Predictors of ischemic bowel in patients with incarcerated hernias.

Diagnosing intestinal strangulation in the setting of incarcerated hernias remains challenging. Hyponatremia has been identified as a predictor of necrotizing soft tissue infections and gangrenous cholecystitis. We hypothesized that hyponatremia could predict bowel ischemia in patients with incarcerated hernias. Medical records for 163 patients with incarcerated hernias over a 5-year period were reviewed. Preoperative clinical, laboratory, and radiologic findings and final intraoperative diagnosis were collected. Thirty-six patients (22.1%) had ischemic bowel requiring resection. Univariate analysis identified multiple significant variables including lower serum sodium (p = 0.002), lower bicarbonate (p = 0.04), elevated glucose (p = 0.0002), elevated white blood cell count (p = 0.001), and skin changes (p = 0.001). In a multivariable model, skin changes were associated with an odds ratio for ischemia of 3.3 (1.3-8.6 p = 0.02). Sodium of less than 135 had an odds ratio for ischemia of 3.9 (1.7-9.1, p = 0.004). Hyponatremia should raise suspicion for underlying strangulated bowel and prompt urgent exploration in patients with incarcerated hernias.