Hori D, Brown C, Ono M, Rappold T, Sieber F, Gottschalk A, Neufeld K J, Gottesman R, Adachi H, Hogue C W
Division of Cardiac Surgery, Department of Surgery, The Johns Hopkins Hospital, 1800 Orleans Ave, Zayed 6208B, Baltimore, MD 21287, USA.
Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Hospital, 1800 Orleans Ave, Zayed 6208B, Baltimore, MD 21287, USA.
Br J Anaesth. 2014 Dec;113(6):1009-17. doi: 10.1093/bja/aeu319. Epub 2014 Sep 25.
Mean arterial pressure (MAP) below the lower limit of cerebral autoregulation during cardiopulmonary bypass (CPB) is associated with complications after cardiac surgery. However, simply raising empiric MAP targets during CPB might result in MAP above the upper limit of autoregulation (ULA), causing cerebral hyperperfusion in some patients and predisposing them to cerebral dysfunction after surgery. We hypothesized that MAP above an ULA during CPB is associated with postoperative delirium.
Autoregulation during CPB was monitored continuously in 491 patients with the cerebral oximetry index (COx) in this prospective observational study. COx represents Pearson's correlation coefficient between low-frequency changes in regional cerebral oxygen saturation (measured with near-infrared spectroscopy) and MAP. Delirium was defined throughout the postoperative hospitalization based on clinical detection with prospectively defined methods.
Delirium was observed in 45 (9.2%) patients. Mechanical ventilation for >48 h [odds ratio (OR), 3.94; 95% confidence interval (CI), 1.72-9.03], preoperative antidepressant use (OR, 3.0; 95% CI, 1.29-6.96), prior stroke (OR, 2.79; 95% CI, 1.12-6.96), congestive heart failure (OR, 2.68; 95% CI, 1.28-5.62), the product of the magnitude and duration of MAP above an ULA (mm Hg h; OR, 1.09; 95% CI, 1.03-1.15), and age (per year of age; OR, 1.01; 95% CI, 1.01-1.07) were independently associated with postoperative delirium.
Excursions of MAP above the upper limit of cerebral autoregulation during CPB are associated with risk for delirium. Optimizing MAP during CPB to remain within the cerebral autoregulation range might reduce risk of delirium.
clinicaltrials.gov NCT00769691 and NCT00981474.
体外循环（CPB）期间平均动脉压（MAP）低于脑自动调节下限与心脏手术后的并发症相关。然而，在CPB期间单纯提高经验性MAP目标可能会导致MAP高于自动调节上限（ULA），在一些患者中引起脑灌注过多，并使他们在术后易发生脑功能障碍。我们假设CPB期间MAP高于ULA与术后谵妄相关。
在这项前瞻性观察研究中，对491例患者采用脑氧饱和度指数（COx）连续监测CPB期间的自动调节。COx代表局部脑氧饱和度（用近红外光谱法测量）的低频变化与MAP之间的Pearson相关系数。根据前瞻性定义的方法通过临床检测在术后住院期间全程定义谵妄。
45例（9.2%）患者发生谵妄。机械通气>48小时[比值比（OR），3.94；95%置信区间（CI），1.72 - 9.03]、术前使用抗抑郁药（OR，3.0；95% CI，1.29 - 6.96）、既往中风（OR，2.79；95% CI，1.12 - 6.96）、充血性心力衰竭（OR，2.68；95% CI，1.28 - 5.62）、MAP高于ULA的幅度与持续时间的乘积（mmHg·h；OR，1.09；95% CI，1.03 - 1.15）以及年龄（每年；OR，1.01；95% CI，1.01 - 1.07）与术后谵妄独立相关。
CPB期间MAP超过脑自动调节上限与谵妄风险相关。在CPB期间优化MAP使其保持在脑自动调节范围内可能会降低谵妄风险。
clinicaltrials.gov NCT00769691和NCT00981474。
