A comparison of hypertonic saline and mannitol on intraoperative brain relaxation in patients with raised intracranial pressure during supratentorial tumors resection: A randomized control trial

Introduction: Hyperosmotic agents are used to decrease intracranial pressure (ICP). We aim to compare the effect of euvolemic solutions of 3% hypertonic saline (HTS) and 20% mannitol on intraoperative brain relaxation in patients with clinical or radiological evidence of raised ICP undergoing surgery for supratentorial tumors. Materials and Methods: A prospective double-blind study was conducted on 30 patients randomized into two equal groups. Each patient was administered 5 ml/kg of either 20% mannitol or 3% HTS over 15 minutes (min) after skin incision. Hemodynamic data, brain relaxation and serum electrolyte levels were recorded. Results: Intraoperative brain relaxation was comparable between the two groups. There was a statistically significant difference in the mean arterial pressures (MAPs) between the two groups after one minutes (min) with a greater degree of decrease in blood pressure recorded in the mannitol group (P = 0.041). MAP with mannitol was significantly lower than the preinduction value after 75 min of administration of drug (P = 0.003). Urine output was significantly higher in the mannitol group (P = 0.00). Administration of HTS was associated with a transient increase in serum sodium concentrations, which was statistically significant but returned to normal within 48 h (P < 0.001). Conclusions: Both mannitol and HTS provided adequate intraoperative brain relaxation. On the contrary, there was no statistically significant fall in blood pressure with HTS. Thus, we advocate the use of HTS over mannitol as it maintains better hemodynamic stability.