Hypertonic saline more efficacious than mannitol in lethal intracranial hypertension model

Abstract

Background: Medical management of brain edema and elevated intracranial pressure (ICP) is a crucial challenge in neurosurgical practice. Depending on the cause, the treatments for brain edema fall into three categories: stabilization of the blood-brain barrier, depletion of brain water and surgical decompression. Although mannitol is the mainstay of hyperosmolar therapy, hypertonic saline (HS) is emerging as an effective alternative to traditional osmotic agents.Methods: Experimental elevated ICP (50 mmHg) was induced in rabbits using an intracranial balloon. The effects of mannitol and HS (10% NaCl) were compared in this specific physiopathological model. Twelve animals were divided into three groups (control, HS and mannitol) according to intravenous administration of 0·9% NaCl, 10% NaCl or 20% mannitol 5 minutes after the elevation of ICP. The doses of 10% NaCl and 20% mannitol were iso-osmolar. During 90 minutes, continuous recording of ICP, mean arterial pressure (MAP) and cerebral perfusion pressure (CPP) was realized.Results: The control group had a median survival of only 53 minutes, significantly lower than the treated groups (p = 0·0002). There was statistical difference between mannitol and HS; the 10% NaCl group had lower values of ICP (p = 0·0116) and higher values of MAP (p<0·0001) and CPP (p<0·0001).Conclusion: The findings demonstrate higher efficacy of the 10% NaCl treatment in this comparison with 20% mannitol. Further efforts should be directed toward development of clinical studies using iso-osmotic doses of mannitol and HS in specific etiologies of intracranial hypertension.