Expiratory Flow Limitation and Mechanical Ventilation During Cardiopulmonary Bypass in Cardiac Surgery
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 204
- 试验地点
- 2
- 主要终点
- Incidence of expiratory flow limitation in cardiac surgery
研究概览
简要总结
During general anesthesia a reduction of Functional Residual Capacity (FRC) was observed. The reduction of FRC could imply that respiratory system closing capacity (CC) exceeds the FRC and leads to a phenomenon called expiratory flow limitation (EFL). Positive End-Expiratory Pressure (PEEP) test is a validated method to evaluate the presence of EFL during anesthesia. Aim of the study will be to asses if mechanical ventilation during CardioPulmonary Bypass (CPB) in cardiac surgery could reduce the incidence of EFL in the post-CPB period. Primary end-point will be the incidence of EFL, assessed by a PEEP test, performed at different time-points in operating room. Co-primary end-point will be shunt fraction, determined before and after surgery.
This will be a single center single-blind parallel group randomized controlled trial. Patients will be randomly assigned to four parallel arms with an allocation ratio 1:1:1:1, to receive one of four mechanical ventilation strategies during CPB.
- Ventilation with a Positive End-Expiratory Pressure (PEEP) of 5 cmH2O before and after CPB; Continuous Positive Airway Pressure (CPAP) during CPB;
- Ventilation without PEEP before and after CPB; CPAP during CPB;
- Ventilation with a PEEP of 5 cmH2O before and after CPB; No use of mechanical ventilation during CPB
- Ventilation without PEEP before and after CPB; No use of mechanical ventilation during CPB
详细描述
Introduction During general anesthesia a reduction of Functional Residual Capacity (FRC) was observed. The reduction of FRC could imply that respiratory system closing capacity (CC) exceeds the FRC and leads to a phenomenon called expiratory flow limitation (EFL). Several factors contribute to the EFL phenomenon during general anesthesia, including anesthesia induction by itself. High oxygen concentrations, muscle paralysis, supine positioning, increased extravascular water because of perioperative fluid therapy and inflammatory response also play a role in this picture.
Moreover cardiopulmonary bypass (CPB) with aortic cross-clamping, which is necessary for the majority of procedures in cardiac surgery, was associated with direct lung damage. Pulmonary atelectasis, apnea and ischemia during CPB and activation of proteolytic enzymes in the pulmonary circulation influence the incidence of postoperative pulmonary dysfunction after cardiac surgery.
Positive End-Expiratory Pressure (PEEP) test is a validated method to evaluate the presence of EFL during anesthesia. PEEP-test is a feasible and completely safe measure of the reduction of FRC in mechanically ventilated patients.
Aim of the study will be to assess if mechanical ventilation during CPB in cardiac surgery could reduce the incidence of EFL in the post-CPB period.
Primary End-point The primary endpoint will be a composite end-point of the incidence of Expiratory Flow Limitation after the weaning from CPB and post-operative pulmonary complications.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 100 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Elective cardiac surgery, with median sternotomy and two-lungs ventilation;
- •Patients scheduled for mitral valve regurgitation and/or aortic valve regurgitation surgery, performed with CPB and aortic cross-clamping;
- •Adult patients (age 18 or higher);
- •Ability to provide informed consent.
- •High risk for respiratory dysfunction, defined as 1 of: preoperative hypoxemia (arterial oxygen saturation < 92% in room air or arterial oxygen partial pressure < 60 mmHg at blood gas analysis or a PaO2/FiO2 ratio < 200 at basal blood gas analysis); preoperative obesity (BMI > 30); preoperative ejection fraction < 50%; preoperative NYHA class > II; age > 65 years.
排除标准
- •Non-elective cardiac surgery;
- •Anticipated circulatory arrest, TAVI, Mitraclip;
- •Patient's refusal;
- •Pregnancy;
- •Thoracotomic approach, with one lung ventilation;
- •Previous pulmonary resection;
- •Patients with acute kidney injury requiring dialysis;
- •Patients with chronic kidney insufficiency (stage III or greater);
- •Patients already intubated before arrival in operating theatre;
- •Pneumonia in the previous 30 days.
研究组 & 干预措施
PEEP and CPAP
Patients will be ventilated with positive end-expiratory pressure(PEEP) before and after cardiopulmonary bypass(CPB); during CPB continous positive airway pressure(CPAP) will be adopted.
干预措施: Use of PEEP before and after CPB (Procedure)
PEEP and CPAP
Patients will be ventilated with positive end-expiratory pressure(PEEP) before and after cardiopulmonary bypass(CPB); during CPB continous positive airway pressure(CPAP) will be adopted.
干预措施: Ventilation with CPAP during CPB (Procedure)
ZEEP and CPAP
Patients will be ventilated without PEEP(ZEEP) before and after cardiopulmonary bypass(CPB); during CPB continous positive airway pressure(CPAP) will be adopted.
干预措施: No use of PEEP before and after CPB(ZEEP) (Procedure)
ZEEP and CPAP
Patients will be ventilated without PEEP(ZEEP) before and after cardiopulmonary bypass(CPB); during CPB continous positive airway pressure(CPAP) will be adopted.
干预措施: Ventilation with CPAP during CPB (Procedure)
PEEP and NO VM
Patients will be ventilated with positive end-expiratory pressure(PEEP) before and after cardiopulmonary bypass(CPB); during CPB no mechanical ventilation will be adopted(no VM)
干预措施: Use of PEEP before and after CPB (Procedure)
PEEP and NO VM
Patients will be ventilated with positive end-expiratory pressure(PEEP) before and after cardiopulmonary bypass(CPB); during CPB no mechanical ventilation will be adopted(no VM)
干预措施: No ventilation during CPB (Procedure)
ZEEP and NO VM
Patients will be ventilated without PEEP(ZEEP) before and after cardiopulmonary bypass(CPB); during CPB no mechanical ventilation will be adopted(no VM)
干预措施: No use of PEEP before and after CPB(ZEEP) (Procedure)
ZEEP and NO VM
Patients will be ventilated without PEEP(ZEEP) before and after cardiopulmonary bypass(CPB); during CPB no mechanical ventilation will be adopted(no VM)
干预措施: No ventilation during CPB (Procedure)
结局指标
主要结局
Incidence of expiratory flow limitation in cardiac surgery
时间窗: Immediately after weaning from cardiopulmonary bypass
Incidence of Postoperative pulmonary complications in cardiac surgery
时间窗: From immediately after cardiac surgery until discharge from the hospital
次要结局
- Duration of mechanical ventilation(Through study completion, an average of 24 hours after surgery)
- ICU length of stay(Through study completion, an average of 24 hours after surgery)
- Hospital length of stay(Through study completion, an average of 7 days after surgery)
- Re-admission to ICU(Through study completion, an average of 30 days after surgery)
- Need for reintubation(Through study completion, an average of 30 days after surgery)
- Need for non-invasive ventilation(Through study completion, an average of 30 days after surgery)
- Postoperative infections(Through study completion, an average of 30 days after surgery)
- Major adverse cardiac events(Through study completion, an average of 30 days after surgery)
- Incidence of mortality(Through study completion, 30 days and 1 year after surgery)
研究者
Elena Bignami
Professor
Ospedale San Raffaele