HypoxiaNCT02961920
The Effect of Prolonged Inspiratory Time on Pulmonary Mechanics in Obese Patients
A study testing IE ratio 1:1 and IE ratio 1:2 in people with Hypoxia, run by Gachon University Gil Medical Center at 1 site in South Korea.
Trial summary
The area of aesthesia-induced atelectasis is much larger in the obese compared with the non-obese, but there may also be more airway closure and impaired matching of ventilation and lung blood flow. Read more about this study
- Who is it for?
- Ages 20 to 65 years
- Conditions the study is for
- Hypoxia
- What is being tested?
- IE ratio 1:1 and IE ratio 1:2
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteSouth Korea
- Study dates
- Nov 2016to May 2019
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ASA I-II adult patients scheduled for spine surgery under general anesthesia.
- patient age : greater than 20 years and less than 65years
- Body Mass Index(BMI) >25 kg/m2
Who cannot join
- Patients who have severe pulmonary disease:
- history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, history of cardiopulmonary disease, or previous lung surgery are excluded.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Influence of Prolonged Inspiratory Time on Respiratory Mechanics and Oxygenation in Obese Patients Undergoing Spine Surgery in the Prone Position
The area of aesthesia-induced atelectasis is much larger in the obese compared with the non-obese, but there may also be more airway closure and impaired matching of ventilation and lung blood flow.
When an anesthetized patient is turned to the prone position, dynamic compliance (Cdyn) decreases and peak airway pressure increases unless the abdomen hangs freely to prevent the abdominal viscera from compromising the diaphragm movement. Although the Wilson frame is designed to allow the abdomen to hang, it partially compresses the anterior abdominal wall and therefore does not allow the abdomen to hang completely, especially in obese patients.
Read more
This in turn increases peak airway pressure and decreases Cdyn, oxygenation. This study aimed to investigate the effects of a prolonged I:E ratio (i.e., 1:1) compared with the conventional I:E ratio of 1:2 on respiratory mechanics and hemodynamics during spine surgery in the prone position in obese patients.
We hypothesized that, compared with an I:E ratio of 1:2, a ratio of 1:1 improve oxygenation without hemodynamic instability .
Read the detailed description
After written informed consent was obtained from all patients, 50 adult patients were enrolled in the study.
The patients met the following inclusion criteria: (1) body mass index (BMI, weight in kilograms divided by the square of height in metres) > 25 kg/m2; (2) American Society of Anesthesiology (ASA) physical status classification grade I or II (BMI by itself was not used as the basis for the ASA classification); (3) aged 20 - 65 years; and (4) scheduled for elective spine surgery in prone position.
Exclusion Criteria:
- Patients who have severe pulmonary disease: history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, The enrolled patients were randomly allocated according to a predetermined allocation sequence to receive an I:E ratio of either 1:1 (group 1:1) or 1:2 (group 1:2).
The allocation sequence with no blocking was generated in an Internet website Standard monitoring techniques, including electrocardiography, pulse oximetry, and noninvasive arterial blood pressure measurement, are applied upon arrival at the operating room.
Anesthesia was induced with intravenous propofol 1.5 mg_kg-1 and rocuronium 0.8 mg_kg-1 was administered intravenously.
After tracheal intubation, volume-controlled ventilation was initiated with an I:E ratio of 1:2 or 1:1, no positive end-expiratory pressure, and a tidal volume of 10 mL per ideal body weight (kg). A respiratory rate was adjusted in order to end-tidal carbon dioxide (EtCO2) of 33 - 36 mmHg during surgery. Anesthesia was maintained with an end-tidal concentration of 2-2.5 vol% sevoflurane in 40% oxygen/air. The bispectral index score was monitored continuously in order to maintain an adequate anesthetic depth and was targeted at a range of 40-60 during surgery.
Radial artery cannulation was conducted for monitoring continuous arterial blood pressure and blood sampling.
Respiratory, hemodynamic, and arterial blood gas data were assessed and recorded at three time points: ten minutes after tracheal intubation in the supine position (T1), 30 min after prone positioning (T2), 90 min after prone positioning(T3). Respiratory data consisted of peak airway pressure, plateau airway pressure, mean airway pressure, static compliance, EtCO2, respiratory rate, and minute volume. Arterial pH, arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), and lactate level were obtained from arterial blood gas analysis.
- Conditions
- Hypoxia
- Being tested
- IE ratio 1:1, IE ratio 1:2
- Medical subject headings
- Hypoxia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IE ratio 1:1Device
Also called one and one
Set an I:E ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients.
IE ratio 1:2Device
Also called one and two
Set an I:E ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients.
| Study group | Role | What they receive |
|---|---|---|
| IE ratio 1:1 | Experimental | Set an I(inspiration):E(expiration) ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients. Receives: Device: IE ratio 1:1 |
| IE ratio 1:2 | Active comparator | Set an I(inspiration):E(expiration) ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients. Receives: Device: IE ratio 1:2 |
What is being measured
The primary outcome is the main question the study is designed to answer.
PaO2(Partial Pressure of Oxygen in Arterial Blood)
ten minutes after tracheal intubation to 90 min after prone position
Measured: ten minutes after tracheal intubation to 90 min after prone position
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Nov 2016 (estimated)
- Study startNov 2016
- Primary completionApr 2019
- Study completionMay 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for HypoxiaStudies 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
- Masking
- None (open label)
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Gachon University Gil Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jung Ju Choi, Gachon University Gil Medical Center
- Investigators
- Kyung Cheon Lee, MD, Study chair, Gachon University Gil Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02961920
- Sponsor's protocol ID
- PrIspSp
- Status last verified
- Oct 2019
- First submitted
- 9 Nov 2016
- Last updated
- 5 Nov 2019
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Nov 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Influence of Prolonged Inspiratory Time on Respiratory Mechanics and Oxygenation in Obese Patients Undergoing Spine Surgery in the Prone Position
- ClinicalTrials.gov ID
- NCT02961920
- Acronym / sponsor ID
- PrIspSp
- Conditions
- Hypoxia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Gachon University Gil Medical CenterUniversity, hospital or other
- Study start
- Nov 2016 (actual)
- Primary completion
- Apr 2019 (actual)
- Study completion
- May 2019 (actual)
- First posted
- 11 Nov 2016 (estimated)
- Results
- Posted 7 Oct 2019
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The area of aesthesia-induced atelectasis is much larger in the obese compared with the non-obese, but there may also be more airway closure and impaired matching of ventilation and lung blood flow.
When an anesthetized patient is turned to the prone position, dynamic compliance (Cdyn) decreases and peak airway pressure increases unless the abdomen hangs freely to prevent the abdominal viscera from compromising the diaphragm movement. Although the Wilson frame is designed to allow the abdomen to hang, it partially compresses the anterior abdominal wall and therefore does not allow the abdomen to hang completely, especially in obese patients.
This in turn increases peak airway pressure and decreases Cdyn, oxygenation. This study aimed to investigate the effects of a prolonged I:E ratio (i.e., 1:1) compared with the conventional I:E ratio of 1:2 on respiratory mechanics and hemodynamics during spine surgery in the prone position in obese patients.
We hypothesized that, compared with an I:E ratio of 1:2, a ratio of 1:1 improve oxygenation without hemodynamic instability .
Detailed description
After written informed consent was obtained from all patients, 50 adult patients were enrolled in the study.
The patients met the following inclusion criteria: (1) body mass index (BMI, weight in kilograms divided by the square of height in metres) > 25 kg/m2; (2) American Society of Anesthesiology (ASA) physical status classification grade I or II (BMI by itself was not used as the basis for the ASA classification); (3) aged 20 - 65 years; and (4) scheduled for elective spine surgery in prone position.
Exclusion Criteria:
- Patients who have severe pulmonary disease: history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, The enrolled patients were randomly allocated according to a predetermined allocation sequence to receive an I:E ratio of either 1:1 (group 1:1) or 1:2 (group 1:2).
The allocation sequence with no blocking was generated in an Internet website Standard monitoring techniques, including electrocardiography, pulse oximetry, and noninvasive arterial blood pressure measurement, are applied upon arrival at the operating room.
Anesthesia was induced with intravenous propofol 1.5 mg_kg-1 and rocuronium 0.8 mg_kg-1 was administered intravenously.
After tracheal intubation, volume-controlled ventilation was initiated with an I:E ratio of 1:2 or 1:1, no positive end-expiratory pressure, and a tidal volume of 10 mL per ideal body weight (kg). A respiratory rate was adjusted in order to end-tidal carbon dioxide (EtCO2) of 33 - 36 mmHg during surgery. Anesthesia was maintained with an end-tidal concentration of 2-2.5 vol% sevoflurane in 40% oxygen/air. The bispectral index score was monitored continuously in order to maintain an adequate anesthetic depth and was targeted at a range of 40-60 during surgery.
Radial artery cannulation was conducted for monitoring continuous arterial blood pressure and blood sampling.
Respiratory, hemodynamic, and arterial blood gas data were assessed and recorded at three time points: ten minutes after tracheal intubation in the supine position (T1), 30 min after prone positioning (T2), 90 min after prone positioning(T3). Respiratory data consisted of peak airway pressure, plateau airway pressure, mean airway pressure, static compliance, EtCO2, respiratory rate, and minute volume. Arterial pH, arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), and lactate level were obtained from arterial blood gas analysis.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| IE ratio 1:1 | Experimental | Device: IE ratio 1:1Set an I(inspiration):E(expiration) ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients. |
| IE ratio 1:2 | Active comparator | Device: IE ratio 1:2Set an I(inspiration):E(expiration) ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients. |
Who may qualify
- Ages
- 20 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- ASA I-II adult patients scheduled for spine surgery under general anesthesia.
- patient age : greater than 20 years and less than 65years
- Body Mass Index(BMI) >25 kg/m2
Key exclusion criteria (2 listed)
- Patients who have severe pulmonary disease:
- history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, history of cardiopulmonary disease, or previous lung surgery are excluded.
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 |
|---|---|---|
| IE ratio 1:1Also: one and oneSet an I:E ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients. | Device | IE ratio 1:1 |
| IE ratio 1:2Also: one and twoSet an I:E ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients. | Device | IE ratio 1:2 |
Primary outcome
PaO2(Partial Pressure of Oxygen in Arterial Blood)
Time frame: ten minutes after tracheal intubation to 90 min after prone position
ten minutes after tracheal intubation to 90 min after prone position
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Nov 2019.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- 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.
Kyung Cheon Lee, MD study chair
Gachon University Gil Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing IE ratio 1:1 and IE ratio 1:2 in people with Hypoxia, run by Gachon University Gil Medical Center at 1 site in South Korea.
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 2 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 5 Nov 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 South Korea. 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?
Yes. Results are posted in the registry (first posted 7 Oct 2019). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
PaO2(Partial Pressure of Oxygen in Arterial Blood) (time frame: ten minutes after tracheal intubation to 90 min after prone position). 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 5 Nov 2019.