Hypertonic saline solution reduces the oxidative stress responses in traumatic brain injury patients

Oxidative stress processes play an important role in the pathogenesis of secondary brain injury after traumatic brain injury (TBI). Hypertonic saline (HTS) has advantages as being preferred osmotic agent, but few studies investigated oxidant and antioxidant effects of HTS in TBI. This study was designed to compare two different regimens of HTS 5% with mannitol on TBI-induced oxidative stress.

Thirty-three adult patients with TBI were recruited and have randomly received one of the three protocols: 125 cc of HTS 5% every 6 h as bolus, 500 cc of HTS 5%as infusion for 24 h or 1 g/kg mannitol of 20% as a bolus, repeated with a dose of 0.25-0.5 g/kg every 6 h based on patient's response for 3 days. Serum total antioxidant power (TAP), reactive oxygen species (ROS) and nitric oxide (NO) were measured at baseline and daily for 3 days.

Initial serum ROS and NO levels in patients were higher than control(6.86± [3.2] vs. 1.57± [0.5] picoM, P = 0.001, 14.6± [1.6] vs. 7.8± [3.9] mM, P = 0.001, respectively). Levels of ROS have decreased for all patients, but reduction was significantly after HTS infusion and mannitol (3. 08 [±3.1] to 1.07 [±1.6], P = 0.001, 5.6 [±3.4] to 2.5 [±1.8], P = 0.003 respectively). During study, NO levels significantly decreased in HTS infusion but significantly increased in mannitol. TAP Levels had decreased in all patients during study especially in mannitol (P = 0.004).

Hypertonic saline 5% has significant effects on the oxidant responses compared to mannitol following TBI that makes HTS as a perfect therapeutic intervention for reducing unfavorable outcomes in TBI patients.