driving pressure-guided lung protective ventilation

Conditions: Hypoxemia; Ventilator Lung

Summary: the study, named as "the efficacy of driving pressure-guided lung protective ventilation in surgical repair of acute type a aortic dissection: an open-label, randomized control clinical trial", aims to investigate whether driving pressure-guided lung protective ventilation can reduce postoperative oxygenation function in patients who have undergone surgical repair of acute type a aortic dissection. the primary outcomes is the incidence of postoperative hypoxemia (a partial pressure of arterial oxygen to inspiratory oxygen fraction ratio less than 300 mm hg or a peripheral blood oxygen saturation less than 93% at any concentration of inspiratory oxygen) within 7 days after the surgery.

postoperative hypoxemia is defined as a partial pressure of arterial oxygen to inspiratory oxygen fraction ratio less than 300 mm hg or a peripheral blood oxygen saturation less than 93% at any concentration of inspiratory oxygen. acute type a aortic dissection is a lethal disease requiring emergency surgery. compared with non-cardiac surgery, hypoxemia frequently occurs after surgical repair for acute type a aortic dissection which has been reported to be 52%-67.6%, and the possible mechanisms are as followed: (1) systemic inflammatory reaction induced by massive thrombosis formation and long duration of extracorporeal circulation; (2) ischemia-perfusion injury in lung; and (3) a massive perioperative transfusion. postoperative hypoxemia has been reported to be associated with prolonged duration of extubation, length of stay in icu and respiratory failure, which contributes a high mortality of 20% to 44%. driving pressure, defined as the difference between platform airway pressure and positive end-expiratory pressure, was first introduced by amato and his colleagues in their meta-analysis study on acute respiratory distress syndrome in 2015, demonstrating that driving pressure was most strongly associated with survival among various ventilation parameters. a lower driving pressure has been verified to be closely relative to an ameliorative prognosis after surgery. however, controversy persists regarding whether driving pressure-guided ventilation can decrease the incidences of postoperative hypoxemia and other pulmonary complications in the patients underwent surgical repair of acute type a aortic dissection. given the need for additional evidence to confirm the relationship between driving pressure and postoperative hypoxemia in the patients with acute type a aortic dissection, this open-label, randomized control clinical trial aims to assess the efficacy and safety of the driving pressure-guided lung protective ventilation strategy in preventing hypoxemia and other pulmonary complications after the surgical repair for acute type a aortic dissection.

Eligibility criteria:
inclusion criteria: 1. able to sign informed consent and release of medical information forms; 2. age ≥ 14 years and ≤ 70 years old; 3. being confirmed the diagnosis by chest computed tomography angiography and receiving the surgical repair of acute type a aortic dissection. exclusion criteria: 1. age \ 70 years old; 2. sepsis before surgery; 3. chronic pulmonary disease including lung infection or asthma requiring long-term pharmacotherapy; 4. history of lung tumor; 5. obstructive sleep apnea hypopnea syndrome requiring long-term noninvasive mechanical ventilation support; 6. heart failure requiring catecholamines or invasive mechanical ventilation support; 7. body mass index \> 30 kg·m-2; 8. being reluctance to participate this study.

Keywords: driving pressure lung protective ventilation aortic dissection hypoxia postoperative pulmonary complications