Anesthesia & Clinical Research
Open Access

Abstract

Optic Nerve Sheath Diameter: An Ultrasonographic Window for Comparing between Hypertonic Saline and Mannitol in Severe Traumatic Brain Injuries

Huda Fahmy and Ayman Mohamady Eldemrdash

Background: Clinically both mannitol and hypertonic saline (HTS) have been utilized successfully to manage elevated intracranial pressure (ICP), although which therapy is superior is yet unclear.
Aim of the work: To compare the efficacy of hypertonic saline 3% and mannitol 20% in the reduction of increased intracranial pressure in sever traumatic brain injuries by ultrasonographic measurement of optic nerve sheath diameter (ONSD).
Patient and methods: This prospective, double blind, randomized, observational, comparative study was performed on 30 patients who admitted to surgical intensive care unit in Aswan University Hospital with severe traumatized brain injury. All patients were examined by ultrasound to measure ONSD, we used a cut off value for ONSD as 5.5 mm to diagnose increase in ICP>20 mm Hg. Patients with signs of increased ICP were allocated into 2 groups; Group A: Patients received Mannitol 20% in a dose of 0.5gm/kg (2.5ml/kg) every 6 hours intravenously over a period of 20 minutes for 48 hours, Group B: Patients received hypertonic saline 3% in a dose of 3ml/kg every 6 hours (0.5ml/kg/hr) infusion intravenously for 48 hours.
Results: The ONSD values in HTS and mannitol groups were statistically significant decreased from admission values at 6 hours, 12 hours, 24 hours & 48 hours after treatment. The ultrasonographic ONSD values were significant lower in HTS group than mannitol group at 12 hours, 24 hours & 48 hours (P=0.012, 0.039, 0.001respectively). The percentage decrease of the ultrasonographic values of ONSD at 48 hour of treatment was higher in HTS group than mannitol group (P=0.001), while there was no statistically significant difference at 24 hours of treatment between the two study groups.
Conclusion: ONSD routine monitoring in ICU helped to early detect patients with raised intracranial pressure when invasive ICP monitoring is not available. Hypertonic saline causes decrease ICP more effectively than mannitol with less rebound elevation to ICP than mannitol and there was no significant effect of hyperosmolar therapy on hemodynamics.