The effect of hyperoxia on ventilation during recovery from general anesthesia: A randomized pilot study for a parallel randomized controlled trial
Affiliation:
1. Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, United States of America;2. Center for Sleep and Circadian Sciences, Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States of America;3. Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, United States of America;4. Department of Psychiatry and Behavioral Sciences, and Center for Sleep Sciences and Medicine, Stanford University School of Medicine, Stanford, CA, United States of America;5. Nox Research, Nox Medical ehf, Reykjavík, Iceland;6. Department of Urology, Stanford University School of Medicine, Stanford, CA, United States of America;1. Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, United States of America;2. Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, United States of America;3. Department of Intensive Care and Resuscitation, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, United States of America;4. Division of Cardiology, Department of Medicine, NYU Grossman School of Medicine, New York, NY, United States of America;5. Cardiology Section, Department of Medicine, VA New York Harbor Healthcare System, New York, NY, United States of America;6. Department of Quantitative Health Sciences, Cleveland Clinic, OH, United States of America;1. Department of Anesthesiology, University of Michigan: Michigan Medicine, Ann Arbor, MI, United States;2. Department of Epidemiology, University of Michigan, Ann Arbor, MI, United States;1. Department of Anaesthesia and Perioperative Medicine, University College London Hospital, 235 Euston Road, London NW1 2BU, UK;2. The University of Texas Health Science Center at San Antonio, Department of Anesthesiology, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA;3. Department of Anesthesiology, Perioperative and Pain Medicine, 300 Pasteur Drive, Room H3580, Stanford, CA 94305, USA;1. Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical University, China;2. School of Nursing, Xuzhou Medical University, China;3. Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, China;4. Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, China;5. NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou Medical University, China
Abstract:
Study objectiveWhile supplemental O2 inhalation corrects hypoxemia, its effect on post-anesthesia ventilation remains unknown. This pilot trial tested the hypothesis that hyperoxia increases the time spent with a transcutaneous PCO2 (TcPCO2) > 45 mmHg, compared with standard O2 supplementation.DesignSingle-blinded, parallel two-arm randomized pilot trial.SettingUniversity hospital.Patients20 patients undergoing robotic-assisted laparoscopic nephrectomy.MeasurementsAfter institutional approval and informed consent, patients were randomized to receive O2 titrated to arterial saturation (SpO2): 90–94% (Conservative O2, N =10), or to SpO2 > 96% (Liberal O2, N = 10) for up to 90 min after anesthesia. Continuous TcPCO2, respiratory inductance plethysmography (RIP), and SpO2, were recorded. We calculated the percentage of time at TcPCO2 > 45 mmHg for each patient and compared the two groups using analysis of covariance, adjusting for sex, age, and body mass index. We also estimated the sample size required to detect the between-group difference observed in this pilot trial. RIP signals were used to calculate apnea/hypopnea index (AHI), which was then compared between two groups.Main resultsThe mean percentage of time with a TcPCO2 > 45 mmHg was 80.6% for the Conservative O2 (N=9) and 61.2% for the Liberal O2 (N=10) group [between-group difference of 19.4% (95% CI: −18.7% to 57.6%), P = 0.140]. With an observed effect size of 0.73, we estimated that 30 participants per group are required, to demonstrate this difference with a power of 80% at a two-sided alpha of 5%. Means SpO2 were 94.5% and 99.9% for the Conservative O2 and the Liberal O2 groups, respectively. AHI was significantly higher in the Conservative O2, compared with the Liberal O2 group (median AHI: 16 vs. 3; P = 0.0014).ConclusionsHyperoxia in the post-anesthesia period reduced the time spent at TcPCO2 > 45 mmHg and significantly decreased AHI, while mean SpO2 ranged inside the a priori defined limits.Trial registrationClinicalTrials.gov identifier: NCT04723433
