Epidural naloxone reduces intestinal hypomotility but not analgesia of epidural morphine

Abstract

Purpose: 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 µg·kg -1 ·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 (51.9 ± 16.6 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.Conclusion: Epidural naloxone reduces epidural morphine-induced intestinal hypomotility without reversing its analgesic effects.Objectif : L'administration péridurale de morphine est associée à une baisse de la motilité intestinale et à une augmentation de la durée du transit. De faibles doses de naloxone intraveineuse réduisent le prurit induit par la morphine sans renverser l'analgésie, mais l'effet de l'administration péridurale de naloxone sur la motilité intestinale n'a pas encore été étudié. C'est pourquoi nous avons évalué cette action et l'analgésie de la naloxone administrée avec de la morphine dans l'espace péridural.Méthode : Quarante-trois patients qui recevaient une anesthésie péridurale thoracique et générale combinée, pour une gastrectomie partielle, ont été répartis au hasard en deux groupes. Tous ont reçu un bolus de 3 mg de morphine péridurale au début de l'intervention, suivi d'une perfusion péridurale continue de 3 mg de morphine dans 100 ml de bupivacaïne à 0,125 % sans naloxone (groupe témoin, n=18) ou avec une dose calculée de 0,208 µg·kg -1 ·h -1 de naloxone (groupe expérimental, n=25) pendant 48 h. Nous avons mesuré le temps écoulé avant la première expulsion des gaz intestinaux et des selles afin d'évaluer la restauration de la fonction intestinale et mesuré les scores de douleur à l'aide de l'échelle visuelle analogique (EVA), au repos et pendant le mouvement. Les scores postopératoires ont été relevés à 2, 4, 8, 16, 24, 36 et à 48 h.Résultats : Dans le groupe expérimental, le temps précédant le premier passage postopératoire des gaz (51,9 ± 16,6 h vs 87,0 ± 19,5 h, P < 0,001) et des selles (95,...

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