Mannitol and hypertonic saline

Intravenous mannitol is invaluable as a first aid measure in a patient with brain herniation as a result of raised ICP. In practice, mannitol tends to be given as an intermittent bolus (2 ml kg of a 20 solution over 15-20 minutes) whenever the individual patient's ICP rises significantly above the threshold of 20-25 mmHg. Effects last for up to four hours. As osmotic diuresis may lead to hypovolaemia it is crucial to avoid dehydration and latent hypotension with careful attention to fluid...