Editorial
Copyright ©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Aug 7, 2007; 13(29): 3909-3917
Published online Aug 7, 2007. doi: 10.3748/wjg.v13.i29.3909
Mechanisms underlying feed intolerance in the critically ill: Implications for treatment
Adam Deane, Marianne J Chapman, Robert J Fraser, Laura K Bryant, Carly Burgstad, Nam Q Nguyen
Adam Deane, Marianne J Chapman, Intensive Care Unit, Royal Adelaide Hospital, Adelaide, South Australia
Robert J Fraser, Discipline of Medicine, University of Adelaide and Investigation and Procedures Unit, Repatriation General Hospital, Adelaide, South Australia
Laura K Bryant, Investigation and Procedures Unit, Repatriation General Hospital, Adelaide, South Australia
Carly Burgstad, Nam Q Nguyen, Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, South Australia
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Adam Deane, Intensive Care Unit, Royal Adelaide Hospital, North Terrace, Adelaide 5000, Australia. adam.deane@adelaide.edu.au
Telephone: +61-4-31967560 Fax: +61-8-82225885
Received: May 28, 2007
Revised: June 1, 2007
Accepted: June 4, 2007
Published online: August 7, 2007
Abstract

Malnutrition is associated with poor outcomes in critically ill patients. Although nutritional support is yet to be proven to improve mortality in non-malnourished critically ill patients, early enteral feeding is considered best practice. However, enteral feeding is often limited by delayed gastric emptying. The best method to clinically identify delayed gastric emptying and feed intolerance is unclear. Gastric residual volume (GRV) measured at the bedside is widely used as a surrogate marker for gastric emptying, but the value of GRV measurement has recently been disputed. While the mechanisms underlying delayed gastric emptying require further investigation, recent research has given a better appreciation of the pathophysiology. A number of pharmacological strategies are available to improve the success of feeding. Recent data suggest a combination of intravenous metoclopramide and erythromycin to be the most successful treatment, but novel drug therapies should be explored. Simpler methods to access the duodenum and more distal small bowel for feed delivery are also under investigation. This review summarises current understanding of the factors responsible for, and mechanisms underlying feed intolerance in critical illness, together with the evidence for current practices. Areas requiring further research are also highlighted.

Keywords: Critical illness; Enteral nutrition; Gastric emptying; Gastric motility; Gastrointestinal hormones; Metoclopramide; Erythromycin; Prokinetic therapy