Using Digestive Fluid Biomarkers to Predict Acute Gastrointestinal Injury in Critically Ill Patients: A Pilot Study.

Background Acute gastrointestinal injury is associated with significantly increased mortality in critically ill patients. However, markers for measuring acute gastrointestinal injury are neither sensitive nor specific. Objective To determine whether enzymes in digestive fluid are predictive of the severity of acute gastrointestinal injury. Methods A prospective observational study was conducted between June 2015 and December 2015 in a surgical intensive care unit. Enrolled patients were classified by acute gastrointestinal injury grade according to the 2012 European Society of Intensive Care Medicine system. Digestive fluid was collected through nasointestinal tubes and analyzed 24 hours after the diagnosis of acute gastrointestinal injury. Intestinal markers of injury (pH, interleukin 6, interleukin 10, tumor necrosis factor alpha, and secretory immunoglobulin A) were measured in digestive fluid. Results Of the 76 patients included, acute gastrointestinal injury was grade I in 41, grade II in 20, grade III in 8, and grade IV in 7. Secretory immunoglobulin A was an independent predictor of grade III acute gastrointestinal injury. When data from patients with grades I and II injury and patients with grades III and IV injury were grouped together, analysis revealed that pH, interleukin 10, and secretory immunoglobulin A were independent predictors of acute gastrointestinal failure. Conclusions Secretory immunoglobulin A was predictive of grade III acute gastrointestinal injury. Digestive fluid markers of injury (pH, interleukin 10, and secretory immunoglobulin A) were predictors of acute gastrointestinal failure. Further study is required to determine if other markers are specific or sensitive for acute gastrointestinal injury.