Changes in Serum Analytics and Biochemical Urinary Parameters Following Brain Tumor Operation

Background: Changes in the body fluid and serum electrolyte status following major operations, such as brain tumor resection, are always expected. These changes can increase post-operation morbidity and mortality. Objectives: We aimed to evaluate the changes in serum electrolyte levels and renal function parameters in brain tumor patients after operation. Materials & Methods: This cross-sectional study was performed on 168 patients with supratentorial tumors in Poursina Hospital, Rasht City, Iran, in 2020. The study parameters included patients’ demographics, hemodynamic stability, serum sodium, potassium, blood urea nitrogen (BUN) and creatinine levels, urine specific gravity, and urinary output, measured immediately and 12 hours after the operation. Results: This study revealed statistically significant increases in serum sodium level (from 139.70±5.60 meq/L to 140.34±6.23 meq/L, P=0.002), urinary output (from 1043.70±455.00 mL to 1967.50±661.10 mL, P=0.008), urine specific gravity (from 1.010±0.007 to 1.012±0.008, P=0.011), and in serum BUN level (from 17.46±6.92 to 18.41±6.40, P=0.001), but significant decrease in serum potassium level (from 3.88±0.49 meq/L to 3.78±0.28 meq/L, P=0.017) during the first 12 hours after operation. However, the change in serum creatinine level was not significant (from 1.18±2.08 mg/dL to 1.17±2.08 mg/dL, P=0.787). Conclusion: Significant changes in serum electrolytes (sodium and potassium) and renal function indicators (urine output, specific gravity, and serum BUN) are expected within the first 12 hours after brain tumor operation.