Initial Ventilation Strategy for Adult Immunocompromised Patients With Acute Respiratory Failure

Exclusion Criteria

• •Age\<18 or \>80 years old;
• •Partial pressure of arterial carbon dioxide (PaCO2) \> 50 mmHg or arterial pH \< 7.20;
• •PaO2/FiO2 \>170 or PaO2/FiO2\< 85;
• •Patients have been treated with NIV or IMV within 30 days.
• •NIV is contraindicated or IMV is definitely indicated, including PaO2/FiO2\< 85, respiratory arrest, hemodynamic instability, inability to fit the face mask, pneumothorax, vomiting, development of airway bleeding, inability to protect the airway, or copious respiratory secretions;
• •Comorbided with other severe diseases, including New York Heart Association functional class ≥ II, valvular heart disease, dilated cardiomyopathy, cardiogenic pulmonary edema, implanted cardiac pacemaker, unstable angina, myocardial infarction, or cardiac surgery within the previous 3 months; systolic arterial pressure \<90 mmHg after optimal fluid therapy; history of chronic obstructive pulmonary disease (COPD) or asthma; impaired consciousness (Glasgow Coma Scale score \<13); postoperative acute respiratory failure; pregnancy or breastfeeding;
• •Lack of consent, do-not-intubate decision, and any other situations where obvious bias are expected