ObesityNCT04627883
Effect of Inverse Ratio Ventilation During Induction of General Anesthesia on Safe Apnea Time in Obese Patients
A study testing Inspiratory-to-expiratory (I : E) ratio of 1:2 and Inspiratory-to-expiratory (I : E) ratio of 2:1 in people with Obesity, run by General Hospital of Ningxia Medical University at 2 sites in China.
Trial summary
The purpose of this study is to investigate the clinical application value of inverse ratio ventilation in obese patients during induction of general anesthesia by studying the effect of inverse ratio ventilation on the safe apnea time. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Obesity
- What is being tested?
- Inspiratory-to-expiratory (I : E) ratio of 1:2 and Inspiratory-to-expiratory (I : E) ratio of 2:1
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 2 sitesChina
- Study dates
- 17 Aug 2020to 1 Jan 2022
- 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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Obese patients, aged 18-65 years, of either gender, ASA grade II-III, body mass index (BMI) > 30 kg / m2, scheduled for general anesthesia under tracheal intubation, signed informed consent.
Who cannot join
- Patients who need rapid sequence induction (RSI); patients with expected difficult airway; severe chronic respiratory diseases, such as tuberculosis, bronchitis, bronchial asthma and COPD; patients with severe cardiovascular diseases, such as severe ischemic heart disease and pulmonary hypertension; patients with severe cerebrovascular diseases, such as cerebral hemorrhage and cerebral infarction; patients with abnormal basal metabolic rate, such as pregnancy, thyrotoxicosis, pheochromocytoma; and severe stomach reflux disease; patients with abnormal hemoglobin and hematocrit.
Trial locations and contacts
2 sites in 1 country.
China2 sites
General Hospital of Ningxia Medical University
General Hospital of Ningxia Medical University, Ningxia, 750004
General Hospital of Ningxia Medical University
Yinchuan, Ningxia, 750004
About this study
Official title: Effect of Inverse Ratio Ventilation During Induction of General Anesthesia on Safe Apnea Time in Obese Patients:A Randomized Controlled Trial
The purpose of this study is to investigate the clinical application value of inverse ratio ventilation in obese patients during induction of general anesthesia by studying the effect of inverse ratio ventilation on the safe apnea time.
Read the detailed description
Inverse ratio ventilation(IRV) can produce mean airway pressure(Pmean)similar to external positive end expiratory pressure(Peep) by increasing inspiratory time. Moreover, the increase of Pmean was not accompanied by the further increase of peak airway pressure (Ppeak) and airway plateau pressure (Pplat), while the application of external peep accompanied with the increase of Pplat increased the risk of barotrauma . High level of Peep increased cardiac load and decreased cardiac output. A number of studies have found that the hemodynamic stability of patients can be achieved when IRV regulates the inspiratory / expiratory ratio in an appropriate range (I: E < 2:1). Therefore, the inverse ratio is considered to be superior to Peep in terms of gas exchange and respiratory mechanics.
- Conditions
- Obesity
- Being tested
- Inspiratory-to-expiratory (I : E) ratio of 1:2, Inspiratory-to-expiratory (I : E) ratio of 2:1
- Keywords
- inverse ratio ventilation, safe apnea time
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Inspiratory-to-expiratory (I : E) ratio of 1:2Other
After preoxygenation and induction of anesthesia, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 1:2 for 5 min before endotracheal intubation.
Inspiratory-to-expiratory (I : E) ratio of 2:1Other
After preoxygenation and induction of anesthesian, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 2:1 for 5 min before endotracheal intubation.
| Study group | Role | What they receive |
|---|---|---|
| Group 1:2 | Other | Patients in the control group had noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 1:2. Receives: Other: Inspiratory-to-expiratory (I : E) ratio of 1:2 |
| Group 2:1 | Other | Patients in the IRV group had noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 2:1. Receives: Other: Inspiratory-to-expiratory (I : E) ratio of 2:1 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safe Apnea Time
The safe apnea time was defined as that period of time during which the arterial saturation as measured by pulse oximetry remained at or above 93% .
Measured: The arterial saturation as measured by pulse oximetry remained at or above 93% after endotracheal intubation immediately.
Secondary outcomes (3)
EtO2
Fractional concentration of oxygen in end-tidal gas
Measured: After 3 minutes of preoxygenation After 5 minutes of noninvasive positive pressure ventilation
EtO2
Fractional concentration of oxygen in end-tidal gas
Measured: After 3 minutes of noninvasive positive pressure ventilation
EtO2
Fractional concentration of oxygen in end-tidal gas
Measured: After 5 minutes of noninvasive positive pressure ventilation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Nov 2020
- Study start17 Aug 2020
- Primary completion1 Jan 2022
- Study completion1 Jan 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies 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 N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel Assignment
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- General Hospital of Ningxia Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04627883
- Sponsor's protocol ID
- 2020-718
- Status last verified
- Oct 2020
- First submitted
- 11 Oct 2020
- Last updated
- 17 Feb 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Inverse Ratio Ventilation During Induction of General Anesthesia on Safe Apnea Time in Obese Patients:A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT04627883
- Acronym / sponsor ID
- 2020-718
- Conditions
- Obesity
- Keywords
- inverse ratio ventilation, safe apnea time
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- General Hospital of Ningxia Medical UniversityUniversity, hospital or other
- Study start
- 17 Aug 2020 (actual)
- Primary completion
- 1 Jan 2022 (actual)
- Study completion
- 1 Jan 2022 (actual)
- First posted
- 13 Nov 2020 (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.
The purpose of this study is to investigate the clinical application value of inverse ratio ventilation in obese patients during induction of general anesthesia by studying the effect of inverse ratio ventilation on the safe apnea time.
Detailed description
Inverse ratio ventilation(IRV) can produce mean airway pressure(Pmean)similar to external positive end expiratory pressure(Peep) by increasing inspiratory time. Moreover, the increase of Pmean was not accompanied by the further increase of peak airway pressure (Ppeak) and airway plateau pressure (Pplat), while the application of external peep accompanied with the increase of Pplat increased the risk of barotrauma . High level of Peep increased cardiac load and decreased cardiac output. A number of studies have found that the hemodynamic stability of patients can be achieved when IRV regulates the inspiratory / expiratory ratio in an appropriate range (I: E < 2:1). Therefore, the inverse ratio is considered to be superior to Peep in terms of gas exchange and respiratory mechanics.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Parallel Assignment
| Arm | Type | Receives |
|---|---|---|
| Group 1:2 | Other | Other: Inspiratory-to-expiratory (I : E) ratio of 1:2Patients in the control group had noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 1:2. |
| Group 2:1 | Other | Other: Inspiratory-to-expiratory (I : E) ratio of 2:1Patients in the IRV group had noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 2:1. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Obese patients, aged 18-65 years, of either gender, ASA grade II-III, body mass index (BMI) > 30 kg / m2, scheduled for general anesthesia under tracheal intubation, signed informed consent.
Key exclusion criteria (1 listed)
- Patients who need rapid sequence induction (RSI); patients with expected difficult airway; severe chronic respiratory diseases, such as tuberculosis, bronchitis, bronchial asthma and COPD; patients with severe cardiovascular diseases, such as severe ischemic heart disease and pulmonary hypertension; patients with severe cerebrovascular diseases, such as cerebral hemorrhage and cerebral infarction; patients with abnormal basal metabolic rate, such as pregnancy, thyrotoxicosis, pheochromocytoma; and severe stomach reflux disease; patients with abnormal hemoglobin and hematocrit.
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 |
|---|---|---|
| Inspiratory-to-expiratory (I : E) ratio of 1:2After preoxygenation and induction of anesthesia, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 1:2 for 5 min before endotracheal intubation. | Other | Group 1:2 |
| Inspiratory-to-expiratory (I : E) ratio of 2:1After preoxygenation and induction of anesthesian, noninvasive positive pressure ventilation with inspiratory-to-expiratory (I : E) ratio of 2:1 for 5 min before endotracheal intubation. | Other | Group 2:1 |
Primary outcome
Safe Apnea Time
Time frame: The arterial saturation as measured by pulse oximetry remained at or above 93% after endotracheal intubation immediately.
The safe apnea time was defined as that period of time during which the arterial saturation as measured by pulse oximetry remained at or above 93% .
3 secondary outcomes
EtO2
Time frame: After 3 minutes of preoxygenation After 5 minutes of noninvasive positive pressure ventilation
EtO2
Time frame: After 3 minutes of noninvasive positive pressure ventilation
EtO2
Time frame: After 5 minutes of noninvasive positive pressure ventilation
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 17 Feb 2025.
- 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.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Inspiratory-to-expiratory (I : E) ratio of 1:2 and Inspiratory-to-expiratory (I : E) ratio of 2:1 in people with Obesity, run by General Hospital of Ningxia Medical University at 2 sites in China.
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 1 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 17 Feb 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in China. 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?
Safe Apnea Time (time frame: The arterial saturation as measured by pulse oximetry remained at or above 93% after endotracheal intubation immediately.). 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 17 Feb 2025.