1. Cerebral Oxygenation in the Sitting Position Is Not Compromised During Spontaneous or Positive-Pressure Ventilation.
- Author
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YaDeau JT, Kahn RL, Lin Y, Goytizolo EA, Gordon MA, Gadulov Y, Garvin S, Fields K, Goon A, Armendi I, Dines DM, and Craig EV
- Abstract
Background: 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., Methods: 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., Results: 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., Conclusions: 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., Competing Interests: Conflict of InterestRichard L. Kahn, MD, Yi Lin, MD, PhD, Enrique A. Goytizolo, MD, Michael A. Gordon, MD, Yuliya Gadulov, MD, Sean Garvin, MD, Kara Fields, MS, Amanda Goon, BA, and Isabel Armendi, BSc, declare that they have no conflicts of interest. Jacques T. YaDeau, MD, PhD, reports receiving grants and personal fees from Mallinckrodt, outside the submitted work. David M. Dines, MD, and Edward V. Craig, MD, MPH, both report receiving royalties and other fees from Zimmer Biomet, during the conduct of this study.
- Published
- 2019
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