A prospective, randomized, crossover pilot study of inhaled nitric oxide versus inhaled prostacyclin in heart transplant and lung transplant recipients.
OBJECTIVE
Inhaled nitric oxide has been shown to reduce pulmonary vascular resistance in patients undergoing cardiothoracic surgery, but it is limited by toxicity, the need for special monitoring, and cost. Inhaled prostacyclin also decreases pulmonary artery pressure, is relatively free of toxicity, requires no specific monitoring, and is less expensive. The objective of this study was to compare nitric oxide and prostacyclin in the treatment of pulmonary hypertension, refractory hypoxemia, and right ventricular dysfunction in thoracic transplant recipients in a prospective, randomized, crossover pilot trial.


METHODS
Heart transplant and lung transplant recipients were randomized to nitric oxide or prostacyclin as initial treatment, followed by a crossover to the other agent after 6 hours. Pulmonary vasodilators were initiated in the operating room for pulmonary hypertension, refractory hypoxemia, or right ventricular dysfunction. Nitric oxide was administered at 20 ppm, and prostacyclin was administered at 20,000 ng/mL. Hemodynamic and oxygenation parameters were recorded before and after initiation of pulmonary vasodilator therapy. At 6 hours, the hemodynamic and oxygenation parameters were recorded again, just before discontinuing the initial agent. Crossover baseline parameters were measured 30 minutes after the initial agent had been stopped. The crossover agent was then started, and the hemodynamic and oxygenation parameters were measured again 30 minutes later.


RESULTS
Heart transplant and lung transplant recipients (n = 25) were randomized by initial treatment (nitric oxide, n = 14; prostacyclin, n = 11). Nitric oxide and prostacyclin both reduced pulmonary artery pressure and central venous pressure, and improved cardiac index and mixed venous oxygen saturation on initiation of therapy. More importantly, at the 6-hour crossover trial, there were no significant differences between nitric oxide and prostacyclin in the reduction of pulmonary artery pressures or central venous pressure, or in improvement in cardiac index or mixed venous oxygen saturation. Nitric oxide and prostacyclin did not affect the oxygenation index or systemic blood pressure. There were no complications associated with nitric oxide or prostacyclin.


CONCLUSIONS
In heart transplant and lung transplant recipients, nitric oxide and prostacyclin similarly reduce pulmonary artery pressures and central venous pressure, and improve cardiac index and mixed venous oxygen saturation. Inhaled prostacyclin may offer an alternative to nitric oxide in the treatment of pulmonary hypertension in thoracic transplantation.
Khan
Tanveer A
TA
Division of Cardiothoracic Surgery, Department of Surgery, UCLA School of Medicine, Los Angeles, CA 90095-1741, USA.
Schnickel
Gabriel
G
Ross
David
D
Bastani
Sam
S
Laks
Hillel
H
Esmailian
Fardad
F
Marelli
Daniel
D
Beygui
Ramin
R
Shemin
Richard
R
Watson
Larry
L
Vartapetian
Irina
I
Ardehali
Abbas
A
D000280:Administration, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D002496:Central Venous Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D011464:Epoprostenol / Q000008:administration & dosage*; D005260:Female; D016027:Heart Transplantation; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000517:prevention & control*; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage*; D010101:Oxygen Consumption / Q000187:drug effects; D010865:Pilot Projects; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000187:drug effects; D016896:Treatment Outcome
D009569:Nitric Oxide; D011464:Epoprostenol