Gastrointestinal dysmotility in the critically ill: a role for nutrition

The role of enteral nutrition on gastrointestinal dysmotility in the critically ill remains controversial.

The mechanisms of gastrointestinal dysmotility during critical illness remain poorly investigated. Low amounts of enteral feeding stimulate motility and have trophic effects. Therefore, enteral feeding is feasible even during gastrointestinal dysmotility as seen in the hemodynamically compromised patient. Rapid 'ramp-up' of administration rate of tube feeding bears the risk of overload and even detrimental ischemic bowel necrosis. The recent American Society for Parenteral and Enteral Nutrition guidelines do not recommend the measurement of gastric residual volume. The use of concentrated enteral solutions with 1.5 kcal/ml may result in greater calorie delivery. Biomarkers like plasma citrulline and plasma or urine intestinal fatty-acid-binding protein reflect the functional integrity of the bowel and may potentially support monitoring.

To improve enteral nutrition protocols, the definitions of gastrointestinal dysfunction, gastric dysmotility, and feeding intolerance should be clearly defined in the future. In the concept of integrity of the gut, enteral nutrition should not be stopped completely during gastrointestinal dysfunction but restricted to a 'minimal' trophic feeding rate. In malnourished and high-risk patients intolerant to enteral feeding supplemental parenteral nutrition should be started on day 4 or earlier.