Department of Anesthesiology and Pain Medicine, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
Department of Cardiovascular Surgery, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
J Artif Organs. 2021 Dec;24(4):433-441. doi: 10.1007/s10047-021-01263-7. Epub 2021 Apr 7.
Baseline cerebral regional saturation (rSO) measured using the INVOS 5100C (Medtronic, MN, USA) varies widely among patients with cardiac and/or renal diseases. To identify significant correlates of baseline rSO and to investigate intraoperative rSO changes, we conducted a retrospective study in 494 patients undergoing on-pump cardiovascular surgery. Correlations between preoperative blood laboratory test variables and baseline rSO before anesthesia were examined. Intraoperative rSO changes were analyzed. Of all the variables examined, log-transformed B-type natriuretic peptide (BNP) most significantly and negatively correlated with baseline rSO (r = - 0.652, p < 0.0001). Intraoperatively, rSO showed the lowest value during cardiopulmonary bypass (CPB) (median rSO: 56.2% during CPB vs. 63.9% at baseline, p < 0.0001). Although rSO during CPB correlated positively with hemoglobin concentration and oxygen delivery during CPB (r = 0.192, p < 0.0001; and r = 0.172, p = 0.0001, respectively), it correlated much more closely with baseline rSO (r = - 0.589, p < 0.0001). Thus, patients showing low baseline rSO primarily associated with preoperatively high BNP continued to show low rSO even during CPB independent of hemodynamics artificially controlled by CPB. Our findings suggest that low baseline rSO in patients with high BNP due to cardiac and/or renal diseases is more likely to result from tissue edema causing alterations in optical pathlength and thus in calculated rSO values, not readily modifiable with CPB, rather than actual cerebral hemodynamic alterations readily modifiable with CPB. These may partly explain why the INVOS oximeter is a trend monitor requiring baseline measures.
基线脑区域性饱和度（rSO）使用 INVOS 5100C（美敦力，明尼苏达州，美国）测量在患有心脏和/或肾脏疾病的患者中差异很大。为了确定基线 rSO 的显著相关因素，并研究术中 rSO 的变化，我们对 494 例接受体外循环心血管手术的患者进行了回顾性研究。检查了麻醉前术前血液实验室检查变量与基线 rSO 之间的相关性。分析了术中 rSO 的变化。在所检查的所有变量中，经对数转换的 B 型利钠肽（BNP）与基线 rSO 呈最显著负相关（r = -0.652，p <0.0001）。术中，rSO 在体外循环（CPB）期间显示最低值（CPB 期间的中位数 rSO：56.2%与基线时的 63.9%相比，p <0.0001）。尽管 CPB 期间的 rSO 与血红蛋白浓度和 CPB 期间的氧输送呈正相关（r = 0.192，p <0.0001；和 r = 0.172，p = 0.0001），但与基线 rSO 的相关性更密切（r = -0.589，p <0.0001）。因此，基线 rSO 较低的患者主要与术前 BNP 较高有关，即使在 CPB 期间，rSO 也较低，这与 CPB 人工控制的血液动力学无关。我们的研究结果表明，由于心脏和/或肾脏疾病而导致 BNP 较高的患者的低基线 rSO 更可能是由于组织水肿导致光程和因此计算的 rSO 值发生变化，而不是 CPB 容易改变的实际脑血流动力学变化。这可能部分解释了为什么 INVOS 血氧计是一种需要基线测量的趋势监测器。
