Case Report: The role of nitric oxide inhalation and prone positioning ventilation in oxygen improvement in patients with refractory hypoxemia following acute type A aortic dissection surgery: two cases report and literature review

Refractory hypoxemia following Acute Type A Aortic Dissection (ATAAD) surgery presents a significant clinical challenge. How to improve the refractory hypoxemia after ATAAD surgery is very critical for achiving perfect outcome of these patients. We report two cases of severe hypoxemia after ATAAD surgery that improved with inhaled nitric oxide (iNO) and prone positioning ventilation (PPV) therapy, despite traditional treatments including ventilator parameter optimization, performance of recruitment maneuvers, administration of glucocorticoids, diuresis and/or CRRT used for maintenance of a negative fluid balance, and secretion aspiration via fiberoptic bronchoscopy. Finally, these two patients were successful weaned from mechanical ventilation and subsequent discharge from the hospital.We provide the successful experience in the application of combination treatment of iNO and PPV in patients with refractory hypoxemia after ATAAD surgery, which will pave the way for the following randomized controlled clinical trials.