Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 12 3 2026 01 01 246 253 Sohrab Salimi Associate Professor, Department of Anesthesiology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Shahram Sayadi Associate Professor of Anesthesiology, Anesthesiology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran Dariush Abtahi Associate Professor, Department of Anesthesiology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mona Varzandeh Department of Anesthesiology, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Arman Jami Emergency Department, MEKPCO (Middle East Kimia Petrochemical Company), Asaluyeh, Iran Sepide Ghesmati Tabrizi Health Division, Local Office, MEKPCO (Middle East Kimia Petrochemical Company), Tehran, Iran 2025 05 27 2025 06 15 Background: Managing intracranial pressure and brain swelling during supratentorial brain tumor surgery often involves hyperosmolar solutions like hypertonic saline and mannitol. However, using these solutions alongside hydroxyethyl starch (HES) could potentially affect blood clotting. This study aimed to compare the impact of hypertonic saline and mannitol, when combined with HES, on blood coagulation in patients undergoing these surgeries. Materials and Methods: This clinical trial compared 20% mannitol and 3% hypertonic saline in patients undergoing brain tumor surgery. Patients were divided into two groups, each receiving one of these osmotic agents along with hydroxyethyl starch. The study focused on assessing any blood clotting abnormalities. Results: The study included 30 patients (15 in each group). Their initial characteristics were similar. The study found no significant differences in blood coagulation tests between the groups. Additionally, osmolality levels and measures of brain tension were comparable in both groups. There were also no significant differences in intraoperative hemodynamic parameters. Conclusion: Both hypertonic saline and mannitol, when used with HES, effectively manage intracranial pressure without significantly affecting blood clotting during supratentorial tumor surgeries. Further research is needed to refine fluid management strategies and minimize potential clotting risks in these procedures. https://aacc.tums.ac.ir/index.php/aacc/article/view/1298