Skin perfusion pressure as an indicator of tissue perfusion in valvular heart surgery: Preliminary results from a prospective, observational study

Hemodynamic management aims to provide adequate tissue perfusion, which is often altered during cardiac surgery with cardiopulmonary bypass (CPB). We evaluated whether skin perfusion pressure (SPP) can be used for monitoring of adequacy of tissue perfusion in patients undergoing valvular heart surgery. Seventy-two patients undergoing valve replacement were enrolled. SPP and serum lactate level were assessed after anaesthesia induction (baseline), during CPB, after CPB-off, end of surgery, arrival at intensive care unit, and postoperative 6 h. Lactate was further measured until postoperative 48 h. Association of SPP with lactate and 30-day morbidity comprising myocardial infarction, acute kidney injury, stroke, prolonged intubation, sternal infection, reoperation, and mortality was assessed. Among the lactate levels, postoperative 6 h peak value was most closely linked to composite of 30-day morbidity. The SPP value during CPB and its % change from the baseline value were significantly associated with the postoperative 6 h peak lactate (r = -0.26, P = 0.030 and r = 0.47, P = 0.001, respectively). Optimal cut-off of % decrease in SPP during CPB from baseline value for the postoperative 6 h hyperlactatemia was 48% (area under curve, 0.808; 95% confidence interval (CI), 0.652–0.963; P = 0.001). Decrease in SPP >48% during CPB from baseline value was associated with a 12.8-fold increased risk of composite endpoint of 30-day morbidity (95% CI, 1.48–111.42; P = 0.021) on multivariate logistic regression. Large decrease in SPP during CPB predicts postoperative 6 h hyperlactatemia and 30-day morbidity, which implicates a promising role of SPP monitoring in the achievement of optimal perfusion during CPB.血流动力学管理的目标是维持充足的组织灌注，而在体外循环（cardiopulmonary bypass, CPB）下的心脏手术中，组织灌注状态常发生改变。本研究旨在评估皮肤灌注压（skin perfusion pressure, SPP）是否可用于监测心脏瓣膜手术患者的组织灌注充足性。本研究共纳入72例行瓣膜置换术的患者。分别于麻醉诱导后（基线状态）、体外循环期间、停体外循环后、手术结束时、抵达重症监护病房时以及术后6小时，对患者的SPP与血清乳酸水平进行检测；乳酸水平的检测持续至术后48小时。本研究分析了SPP与乳酸水平，以及包含心肌梗死、急性肾损伤、脑卒中、气管插管时间延长、胸骨切口感染、再次手术及死亡在内的30天并发症发生率之间的关联。在所有乳酸检测值中，术后6小时的乳酸峰值与30天复合不良结局的相关性最强。体外循环期间的SPP值及其相较于基线值的变化百分比，均与术后6小时乳酸峰值存在显著相关性（相关系数r分别为-0.26、0.47，对应P值分别为0.030、0.001）。针对术后6小时高乳酸血症，体外循环期间SPP较基线值下降百分比的最佳截断值为48%（曲线下面积为0.808；95%置信区间（confidence interval, CI）为0.652~0.963；P=0.001）。多因素logistic回归分析显示，体外循环期间SPP较基线值下降超过48%的患者，其30天复合不良结局的发生风险升高12.8倍（95%CI：1.48~111.42；P=0.021）。体外循环期间SPP大幅下降可预测术后6小时高乳酸血症及30天并发症发生率，提示SPP监测在优化体外循环期间灌注效果方面具有潜在应用价值。