YaDeau Jacques T, Kahn Richard L, Lin Yi, Goytizolo Enrique A, Gordon Michael A, Gadulov Yuliya, Garvin Sean, Fields Kara, Goon Amanda, Armendi Isabel, Dines David M, Craig Edward V
1Department of Anesthesiology, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
2Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 USA.
HSS J. 2019 Jul;15(2):167-175. doi: 10.1007/s11420-018-9642-4. Epub 2018 Nov 9.
General anesthesia with neuromuscular blockade may facilitate total shoulder arthroplasty but appears to increase risk of cerebral oxygen desaturation. Cerebral desaturation is undesirable and is a proxy for risk of stroke.
PURPOSES/QUESTIONS: This study tested the hypothesis that cerebral oxygen desaturation occurs frequently during general anesthesia with neuromuscular blockade and positive-pressure ventilation but does not occur with spontaneous ventilation. Correlations were sought among cerebral oxygen saturation, blood pressure, and cardiac index.
We designed a prospective, observational, cohort study to measure cerebral oxygenation in 25 patients during general anesthesia, both with and without positive-pressure ventilation. Patients undergoing elective shoulder arthroplasty in the sitting position received an arterial catheter, near-infrared spectroscopic measurement of cerebral oxygenation, and non-invasive cardiac output measurement. Moderate hypotension was allowed. Blood pressure was supported as needed with ephedrine or low-dose epinephrine (but avoiding phenylephrine). Hypercapnia (45 to 55 mmHg) was targeted during positive-pressure ventilation.
No cerebral oxygen desaturations occurred, regardless of ventilation mode. Under positive-pressure ventilation, the median (interquartile range: Q1, Q3) cerebral oxygenation was 110% of baseline (104, 113), the mean arterial pressure was 62% of baseline (59, 69), and the cardiac index was 82% of baseline (71, 104). Cerebral oxygenation did not correlate with blood pressure or cardiac index but had moderate correlation with end-tidal carbon dioxide. No strokes occurred.
There were no signs of inadequate brain perfusion during general anesthesia using paralytic agents. Positive-pressure ventilation with moderate hypotension in the sitting position does not endanger patients, in the context of moderate hypercapnia and hemodynamic support using ephedrine or epinephrine.
全身麻醉联合神经肌肉阻滞可能有助于全肩关节置换术，但似乎会增加脑氧饱和度降低的风险。脑氧饱和度降低是不可取的，并且是中风风险的一个指标。
目的/问题：本研究检验了以下假设，即在全身麻醉联合神经肌肉阻滞和正压通气期间，脑氧饱和度降低经常发生，但在自主通气时不会发生。研究脑氧饱和度、血压和心脏指数之间的相关性。
我们设计了一项前瞻性观察队列研究，以测量25例患者在全身麻醉期间（包括有和没有正压通气的情况）的脑氧合情况。接受择期坐位肩关节置换术的患者接受动脉导管置入、近红外光谱法测量脑氧合以及无创心输出量测量。允许出现中度低血压。根据需要使用麻黄碱或低剂量肾上腺素（但避免使用去氧肾上腺素）维持血压。在正压通气期间，目标是使二氧化碳分压达到45至55 mmHg。
无论通气模式如何，均未发生脑氧饱和度降低。在正压通气下，脑氧合的中位数（四分位间距：Q1，Q3）为基线的110%（104，113），平均动脉压为基线的62%（59，69），心脏指数为基线的82%（71，104）。脑氧合与血压或心脏指数无相关性，但与呼气末二氧化碳有中度相关性。未发生中风。
在使用麻痹剂的全身麻醉期间，没有脑灌注不足的迹象。在中度高碳酸血症以及使用麻黄碱或肾上腺素进行血流动力学支持的情况下，坐位时的正压通气联合中度低血压不会危及患者。
