Detecting central-venous oxygen desaturation without a central-venous catheter: Utility of the difference between invasively and noninvasively measured blood pressure ☆ ☆☆ ☆☆☆ ★

Abstract Objective The objective was to determine whether central-venous oxygen saturation (ScvO 2 Methods This is a cross-sectional study at a single medical and surgical intensive care unit in Japan. All hypotensive patients admitted to intensive care unit were eligible. Arterial BP was measured via a radial-artery catheter, and noninvasive BP on the same side was measured via a brachial cuff. ScvO 2 was measured by gas analysis of blood sampled from a central-venous chatheter (CVC). We calculate the area under the curve for ΔBP as an indicator of ScvO 2 Results Usable data were obtained from the records of 111 patients. The median and interquartile range of ΔBP and ScvO 2 were − 4 mm Hg (− 11, 6) and 67% (60.9, 73.9), respectively. The area under the curve of ΔBP as an indicator of ScvO 2 Conclusions ΔBP can indicate whether ScvO 2 is lower than 70%. When that difference is greater than 0, ScvO 2 is very likely to be lower than 70%.