Evaluation of Ventilation Distribution After Bariatric Surgery - High Flow Nasal Cannulas Versus Continuous Positive Airway Pressure
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 15
- 试验地点
- 2
- 主要终点
- Change of global inhomogeneity index
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •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
排除标准
- •Obesity hypoventilation syndrome
- •Contraindication to EIT (e.g. implantable cardioverter-defibrillator)
结局指标
主要结局
Change of global inhomogeneity index
时间窗: 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).
次要结局
- 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 patient's comfort: modified Borg dyspnea scale(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 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 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.)
- Change of respiratory rate(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.)
研究者
Lucia Comuzzi
Principal investigator
University of Trieste