AnesthesiaPhase 4NCT00321191
Measurement of the Second Gas Effect on Sevoflurane in Anaesthetised Patients
A Phase 4 study testing No nitrous oxide and Administration of N2O in people with Anesthesia, run by Austin Health at 1 site in Australia.
Trial summary
This study is investigating the "second gas effect", a phenomenon produced by the uptake of nitrous oxide (N2O) by the lungs, during the course of a typical anaesthetic. The effect is to increase the concentration of other breathed gases in the lung. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anesthesia
- What is being tested?
- No nitrous oxide and Administration of N2O
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 14 participants
- Where
- 1 siteAustralia
- Study dates
- May 2006to Sep 2006
- Phase
- Phase 4
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients scheduled for elective surgery requiring relaxant general anaesthesia with arterial blood pressure monitoring via an arterial line.
Who cannot join
- Patients with moderately or severely impaired respiratory disease (FEV1 < 1.5L, or FVC < 2.0L).
- Patients under 18 years of age.
- Morbidly obese patients: BMI > 30
- Patients unable to give informed consent.
Trial locations and contacts
1 site in 1 country.
About this study
This study is investigating the "second gas effect", a phenomenon produced by the uptake of nitrous oxide (N2O) by the lungs, during the course of a typical anaesthetic. The effect is to increase the concentration of other breathed gases in the lung. These include oxygen and volatile anaesthetic agents such as sevoflurane, which are also normally administered along with N2O. We wish to i) measure the magnitude of the second gas effects on both blood and expired concentrations of sevoflurane (Part 1), and ii) see if a demonstrable difference exists between the effects on blood and expired concentrations.
Read the detailed description
This study is investigating the "second gas effect", a phenomenon produced by the uptake of nitrous oxide (N2O) by the lungs, during the course of a typical anaesthetic. The effect is to increase the concentration of other breathed gases in the lung. These include oxygen and volatile anaesthetic agents such as sevoflurane, which are also normally administered along with N2O.
While the second gas effect has been demonstrated previously, by measuring the concentration of volatile anaesthetic in the expired breath, no study has yet shown that it has a significant effect on the concentrations in the blood. The blood concentration is in fact more important, as it directly determines the concentration of anaesthetic reaching the brain, and therefore the effect on the depth of anaesthesia. The second gas effect on blood concentrations may be more powerful than that on expired concentrations, due to the detrimental effect of anaesthesia on the evenness of distribution of ventilation and blood flow in the lung.
The proposed study will have two parallel components or Parts. We wish to i) measure the magnitude of the second gas effects on both blood and expired concentrations of sevoflurane (Part 1), and ii) see if a demonstrable difference exists between the effects on blood and expired concentrations.
- Conditions
- Anesthesia
- Being tested
- No nitrous oxide, Administration of N2O
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No nitrous oxideDrug
Administration of N2ODrug
| Study group | Role | What they receive |
|---|---|---|
| N2O | Experimental | Not described Receives: Drug: Administration of N2O |
| No N2O | Placebo comparator | Not described Receives: Drug: No nitrous oxide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fa/FI sevoflurane in 100% O2 vs in 70% N2O and 30% O2 during 1st 60 min anaesthesia
Change in Fa/FI sevoflurane in 100% O2 vs in 70% N2O and 30% O2 after 60 minutes anaesthesia
Secondary outcomes (1)
Fa/FI and FA/FI for N2O will also be recorded.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 May 2006 (estimated)
- Study startMay 2006
- Study completionSep 2006
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnesthesiaStudies 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 4
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 14 participants (actual)
Sponsor and investigators
- Lead sponsor
- Austin Health
- Sponsor type
- Other government
- Investigators
- Philip J Peyton, MD FANZCA, Principal investigator, Austin Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00321191
- Sponsor's protocol ID
- 02531
- Status last verified
- Aug 2008
- First submitted
- 2 May 2006
- Last updated
- 24 Jun 2015
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Jun 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measurement of the Second Gas Effect on Sevoflurane in Anaesthetised Patients
- ClinicalTrials.gov ID
- NCT00321191
- Acronym / sponsor ID
- 02531
- Conditions
- Anesthesia
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 14 participants (actual)
- Lead sponsor
- Austin HealthOther government
- Study start
- May 2006
- Study completion
- Sep 2006 (actual)
- First posted
- 3 May 2006 (estimated)
- 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.
This study is investigating the "second gas effect", a phenomenon produced by the uptake of nitrous oxide (N2O) by the lungs, during the course of a typical anaesthetic. The effect is to increase the concentration of other breathed gases in the lung. These include oxygen and volatile anaesthetic agents such as sevoflurane, which are also normally administered along with N2O. We wish to i) measure the magnitude of the second gas effects on both blood and expired concentrations of sevoflurane (Part 1), and ii) see if a demonstrable difference exists between the effects on blood and expired concentrations.
Detailed description
This study is investigating the "second gas effect", a phenomenon produced by the uptake of nitrous oxide (N2O) by the lungs, during the course of a typical anaesthetic. The effect is to increase the concentration of other breathed gases in the lung. These include oxygen and volatile anaesthetic agents such as sevoflurane, which are also normally administered along with N2O.
While the second gas effect has been demonstrated previously, by measuring the concentration of volatile anaesthetic in the expired breath, no study has yet shown that it has a significant effect on the concentrations in the blood. The blood concentration is in fact more important, as it directly determines the concentration of anaesthetic reaching the brain, and therefore the effect on the depth of anaesthesia. The second gas effect on blood concentrations may be more powerful than that on expired concentrations, due to the detrimental effect of anaesthesia on the evenness of distribution of ventilation and blood flow in the lung.
The proposed study will have two parallel components or Parts. We wish to i) measure the magnitude of the second gas effects on both blood and expired concentrations of sevoflurane (Part 1), and ii) see if a demonstrable difference exists between the effects on blood and expired concentrations.
Study design
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| N2O | Experimental | Drug: Administration of N2O |
| No N2O | Placebo comparator | Drug: No nitrous oxide |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Patients scheduled for elective surgery requiring relaxant general anaesthesia with arterial blood pressure monitoring via an arterial line.
Key exclusion criteria (4 listed)
- Patients with moderately or severely impaired respiratory disease (FEV1 < 1.5L, or FVC < 2.0L).
- Patients under 18 years of age.
- Morbidly obese patients: BMI > 30
- Patients unable to give informed consent.
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 |
|---|---|---|
| No nitrous oxide | Drug | No N2O |
| Administration of N2O | Drug | N2O |
Primary outcome
Fa/FI sevoflurane in 100% O2 vs in 70% N2O and 30% O2 during 1st 60 min anaesthesia
Change in Fa/FI sevoflurane in 100% O2 vs in 70% N2O and 30% O2 after 60 minutes anaesthesia
1 secondary outcome
Fa/FI and FA/FI for N2O will also be recorded.
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 24 Jun 2015.
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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.
Philip J Peyton, MD FANZCA principal investigator
Austin Health
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing No nitrous oxide and Administration of N2O in people with Anesthesia, run by Austin Health at 1 site in Australia.
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 1 inclusion and 4 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 24 Jun 2015. 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 Australia. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
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?
Fa/FI sevoflurane in 100% O2 vs in 70% N2O and 30% O2 during 1st 60 min anaesthesia. 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?
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 24 Jun 2015.