3. HYPEROSMOLAR THERAPY
LEVEL I, II, AND III
Although hyperosmolar therapy may lower intracranial pressure, there was insufficient evidence about effects on clinical outcomes to support a specific recommendation, or to support use of any specific hyperosmolar agent, for patients with severe traumatic brain injury.
The Level II and III recommendations from the 3rd Edition of these guidelines are not supported by evidence meeting current standards because they were derived from studies that do not meet Class 3 criteria for this topic. While there is increasing use of hypertonic saline as an alternative hyperosmotic agent there is insufficient evidence available from comparative studies to support a formal recommendation. The Committee thus chose to re-state here the 3rd Edition recommendations. The rationale for doing so is to maintain sufficient recognition of the potential need for hyperosmolar therapy to reduce intracranial pressure, while acknowledging that more research is needed to inform more specific recommendations.
RECOMMENDATIONS FROM THE PRIOR (3RD) EDITION NOT SUPPORTED BY EVIDENCE MEETING CURRENT STANDARDS
Mannitol is effective for control of raised intracranial pressure (ICP) at doses of 0.25 g/kg to 1 g/kg body weight. Arterial hypotension (systolic blood pressure <90 mm Hg) should be avoided.
Restrict mannitol use prior to ICP monitoring to patients with signs of transtentorial herniation or progressive neurological deterioration not attributable to extracranial causes.
CHANGES FROM PRIOR EDITION
The Committee is universal in its belief that hyperosmolar agents are useful in the care of patients with severe TBI. However, the literature does not currently support recommendations that meet the strict criteria for contemporary evidenced-based medicine approaches for guideline development.
The recommendations in the 3rd Edition of these guidelines about administration of hyperosmolar agents were based on one Class 2 study and nine Class 3 studies. The study included as Class 2 study was not a comparative study for this topic (it is a Class 2 trial about the use of barbiturates), and six of the studies that were rated as Class 3 studies were not comparative, and therefore did not meet current inclusion criteria.
In this 4th Edition we focused the search for new evidence explicitly on the comparative effectiveness of different hyperosmolar agents and means of administration.
