Clinical utility of the cobalt-albumin binding assay in the diagnosis of intestinal ischemia.

Currently, the rapid diagnosis of mesenteric ischemia is problematic because of the nonspecificity of most laboratory assays and the unreliability of physical examinations. The evaluation of the cobalt-albumin binding assay (CABA) as a diagnostic marker for short-term risk stratification of emergency department patients presenting with symptoms of intestinal ischemia is reported. This preliminary study includes patients scheduled for exploratory laparotomy with symptoms of ischemic bowel and/or bowel obstruction. Approximately 10 mL of blood was drawn from each patient 1 hour preoperatively into a serum separator gel tube. After 30 minutes of clotting time, serum was collected and frozen at -80 degrees C. The CABA test was performed on the samples by an investigator blinded to the patient's condition, and values were compared with the clinical and pathologic diagnosis of ischemic bowel postoperatively. CABA test values are reported as absorbance units (ABSU) at 470 nm. Of the 26 patients enrolled in the study, 12 were clinically diagnosed with intestinal ischemia. These patients had significantly higher CABA test values (0.52 ABSU +/- 0.04 SEM) than patients without intestinal ischemia (0.31 ABSU +/- 0.02 SEM, p = 0.00023). Only two false-positives and no false-negatives were recorded. This resulted in a sensitivity of 100% and a specificity of 85.7% for the CABA test for these particular samples. The CABA test could be a useful tool for clinicians in the risk stratification of intestinal ischemia.