Abstract

Purpose: To characterize the microvascular effects of a brief period of hyperoxia, in patients with septic shock and in healthy volunteers. Materials and methods: In 20 patients with septic shock, we assessed systemic hemodynamics, sublingual micro-circulation by SDF-videomicroscopy, and skin perfusion by capillary refill time (CRT), central-peripheral temperature (Delta T degrees), and perfusion index. Measurements were performed at baseline and after 5 min of inspired oxygen fraction of 1.00. Additionally, we studied 8 healthy volunteers, in whom hyperoxia was prolonged to 30 min. Results: In septic patients, hyperoxia increased mean arterial pressure and systemic vascular resistance, but cardiac output remained unchanged. The only significant change in sublingual microcirculation was a decreased heterogeneity flow index (1.03 [1.01-1.07] vs 1.01 [0.34-1.05], P =.002). Perfused vascular density (13.1 [12.0-15.0] vs 14.0 [12.2-14.8] mm/mm(2), P = .21) and the other sublingual microvascular variables were unmodified. CRT and Delta T degrees did not change but perfusion index slightly decreased. In healthy volunteers, sublingual microcirculation and skin perfusion were stable. Conclusions: Short-term hyperoxia induced systemic cardiovascular changes but was not associated with noticeable derangement in sublingual microcirculation and skin perfusion. Nevertheless, longer exposures to hyperoxia might have produced different results. (C) 2019 Elsevier Inc. All rights reserved.