title: Inhaled nitric oxide versus sodium nitroprusside for preoperative evaluation of pulmonary hypertension in heart transplant candidates.
abstract: OBJECTIVE
  The development of pulmonary hypertension before heart transplantation increases the risk for postoperative right ventricular failure. Reversibility of pulmonary vascular resistance (PVR), which indicates the feasibility of heart transplantation, can be tested with the use of intravenous vasodilators, such as sodium nitroprusside (NaNTP) or prostacyclin. However, the drawback of these drugs is the development of systemic hypotension. The aim of this study was to evaluate the safely and feasibility of inhaled nitric oxide (iNO) compared with sodium nitroprusside to test PVR reversibility, while avoiding systemic hypotension.
  
  
  METHODS
  We included all patients who were affected by end stage heart failure undergoing evaluation for heart transplantation if they showed elevated PVR > 2.5 Wood units and mean pulmonary arterial pressure (mPAP) >25 mm Hg. The hemodynamic parameters measured by right heart catheterization were: systolic blood pressure (SBP), mPAP, pulmonary capillary wedge pressure, and cardiac index (CI). The following variables were derived: transpulmonary gradient (TPG) and PVR. All patients were tested by both iNO (20-40 ppm) and intravenous NaNTP, at increasing dosages which were titrated based on systemic pressure. We randomly assigned the order of administration of iNO and NaNTP.
  
  
  RESULTS
  The 9 male candidates has an average age of 56 ± 4 years. Seven of the 9 (71%) had postischemic cardiomyopathy, and 2 had idiopathic cardiomyopathy. We observed a reduction of mPAP (32% and 14%), PVR (41% and 32%), TPG (20% and 26%), and SBP (17% and 5%) and an increase of CI with administration of NaNTP and iNO, respectively.
  
  
  CONCLUSIONS
  We observed a reduction in PVR and mPAP with administration of either iNO and NaNTP. A better effect of NaNTP was attributed to reducted post-load of the left ventricle. However, the main advantage of iNO was the absence of systemic hypotension and its selectivity for pulmonary vascular system, as underscored by TPG reduction.
authors.affiliation: Cardiac Intensive Care Unit, Department of Anesthesiology and Critical Care Medicine, A.O. Città della Salute e della Scienza, San Giovanni Battista Hospital, Turin, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Pasero
authors.forename: N K
authors.initials: NK
authors.lastname: Rana
authors.forename: R
authors.initials: R
authors.lastname: Bonato
authors.forename: M
authors.initials: M
authors.lastname: Ribezzo
authors.forename: F
authors.initials: F
authors.lastname: Ivaldi
authors.forename: D
authors.initials: D
authors.lastname: Ricci
authors.forename: W
authors.initials: W
authors.lastname: Grosso Marra
authors.forename: L
authors.initials: L
authors.lastname: Checco
authors.forename: M
authors.initials: M
authors.lastname: Lupo
authors.forename: M
authors.initials: M
authors.lastname: Boffini
authors.forename: M
authors.initials: M
authors.lastname: Rinaldi
mesh_terms: D000280:Administration, Inhalation; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000008:administration & dosage*; D009599:Nitroprusside / Q000008:administration & dosage*; D011300:Preoperative Care; D011446:Prospective Studies
chemical_list: D009599:Nitroprusside; D009569:Nitric Oxide