Bariatric Surgery CandidateNCT03975348
Ventilation Distribution After Bariatric Surgery
A study testing High flow nasal cannula, Continuous positive airway pressure and Facemask in people with Bariatric Surgery Candidate and Atelectasis, Postoperative Pulmonary, run by University of Trieste at 1 site in Italy.
Trial summary
Obese patients have an increased risk of developing post-operative respiratory complications due to their comorbidities. They have a restrictive ventilatory defect with reduction of lung volumes and expiratory flow limitation, higher airway resistance and collapsibility of the upper respiratory tract. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Bariatric Surgery Candidate, Atelectasis, Postoperative Pulmonary
- What is being tested?
- High flow nasal cannula, Continuous positive airway pressure and Facemask
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteItaly
- Study dates
- 15 Apr 2019to 30 Sep 2019
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patient's consent to the trial
- Candidate to laparoscopic bariatric surgery (sleeve gastrectomy or Roux-en-Y gastric bypass)
- BMI 35-50 kg/m2
- ASA class 1-3
Who cannot join
- Obesity hypoventilation syndrome
- Contraindication to EIT (e.g. implantable cardioverter-defibrillator)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Ventilation Distribution After Bariatric Surgery - High Flow Nasal Cannulas Versus Continuous Positive Airway Pressure
Obese patients have an increased risk of developing post-operative respiratory complications due to their comorbidities. They have a restrictive ventilatory defect with reduction of lung volumes and expiratory flow limitation, higher airway resistance and collapsibility of the upper respiratory tract. These abnormalities are worsened by general anesthesia and opioid administration. It has been proved that oxygen therapy with HFNC (high flow nasal cannula) increases lung volumes through a continuous positive airway pressure (CPAP)-effect. This also improves gas exchange and decreases anatomical dead space. At the present time, CPAP represents the gold standard for the prevention of postoperative pulmonary complications. The purpose of this study is to evaluate lung ventilation, gas exchange and comfort with HFNC compared with CPAP during the post-operative period in patients who undergo laparoscopic bariatric surgery.
Read the detailed description
Immediately after bariatric surgery, patients will follow a pre-determined schedule of oxygen therapy with conventional facemask (from the beginning to minute 10), HFNC (with a flow of 40 L/min from minute 11 to 20, 60 L/min from minute 21to 30, 80 L/min from minute 31 to 40, 100 L/min from minute 41 to 50, 80 L/min from minute 51 to 60, 60 L/min from minute 61 to 70, 40 L/min from minute 71 to 80), conventional facemask again (washout, from minute 81 to 90) and CPAP (10 cmH2O, from minute 91 to 100). Lung ventilation will be evaluated with electrical impedance tomography (EIT), which measures thoracic impedance variations related to changes in lung aeration. At the end of each 10 minutes-period the following data will be collected: electrical impedance tomography data (to calculate the global inhomogeneity index, Δ end-expiratory lung impedance and tidal impedance variation), hemodynamic parameters, respiratory rate, SpO2, pain (numerical rating scale), level of sedation (Ramsey score) and patient comfort (modified Borg scale). An arterial blood gas will be collected at the end of the following steps: baseline facemask, HFNC 40 and 100 L/min, washout facemask and CPAP. Data about anesthetic/analgesic drugs and ventilation parameters will also be collected.
- Being tested
- High flow nasal cannula, Continuous positive airway pressure, Facemask
- Keywords
- High flow nasal cannula, Bariatric surgery, Postoperative atelectasis, Electrical impedance tomography
- Medical subject headings
- Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High flow nasal cannulaDevice
High flow of warm and humidified oxygen/air mixture delivered through nasal cannula
Continuous positive airway pressureDevice
Positive airway pressure applied through a sealed face mask
FacemaskDevice
Oxygen therapy through a conventional facemask
| Study group | Role | What they receive |
|---|---|---|
| Baseline conventional facemask | Other | The patients will receive oxygen therapy through conventional facemask for 10 minutes Receives: Device: Facemask |
| HFNC 40 L/min up | Experimental | The patients will receive oxygen/air mixture through high flow nasal cannula at incremental, then decremental flows, starting at 40 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 60 L/min up | Experimental | High flow nasal cannula at 60 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 80 L/min up | Experimental | High flow nasal cannula at 80 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 100 L/min | Experimental | High flow nasal cannula at 100 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 80 L/min down | Experimental | High flow nasal cannula at 80 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 60 L/min down | Experimental | High flow nasal cannula at 60 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| HFNC 40 L/min down | Experimental | High flow nasal cannula at 40 L/min for 10 minutes Receives: Device: High flow nasal cannula |
| Washout conventional facemask | Other | Again, the patients will receive oxygen therapy through conventional facemask for 10 minutes, to reduce the influence of HFNC on CPAP therapy Receives: Device: Facemask |
| CPAP | Active comparator | The patients will receive CPAP at 10 cmH2O for 10 minutes Receives: Device: Continuous positive airway pressure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change of global inhomogeneity index
This parameter, calculated from data collected with EIT, evaluates lung ventilation distribution. To calculate this index, the median value of regional impedance changes from ventilated regions within the tidal image has to be computed, then the sum of differences between the median and every pixel value needs to be calculated, and the result must be normalised by the sum of impedance values within the lung area. The minimum value of the index is 0 and corresponds to homogeneous ventilation, whereas the maximum value is 1 and corresponds to inhomogeneous ventilation (in this context likely due to atelectasis).
Measured: The data needed to calculate the index will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Secondary outcomes (7)
Change of Δ end expiratory lung impedance (ΔEELI)
The parameter, measured with EIT, expresses deviations of the regional end-expiratory lung impedance in relation to the global tidal impedance variation. ΔEELI closely correlates with changes of end-expiratory lung volume of the EIT sensitivity region.
Measured: The data will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of tidal impedance variation
This parameter, measured with EIT, corresponds to the difference between end-expiratory and end-inspiratory lung impedance and is related to tidal volume. It will be expressed in units, where one unit corresponds to the tidal impedance variation of the patient breathing with baseline conventional facemask.
Measured: The data will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of oxygenation
Oxygen arterial partial pressure
Measured: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of carbon dioxide
Carbon dioxide arterial partial pressure
Measured: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of pH
Arterial pH
Measured: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of respiratory rate
Respiratory rate
Measured: The parameter will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of patient's comfort: modified Borg dyspnea scale
Comfort related to the oxygen therapy will be evaluated with the modified Borg dyspnea scale (0: nothing at all, 0.5: very, very slight, 1: very slight, 2: slight, 3: moderate, 4: somewhat severe, 5: severe, 6, 7: very severe, 8, 9: very, very severe - almost maximal, 10: maximal)
Measured: The parameter will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2019
- Study start15 Apr 2019
- Primary completion30 Sep 2019
- Study completion30 Sep 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bariatric Surgery CandidateStudies 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
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Trieste
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Lucia Comuzzi, University of Trieste
- Investigators
- Lucia Comuzzi, Principal investigator, Azienda Sanitaria Universitaria Integrata di Trieste
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03975348
- Sponsor's protocol ID
- 123/2018
- Status last verified
- Jul 2020
- First submitted
- 3 May 2019
- Last updated
- 30 Jul 2020
- Results posted
- No
- Data monitoring committee
- No
- 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 30 Jul 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Ventilation Distribution After Bariatric Surgery - High Flow Nasal Cannulas Versus Continuous Positive Airway Pressure
- ClinicalTrials.gov ID
- NCT03975348
- Acronym / sponsor ID
- 123/2018
- Keywords
- High flow nasal cannula, Bariatric surgery, Postoperative atelectasis, Electrical impedance tomography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- University of TriesteUniversity, hospital or other
- Study start
- 15 Apr 2019 (actual)
- Primary completion
- 30 Sep 2019 (actual)
- Study completion
- 30 Sep 2019 (actual)
- First posted
- 5 Jun 2019 (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.
Obese patients have an increased risk of developing post-operative respiratory complications due to their comorbidities. They have a restrictive ventilatory defect with reduction of lung volumes and expiratory flow limitation, higher airway resistance and collapsibility of the upper respiratory tract. These abnormalities are worsened by general anesthesia and opioid administration. It has been proved that oxygen therapy with HFNC (high flow nasal cannula) increases lung volumes through a continuous positive airway pressure (CPAP)-effect. This also improves gas exchange and decreases anatomical dead space. At the present time, CPAP represents the gold standard for the prevention of postoperative pulmonary complications. The purpose of this study is to evaluate lung ventilation, gas exchange and comfort with HFNC compared with CPAP during the post-operative period in patients who undergo laparoscopic bariatric surgery.
Detailed description
Immediately after bariatric surgery, patients will follow a pre-determined schedule of oxygen therapy with conventional facemask (from the beginning to minute 10), HFNC (with a flow of 40 L/min from minute 11 to 20, 60 L/min from minute 21to 30, 80 L/min from minute 31 to 40, 100 L/min from minute 41 to 50, 80 L/min from minute 51 to 60, 60 L/min from minute 61 to 70, 40 L/min from minute 71 to 80), conventional facemask again (washout, from minute 81 to 90) and CPAP (10 cmH2O, from minute 91 to 100). Lung ventilation will be evaluated with electrical impedance tomography (EIT), which measures thoracic impedance variations related to changes in lung aeration. At the end of each 10 minutes-period the following data will be collected: electrical impedance tomography data (to calculate the global inhomogeneity index, Δ end-expiratory lung impedance and tidal impedance variation), hemodynamic parameters, respiratory rate, SpO2, pain (numerical rating scale), level of sedation (Ramsey score) and patient comfort (modified Borg scale). An arterial blood gas will be collected at the end of the following steps: baseline facemask, HFNC 40 and 100 L/min, washout facemask and CPAP. Data about anesthetic/analgesic drugs and ventilation parameters will also be collected.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 10
| Arm | Type | Receives |
|---|---|---|
| Baseline conventional facemask | Other | Device: FacemaskThe patients will receive oxygen therapy through conventional facemask for 10 minutes |
| HFNC 40 L/min up | Experimental | Device: High flow nasal cannulaThe patients will receive oxygen/air mixture through high flow nasal cannula at incremental, then decremental flows, starting at 40 L/min for 10 minutes |
| HFNC 60 L/min up | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 60 L/min for 10 minutes |
| HFNC 80 L/min up | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 80 L/min for 10 minutes |
| HFNC 100 L/min | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 100 L/min for 10 minutes |
| HFNC 80 L/min down | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 80 L/min for 10 minutes |
| HFNC 60 L/min down | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 60 L/min for 10 minutes |
| HFNC 40 L/min down | Experimental | Device: High flow nasal cannulaHigh flow nasal cannula at 40 L/min for 10 minutes |
| Washout conventional facemask | Other | Device: FacemaskAgain, the patients will receive oxygen therapy through conventional facemask for 10 minutes, to reduce the influence of HFNC on CPAP therapy |
| CPAP | Active comparator | Device: Continuous positive airway pressureThe patients will receive CPAP at 10 cmH2O for 10 minutes |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Patient's consent to the trial
- Candidate to laparoscopic bariatric surgery (sleeve gastrectomy or Roux-en-Y gastric bypass)
- BMI 35-50 kg/m2
- ASA class 1-3
Key exclusion criteria (2 listed)
- Obesity hypoventilation syndrome
- Contraindication to EIT (e.g. implantable cardioverter-defibrillator)
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 |
|---|---|---|
| High flow nasal cannulaHigh flow of warm and humidified oxygen/air mixture delivered through nasal cannula | Device | HFNC 100 L/min, HFNC 40 L/min down, HFNC 40 L/min up, HFNC 60 L/min down, HFNC 60 L/min up, HFNC 80 L/min down, HFNC 80 L/min up |
| Continuous positive airway pressurePositive airway pressure applied through a sealed face mask | Device | CPAP |
| FacemaskOxygen therapy through a conventional facemask | Device | Baseline conventional facemask, Washout conventional facemask |
Primary outcome
Change of global inhomogeneity index
Time frame: The data needed to calculate the index will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
This parameter, calculated from data collected with EIT, evaluates lung ventilation distribution. To calculate this index, the median value of regional impedance changes from ventilated regions within the tidal image has to be computed, then the sum of differences between the median and every pixel value needs to be calculated, and the result must be normalised by the sum of impedance values within the lung area. The minimum value of the index is 0 and corresponds to homogeneous ventilation, whereas the maximum value is 1 and corresponds to inhomogeneous ventilation (in this context likely due to atelectasis).
7 secondary outcomes
Change of Δ end expiratory lung impedance (ΔEELI)
Time frame: The data will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of tidal impedance variation
Time frame: The data will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of oxygenation
Time frame: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of carbon dioxide
Time frame: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of pH
Time frame: The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
Change of respiratory rate
Time frame: The parameter will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
Change of patient's comfort: modified Borg dyspnea scale
Time frame: The parameter will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.
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 30 Jul 2020.
- 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.
Lucia Comuzzi principal investigator
Azienda Sanitaria Universitaria Integrata di Trieste
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High flow nasal cannula, Continuous positive airway pressure and Facemask in people with Bariatric Surgery Candidate and Atelectasis, Postoperative Pulmonary, run by University of Trieste at 1 site in Italy.
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 4 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 30 Jul 2020. 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 Italy. 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?
Change of global inhomogeneity index (time frame: The data needed to calculate the index will be collected at minute 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (i.e. at the end of every step of oxygen therapy). The values obtained will then all be compared each other.). 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 30 Jul 2020.