Inhaled NO in Surgical Patients With Recent COVID-19 Infection

The aim of this study is to evaluate the effect of perioperative inhalation of NO on reducing the incidence of postoperative pulmonary complications in patients with recent COVID-19 infection, and to evaluate whether inhaled NO can improve the prognosis of patients.The investigators will enroll 660 surgical patients who was infected with SARS-CoV-2 within 42days (7 weeks ) prior to planed surgery under general anesthesia. Patients will be randomized to receive either inhaled nitric oxide (per protocol) or a placebo. Perioperative standards of care will be the institution's own protocols (such as ventilation strategies and use and dose of anesthetics, analgesia and fluid management, etc).

Inclusion Criteria:≥ 18 years oldPlanned for surgery under general anesthesiaWith a history of COVID-19 infection within 7 weeks prior to surgery.Exclusion Criteria:Physician makes a decision that trial involvement is not in the patient's best interest or any condition that does not allow the protocol to be followed safelyASA ≥ IV, life expectancy< 24 h.Pregnant or lactating women.Severe liver disease (Child-Pugh score ≥ 12).Patients with severe respiratory failure need mechanical ventilation support or ECMO life support before the operation.Severe renal dysfunction (eGFRC≤30 ml/min/1.73m2) or receiving continuous renal replacement therapy, hemodialysis, and peritoneal dialysis.Having received or participated in other clinical trials within the previous month.