Adverse Hemodynamic Effects Observed with Inhaled Nitric Oxide After Surgical Repair of Total Anomalous Pulmonary Venous Return

Abstract.

The following is a case report of a 1-month-old patient who developed adverse hemodynamic sequelae during the use of nitric oxide (NO) in the postoperative period for pulmonary hypertension after correction of total anomalous pulmonary venous return. At the time of diagnosis, the patient had evidence of systemic right ventricular pressures estimated by continuous-wave Doppler. He was sedated and paralyzed for hyperventilation in preparation for surgery and underwent pulmonary vein confluence to left atrial anastomosis. Postoperative pulmonary hypertension was managed by hyperventilation, sedation, and paralysis until a sudden onset of systemic-level pulmonary pressure required NO therapy. Satisfactory results were obtained in minutes, but a rebound pulmonary hypertension occurred with concomitant systemic hypertension and no radiographic changes. We suspected left atrial hypertension secondary to a sudden increase in pulmonary blood flow to an noncompliant left ventricle. Discontinuation of NO resulted in stabilization of the hemodynamic profile of the patient and he continued to be managed with paralysis, hyperventilation, and sedation. Based on this experience we suggest that NO should be used with caution in patients with obstructive lesions at the atrial level prior to surgery (mitral valve stenosis and cor triatriatum) or in patients with a poorly compliant left ventricle (cardiomyopathy and left ventricular dysfunction). These entities are unable to tolerate a sudden increase in pulmonary blood return thus creating paradoxical pulmonary hypertension.