Ventilatory DepressionNCT05922020
Hyperoxia on Ventilation During Recovery From General Anesthesia
A study testing Oxygen gas in people with Ventilatory Depression and Postoperative Respiratory Failure, run by Stanford University at 1 site in United States.
Trial summary
In this preliminary, crossover investigation the investigators will examine the effect of oxygen supplementation on the recovery of breathing in the immediate post-anesthesia period. Read more about this study
- Who is it for?
- Ages 20 to 90 years
- Conditions the study is for
- Ventilatory Depression, Postoperative Respiratory Failure
- What is being tested?
- Oxygen gas
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 8 Aug 2023to 12 Dec 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- American Society of Anesthesiologists (ASA) physical status I-III
- Body mass index (BMI) less than 35 kg/m2
- Scheduled to undergo robotic-assisted radical laparoscopic nephrectomy.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
Stanford University School of Medicine
Stanford, California, 94305
About this study
Official title: The Effect of Hyperoxia on Ventilation During Recovery From General Anesthesia: A Crossover Preliminary Investigation
In this preliminary, crossover investigation the investigators will examine the effect of oxygen supplementation on the recovery of breathing in the immediate post-anesthesia period.
Read the detailed description
In a pilot randomized-controlled trial (NCT04723433) the investigators found that, compared with standard O2 supplementation, hyperoxia 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% Confidence Intervals: -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 a follow-up RCT (IRB-63878, NCT05379673) in 18 patients the investigators found that over a 90-minute window, the average percentage of time spent at TcPCO2 > 45mmHg for patients in the Conservative O2 group (N=9) was 57.8% (52 ± 44 minutes), compared with a 45.6% (41 ± 46 minutes) for those in the Liberal O2 group (N=9), (P=0.6134; two-sided two sample t-test). In addition, during the same period, respiratory disturbance index (RDI; events per hour) was higher in the Conservative O2 [median (range): 23.9 (11.0-78.6)], compared with the Liberal O2 group [19.6 (2.8-40.4), Mann-Whitney test, P=0.1615].
Due to the high variability observed in the evaluated respiratory parameters (i.e., TcPCO2 and upper airway obstruction expressed by Respiratory Disturbance Index), the researchers believe that a crossover, rather than a randomized controlled trial, design would improve the power and efficiency of this investigation and also provide an opportunity to characterize better those patients who respond, and separate them from those who do not respond to hyperoxia treatment.
This preliminary investigation will assess how ventilation during recovery from general anesthesia is affected by conservative (Conservative O2: 90% ≤ SpO2 ≤ 94%), compared with liberal (Liberal O2: SpO2 > 96%) O2 supplementation. Using a crossover study design, the investigators aim to: a) assess the breathing pattern and estimate and compare the number of apnea/hypopnea episodes between the two interventions, and b) estimate and compare the cumulative segment of time during which the transcutaneous partial pressure of carbon dioxide (TcPCO2) will exceed 45 mmHg, between the two interventions.
Hypothesis: Conservative O2 will be associated with more unstable and obstructed breathing and less time spent with TcPCO2 > 45 mmHg, compared with Liberal O2 supplementation, during recovery from anesthesia.
- Being tested
- Oxygen gas
- Medical subject headings
- Respiratory Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oxygen gasOther
Administration of Oxygen by inhalation
| Study group | Role | What they receive |
|---|---|---|
| "Conservative O2" | Active comparator | During the first treatment session, which will last for 40 minutes, O2 supplementation will be titrated to an SpO2 between 90% and 94%. Receives: Other: Oxygen gas |
| "Liberal O2" | Experimental | During the second treatment session, which will last for 40 minutes, O2 supplementation will be titrated to an SpO2 > 96%. Receives: Other: Oxygen gas |
What is being measured
The primary outcome is the main question the study is designed to answer.
Respiratory disturbance index (RDI)
The number of apnea/hypopnea episodes detected using respiratory inductance plethysmography and nasal flow.
Measured: Forty minutes of monitoring for each treatment arm
Transcutaneous carbon dioxide pressure (TcPCO2)
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)
Measured: Forty minutes of monitoring for each treatment arm
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jun 2023
- Study start8 Aug 2023
- Primary completion12 Dec 2023
- Study completion12 Dec 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Ventilatory DepressionStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Model description
- With the patients' admission to the post-anesthesia care unit and after a 20-minute-long stabilization period, two 40-minute-long treatment sessions will be applied to the study patients. In the first 6 patients Conservative O2 treatment will be applied first, whereas in the rest (patients 7-10) the order of the interventions will be reversed. The order of the interventions will not be revealed to the participants before completing the study. In the Conservative O2 treatment session, O2 supplementation will be titrated to an SpO2 between 90% and 94%, while in the Liberal O2, O2 administration will be titrated to an SpO2 \> 96%.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anthony Doufas, Stanford University
- Investigators
- Anthony Doufas, MD, PhD, Principal investigator, Professor, Department of Anesthesiology, Stanford University Medical School
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05922020
- Sponsor's protocol ID
- IRB-70628
- Status last verified
- Mar 2024
- First submitted
- 18 Jun 2023
- Last updated
- 13 Mar 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Kutscher S, Finnsson E, Tian L, Panousis P, Chung BI, Doufas AG. The effect of hyperoxia on disordered breathing during recovery from general anesthesia: A single-blinded, crossover, non-randomized -controlled, trial. J Clin Anesth. 2026 Jan;108:112057. doi: 10.1016/j.jclinane.2025.112057. Epub 2025 Oct 31.
PubMed 41175776
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Hyperoxia on Ventilation During Recovery From General Anesthesia: A Crossover Preliminary Investigation
- ClinicalTrials.gov ID
- NCT05922020
- Acronym / sponsor ID
- IRB-70628
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- 8 Aug 2023 (actual)
- Primary completion
- 12 Dec 2023 (actual)
- Study completion
- 12 Dec 2023 (actual)
- First posted
- 28 Jun 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In this preliminary, crossover investigation the investigators will examine the effect of oxygen supplementation on the recovery of breathing in the immediate post-anesthesia period.
Detailed description
In a pilot randomized-controlled trial (NCT04723433) the investigators found that, compared with standard O2 supplementation, hyperoxia 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% Confidence Intervals: -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 a follow-up RCT (IRB-63878, NCT05379673) in 18 patients the investigators found that over a 90-minute window, the average percentage of time spent at TcPCO2 > 45mmHg for patients in the Conservative O2 group (N=9) was 57.8% (52 ± 44 minutes), compared with a 45.6% (41 ± 46 minutes) for those in the Liberal O2 group (N=9), (P=0.6134; two-sided two sample t-test). In addition, during the same period, respiratory disturbance index (RDI; events per hour) was higher in the Conservative O2 [median (range): 23.9 (11.0-78.6)], compared with the Liberal O2 group [19.6 (2.8-40.4), Mann-Whitney test, P=0.1615].
Due to the high variability observed in the evaluated respiratory parameters (i.e., TcPCO2 and upper airway obstruction expressed by Respiratory Disturbance Index), the researchers believe that a crossover, rather than a randomized controlled trial, design would improve the power and efficiency of this investigation and also provide an opportunity to characterize better those patients who respond, and separate them from those who do not respond to hyperoxia treatment.
This preliminary investigation will assess how ventilation during recovery from general anesthesia is affected by conservative (Conservative O2: 90% ≤ SpO2 ≤ 94%), compared with liberal (Liberal O2: SpO2 > 96%) O2 supplementation. Using a crossover study design, the investigators aim to: a) assess the breathing pattern and estimate and compare the number of apnea/hypopnea episodes between the two interventions, and b) estimate and compare the cumulative segment of time during which the transcutaneous partial pressure of carbon dioxide (TcPCO2) will exceed 45 mmHg, between the two interventions.
Hypothesis: Conservative O2 will be associated with more unstable and obstructed breathing and less time spent with TcPCO2 > 45 mmHg, compared with Liberal O2 supplementation, during recovery from anesthesia.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- With the patients' admission to the post-anesthesia care unit and after a 20-minute-long stabilization period, two 40-minute-long treatment sessions will be applied to the study patients. In the first 6 patients Conservative O2 treatment will be applied first, whereas in the rest (patients 7-10) the order of the interventions will be reversed. The order of the interventions will not be revealed to the participants before completing the study. In the Conservative O2 treatment session, O2 supplementation will be titrated to an SpO2 between 90% and 94%, while in the Liberal O2, O2 administration will be titrated to an SpO2 > 96%.
| Arm | Type | Receives |
|---|---|---|
| "Conservative O2" | Active comparator | Other: Oxygen gasDuring the first treatment session, which will last for 40 minutes, O2 supplementation will be titrated to an SpO2 between 90% and 94%. |
| "Liberal O2" | Experimental | Other: Oxygen gasDuring the second treatment session, which will last for 40 minutes, O2 supplementation will be titrated to an SpO2 > 96%. |
Who may qualify
- Ages
- 20 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- American Society of Anesthesiologists (ASA) physical status I-III
- Body mass index (BMI) less than 35 kg/m2
- Scheduled to undergo robotic-assisted radical laparoscopic nephrectomy.
Key exclusion criteria (3 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Oxygen gasAdministration of Oxygen by inhalation | Other | "Conservative O2", "Liberal O2" |
Primary outcome
Respiratory disturbance index (RDI)
Time frame: Forty minutes of monitoring for each treatment arm
The number of apnea/hypopnea episodes detected using respiratory inductance plethysmography and nasal flow.
Transcutaneous carbon dioxide pressure (TcPCO2)
Time frame: Forty minutes of monitoring for each treatment arm
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)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2024.
- Derived from this study: PubMed 41175776Kutscher S, Finnsson E, Tian L, Panousis P, Chung BI, Doufas AG. The effect of hyperoxia on disordered breathing during recovery from general anesthesia: A single-blinded, crossover, non-randomized -controlled, trial. J Clin Anesth. 2026 Jan;108:112057. doi: 10.1016/j.jclinane.2025.112057. Epub 2025 Oct 31.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anthony Doufas, MD, PhD principal investigator
Professor, Department of Anesthesiology, Stanford University Medical School
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Oxygen gas in people with Ventilatory Depression and Postoperative Respiratory Failure, run by Stanford University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Mar 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Respiratory disturbance index (RDI) (time frame: Forty minutes of monitoring for each treatment arm). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05922020, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2024.