NCT03975348

Ventilation Distribution After Bariatric Surgery

Evaluation of Ventilation Distribution After Bariatric Surgery - High Flow Nasal Cannulas Versus Continuous Positive Airway Pressure

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 15 (actual)
• Sponsor: University of Trieste · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

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.

Conditions

• Bariatric Surgery Candidate
• Atelectasis, Postoperative Pulmonary

Interventions

Type	Name	Description
DEVICE	High flow nasal cannula	High flow of warm and humidified oxygen/air mixture delivered through nasal cannula
DEVICE	Continuous positive airway pressure	Positive airway pressure applied through a sealed face mask
DEVICE	Facemask	Oxygen therapy through a conventional facemask

Timeline

• Start date: 2019-04-15
• Primary completion: 2019-09-30
• Completion: 2019-09-30
• First posted: 2019-06-05
• Last updated: 2020-07-30

Locations

1 site across 1 country: Italy