A comparison of inhaled nitric oxide and milrinone for the treatment of pulmonary hypertension in adult cardiac surgery patients

Objective: To investigate the relative effects of milrinone and nitric oxid e on pulmonary and systemic hemodynamic responses in cardiac surgery patien ts with a history of pulmonary hypertension. Design: Prospective and randomized. Setting: University hospital. Participants: Forty-five adult cardiac surgery patients. Interventions: Cardiac surgery patients with pulmonary hypertension were ra ndomly assigned to one of three study groups: Group 1 patients (n = 15) wer e treated with intravenous milrinone on separation from cardiopulmonary byp ass, group 2 patients (n = 15) with 20 ppm of inhaled nitric oxide, and gro up 3 patients (n = 15) with 40 ppm of inhaled nitric oxide. Heart rate, rig ht ventricular ejection fraction, and pulmonary vascular resistance were me asured throughout the perioperative period at specific data points. Measurements and Main Results: There were no significant differences in dem ographics, anesthesia, surgery, or baseline hemodynamics among the groups. The group receiving 40 ppm nitric oxide had a significantly higher (p < 0.0 5) right ventricular ejection fraction on arrival in the intensive care uni t (40% v 30% for the milrinone group and 33% for the nitric oxide 20 ppm gr oup). The milrinone group required significantly more phenylephrine in the intensive care unit (p < 0.05). Conclusions: Treatment of pulmonary hypertension in adult cardiac surgery p atients with inhaled nitric oxide compared with milrinone is associated wit h lower heart rates, higher right ventricular ejection fraction, and a lowe r requirement for treatment with vasopressor agents. Copyright (C) 2000 by W.B. Saunders Company.