title: Exhaled nitric oxide and impaired oxygenation in cirrhotic patients before and after liver transplantation.
abstract: BACKGROUND
  Nitric oxide may be involved in the impaired oxygenation of cirrhotic patients, a condition that improves in most patients after liver transplantation.
  
  
  OBJECTIVE
  To compare oxygenation and nitric oxide concentrations before and after liver transplantation.
  
  
  METHODS
  Before-and-after observational study.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  18 patients with cirrhosis and no obvious cardiopulmonary disease who underwent successful orthotopic liver transplantation.
  
  
  METHODS
  Orthotopic liver transplantation.
  
  
  METHODS
  Blood gas analysis, measurement of exhaled nitric oxide, contrast-enhanced echocardiography, and pulmonary function tests.
  
  
  RESULTS
  Before transplantation, the mean (+/- SD) exhaled nitric oxide concentration was higher in patients than in normal controls (13 +/- 4.9 parts per billion [ppb] compared with 5.75 +/- 1.9 ppb; P < 0.001). After transplantation, the alveolar-arterial oxygen gradient significantly decreased (from 17.3 +/- 7.1 mm Hg to 9 +/- 5.2 mm Hg; P < 0.001), as did the exhaled nitric oxide concentration (from 13 +/- 4.9 ppb to 6.2 +/- 2.8 ppb; P < 0.001). The decrease in the exhaled nitric oxide concentration was significantly correlated with the decrease in the alveolar-arterial oxygen gradient (r = 0.56; P = 0.014). Five patients met the criteria for the diagnosis of the hepatopulmonary syndrome before transplantation; the syndrome was cured by transplantation.
  
  
  CONCLUSIONS
  The correlation between the decrease in exhaled nitric oxide concentration after liver transplantation and the improvement in oxygenation reinforces the hypothesis that nitric oxide is an important mediator of impaired oxygenation in patients with cirrhosis.
authors.affiliation: University of Torino and Ospedale Molinette di Torino, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Rolla
authors.forename: L
authors.initials: L
authors.lastname: Brussino
authors.forename: P
authors.initials: P
authors.lastname: Colagrande
authors.forename: E
authors.initials: E
authors.lastname: Scappaticci
authors.forename: M
authors.initials: M
authors.lastname: Morello
authors.forename: S
authors.initials: S
authors.lastname: Bergerone
authors.forename: A
authors.initials: A
authors.lastname: Ottobrelli
authors.forename: E
authors.initials: E
authors.lastname: Cerutti
authors.forename: S
authors.initials: S
authors.lastname: Polizzi
authors.forename: C
authors.initials: C
authors.lastname: Bucca
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000503:physiopathology* / Q000601:surgery*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis* / Q000502:physiology; D010100:Oxygen / Q000097:blood; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012044:Regression Analysis; D012129:Respiratory Function Tests
chemical_list: D002245:Carbon Dioxide; D009569:Nitric Oxide; D010100:Oxygen