The Effect of Hyperoxia on Ventilation During Recovery From General Anesthesia

Recovery of Ventilation After General Anesthesia for Robotic-Assisted Laparoscopic Nephrectomy or Prostatectomy: The Effect of Oxygen Supplementation

In this randomized-controlled trial the investigators will examine the effect of oxygen supplementation on the recovery of breathing for 90 minutes in the immediate post-anesthesia period starting from extubation of the trachea.

Study Overview

• Status: Recruiting
• Conditions: Ventilatory Depression; Postoperative Respiratory Failure
• Intervention / Treatment: Other: Oxygen Gas for Inhalation

Detailed Description

In a pilot randomized-controlled trial (NCT04723433) the investigators found that hyperoxia, compared with standard O2 supplementation, enhanced ventilation, as estimated by the fraction of time at a transcutaneous PCO2 (TcPCO2) > 45 mmHg.

More specifically, patients treated with hyperoxia (O2 titrated to: SpO2 > 96%, N=10; Liberal O2) for 90 minutes post-anesthesia, spent 61.2% of the time at TcPCO2 > 45 mmHg, compared with 80.6% of the time in those receiving standard O2 supplementation (O2 titrated to: SpO2 between 90-94%, N=9; Conservative O2 - between-group difference of 19.4% (95% CI: -18.7% to 57.6%), ANCOVA adjusted P = 0.140]. Results were consistent across the 90-min monitoring period. With an observed effect size of 0.73, it was estimated that 30 participants per group are required, to demonstrate this difference with a power of 80% at a two-sided alpha of 5%.

In the present confirmative randomized controlled trial, the investigators plan to estimate and compare the cumulative segment of time during which the transcutaneous partial pressure of carbon dioxide will exceed an upper limit of 45 mmHg (i.e., TcPCO2 > 45 mmHg) for the 90-min-long post-anesthesia period, between the conventional (titrated to an oxygen saturation > 96%) and the conservative (titrated to O2 saturation 90-94%) O2 supplementation interventions.

Hypothesis: Conservative use of O2 (titrated to an SpO2: 90 - 94%), will be associated with more hypoventilation (i.e., more time spent with an TcPCO2 > 45 mmHg) during recovery from general anesthesia, compared to liberal O2 supplementation (SpO2 > 96%).

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anthony Doufas, MD, PhD; Phone Number: 650-498-7699; Email: agdoufas@stanford.edu

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Recruiting
      • Stanford University School of Medicine
      • Contact: Anthony Doufas, MD, PhD; Phone Number: 650-498-7699; Email: agdoufas@stanford.edu
      • Principal Investigator: Anthony Doufas, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status I-III
• Body mass index (BMI) less than 40 kg/m2
• Scheduled to undergo robotic-assisted radical laparoscopic nephrectomy or prostatectomy.

Exclusion Criteria:

• Patients with a diagnosis of chronic obstructive pulmonary disorder (COPD), severe neurological, cardiopulmonary, psychiatric, or untreated thyroid disorder
• Chronic pain condition that is being treated with opioids
• Patients with a hematocrit lower than 30% at the end of surgery, or those with an excessive blood loss, requiring transfusion of blood products during surgery.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: "Conservative O2 Supplementation"; Oxygen administration will be titrated to a oxyhemoglobin saturation (SpO2) between 90 and 94%.	Other: Oxygen Gas for Inhalation; Oxyhemoglobin saturation (SpO2) higher than 96% vs SpO2 between 90% and 94%.
Experimental: "Liberal O2 Supplementation"; Oxygen administration will be titrated to an SpO2 > 96%.	Other: Oxygen Gas for Inhalation; Oxyhemoglobin saturation (SpO2) higher than 96% vs SpO2 between 90% and 94%.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Transcutaneous partial pressure of carbon dioxide (TcPCO2)	The cumulative segment of time during which the transcutaneous partial pressure of carbon dioxide (TcPCO2: primary outcome) will exceed an upper limit of 45 mmHg (i.e., TcPCO2 > 45 mmHg)	Ninety -minute period beginning immediately post-anesthesia.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Apnea / hypopnea index (AHI)	The number of apnea /hypopnea episodes detected using respiratory inductance plethysmography and nasal pressure.	Ninety -minute period beginning immediately post-anesthesia.

Collaborators and Investigators

• Sponsor: Stanford University
• Investigators: Principal Investigator: Anthony Doufas, MD, PhD, Professor, Department of Anesthesiology, Stanford University Medical School

Study record dates

Study Major Dates

• Study Start (Actual): October 4, 2022
• Primary Completion (Estimated): July 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: May 12, 2022
• First Submitted That Met QC Criteria: May 12, 2022
• First Posted (Actual): May 18, 2022

Study Record Updates

• Last Update Posted (Actual): March 20, 2024
• Last Update Submitted That Met QC Criteria: March 18, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: IRB-63878

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes