Open Access Highly Accessed Research article

A comparative study on the efficacy of 10% hypertonic saline and equal volume of 20% mannitol in the treatment of experimentally induced cerebral edema in adult rats

Hong-Ke Zeng1*, Qiao-Sheng Wang12, Yi-Yu Deng1, Wen-Qiang Jiang1, Ming Fang1, Chun-Bo Chen1 and Xin Jiang13

Author Affiliations

1 Department of Emergency & Critical Care Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China

2 Department of Critical Care Medicine, The First Affiliated Hospital, University of South China, Hengyang 421001, Hunan Province, PR China

3 Graduate School, Southern Medical University, 1838 North Guangzhou Avenue, Guangzhou 510515, PR China

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BMC Neuroscience 2010, 11:153  doi:10.1186/1471-2202-11-153

Published: 10 December 2010

Abstract

Background

Hypertonic saline and mannitol are commonly used in the treatment of cerebral edema and elevated intracranial pressure (ICP) at present. In this connection, 10% hypertonic saline (HS) alleviates cerebral edema more effectively than the equal volume of 20% mannitol. However, the exact underlying mechanism for this remains obscure. This study aimed to explore the possible mechanism whereby 10% hypertonic saline can ameliorate cerebral edema more effectively than mannitol.

Results

Adult male Sprague-Dawley (SD) rats were subjected to permanent right-sided middle cerebral artery occlusion (MCAO) and treated with a continuous intravenous infusion of 10% HS, 20% mannitol or D-[1-3H(N)]-mannitol. Brain water content (BWC) as analyzed by wet-to-dry ratios in the ischemic hemisphere of SD rats decreased more significantly after 10% HS treatment compared with 20% mannitol. Concentration of serum Na+ and plasma crystal osmotic pressure of the 10% HS group at 2, 6, 12 and 18 h following permanent MCAO increased significantly when compared with 20% mannitol treated group. Moreover, there was negative correlation between the BWC of the ipsilateral ischemic hemisphere and concentration of serum Na+, plasma crystal osmotic pressure and difference value of concentration of serum Na+ and concentration of brain Na+ in ipsilateral ischemic hemisphere in the 10% HS group at the various time points after MCAO. A remarkable finding was the progressive accumulation of mannitol in the ischemic brain tissue.

Conclusions

We conclude that 10% HS is more effective in alleviating cerebral edema than the equal volume of 20% mannitol. This is because 10% HS contributes to establish a higher osmotic gradient across BBB and, furthermore, the progressive accumulation of mannitol in the ischemic brain tissue counteracts its therapeutic efficacy on cerebral edema.