Inhaled nitric oxide for elevated cavopulmonary pressure and hypoxemia after cavopulmonary operations

Background. Elevated cavopulmonary pressure early after surgical creation of cavopulmonary connections is an important hemodynamic problem with grave prognostic significance. We examined the effect of administration of inhaled nitric oxide (iNO) to patients with elevated cavopulmonary pressure in the early postoperative period. Methods. We retrospectively reviewed data pertaining to all 14 patients with superior (n = 6) and total (n = 8) cavopulmonary connections who were treated with iNO in the early postoperative period during an interval of six years. Changes in the cavopulmonary pressure, the transpulmonary gradient, and the oxygen saturation after the institution of iNO were evaluated. The preoperative characteristics of the patients were compared to those of a control group of patients with cavopulmonary operations not treated with iNO postoperatively. Results. Twelve hours after the initiation of iNO therapy, significant reduction in the cavopulmonary pressure (16.6 ± 3.5 mm Hg vs 18.1 ± 2.3 mm Hg, P = .006), reduction in the cavopulmonary gradient (7.0 ± 3.5 mm Hg vs 9.8 ± 3.7 mm Hg, P = .009), and elevation of the arterial oxygen saturation (84.5% ± 6.0% vs 78.7% ± 5.9%, P = .001) were observed. Linear correlation analysis confirmed tendencies for reduction in the cavopulmonary pressure (P = .13), reduction in the cavopulmonary gradient (P = .02), and elevation of the oxygen saturation (P = .10). Compared to the control group, the treated patients tended to have higher preoperative pulmonary arterial pressures (PAPs) 17 (11-30) mm Hg versus 12 (10-25) mm Hg, P = .10; higher pulmonary vascular resistance (PVR) 2.04 (0.27-6.94) Wood units versus 1.02 (0.49-5.20) Wood units, P = .37; and longer bypass times 154 (41-218) versus 91 (15-276) minutes, P = .13. Conclusions. Administration of iNO was associated with diminuition of cavopulmonary pressure and transpulmonary gradient and increasing oxygen saturation in our small group of patients. In our experience selected patients with preoperatively elevated PAP above 17 mm and PVR above 2 Wood units can undergo cavopulmonary operations with iNO treatment early postoperatively.