Cerebral Oxygenation in the Sitting Position Is Not Compromised During Spontaneous or Positive-Pressure Ventilation

Jacques T YaDeau; Richard L Kahn; Yi Lin; Enrique A Goytizolo; Michael A Gordon; Yuliya Gadulov; Sean Garvin; Kara Fields; Amanda Goon; Isabel Armendi; David M Dines; Edward V Craig

doi:10.1007/s11420-018-9642-4

Cerebral Oxygenation in the Sitting Position Is Not Compromised During Spontaneous or Positive-Pressure Ventilation

HSS J. 2019 Jul;15(2):167-175. doi: 10.1007/s11420-018-9642-4. Epub 2018 Nov 9.

Authors

Jacques T YaDeau^{1

2}, Richard L Kahn^{1

2}, Yi Lin^{1

2}, Enrique A Goytizolo^{1

2}, Michael A Gordon^{1

2}, Yuliya Gadulov^{1

2}, Sean Garvin^{1

2}, Kara Fields³, Amanda Goon^{1

4}, Isabel Armendi¹, David M Dines^{2

5}, Edward V Craig^{2

6}

Affiliations

¹ 1Department of Anesthesiology, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
² 2Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065 USA.
³ 3Healthcare Research Institute, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
⁴ Harrison and Star, New York, NY USA.
⁵ 5Department of Orthopedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
⁶ TRIA Orthopedic Center, Bloomington, MN USA.

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.

Keywords: cerebral oxygenation; positive-pressure ventilation; shoulder arthroplasty.