Hypertonic saline achieves superior brain relaxation in tumor craniotomy: An updated systematic-network meta-analysis.

BACKGROUND

Brain tumor craniotomy requires relaxation of the brain through decreasing the intracranial pressure (ICP). Osmo-hyperosmolar therapy can be used to lower the ICP.

OBJECTIVES

This study was aimed at updating previous studies to determine the effects and safety of using hypertonic saline (HTS) and mannitol to decrease ICP in adult patients with brain tumors undergoing craniotomy.

METHODS

To identify randomized controlled trials (RCTs) comparing HTS vs mannitol, we performed a systematic literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, by examining records from 2013 to December of 2023 in five databases. The primary outcome was brain relaxation, and the secondary outcomes were cerebral perfusion pressure (CPP), urine output (UO), fluid input, mean arterial pressure (MAP), and plasma sodium. Conventional meta-analysis, Bayesian meta-insight analysis, trial-sequential analysis, and trial quality assessment were conducted.

RESULTS

Eleven RCTs involving 593 participants were included in the meta-analysis. Use of HTS, compared with mannitol, was associated with significantly greater brain relaxation, and significantly lower UO and fluid input. HTS was also significantly associated with elevated MAP. Plasma sodium was significantly higher in the HTS group than the mannitol group. No significant difference in CPP was observed between groups. Trial sequential analysis indicated true significance for the brain relaxation outcomes. Bayesian analysis demonstrated the superiority of 3% HTS at 5 ml/kg in achieving brain relaxation, followed by 3% HTS at 5.3 ml/kg and 20% mannitol at 5 ml/kg.

CONCLUSIONS

HTS is superior to mannitol in achieving optimal brain relaxation, maintaining stable blood flow, and minimizing diuretic effects. However, use of HTS during tumor craniotomy procedures can increase plasma sodium levels. The optimal dose for achieving brain relaxation appears to be 3% HTS at 5 ml/kg body weight.