Contraction of canine stomach and small bowel by intravenous administration of serotonin. A physiologic response?

Serotonin is found in large quantities in the gastrointestinal tract, where it can increase gastrointestinal motility. Whether this response represents a physiologic event has not previously been shown. In our investigation eight conscious dogs were fitted with strain gauges to monitor motility responses to serotonin. When infused intravenously, serotonin significantly increased the contraction rate and force of canine stomach, small bowel, and isolated Thirty-Vella loops. Whole blood serotonin levels monitored by radioimmunoassay showed no significant increase in levels during these infusions. Serotonin may have a physiologic function in the mediation of gastrointestinal motility.

Intraluminal release of serotonin during the interdigestive migrating complex in the canine small intestine.

Intraluminal release of serotonin (5-HT) was evaluated in relation to the interdigestive migrating complex (IMC) in the canine small intestine. Thirty-Vella loops (TVL) were constructed in the proximal jejunum of eight dogs. After recovery, the loops were continuously perfused with normal saline at 37 degrees C and changes in intraluminal pressure recorded. For each 10-min period, a motility index (MI) was calculated using computer-assisted planimetry and expressed in mm2/10 min. Serotonin contents in the effluent perfusates were measured by radioimmunoassay. A characteristic phasic motor activity was recognized in the TVL with periods of rest or minimal activity (MI = 406 +/- 45 mm2/10 min, Phase I) alternating with periods of vigorous activity (MI = 2082 +/- 134 mm2/10 min, Phases II and III). Serotonin was constantly found in the effluent perfusates in relatively high concentrations, but 5-HT levels did not vary significantly with intestinal activity; levels averaged 120 +/- 19 ng/ml during Phase I and 110 +/- 13 ng/ml during phases II and III. We conclude that intraluminal 5-HT plays no major role in the physiologic local regulation of the canine IMC in the small intestine.

Prolonged enteral nutrition in malnourished patients with nonelemental feeding. Reappraisal of surgical technique, safety, and costs.

In a 2 year period, 60 consecutive feeding enterostomies were placed in malnourished patients. The major complication rate was 1.6 percent. Total complications were 8 percent. Thirty day mortality was 13 percent. Nearly all patients were given isosmotic nonelemental diets. The incidence of diarrhea was 2 percent with this regimen. Four of five patients given elemental diets had diarrhea. Serum albumin levels increased significantly from a preoperative mean of 2.75 to 3.03 g/dl. Best overall results were achieved in patients undergoing upper gastrointestinal surgery or pancreatobilary procedures for nonmalignant lesions. More than $60,000 was saved in 2 years by substituting isosmotic formulas for elemental ones. It appears that many patients are given elemental formulas who do not actually require them. Since isosmotic solutions will not infuse through needle catheters, we advocate placing 12 F. catheters and have documented the safety of this change. By using these larger catheters, the surgeon will not lose the option of using isosmotic preparations. We have shown these preparations to be nutritionally effective with a marked lessening of diarrhea and a cost approximately a sixth of that of elemental products.

Re-operation for intra-abdominal sepsis. Indications and results in modern critical care setting.

In a 2-year period (1981-1983), 87 abdominal re-explorations (1.6% of total laparotomies) were performed on 77 patients for sepsis in five Downstate hospitals. Fifty-one patients were re-explored solely on clinical grounds, 21 on clinical plus radiographic criteria, four solely on radiographic grounds, and 11 for multiple organ failure. The overall mortality rate was 43%. As expected, the most common laparotomy finding was intra-abdominal abscess (47); other findings included anastomotic leak (14), necrotic bowel (10), evidence of technical error (five), and acalculous cholecystitis (two). The most common clinical findings were localized tenderness, fever, and absent bowel sounds (85%). Fifty-four special studies were performed with an overall accuracy rate of 76%. CAT scans and contrast radiographs were most accurate (92% and 81%) while sonography and gallium scans were less useful (59% and 60%). Seven patients had negative laparotomies. While all were distended and six were febrile, only one patient had focal tenderness. In the 11 patients explored solely for multiple organ failure, six patients had drainable pus despite negative radiographic studies, and two survived. The other five patients had negative laparotomies, and all died. Factors correlated with mortality were age over 50, peritonitis at the primary operation, and multiple organ failure. The approach to these seriously ill patients should be governed by a high index of suspicion. Clinical findings are at least as reliable as sophisticated radiographic modalities of which CAT scan appears to be the most accurate. Re-exploration for multiple organ failure alone will yield a significant group of patients with drainable septic foci and some survivors; thus, exploration for this indication appears to be defensible.