Piot J, Hébrard A, Durand M, Payen J F, Albaladejo P
PAR CHU Grenoble Alpes, CS 10217, 30043, Grenoble Cedex 9, France.
J Clin Monit Comput. 2019 Feb;33(1):145-153. doi: 10.1007/s10877-018-0137-0. Epub 2018 Apr 17.
Following cardiac surgery, hyperlactatemia due to anaerobic metabolism is associated with an increase in both morbidity and mortality. We previously found that an elevated respiratory quotient (RQ) predicts anaerobic metabolism. In the present study we aimed to demonstrate that it is also associated with poor outcome following cardiac surgery. This single institution, prospective, observational study includes all those patients that were consecutively admitted to the intensive care unit (ICU) after cardiac surgery with cardiopulmonary bypass, that had also been monitored using pulmonary artery catheter. Data were recorded at admission (H0) and after one hour (H1) including: oxygen consumption ([Formula: see text]), carbon dioxide production ([Formula: see text]), RQ ([Formula: see text]), lactate levels and mixed venous oxygen saturation ([Formula: see text]). The primary endpoint was defined as mortality at 30 days. Comparison of the area under the curve (AUC) for receiver operating characteristic curves was used to analyze the prognostic predictive value of RQ, lactate levels and [Formula: see text], in terms of patient outcome. We studied 151 patients admitted to the ICU between May 2015 and February 2016. Seventy eight patients experienced a worse than expected outcome in the post-operative period, and among those seven died. RQ at H1 in non-survivors ([Formula: see text]) was higher than in survivors ([Formula: see text]; p = 0.02). The AUC for RQ to predict mortality was 0.77 (IC [0.70-0.84]), with a threshold value of 0.76 (sensitivity 64%, specificity 100%). By comparison, the AUC for lactate levels was significantly superior (AUClact 0.89, IC [0.83-0.93], p = 0.02). In this study, elevated RQ appeared to be predictive of mortality after cardiac surgery with CPB.
心脏手术后，无氧代谢所致的高乳酸血症与发病率和死亡率的增加相关。我们之前发现呼吸商（RQ）升高预示无氧代谢。在本研究中，我们旨在证明其也与心脏手术后的不良结局相关。这项单中心、前瞻性、观察性研究纳入了所有在接受体外循环心脏手术后连续入住重症监护病房（ICU）且使用肺动脉导管进行监测的患者。在入院时（H0）和1小时后（H1）记录数据，包括：氧耗量（[公式：见正文]）、二氧化碳产生量（[公式：见正文]）、RQ（[公式：见正文]）、乳酸水平和混合静脉血氧饱和度（[公式：见正文]）。主要终点定义为30天死亡率。采用受试者工作特征曲线下面积（AUC）比较来分析RQ、乳酸水平和[公式：见正文]对患者结局的预后预测价值。我们研究了2015年5月至2016年2月期间入住ICU的151例患者。78例患者术后结局比预期差，其中7例死亡。非存活者H1时的RQ（[公式：见正文]）高于存活者（[公式：见正文]；p = 0.02）。RQ预测死亡率的AUC为0.77（95%可信区间[0.70 - 0.84]），阈值为0.76（敏感性64%，特异性100%）。相比之下，乳酸水平的AUC显著更高（乳酸AUC 0.89，95%可信区间[0.83 - 0.93]，p = 0.02）。在本研究中，RQ升高似乎可预测体外循环心脏手术后的死亡率。
