Vasopressors Do Not Influence Cerebral Critical Closing Pressure During Systemic Inflammation Evoked by Experimental Endotoxemia and Sepsis in Humans

Aim: The aim of this study was to investigate the effects of different vasopressors on the cerebral vasculature during experimental human endotoxemia and sepsis. We used the critical closing pressure (CrCP) as a measure of cerebral vascular tone. Methods: We performed a prospective pilot study, at the intensive care department (ICU) of a tertiary care university hospital in the Netherlands, in 40 healthy male subjects during experimental human endotoxemia (administration of bacterial lipopolysaccharide [LPS]) and in 10 patients with severe sepsis or septic shock. Subjects in the endotoxemia study were randomized to receive a 5 h infusion of either 0.05 μg/kg/min noradrenaline (n = 10, “LPS-nor”), 0.5 μg/kg/min phenylephrine (n = 10, “LPS-phenyl”), 0.04 IU/min vasopressin (n = 10, “LPS-AVP”), or saline (n = 10, “LPS-placebo”) starting 1 h before intravenous administration of 2 ng/kg LPS. In patients with sepsis, fluid resuscitation and vasopressor use was at the discretion of the medical team, aiming at normovolemia and a mean arterial pressure (MAP) > 65 mm Hg, using noradrenaline. The mean flow velocity in the middle cerebral artery (MFVMCA) was measured by transcranial Doppler (TCD) with simultaneously recording of heart rate, arterial blood pressure, respiratory rate, and oxygen saturation. CrCP was estimated using the cerebrovascular impedance model. Results: The CrCP decreased in the LPS-placebo group from 52.6 [46....
Source: Shock - Category: Emergency Medicine Tags: Clinical Science Aspects Source Type: research