Can the Intestinal Dysmotility of Critical Illness be Differentiated from Postoperative Ileus?

Abstract

Gastrointestinal dysmotility is commonly noted in the intensive care unit and postoperative settings. Characterized by delayed passage of stool and flatus, nausea, vomiting, and abdominal distention, the condition is associated with nutritional deficiencies, risk of aspiration, and considerable allocation of health care resources. Knowledge of gastrointestinal function in health and illness continues to expand. While the factors that precipitate ileus differ between postoperative and critically ill patients, the two clinical scenarios seem to have similar mechanisms and share many of the same pathophysiologic patterns. By reviewing and comparing the literature on the respective mechanisms and contributing factors generated in these separate clinical settings, a common more comprehensive management strategy may be derived with the potential for newer innovative therapeutic options.

Feeding the Critically Ill Patient

“…Gut dysfunction in critical illness involves segmental dysmotility, reduced villous height and absorptive surface, disrupted excretion of digestive enzymes, reduced production of trophic epithelial hormones and secretory IgA, and alterations in gut microbiota (60 can be fed through the gut dysfunction, with the feeding itself leading to improved gut integrity, better contractility, increased brush border enzymes, and restoration of the commensal bacteria (8,60).…”

“…Cessation of delivery of EN for reasons related to nursing care, tests and procedures, or perceived intolerance is estimated to be inappropriate 66% of the time (61). A common misconception exists that feeding is inappropriate in the setting of high gastric residual volumes (GRVs) (63), stable blood pressure while on pressor therapy (31), or hypoactive bowel sounds with evidence of ileus (60). Eliminating use of gastric residual volume as a clinical monitor surprisingly has been shown to promote increased EN delivery without adverse sequelae in certain patient groups (64).…”

The Principles and Practice of Nutritional Support

“…The etiology of ileus following abdominal surgery and in non-surgical critical illness is similar and equally complex, as recently reviewed by Caddell et al [171]. As they suggest, a problem with multiple potential causes will have multiple potential treatments, as illustrated by Fig.…”

Nutritional and Metabolic Therapy

“…Early resuscitation remains a cornerstone of ICU therapy. 30 The approach of waiting for these signs can contribute to unnecessary delays in feeding. Volume resuscitation is continued with appropriate arterial and central pressure, cardiac output, and/or tissue perfusion goals; if unable to reach these goals, vasopressor medications are added in the hypotensive (mean arterial pressures <65 mm Hg) vasodilated patient (see Chapters 22 & 33).…”

“…[34][35][36][37] Membrane toll-like receptors (TLR) have been implicated in altered motility with resultant changes in intestinal bacterial flora and the potential for translocation. 30 Gastrointestinal intolerance should be continually reassessed signaling the successful resuscitation of the critically ill patient in shock remains elusive. 38 The proposed mechanisms inducing postoperative ileus following bowel manipulation have recently been described ( Figure 28-2).…”