Abstracts
2000 Digestive Disease Week

# 2327 Cardiopulmonary Bypass, Mesenteric Perfusion, & Small Intestinal Epithelial Integrity: Preliminary Analysis Using a Novel Protein Marker.
James H. Holmes, Joshua M. Lieberman, William H. Marks, Charles B. Probert, Mark E. Hill, Daniel L. Paull, Steven W. Guyton, James Sacchettini, R. Alan Hall, College Station, TX, Seattle, WA

Background: Cardiopulmonary bypass (CPB) is associated with poorly understood alterations in GI perfusion, with reports of both increased and decreased mesenteric perfusion during CPB. Intestinal fatty acid binding protein (IFABP) is a cytosolic protein uniquely located in mature small intestinal enterocytes which has been shown to be a sensitive biochemical marker of early intestinal ischemia when assayed in urine or serum. We hypothesized that if significant small intestinal ischemia occurs with CPB, then urine IFABP levels should be concomitantly elevated. Methods: Twenty-nine patients (15 low-risk and 14 high-risk) undergoing cardiac surgery with CPB were studied prospectively. Serial urine IFABP levels were measured and results were correlated with clinical outcomes. Results: None of the low-risk patients had IFABP elevations or experienced GI complications. Five of the high-risk patients had IFABP elevations, and 3 of the 5 developed GI complications. Within the high-risk cohort, the only significant difference between patients with and without IFABP elevations was the GI complication rate (p=0.03); although, there was a trend towards a prolonged time to oral intake (p=0.06). Overall, patients with IFABP elevations had significantly increased mean ASA class, mean CPB time, mean time to oral intake, median ICU and postoperative lengths of stay (LOS), and GI complications [Table]. Conclusions: In this pilot study, the sensitivity and specificity of elevated urine IFABP with respect to GI complications were 100% and 92%, respectively. Urine IFABP may be a useful marker to identify the cardiac patient at risk for post-bypass GI complications.