title: Frequency, clinical characteristics, and respiratory parameters of hepatopulmonary syndrome.
abstract: OBJECTIVE
  To determine the frequency and the clinical characteristics of hepatopulmonary syndrome (HPS) in cirrhotic candidates for orthotopic liver transplantation and to identify the major respiratory parameters predictive of the presence of changes in arterial oxygenation.
  
  
  METHODS
  Patients underwent transthoracic contrast-enhanced echocardiography, pulmonary scintigraphy, pulmonary function test with diffusing capacity of lung for carbon monoxide (DLCO), and measurement of arterial blood gases.
  
  
  RESULTS
  Fifty-six patients were studied. Twenty-five patients (45%) presented with intrapulmonary vascular dilatations, but only 9 (16%) fulfilled the criteria for HPS. The clinical or demographic characteristics considered did not differ in the patients with and without HPS. The DLCO value was significantly lower in patients with HPS (P=.01). However, 32 (80%) of 40 patients with low DLCO values did not fulfill the criteria for HPS. An alveolar arterial oxygen gradient (AaPO2) of more than 20 mm Hg showed a higher diagnostic accuracy (91%) in the assessment of HPS than did the DLCO of less than 80% predicted (41%) and the AaPO2 of more than 15 mm Hg (71%).
  
  
  CONCLUSIONS
  The AaPO2 proved to be a more reliable index than PaO2 and DLCO for the determination of changes in arterial oxygenation in HPS. The DLCO does not seem to be a good marker for HPS screening. Intrapulmonary vascular dilatations were frequent, even in patients who did not fulfill the criteria for HPS.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Medical School of Ribeirão Preto, São Paulo University, São Paulo, Brazil.
authors.forename: Beatriz L G
authors.initials: BL
authors.lastname: Lima
authors.forename: Alex V C
authors.initials: AV
authors.lastname: França
authors.forename: Antonio
authors.initials: A
authors.lastname: Pazin-Filho
authors.forename: Whemberton M
authors.initials: WM
authors.lastname: Araújo
authors.forename: José A B
authors.initials: JA
authors.lastname: Martinez
authors.forename: Benedito C
authors.initials: BC
authors.lastname: Maciel
authors.forename: Marcus V
authors.initials: MV
authors.lastname: Simões
authors.forename: João
authors.initials: J
authors.lastname: Terra-Filho
authors.forename: Ana L C
authors.initials: AL
authors.lastname: Martinelli
mesh_terms: D001784:Blood Gas Analysis; D005260:Female; D020065:Hepatopulmonary Syndrome / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications* / Q000601:surgery; D016031:Liver Transplantation; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011653:Pulmonary Diffusing Capacity / Q000502:physiology