The acceptable level of hypotension in patients with brain injuries has not been determined, and the Brain Trauma Foundation (BTF) Guidelines recommend maintaining systolic blood pressures > 90 mm Hg, but acknowledge that this number is relatively arbitrary and not based on any high-level studies (thus assigning it a designation of Level II evidence) 11. The BTF Guidelines further state that because hypotension is such a poor prognostic variable, it would be unethical to randomize patients to various blood pressure goals, and therefore Level I evidence is not forthcoming. Further complicating the situation is the lack of agreement on how to increase blood pressure (with the hopes of increasing cerebral perfusion pressure)12-15. Many of the pharmacologic agents used to increase mean arterial pressure have significant vasoconstrictive effects, which could counteract any increase blood pressure and lead to unchanged, or even reduced cerebral blood flow.