motilin and Critical-Illness

Gastrointestinal dysmotility and dysfunction underlie our difficulties in providing adequate nutrition by the enteral route to our critically ill patients.. Recent studies have quantified gastric emptying and nutrient absorption. Slow gastric emptying is common and probably mediated by cholecystokinin and reduced active ghrelin concentrations. The cause of impaired nutrient absorption is not yet fully understood but may be related to small intestinal blood flow and/or mucosal factors. The absorption of the different macronutrients may be affected in different ways both by critical illness and by therapies. A better understanding of this may optimize the design of nutrient formulations in the future. New treatment modalities for gastrointestinal dysfunction are being investigated and include small intestinal feeding, nonpharmacological options such as acupuncture, and drugs including novel motilin receptor agonists, and opioid antagonists.. We are gradually developing a better understanding of how the gut works during critical illness, which has implications for optimizing the delivery of nutrition and thereby improving nutritional and clinical outcomes.

Topics: Cholecystokinin; Critical Illness; Enteral Nutrition; Evidence-Based Medicine; Gastric Emptying; Gastrointestinal Agents; Gastrointestinal Diseases; Ghrelin; Humans; Intestine, Small; Motilin; Naltrexone; Quaternary Ammonium Compounds; Randomized Controlled Trials as Topic

Studies consistently show that nasogastric nutrition delivers only about 60% of nutritional goals in critically ill patients. The predominant reason is abnormal gastric motility, leading to delayed gastric emptying, which is evident clinically as large gastric residual volumes. Delayed gastric emptying occurs in about 50%-60% of critically ill patients who are fed enterally and can result in malnutrition. Furthermore, delayed gastric emptying may increase the risk of aspiration of gastric contents. Recent research has improved our understanding of the complex abnormalities of gastric motor function that underlie delayed gastric emptying in the critically ill. Feed intolerance can be treated with prokinetic drugs and/or by the placement of postpyloric feeding catheters. The place of prokinetic agents in the treatment of feed intolerance is as yet unclear, but current evidence supports the administration of erythromycin combined with metoclopramide as first-line therapy. Other novel drugs, such as methylnaltrexone, mitemcinal, ghrelin agonists and dexloxiglumide, have potential advantages over these agents but require further investigation before widespread clinical use.

Topics: Antiemetics; Cholecystokinin; Critical Illness; Dopamine Antagonists; Drug Therapy, Combination; Enteral Nutrition; Erythromycin; Gastric Emptying; Gastrointestinal Agents; Ghrelin; Humans; Metoclopramide; Motilin; Receptors, Opioid, mu; Serotonin Receptor Agonists

Altered concentrations of ghrelin, motilin, and cholecystokinin (CCK) may contribute to gastric hypomotility. The aims of this study were to evaluate the concentrations of these hormones in patients tolerant and intolerant to gastric nutrition, assess the influence of prokinetic therapy on these hormone concentrations, determine the associations between these mediators and gastric emptying, and evaluate whether inflammation influences their concentrations.. Post hoc analyses of 2 prospective studies that enrolled 20 critically ill patients with an aspirated gastric residual (GR) >150 mL while receiving gastric enteral nutrition (intolerant group) and 10 critically ill patients with minimal GR (tolerant group). Patients with intolerance were also assessed 1 day after prokinetic therapy. Fasting serum concentrations of total ghrelin, acyl ghrelin (active), des-acyl ghrelin (inactive), motilin, CCK, and tumor necrosis factor (TNF)-α were determined. Gastric emptying was assessed concurrently using the acetaminophen absorption method.. Compared to the tolerant group, the intolerant group had higher total ghrelin (1324.8 ± 1204.6 vs 285.1 ± 132.5 pg/mL; P < .001), lower acyl ghrelin (70.5 ± 65.4 vs 208.5 ± 186.9 pg/mL; P < .05), and lower acyl ghrelin to des-acyl ghrelin ratio (1.11 ± 1.35 vs 3.47 ± 3.21 pg/mL; P < .05). Concentrations of other hormones and TNF-α were similar. Despite accelerated gastric emptying after prokinetic therapy, concentrations of all hormones and TNF-α were similar to baseline values. Hormone concentrations were not associated with gastric emptying or TNF-α.. Patients intolerant to gastric nutrition generate less acyl ghrelin, which may contribute to gastric hypomotility. Intolerance is not associated with altered concentrations of other hormones. Hormone concentrations are not influenced by prokinetic therapy.

Topics: Adult; Aged; Cholecystokinin; Critical Illness; Enteral Nutrition; Female; Gastric Emptying; Gastrointestinal Hormones; Ghrelin; Humans; Inflammation; Male; Middle Aged; Motilin; Prospective Studies; Respiratory Aspiration; Stomach Diseases; Tumor Necrosis Factor-alpha