Epidural naloxone reduces intestinal hypomotility but not analgesia of epidural morphine.
OBJECTIVE
Epidural morphine is associated with decreased bowel motility and increased transit time. Low doses of intravenous naloxone reduce morphine-induced pruritus without reversing analgesia, but the effect of epidural naloxone on bowel motility has not been studied. Therefore we evaluated bowel motility and analgesia when naloxone was co-administered with morphine into the epidural space.


METHODS
Forty-three patients having combined thoracic epidural and general anesthesia for subtotal gastrectomy were randomly assigned to one of two study groups. All received a bolus dose of 3 mg epidural morphine at the beginning of surgery, followed by a continuous epidural infusion containing 3 mg morphine in 100 ml bupivacaine 0.125% with either no naloxone (control group, n = 18) or a calculated dose of 0.208 microg x kg(-1) x hr(-1) of naloxone (experimental group, n = 25) for 48 hr. We measured the time to the first postoperative passage of flatus and feces to evaluate the restoration of bowel function, and visual analog scales (VAS) for pain during rest and movement. Scores were assessed at 2, 4, 8, 16, 24, 36 and 48 hr postoperatively.


RESULTS
The experimental group had a shorter time to the first postoperative passage of flatus (5 1.9 +/- 1 6.6 hr vs 87.0 +/- 19.5 hr, P < 0.001 ) and feces (95.3 +/- 25.0 hr vs 132.9 +/- 29.4 hr, P < 0.001). No differences were found in either resting or active VAS between the two groups.


CONCLUSIONS
Epidural naloxone reduces epidural morphine-induced intestinal hypomotility without reversing its analgesic effects.
Lee
J
J
Department of Anesthesiology, Kangnam Saint Mary's Hospital, Seoul, Korea.
Shim
J Y
JY
Choi
J H
JH
Kim
E S
ES
Kwon
O K
OK
Moon
D E
DE
Choi
J H
JH
Bishop
M J
MJ
D015360:Analgesia, Epidural; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000037:antagonists & inhibitors; D000779:Anesthetics, Local / Q000627:therapeutic use; D002045:Bupivacaine / Q000627:therapeutic use; D005260:Female; D005743:Gastrectomy; D005767:Gastrointestinal Diseases / Q000139:chemically induced / Q000517:prevention & control*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D007268:Injections, Epidural; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000009:adverse effects / Q000037:antagonists & inhibitors; D009270:Naloxone / Q000008:administration & dosage / Q000627:therapeutic use*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009292:Narcotic Antagonists; D009270:Naloxone; D009020:Morphine; D002045:Bupivacaine