvant to morphine by patient-controlled analgesia (PCA) postoperatively. They were assessed daily for 72 h or until the PCA was discontinued according to standardized guidelines. The outcome variables collected were pain scores (11-point scale), amount of morphine self-administered, duration of PCA use, compliance with study design, incidence of nausea and sedation, and overall patient satisfaction. The acetaminophen group had lower pain scores on Day 1 (2.1 vs 3.3; P = 0.03) and a shorter average duration of PCA use (35.8 vs 45.5 h; P = 0.03). Overall patient satisfaction was also significantly greater in the acetaminophen group (8.7 vs 7.9; P = 0.04). These data suggest that acetaminophen is a useful adjunct to morphine PCA.


CONCLUSIONS
This study assesses the benefit of combining two analgesics for the treatment of postoperative pain. Such a combination improves the quality of pain relief and patient satisfaction.
Schug
S A
SA
Department of Pharmacology, School of Medicine, University of Auckland, New Zealand. s.schug@auckland.ac.nz
Sidebotham
D A
DA
McGuinnety
M
M
Thomas
J
J
Fox
L
L
D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects; D000208:Acute Disease; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage* / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000009:adverse effects; D009325:Nausea / Q000139:chemically induced; D010147:Pain Measurement; D010149:Postoperative Pain / Q000628:therapy*; D017060:Patient Satisfaction; D011183:Postoperative Complications
D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000082:Acetaminophen; D009020:Morphine