Comparing the effects of mannitol and hypertonic saline in severe traumatic brain injury patients with elevated intracranial pressure: a systematic review and meta-analysis

Objectives: Controlling elevated intracranial pressure following brain injury with hyperosmolar agents is one of the mainstay treatments in traumatic brain injury patients. In this study, we compared the effects of hypertonic saline (HS) and mannitol in reducing increased intracranial pressure. Methods: A total of 637 patients from 15 studies were included in our meta-analysis. The primary outcomes were mortality, the length of stay in the hospital and ICU, and the Glasgow Outcome Scale at follow-up. Results: The mortality in the mannitol group was not statistically different compared to the HS group (RR = 1.55; 95% CI = [0.98, 2.47], p = 0.06). The length of stay in the ICU was significantly shorter in the HS group (MD = 1.18, 95% CI = [0.44, 1.92], p < 0.01). In terms of favorable neurological outcomes, there was no significant difference between the two agents (RR = 0.92, 95% CI = [0.11, 7.96], p = 0.94). The duration of the effect was shorter in the mannitol group than in the HS group (MD = -0.67, 95% CI = [−1.00, −0.33], p < 0.01). Discussion: The results showed that HS and mannitol had similar effects in reducing ICP. Although the HS was associated with a longer duration of effect and shorter ICU stay, other secondary outcomes including mortality rate and favorable neurological outcomes were similar between the two drugs. In conclusion, considering the condition of each patient individually, HS could be a reasonable option than mannitol to reduce ICP in TBI patients.