The Effect of Individualized PEEP Compared to Low PEEP on Tissue Oxygenation During One Lung Ventilation in Obese Patients Undergoing Thoracic Surgery
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 发起方
- 试验地点
- 1
- 主要终点
- Cerebral oximetry
研究概览
简要总结
The aim of the prospective crossover study is to investigate the effect of individualized positive end-expiratory pressure (PEEP) on measures of tissue oxygenation, compared with low PEEP.
详细描述
During surgery on the lung, ventilation of one lung at a time is often necessary. During thoracic surgery requiring one-lung ventilation (OLV), hypoxemia (reduced oxygen tension in blood) can present a clinical challenge. Due to multiple factors, the likelihood of hypoxemia during OLV in obese patients is increased. Atelectasis (collapse of the lung airspaces) contributes to hypoxemia and can be mitigated by application of recruitment maneuvers and positive end-expiratory pressure (PEEP). A recruitment maneuver is a breath given in a mechanically ventilated patient that helps to open up collapsed air spaces, and PEEP is application of a continuous amount of positive pressure that helps keep the air spaces open at the end of an exhaled breath. Adjusting the level of PEEP to each individual patient's optimal lung compliance (individualized PEEP) improves blood oxygen levels compared to application of standard low PEEP (5 cmH2O); however, higher levels of PEEP required to achieve optimal lung compliance could increase intrathoracic pressures to a level that impedes normal circulation. This could negatively affect blood flow (cardiac output) and delivery of oxgyen to vital organs.
Evidence addressing OLV in obese patients is lacking. The purpose of this study is to compare brain oxygen levels (cerebral oxygen saturation) and measures of blood flow and gas exchange during OLV with individualized PEEP vs low standard PEEP in obese patients undergoing thoracic surgery. To our knowledge, there is no previous study that compares oxygen delivery to vital organs (such as the brain) during OLV using individualized PEEP versus standard low PEEP, in an obese patient population.
In this study, subjects undergoing OLV during surgery to remove a portion of the lung (lobectomy) will undergo a process to determine their individualized PEEP and then two 20-minute experimental periods-- one period with OLV with low PEEP and one period with OLV with individualized PEEP. Measurements of cerebral oxygen saturation, blood oxygen levels, cardiac output, and blood pressure medication dose will be measuring before and after these experimental periods during surgery.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Subject undergoing elective pulmonary lobectomy requiring one-lung ventilation
- •Body-mass index ≥ 30 kg/m2
- •Age ≥ 18 years and ≤ 80 years
排除标准
- •Age ≤ 18 year or ≥ 80 years
- •Moderate or severe cardiac valvular disease
- •Left ventricular ejection fraction < 30%
- •Moderate or severe right ventricular systolic dysfunction
- •Severe pulmonary hypertension
- •Presence of pulmonary bullae or blebs on preoperative chest imaging studies (e.g., radiograph, computed tomograph)
- •Emergency surgery
- •Previous history of lung surgery on the non-operative lung
- •Incarceration
- •Mental incapacitation
- •Patient refusal
- •Non-English speaking
研究组 & 干预措施
Individualized PEEP
Individualized PEEP will be identified by performing a decremental PEEP protocol which will determine the level of PEEP that correlates with maximal lung compliance in each subject. Subjects will receive one-lung ventilation with individualized PEEP
干预措施: One-lung ventilation with individualized PEEP (Procedure)
Low PEEP
Subjects will receive One-lung ventilation with low PEEP (5 cmH2O)
干预措施: One-lung ventilation with low PEEP (Procedure)
结局指标
主要结局
Cerebral oximetry
时间窗: Change from baseline cerebral oximetry at the end of each intraoperative 20 minute experimental period. All measurements are made during the 4-6 hour surgery.
Cerebral oximetry (a measure of oxygen levels in the brain) as measured by near-infrared spectroscopy (noninvasive monitor applied to the forehead)
次要结局
- Phenylephrine dose(Total dose of phenylephrine administered during each intraoperative 20 minute experimental period. All measurements are made during the 4-6 hour surgery.)
- Venous blood oxygen saturation (SvO2)(Measured at baseline, and then at the end of each 20 minute intraoperative experimental period. All measurements are made during the 4-6 hour surgery.)
- Venous blood oxygen tension (PvO2)(Measured at baseline, and then at the end of each 20 minute intraoperative experimental period. All measurements are made during the 4-6 hour surgery.)
- Cardiac output(Measured at baseline, and then at the end of each 20 minute intraoperative experimental period. All measurements are made during the 4-6 hour surgery.)
- Arterial blood oxygen tension (PaO2)(Measured at baseline, and then at the end of each 20 minute intraoperative experimental period. All measurements are made during the 4-6 hour surgery.)
研究者
Dionne Peacher
Clinical Assistant Professor
University of Iowa