Hyponatremia as a Biochemical Marker of complicated appendicitis: A prospective analysis of factors predicting the complicated course of appendicitis

Objective: To evaluate the role of hyponatremia as a marker of complicated appendicitis. Study Design: A prospective case series was conducted. Place and Duration: The study was carried out at the Surgical Unit of IIMCT-Pakistan Railway Hospital, Rawalpindi over a 6 months period from 20th November 2022 to 20th May 2023. Methodology: Hyponatremia was defined as serum sodium level equal or less than 135 mEq/L. Gangrenous as well as perforated appendix on per-operative examination were considered as complicated appendicitis. Sociodemographic and disease related factors (including gender, age, presenting complaint and hyponatremia) were recorded among the study population and were compared among complicated and uncomplicated cases. Results: A total of 86 (N) patients were studied. The inferential analysis illustrated that gender, chief presenting complaint and postoperative complications had no association with complicated appendicitis. However significantly higher (p=0.002 at chi square value of 9.781) number of complicated appendicitis (CA) cases had hyponatremia preoperatively, when compared to the non-complicated appendicitis cases (NCA). Hyponatremia had an accuracy of 68.6% at predicting complicated appendicitis with a sensitivity of 54.3% and specificity of 78.4%. The receiver operator curve (ROC) of serum sodium level for identification of complicated appendicitis illustrated area under the curve (AUC) of 0.82 with a highly significant p-Value of <0.001 (at 95% CI of 0.734-0.907). Conclusion: Hyponatremia is associated with complicated appendicitis. However, the sensitivity isn’t high enough for its use to rule out the complicated form. Keywords: Appendicitis, Hyponatremia, Perforation, Gangrene, Phlegmon, Peritonitis.