Comparison of mannitol and hypertonic saline in the treatment of severe brain injuries.

Object: The purpose of this study was to compare the effects of mannitol and hypertonic saline in doses of similar osmotic burden for the treatment of intracranial hypertension in patients with severe traumatic brain injury.
Methods: The authors used an alternating treatment protocol to compare the effect of hypertonic saline with that of mannitol given for episodes of increased intracranial pressure in patients treated for severe head injury at their hospital during 2006-2008. Standard guidelines for the management of severe traumatic brain injury were followed. Elevated intracranial pressure (ICP) was treated either with mannitol or hypertonic saline. Doses of similar osmotic burden (mannitol 20%, 2 ml/kg, infused over 20 minutes, or saline 15%, 0.42 ml/kg, administered as a bolus via a central venous catheter) were given alternately to the individual patient with severe brain injury during episodes of increased pressure. The dependent variables were the extent and duration of reduction of increased ICP. The choice of agent for treatment of the initial hypertensive event was determined on a randomized basis; treatment was alternated for every subsequent event in each individual patient. Reduction of ICP and duration of action were recorded after each event. Results obtained after mannitol administration were statistically compared with those obtained after hypertonic saline administration.
Results: Data pertaining to 199 hypertensive events in 29 patients were collected. The mean decrease in ICP obtained with mannitol was 7.96 mm Hg and that obtained with hypertonic saline was 8.43 mm Hg (p = 0.586, equal variances assumed). The mean duration of effect was 3 hours 33 minutes for mannitol and 4 hours 17 minutes for hypertonic saline (p = 0.40, equal variances assumed).
Conclusions: No difference between the 2 medications could be found with respect to the extent of reduction of ICP or duration of action.