Brief 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. 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.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for not_applicable

Timeline

Completed

Started Apr 2019

Shorter than P25 for not_applicable

Geographic Reach

1 country

1 active site

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

6 months study duration

Study Start

First participant enrolled

April 15, 2019

Completed

18 days until next milestone

First Submitted

Initial submission to the registry

May 3, 2019

Completed

1 month until next milestone

First Posted

Study publicly available on registry

June 5, 2019

Completed

4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

September 30, 2019

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

September 30, 2019

Completed

Last Updated

July 30, 2020

Status Verified

July 1, 2020

Enrollment Period

6 months

First QC Date

May 3, 2019

Last Update Submit

July 29, 2020

Conditions

Bariatric Surgery Candidate Atelectasis, Postoperative Pulmonary

Keywords

High flow nasal cannulaBariatric surgeryPostoperative atelectasisElectrical impedance tomography

Outcome Measures

Primary Outcomes (1)

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).
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 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
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
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
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
The blood gas analysis will be performed at minute 10, 20, 50, 90 and 100. The values will then all be compared each other.
+2 more secondary outcomes

Study Arms (10)

Baseline conventional facemask

OTHER

The patients will receive oxygen therapy through conventional facemask for 10 minutes

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