BACKGROUND Near-infrared spectroscopy non-invasively measures regional cerebral oxygen saturation. Intraoperative cerebral desaturations have been associated with worse neurological outcomes. We investigated whether perioperative cerebral desaturations are associated with postoperative delirium in older patients after cardiac surgery. METHODS Patients aged 70 yr and older scheduled for on-pump cardiac surgery were included between 2015 and 2017 in a single-centre, prospective, observational study. Baseline cerebral oxygen saturation was measured 1 day before surgery. Throughout surgery and after ICU admission, cerebral oxygen saturation was monitored continuously up to 72 h after operation. The presence of delirium was assessed using the confusion assessment method for the ICU. Association with delirium was evaluated with unadjusted analyses and multivariable logistic regression. RESULTS Ninety-six of 103 patients were included, and 29 (30%) became delirious. Intraoperative cerebral oxygen saturation was not significantly associated with postoperative delirium. The lowest postoperative cerebral oxygen saturation was lower in patients who became delirious (P=0.001). The absolute and relative postoperative cerebral oxygen saturation decreases were more marked in patients with delirium (13 [6]% and 19 [9]%, respectively) compared with patients without delirium (9 [4]% and 14 [5]%; P=0.002 and P=0.001, respectively). These differences in cerebral oxygen saturation were no longer present after excluding cerebral oxygen saturation values after patients became delirious. Older age, previous stroke, higher EuroSCORE II, lower preoperative Mini-Mental Status Examination, and more substantial absolute postoperative cerebral oxygen saturation decreases were independently associated with postoperative delirium incidence. CONCLUSIONS Postoperative delirium in older patients undergoing cardiac surgery is associated with absolute decreases in postoperative cerebral oxygen saturation. These differences appear most detectable after the onset of delirium. CLINICAL TRIAL REGISTRATION NCT02532530.

中文翻译：

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老年患者心脏手术后谵妄与术后脑氧饱和度下降的关系。

背景技术近红外光谱非侵入性地测量局部脑氧饱和度。术中脑饱和度降低与更差的神经系统结果相关。我们调查了围手术期脑血氧饱和度下降是否与老年患者心脏手术后的术后谵妄有关。方法 2015 年至 2017 年间，一项单中心、前瞻性、观察性研究纳入了计划进行体外循环心脏手术的 70 岁及以上患者。在手术前1天测量基线脑氧饱和度。在整个手术过程中和入住 ICU 后，持续监测脑氧饱和度直至术后 72 小时。使用 ICU 的混乱评估方法评估谵妄的存在。使用未经调整的分析和多变量逻辑回归评估与谵妄的关联。结果 103 名患者中有 96 名被纳入研究，29 名 (30%) 出现神志不清。术中脑氧饱和度与术后谵妄无显着相关性。谵妄患者术后最低脑氧饱和度较低（P=0.001）。与没有谵妄的患者（9 [4]% 和 14 [5]%；P =0.002 和 P=0.001）。在患者变得谵妄后排除脑氧饱和度值后，脑氧饱和度的这些差异不再存在。年龄较大，既往中风，较高的 EuroSCORE II，较低的术前简易精神状态检查和较大幅度的术后脑氧饱和度绝对下降与术后谵妄发生率独立相关。结论 接受心脏手术的老年患者术后谵妄与术后脑氧饱和度的绝对下降有关。这些差异在谵妄发作后最明显。临床试验注册 NCT02532530。这些差异在谵妄发作后最明显。临床试验注册 NCT02532530。这些差异在谵妄发作后最明显。临床试验注册 NCT02532530。