Hypoxia, BrainPhase 2NCT03338907
CO2 (Carbon Dioxide) - Cerebral Oxygenation
A Phase 2 study testing Oxycarbon (5% CO2+ 95% O2) in people with Hypoxia, Brain, run by University of Zurich at 1 site in Switzerland.
Trial summary
Several projects in high altitude research in environments with a low oxygen partial pressure (hypobaric hypoxia) leading to hypoxemia showed, that cerebral perfusion and cerebral performance could be improved by adding C02 (cabon dioxide). Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Hypoxia, Brain
- What is being tested?
- Oxycarbon (5% CO2+ 95% O2)
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteSwitzerland
- Study dates
- 25 Jan 2018to 12 Feb 2019
- Phase
- Phase 2
- 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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients who are designated for bariatric surgery at the University Hospital Zurich (USZ)
- Informed Consent as documented by signature
- BMI >35 kg/m2
Who cannot join
- Severe end-organ damage: chronic obstuctive pulmonary disease (COPD) GOLD (cassification) III and IV, known hepatic insufficiency or elevated liver enzymes, renal creatinine clearance <30ml/min
- Severe cardiovascular disease (NYHA classification III and IV)
- Known pulmonary Hypertension
- Cerebrovascular disease
- Pregnancy and lactation
- Cardiac dysrhythmias
- acidosis, chronic pulmonary disease
- Known or suspected non-compliance, drug or alcohol abuse
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Anesthesia vs Aviation: Does Added Carbon Dioxide in Normobaric Hypoxia Have the Same Effect on Cerebral Oxygenation as in Hypobaric Hypoxia?
Several projects in high altitude research in environments with a low oxygen partial pressure (hypobaric hypoxia) leading to hypoxemia showed, that cerebral perfusion and cerebral performance could be improved by adding C02 (cabon dioxide).
The investigators hypothesize that adding 5% C02 to 02 (Oxygen) also under normobaric conditions increases the time until a significant cerebral hyopxia is measured by near infrared spectroscopy (NIRS) compared to the administration of 95% 02.
lf this hypothesis proves to be true, this approach might be used in situations in which individuals are prone to cerebral hypoxia. In bariatric surgery, patients that experience an apnea phase are more prone to (cerebral) hypoxia due to the fact, that they have a higher body mass index (BMI) leading to a reduced functional residual capacity (FRC), which serves as the oxygen reserve in the body.
Read the detailed description
On the day of surgery patients will be randomized. After induction of anesthesia and endotracheal intubation patients will be managed by the study team to perform the intervention and the measurements.
According to randomization, investigational medical product (IMP) or comparator will be administrated by ventilator 1/ventilator 2.
At time point 1 apnea will be performed by disconnecting the ventilator from the endotracheal tube until the NIRS value has dropped by 20% from baseline. After that, re-ventilation will be resumed immediately, until parameters have returned to baseline.
During apnea time NIRS and vital signs will be recorded permanently, blood samples will be drawn at definite time points.
Application of IMP (or comparator) will be performed in this cross-over study design in the same manner after the baseline level is reached again.
At the end of the study procedure, after the baseline level of end-expiratory CO2 is reached again, patient will be taken over by the clinical anesthesia team and surgeons.
- Conditions
- Hypoxia, Brain
- Being tested
- Oxycarbon (5% CO2+ 95% O2)
- Keywords
- cerebral hypoxia, CO2, cerebral perfusion, hypoxia
- Medical subject headings
- Hypoxia, Brain, Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Oxycarbon (5% CO2+ 95% O2)Drug
Oxycarbon will be administered by mechanical ventilation
| Study group | Role | What they receive |
|---|---|---|
| Oxycarbon (5% CO2 + 95% O2) | Experimental | Patients will be mechanical ventilated with Oxycarbon (5%CO2 +95% O2) after normocapnia is reached until FeO2 is stable for at least 1 min ≥ 80%. At timepoint 1 immediately prior apnea NIRS and vital parameters will be registered and an bloodsample will be drawn. Receives: Drug: Oxycarbon (5% CO2+ 95% O2) |
| Control (95% O2) | Placebo comparator | Same procedure as arm "active comparator" Receives: Drug: Oxycarbon (5% CO2+ 95% O2) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time to decrease of tissue oxygenation index by 20 %
Parameter will be measured by NIRS
Measured: 1 Day
Secondary outcomes (3)
PaO2 (Oxygen partial pressure)
Parametere will be measured by arterial bloodgas
Measured: 1 Day
SpO2 (oxygen saturation)
Parametere will be measured by arterial bloodgas
Measured: 1 Day
PCO2 ( partial pressure of carbon)
Parametere will be measured by arterial bloodgas
Measured: 1Day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Nov 2017
- Study start25 Jan 2018
- Primary completion26 Oct 2018
- Study completion12 Feb 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Hypoxia, BrainStudies of the same condition, open and under way.
- 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Controlled, randomized, single blind, crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Zurich
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Martin Schläpfer, MD, M.Sc., Principal investigator, University of Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03338907
- Sponsor's protocol ID
- 2017-01790
- Other IDs
- 2017
- Status last verified
- Feb 2019
- First submitted
- 30 Oct 2017
- Last updated
- 20 Feb 2019
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Ist not planned to share data with other researchers
Publications
Kety SS, Schmidt CF. THE EFFECTS OF ALTERED ARTERIAL TENSIONS OF CARBON DIOXIDE AND OXYGEN ON CEREBRAL BLOOD FLOW AND CEREBRAL OXYGEN CONSUMPTION OF NORMAL YOUNG MEN. J Clin Invest. 1948 Jul;27(4):484-92. doi: 10.1172/JCI101995. No abstract available.
PubMed 16695569Karl AA, McMillan GR, Ward SL, Kissen AT, Souder ME. Effects of increased ambient CO2 on brain tissue oxygenation and performance in the hypoxic rhesus. Aviat Space Environ Med. 1978 Aug;49(8):984-9.
PubMed 98161Brzecka A. Role of hypercapnia in brain oxygenation in sleep-disordered breathing. Acta Neurobiol Exp (Wars). 2007;67(2):197-206. doi: 10.55782/ane-2007-1648.
PubMed 17691228Kronenberg RS, Drage CW. Attenuation of the ventilatory and heart rate responses to hypoxia and hypercapnia with aging in normal men. J Clin Invest. 1973 Aug;52(8):1812-9. doi: 10.1172/JCI107363.
PubMed 4719663Hannay DR, Maddox EJ. Symptom prevalence and referral behaviour in Glasgow. Soc Sci Med (1967). 1976 Mar-Apr;10(3-4):185-9. doi: 10.1016/0037-7856(76)90046-9. No abstract available.
PubMed 968505Ainslie PN, Poulin MJ. Ventilatory, cerebrovascular, and cardiovascular interactions in acute hypoxia: regulation by carbon dioxide. J Appl Physiol (1985). 2004 Jul;97(1):149-59. doi: 10.1152/japplphysiol.01385.2003. Epub 2004 Mar 5.
PubMed 15004003
Study at a glance
From the registry record, last updated by the sponsor on 20 Feb 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Anesthesia vs Aviation: Does Added Carbon Dioxide in Normobaric Hypoxia Have the Same Effect on Cerebral Oxygenation as in Hypobaric Hypoxia?
- ClinicalTrials.gov ID
- NCT03338907
- Acronym / sponsor ID
- 2017-01790
- Conditions
- Hypoxia, Brain
- Keywords
- cerebral hypoxia, CO2, cerebral perfusion, hypoxia
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- University of ZurichUniversity, hospital or other
- Study start
- 25 Jan 2018 (actual)
- Primary completion
- 26 Oct 2018 (actual)
- Study completion
- 12 Feb 2019 (actual)
- First posted
- 9 Nov 2017 (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.
Several projects in high altitude research in environments with a low oxygen partial pressure (hypobaric hypoxia) leading to hypoxemia showed, that cerebral perfusion and cerebral performance could be improved by adding C02 (cabon dioxide).
The investigators hypothesize that adding 5% C02 to 02 (Oxygen) also under normobaric conditions increases the time until a significant cerebral hyopxia is measured by near infrared spectroscopy (NIRS) compared to the administration of 95% 02.
lf this hypothesis proves to be true, this approach might be used in situations in which individuals are prone to cerebral hypoxia. In bariatric surgery, patients that experience an apnea phase are more prone to (cerebral) hypoxia due to the fact, that they have a higher body mass index (BMI) leading to a reduced functional residual capacity (FRC), which serves as the oxygen reserve in the body.
Detailed description
On the day of surgery patients will be randomized. After induction of anesthesia and endotracheal intubation patients will be managed by the study team to perform the intervention and the measurements.
According to randomization, investigational medical product (IMP) or comparator will be administrated by ventilator 1/ventilator 2.
At time point 1 apnea will be performed by disconnecting the ventilator from the endotracheal tube until the NIRS value has dropped by 20% from baseline. After that, re-ventilation will be resumed immediately, until parameters have returned to baseline.
During apnea time NIRS and vital signs will be recorded permanently, blood samples will be drawn at definite time points.
Application of IMP (or comparator) will be performed in this cross-over study design in the same manner after the baseline level is reached again.
At the end of the study procedure, after the baseline level of end-expiratory CO2 is reached again, patient will be taken over by the clinical anesthesia team and surgeons.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Controlled, randomized, single blind, crossover
| Arm | Type | Receives |
|---|---|---|
| Oxycarbon (5% CO2 + 95% O2) | Experimental | Drug: Oxycarbon (5% CO2+ 95% O2)Patients will be mechanical ventilated with Oxycarbon (5%CO2 +95% O2) after normocapnia is reached until FeO2 is stable for at least 1 min ≥ 80%. At timepoint 1 immediately prior apnea NIRS and vital parameters will be registered and an bloodsample will be drawn. |
| Control (95% O2) | Placebo comparator | Drug: Oxycarbon (5% CO2+ 95% O2)Same procedure as arm "active comparator" |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Patients who are designated for bariatric surgery at the University Hospital Zurich (USZ)
- Informed Consent as documented by signature
- BMI >35 kg/m2
Key exclusion criteria (8 listed)
- Severe end-organ damage: chronic obstuctive pulmonary disease (COPD) GOLD (cassification) III and IV, known hepatic insufficiency or elevated liver enzymes, renal creatinine clearance <30ml/min
- Severe cardiovascular disease (NYHA classification III and IV)
- Known pulmonary Hypertension
- Cerebrovascular disease
- Pregnancy and lactation
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 |
|---|---|---|
| Oxycarbon (5% CO2+ 95% O2)Oxycarbon will be administered by mechanical ventilation | Drug | Control (95% O2), Oxycarbon (5% CO2 + 95% O2) |
Primary outcome
Time to decrease of tissue oxygenation index by 20 %
Time frame: 1 Day
Parameter will be measured by NIRS
3 secondary outcomes
PaO2 (Oxygen partial pressure)
Time frame: 1 Day
SpO2 (oxygen saturation)
Time frame: 1 Day
PCO2 ( partial pressure of carbon)
Time frame: 1Day
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 20 Feb 2019.
- Background: PubMed 16695569Kety SS, Schmidt CF. THE EFFECTS OF ALTERED ARTERIAL TENSIONS OF CARBON DIOXIDE AND OXYGEN ON CEREBRAL BLOOD FLOW AND CEREBRAL OXYGEN CONSUMPTION OF NORMAL YOUNG MEN. J Clin Invest. 1948 Jul;27(4):484-92. doi: 10.1172/JCI101995. No abstract available.
- Background: PubMed 98161Karl AA, McMillan GR, Ward SL, Kissen AT, Souder ME. Effects of increased ambient CO2 on brain tissue oxygenation and performance in the hypoxic rhesus. Aviat Space Environ Med. 1978 Aug;49(8):984-9.
- Background: PubMed 17691228Brzecka A. Role of hypercapnia in brain oxygenation in sleep-disordered breathing. Acta Neurobiol Exp (Wars). 2007;67(2):197-206. doi: 10.55782/ane-2007-1648.
- Background: PubMed 4719663Kronenberg RS, Drage CW. Attenuation of the ventilatory and heart rate responses to hypoxia and hypercapnia with aging in normal men. J Clin Invest. 1973 Aug;52(8):1812-9. doi: 10.1172/JCI107363.
- Background: PubMed 968505Hannay DR, Maddox EJ. Symptom prevalence and referral behaviour in Glasgow. Soc Sci Med (1967). 1976 Mar-Apr;10(3-4):185-9. doi: 10.1016/0037-7856(76)90046-9. No abstract available.
- Background: PubMed 15004003Ainslie PN, Poulin MJ. Ventilatory, cerebrovascular, and cardiovascular interactions in acute hypoxia: regulation by carbon dioxide. J Appl Physiol (1985). 2004 Jul;97(1):149-59. doi: 10.1152/japplphysiol.01385.2003. Epub 2004 Mar 5.
- Individual participant dataSharing planned: No. Ist not planned to share data with other researchers
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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.
Martin Schläpfer, MD, M.Sc. principal investigator
University of Zurich
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Oxycarbon (5% CO2+ 95% O2) in people with Hypoxia, Brain, run by University of Zurich at 1 site in Switzerland.
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 8 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 20 Feb 2019. 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 Switzerland. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
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?
Time to decrease of tissue oxygenation index by 20 % (time frame: 1 Day). 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 NCT03338907, which also lists 6 linked publications.
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 20 Feb 2019; AzTrials last refreshed its copy on 29 Oct 2026.