CHRONIC THERAPEUTIC MORPHINE ADMINISTRATION ALTERS SMALL INTESTINAL MOTOR PATTERNS AND GASTROANAL TRANSIT IN PRETERM INFANTS † 1812

Abstract

Morphine is commonly used to sedate very preterm infants who require ventilator support; however these infants are often given enteral feedings shortly after extubation. Since the small intestine is densely populated with opioid receptors, the purpose of this study was to assess whether exposure to morphine altered small intestinal motor patterns or gastroanal transit in 65 infants who had received morphine for 3 days or more. Using low compliance continuous perfusion manometry we assessed intestinal motor activity on the day enteral feedings were begun. Each infant was also given 2ml of carmine red intragastrically to assess gastroanal transit. This evaluation was done 1-10 days after the last dose of morphine had been given. Motor patterns significantly differed between babies who had initiated feedings <72 hrs compared to those who had begun feedings 72 hrs or more following the last dose of morphine (mean ± SEM; unpaired t-test):Table In addition, the overall duration of small intestinal motor quiescence and gastroanal transit time were significantly inversely related to the hours that had elapsed between the last dose of morphine and the time of the first enteral feedings (r = - 0.33 and r = -0.31, both p<0.01), while the overall duration of phasic cluster activity was significantly related to the hours that had elapsed between the last dose of morphine and the initiation of feedings (r = 0.32, p<0.01). We conclude that the chronic therapeutic use of morphine has a significant effect on small intestinal motor patterns and transit time in the preterm infant. We speculate these effects may result in decreased absorption of enteral nutrients until those intestinal motor effects resolve.