title: Prevalence of hepatopulmonary syndrome in children.
abstract: OBJECTIVE
  The hepatopulmonary syndrome is defined as a triad of liver disease, hypoxemia, and intrapulmonary vascular dilation. The reported prevalence of hepatopulmonary syndrome in adults with cirrhosis ranges from 4% to 29%; however, the prevalence of hepatopulmonary syndrome and its outcome in children is unknown. The objective of this study was to describe prospectively the prevalence of intrapulmonary vascular dilation and hepatopulmonary syndrome in children with liver disease.
  
  
  METHODS
  Pulse oximetry was undertaken in children with liver disease, and those with oxygen saturation < or = 97%, those with cirrhosis, and those with clinically severe portal hypertension from other causes underwent contrast-enhanced echocardiography for detection of intrapulmonary vascular dilations. Patients with intrapulmonary vascular dilation underwent arterial blood gas analysis and technetium-99m-labeled macroaggregated albumin scan.
  
  
  RESULTS
  Oxygen saturation was measured in 301 children and was < or = 97% in 8. These 8 and an additional 18 patients with cirrhosis or portal hypertension underwent contrast-enhanced echocardiography. Seven (27%) patients had intrapulmonary vascular dilation detected by contrast-enhanced echocardiography; 2 of these patients had abnormal arterial blood gas analysis and thus met diagnostic criteria for hepatopulmonary syndrome (representing 8% of patients with cirrhosis or severe portal hypertension). Both patients with hepatopulmonary syndrome had abnormal pulse oximetry. Technetium-99m-labeled macroaggregated albumin scans for 6 patients showed a median 6.5% (range: 4%-12%) tracer uptake outside the lungs.
  
  
  CONCLUSIONS
  Hepatopulmonary syndrome occurs in an important minority of children with cirrhosis or severe portal hypertension. Additional studies should be undertaken to determine the importance of intrapulmonary vascular dilation without hepatopulmonary syndrome and the impact of hepatopulmonary syndrome on the outcomes of affected children.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, Hospital for Sick Children, 555 University Ave, Toronto, Ontario M5G 1X8, Canada.
authors.forename: Khalid
authors.initials: K
authors.lastname: Noli
authors.forename: Melinda
authors.initials: M
authors.lastname: Solomon
authors.forename: Fraser
authors.initials: F
authors.lastname: Golding
authors.forename: Martin
authors.initials: M
authors.lastname: Charron
authors.forename: Simon C
authors.initials: SC
authors.lastname: Ling
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D020065:Hepatopulmonary Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D017093:Liver Failure / Q000175:diagnosis / Q000453:epidemiology*; D008111:Liver Function Tests; D008297:Male; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D016019:Survival Analysis