Salvage Treatment of Inhaled Nitric Oxide in Patients With Refractory Hypoxemia After Aortic Surgery

Several risk factors for severe hypoxemia after aortic surgery have been reported including advanced age, obesity, smoking history, previous heart surgery,emergency surgery,reduced cardiac function, advanced chronic obstructive pulmonary disease, excessive volume of blood transfusion,and prolonged CPB time. The routine treatment includes lung protective mechanical ventilation, recruitment maneuvers and glucocorticoids.

No previous clinical studies have reported the effectiveness and safety of inhaled Nitric Oxide in patients with refractory hypoxemia after aortic surgery.

• Inhaled Nitric Oxide (Drug): Patients are treated with iNO for 3-5 days.The concentration of inhaled Nitric Oxide is around 5-10ppm.
• lung protective mechanical ventilation (Device): Mechanical ventilation in the SIMV mode (ventilators Evita 2 or 4,Dräger, Lübeck, Germany) with VT 6-8ml/kg
• Hemodynamic monitoring (Device): Flotrac/Vigileo (Edwards Lifesciences) are used to guide the fluid management.

Primary outcomes

• Mechanical ventilation time (days) [During whole ICU stay. From date of randomization until the date of death or discharge from ICU, up to 6 months.]

Secondary outcomes

• ICU mortality [From date of randomization until the date of death or discharge from ICU, up to 6 months.]
• length of hospital stay (days) [From date of randomization until the date of death or discharge from hospital, up to 6 months.]
• length of ICU stay (days) [From date of randomization until the date of death or discharge from ICU, up to 6 months.]
• hospital mortality [From date of randomization until the date of death or discharge from hospital, up to 6 months.]

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. Adult patients with refractory hypoxemia after aortic surgery;
2. Accepting invasive mechanical ventilation;
3. Chest X-ray and lung ultrasound to exclude the respiratory factors (eg. pulmonary edema, obstructive atelectasis, pleural effusion, pneumothorax) and hemodynamic factors (pericardial tamponade, acute pulmonary hypertension, intracardiac shunt);
4. The ventilator parameters: PEEP>10cmH2O, VT 6-8ml/kg;
5. The PaO2/FiO2 <= 100mmHg.

Exclusion Criteria:

1. Age <18 years old;
2. Pregnant women;
3. Past medical history included COPD or mental illness;
4. The serious infection or sepsis patients;
5. Patients with pulmonary hypertension and right ventricular dysfunction

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• Zhe Luo, PhD, Study director, Department of Critical Care Medicine