Salt or sugar on the brain: does it matter except for taste?

Hypertonic saline, not mannitol, should be considered gold-standard medical therapy for intracranial hypertension

Hyperosmolar therapy is the principal medical management strategy for elevated intracranial pressure. Mannitol has been the primary hyperosmolar agent for nearly a century and remains the de facto gold standard for medical management of intracranial hypertension. Over the past 25 years, however, hypertonic saline (HTS) has become a progressively more common alternative to mannitol, and several recent studies have suggested its relative superiority. These findings have prompted calls for large-scale comparator trials of mannitol and HTS, but such trials would only be necessary if the designation of mannitol as the gold standard is appropriate and if current evidence suggests its therapeutic equipoise with HTS. Mounting evidence supporting HTS suggests that neither of these conditions is necessarily true and, instead, mandates reassessment of the actual gold-standard agent for hyperosmolar therapy. In the present article I make the case that current evidence supports HTS, not mannitol, as the better choice for gold-standard therapy for medical management of intracranial hypertension. This is accomplished first by examining the evidence on which the apparent designation of mannitol as the presumed gold-standard is based, then by reviewing the recent comparative efficacy data for HTS versus mannitol, and finanally by discussing additional clinical considerations for appropriate designation of a gold-standard agent for hyperosmolar therapy. This assessment has important implications both for patient care and for clinical trial design.