Nitric Oxide Inhalation Therapy Attenuates Postoperative Hypoxemia in Obese Patients with Acute Type A Aortic Dissection

Objective. To investigate the differences between inhaled nitric oxide (iNO) treatment and conventional therapy in the treatment of postoperative hypoxemia in obese patients with acute type A aortic dissection (ATAAD). Methods. ATAAD patients diagnosed and treated with emergency surgery in our hospital from June 2017 to December 2019 were retrospectively analyzed. Patients with postoperative hypoxemia were divided into the iNO group and control group. Propensity score matching was used to analyze clinical characteristics and results of the two groups. Results. A total of 218 ATAAD patients with BMI >= 25 were treated with surgery. Among them, 115 patients developed refractory hypoxemia (64 in the control group and 51 in the iNO group). Patients in the iNO group had significantly shorter invasive mechanical ventilation time, intensive care unit (ICU) stay, and hospital stay. After 6h of iNO treatment, the PaO2/FiO(2) ratio in the iNO group increased significantly, and this ratio was higher than that in the control group at 6, 12, 24, 48, and 72h after treatment. Conclusion. Low-dose iNO could improve oxygenation and shorten mechanical ventilation and ICU stay in patients with hypoxemia after ATAAD surgery, but without significant side effects or increase in postoperative mortality or morbidity. These findings provide a basis for a randomized multicenter controlled trial to assess the efficacy of iNO in the treatment of hypoxemia after ATAAD surgery.