Motor Patterns Of Small Intestine Research Articles

Small intestinal motor patterns in critically ill patients after major abdominal surgery

OBJECTIVES: In patients who have had major surgery or trauma, early enteral feeding is safer and more effective than parenteral or nasogastric feeding but is frequently associated with diarrhea. Limited recordings have shown that the patterning of duodenal interdigestive motor activity is frequently abnormal after surgery or in patients who are critically ill. The aims of this study were to evaluate the effects of major abdominal surgery on small intestinal motility, and to elucidate the motor patterns that occur postoperatively in critically ill patients in response to enteral feeding. METHODS: The effects of elective aortic aneurysm repair on small intestinal motility were studied in 11 patients aged 63–77 yr. A 3.5-mm diameter multilumen extrusion was used to monitor pressures at 12 points, distributed between the antrum and 100 cm distal to the pylorus. An additional lumen allowed enteral feeding into the duodenum. Recordings commenced immediately postoperatively and continued for up to 4 days. Data are given as means and SEMs. RESULTS: Bursts (frequency > 10/min) of small intestinal pressure waves that resembled phase III interdigestive motor activity occurred in all patients immediately after surgery. During mechanical ventilation, the timing of bursts along the segment evaluated was frequently abnormal for true interdigestive phase III activity, with simultaneous onset in multiple channels (46%), multiple or distal origins (8%), or retrograde migration (20%). When patients were not being ventilated, the migration pattern of the bursts was more typical of interdigestive phase III activity. The interval between bursts was unusually short for interdigestive motor activity, although it increased from 30 ± 12 min on day 1 to 41 ± 18 min on day 3 ( p < 0.05). A phase II pattern of pressure waves was virtually absent in all patients on all study days. In six patients who received postoperative enteral nutrition, the bursts of pressure waves were not abolished by feeding, contrary to normal phase III activity. CONCLUSIONS: Small intestinal pressure wave bursts are seen immediately after elective aortic aneurysm repair, but the migration of these bursts is frequently abnormal for phase III interdigestive activity. Duodenal nutrient delivery did not interrupt the occurrence of these bursts. Persistence of pressure wave bursts in this setting may be important in the delivery of enteral nutrition.

Small intestinal motor patterns in critically ill patients after major abdominal surgery.

In patients who have had major surgery or trauma, early enteral feeding is safer and more effective than parenteral or nasogastric feeding but is frequently associated with diarrhea. Limited recordings have shown that the patterning of duodenal interdigestive motor activity is frequently abnormal after surgery or in patients who are critically ill. The aims of this study were to evaluate the effects of major abdominal surgery on small intestinal motility, and to elucidate the motor patterns that occur postoperatively in critically ill patients in response to enteral feeding. The effects of elective aortic aneurysm repair on small intestinal motility were studied in 11 patients aged 63-77 yr. A 3.5-mm diameter multilumen extrusion was used to monitor pressures at 12 points, distributed between the antrum and 100 cm distal to the pylorus. An additional lumen allowed enteral feeding into the duodenum. Recordings commenced immediately postoperatively and continued for up to 4 days. Data are given as means and SEMs. Bursts (frequency > 10/min) of small intestinal pressure waves that resembled phase III interdigestive motor activity occurred in all patients immediately after surgery. During mechanical ventilation, the timing of bursts along the segment evaluated was frequently abnormal for true interdigestive phase III activity, with simultaneous onset in multiple channels (46%), multiple or distal origins (8%), or retrograde migration (20%). When patients were not being ventilated, the migration pattern of the bursts was more typical of interdigestive phase III activity. The interval between bursts was unusually short for interdigestive motor activity, although it increased from 30+/-12 min on day 1 to 41+/-18 min on day 3 (p < 0.05). A phase II pattern of pressure waves was virtually absent in all patients on all study days. In six patients who received postoperative enteral nutrition, the bursts of pressure waves were not abolished by feeding, contrary to normal phase III activity. Small intestinal pressure wave bursts are seen immediately after elective aortic aneurysm repair, but the migration of these bursts is frequently abnormal for phase III interdigestive activity. Duodenal nutrient delivery did not interrupt the occurrence of these bursts. Persistence of pressure wave bursts in this setting may be important in the delivery of enteral nutrition.

Canine small bowel motor patterns and contractions are not neurally regulated during enteric nutrient infusion.

The aims of this study were to determine the effects of duodenal and jejunoileal nutrient infusions on small intestinal motor patterns and intestinal contractions in neurally intact and neurally isolated small bowel. Fifteen dogs were prepared with duodenal and jejunal infusion and manometry catheters and a diverting jejunal cannula. Ten of the dogs underwent in situ neural isolation of the jejunoileum. A mixed nutrient meal (0.5 kcal/ml) was infused into the duodenum or jejunum at 3 ml/min for 5 h. Control experiments involved infusion of a balanced salt solution. Manometric data collected on-line to a microcomputer were analyzed for direction, distance, and velocity of spread of single pressure waves (SPW) and clustered contractions. Isolated duodenal and jejunoileal nutrient infusions inhibited the fasting motor pattern in neurally intact and neurally isolated small bowel. Motor activity (motility index) increased slightly during nutrient infusion within groups, but there were few differences between groups. Neither neural isolation nor nutrient infusion had a consistent effect on spread of SPW or migration of clustered contractions. Isolated duodenal and jejunoileal nutrient infusions in the dog inhibit fasting motor patterns and increase motor activity slightly but have little effect on characteristics of individual and clustered contractions. Extrinsic innervation to the jejunoileum or intrinsic neural continuity of the jejunum with the duodenum had little effect on single or grouped contractions. Although the changes in motor activity demonstrated in this study appear small, alterations in intestinal transit and absorption may still occur and may be of importance physiologically.

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

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.

Isolated duodenal and isolated jejunoileal infusions of a non-nutrient solution do not alter fasting canine small intestinal motor patterns

Isolated duodenal and isolated jejunoileal infusions of a non-nutrient solution do not alter fasting canine small intestinal motor patterns

Gastrointestinal correlates of the development of hunger in man

Experiments were carried out on ten healthy male volunteers to investigate the relationship between the return of hunger after a meal and gastric emptying, blood glucose levels and small intestinal motor patterns. There was a significant correlation between the postprandial increase in hunger ratings and the time for 90% of the meal to empty ( r = 0.75, p < 0.02): hunger ratings started to increase in three subjects when over 40% of the food still remained in the stomach, and they continued to increase in all subjects even when the meal had ceased to empty from the stomach. These results suggest the reduction of gastric distension may have a permissive role in the development of hunger after a meal. The increase in hunger was not related to any consistent change in plasma glucose concentration. Finally, the postprandial onset of a fasting motor pattern (phase-III-like activity) always occurred when the stomach had emptied more than 80% of its contents and after hunger had increased. Our data are compatible with the hypothesis that the return of hunger is directly related to a decline in the exposure of the upper small intestine to nutrient stimuli, but could be modulated by gastric distension.

Motor patterns of small intestine determined by closely spaced extraluminal transducers and videofluoroscopy.

In the canine small intestine several simple (S) and complex (C) patterns of propulsive and nonpropulsive activities were found. The nonpropulsive activity consisted of 1) stationary individual contractions (S) and 2) stationary clusters of contractions (C). Patterns leading to aboral propulsion of luminal contents were 1) propagating contractions (S), 2) propagating power contractions (S), 3) phase III of the migrating motor complex (C), and 4) migrating clusters of contractions (C). The propagation velocities of the propulsive motor patterns differed markedly; they increased in the following order: phase III, migrating clustered contractions, propagating power contractions, propagating contractions. A retrograde transport of luminal contents was produced by two different activities: 1) retrograde propagating contractions (S) and 2) retrograde power contractions (S). They were accompanied with enterogastric reflux.