Full Enteral Feeding during Severe Hypotension does not Adversely Affect Gastrointestinal Microcirculation in a Porcine (Sus scrofa) Model of Endotoxic Shock

Abstract

Introduction: The use of enteral nutrition in septic shock is controversial during periods of significant hypotension due to concern of possible metabolic stimulation of an ischemic gastrointestinal system. In this study, using a piglet model of endotoxic shock, we tested the hypothesis that full enteral feeding during shock would not adversely affect gastrointestinal microcirculation. Methods: Yorkshire cross pigs were either fed or non-fed during endotoxic shock and compared against controls. Severe hypotension was induced by administration of E. coli. Hemodynamics and microcirculatory blood flow (measured via colored microspheres) were compared throughout the experiment. Post-mortem biopsies of the stomach, small bowel, and large bowel were examined from representative pigs in each group. Results: Despite a sustained decrease in MAP with ETX exposure, regional blood flow (RBF) to the stomach was maintained throughout the experiment. RBF to the small intestine dropped, and remained low, with lowered MAP. The large intestine followed the small intestine pattern but with consistency issues within the data. Post-mortem biopsies revealed normal stomach tissue in both groups. Both fed and non-fed ETX animals showed mild to moderate erosion in the small and large bowel but there was no significant effect of feeding compared to not feeding. Conclusion: While this study is limited in duration, it does appear that initially there is no harm to the microcirculation or integrity of the gastrointestinal tract with addition of feeding during severe septic shock. Results indicate that feeding during severe hypotension, which would help maintain nutrition, should be considered.