Predictive value of serum sodium level in determining perforated appendicitis

BACKGROUND: The aim of the study was to investigate the predictive value of hyponatremia as a new biochemical marker for the early and accurate preoperative diagnosis of complicated appendicitis in the adult population. METHODS: 732 patients who were operated for acute appendicitis (AA) and diagnosed as perforation intraoperatively were evaluated retrospectively. Serum sodium, C-reactive protein (CRP), and leukocyte levels of patients with perforated and nonperforated appendicitis were compared. RESULTS: Perforated appendicitis patients had statistically lower serum Na values (p<0.001). Similarly, patients without perforated appendicitis had higher serum CRP values (p<0.001). In patients diagnosed with perforated AA, the sensitivity of plasma sodium concentration was 63%, and the specificity was 66%. The threshold value of plasma sodium concentration ≤137.5 mEq/L had the best possible sensitivity and specificity. CONCLUSION: Hyponatremia is a new marker of perforated appendicitis and therefore, serum sodium level measurement should be considered in patients with a clinical presentation consistent with appendicitis if complications are suspected.