Beneficial effects of inhaled nitric oxide in adult cardiac surgical patients

Abstract

Background. Pulmonary hypertension with associated right ventricular dysfunction may complicate the postoperative cardiac patient despite maximum pharmacologic and ventilatory support. The purpose of this study was to retrospectively review our experience with inhaled nitric oxide (INO) in adult postoperative cardiac patients with pulmonary hypertension. Methods. We retrospectively reviewed the medical records of 17 adult cardiac patients treated with INO postoperatively between November 1998 and February 2000. The INO was used to manage pulmonary hypertension postoperatively in patients who had undergone coronary artery bypass graft (CABG) (n = 13), valve operation (n = 3), and combined CABG/aortic valve replacement (n = 1). Hemodynamic and respiratory measurements before INO and again 6 hours after administration were examined. Student’s t test was used to analyze the data. Results. Inhaled nitric oxide (20 ppm to 30 ppm) was administered for a median duration of 30.2 hours. The group, as a whole, demonstrated a significant decrease in both mean pulmonary artery pressure and right ventricular stroke work index. In addition, a significant increase in posttherapeutic cardiac index and Pa o 2/Fi o 2 ratio was observed. The vasodilatory effects of nitric oxide were specific to the pulmonary circulation as no significant change in mean arterial pressure was noted. Overall mortality was 6%. Conclusions. Inhaled nitric oxide effectively and selectively lowered right ventricular afterload and right ventricular work in critically ill adult cardiac patients with acute pulmonary hypertension.