Evaluation of the Effects of 20% Mannitol and 3% Hypertonic Saline Use in Supratentorial Tumor Surgery on Brain Relaxation, Hemodynamic Parameters, Serum Osmolarity and Electrolytes

Objective: Different drugs or methods can be applied to provide brain relaxation in supratentorial tumor surgery. In our study, we aimed to evaluate effects of 20% Mannitol and 3% Hypertonic Saline (HS) used during supratentorial tumor surgery on brain relaxation, hemodynamic parameters, urine flow, fluid volume, pulse pressure variability (PPV), pleth variability index (PVI), serum osmolarity and electrolytes. Methods: The study included 60 patients aged 18-65 years, ASA I-II class, who were scheduled to undergo supratentorial tumor surgery. General anesthesia was administered with sevoflurane and remifentanil to achieve a state entropy of 40-60. Patients were allocated into two groups, with Group Mannitol receiving 20% mannitol (2.5 mL kg-1) and Group Hypertonic Saline receiving 3% HS (2.5 mL kg-1). In all patients, PPV and PVI values were planned to be ≤13%. After the dura was opened, brain relaxation scores were evaluated. Perioperative hemodynamic variables, blood gases, PVI, PPV values were recorded. Na+, K+ values, urine volume and administered fluid were recorded at 30, 45 and 60 minutes and 2-3 hours after the end of the infusion. Preoperative and postoperative BUN, creatinine and osmolarity values were recorded. Results: No statistical difference was found between demographic characteristics, brain relaxation and hemodynamic data. In HS group, PVI and PPV values were higher than Mannitol group from the beginning of infusion. In mannitol group, urine and administered fluid amounts were higher. Decrease in Na+ values was detected with Mannitol and increase with HS. It was determined that BUN and creatinine values were similar, serum osmolarity did not change at postoperative period in mannitol group and increased HS. Average intensive care and length of hospital stay were similar. Conclusion: In supratentorial tumor surgery, effective brain relaxation was achieved with Mannitol and HS, without affect to hemodynamics. Pulse pressure variability and PVI decreased with Mannitol. Blood gases, Na+, K+, BUN creatinine, osmolarity levels did not show serious changes. It was concluded that HS could be an alternative to mannitol in supratentorial surgery. Keywords: Hypertonic saline,mannitol, serum osmolarity, supratentorial tumor surgery