Disclosed are methods of reducing the risk that a medical treatment comprising inhalation of nitric oxide gas will induce an increase in pulmonary capillary wedge pressure in pediatric patients, leading to pulmonary edema. The methods include avoiding or discontinuing administration of inhaled nitric oxide to a pediatric patient determined to have pre-existing left ventricular dysfunction but who otherwise is a candidate for inhaled nitric oxide treatment (e.g., for pulmonary hypertension), and administering inhaled nitric oxide to pediatric patients who are candidates for such treatment and who are determined not to have pre-existing left ventricular dysfunction.