Evaluation of equiosmolar 20% mannitol, 3% hypertonic saline and 8.4% sodium bicarbonate on intraoperative brain relaxation and hemodynamic parameters in patients undergoing craniotomy for supratentorial tumors: a prospective randomized study.

Abstract

Research comparing 20% mannitol, 3% hypertonic saline and 8.4% sodium bicarbonate for intraoperative hyperosmolar therapy during supratentorial tumor excision is sparse. With the hypothesis that equiosmolar concentration of these agents will produce equivalent effects, this study was conducted to compare the effects on intraoperative brain relaxation and hemodynamics. The prospective study was conducted over a period of one year. Ninety patients, aged 18-60 years, American Society of Anesthesiologists class Ι and ΙΙ with supratentorial tumor and scheduled for surgery were randomized into three groups to receive equiosmolar 20% mannitol (group 1), 3% hypertonic saline (group 2) and 8.4% sodium bicarbonate (group 3). Primary outcome assessed was the effect on intraoperative brain relaxation score while hemodynamic parameters, changes in arterial blood gas parameters, serum electrolytes, serum osmolarity, urine output, fluid intake, post-operative course, hospital stay were the secondary outcomes. Demographic characteristics, surgical and anesthetic variables, were comparable between the three groups. Brain relaxation scores were significantly better in group 3 compared to group 2 and group 1 respectively. Patients in group 1 had lower mean blood pressure and central venous pressure values, higher urine output, fluid intake compared to other groups. Patients of group 3 had significantly higher pH, bicarbonate, partial pressure of carbon dioxide, serum sodium and serum osmolarity values compared to groups 1 and 2. Eight point four percent sodium bicarbonate solution infusion is associated with superior intraoperative brain relaxation scores and improved haemodynamic stability compared to equiosmolar 3% hypertonic saline solution and 20% mannitol.