Osmotherapy in neurocritical care

Osmotherapy is the mainstay in the medical management of cerebral edema with or without elevations in intracranial pressure. Several osmotic agents have been utilized in clinical practice over the past five decades in a variety of brain injury paradigms. The over-riding premise for their beneficial effects has been via egress of water from the brain into the vascular compartment. In addition, many of these agents have beneficial extraosmotic properties that portend their use in cerebral resuscitation and treatment of cerebral edema. Although there is a paucity of large, randomized clinical trials that compare various osmotic agents, data are emerging from prospective clinical case series. This article provides a historical perspective of osmotherapy, examines characteristics of osmotic agents, and discusses caveats in their use in the clinical setting. Furthermore, this review highlights the utility of osmotic agents as tools to understand emerging mechanistic concepts in the evolution of brain edema, which are yielding important data of translational significance from laboratory-based research.