Gastrointestinal Tract: A Neglected Guardian Angel?

Abstract

Role of the gastrointestinal (GI) system is not limited to the digestion of food and absorption of water and nutrients. Gastrointestinal mucosa forms a barrier preventing translocation of microbes into the blood. Upper GI tract performs important function of swallowing and prevention of aspiration, failure of which mandates enteral tube feeding. Rate of gastric emptying depends on gastric volume and contents and delayed emptying is observed both in solid and in fatty food. Cricoid pressure during intubation is an important intervention for prevention of aspiration in critically ill patients who are considered as full stomach. To utilize mucosal barrier function optimally, hemodynamically stable patients should preferably receive enteral nutrition even if they are on small doses of vasopressors. Post-pyloric feeds may reduce risk of aspiration and hence are recommended for patients who are deemed to have high risk for aspiration. Bowel sounds have poor reproducibility, sensitivity, specificity, accuracy, and interobserver agreement, and absent bowel sounds should not be considered as a contraindication to enteral feeding. How to cite this article: Kothekar AT, Kulkarni AP. Gastrointestinal Tract: A Neglected Guardian Angel? Indian J Crit Care Med 2020;24(Suppl 4):S146-S151.

Keywords: Aspiration pneumonia; Bowel sounds; Cricoid pressure; Enteral nutrition; Gastric emptying; Gastric motility; Paralytic ileus; Physiology of gastrointestinal tract; Trophic feeding.

Fig. 1

Time taken for gastric passage by solid feeds and liquids (adapted from ref. 5)

Fig. 2

Gut wall layers and the nervous system (adapted from ref. 16)