title: Serial pulse oximetry in hepatopulmonary syndrome.
abstract: OBJECTIVE
  The natural history of hepatopulmonary syndrome (HPS) is poorly characterized and how hypoxemia develops and progresses over time is unclear. We evaluated oxygenation over time in advanced liver disease patients with and without HPS using serial pulse oximetry.
  
  
  METHODS
  Data from a prospective cohort of patients evaluated for liver transplantation were analyzed. All patients with significant cardiopulmonary disease were excluded and patients with and without HPS were compared. Arterial oxygen saturation measurements with pulse oximetry (SpO(2)) were recorded serially from initial evaluation until transplantation or last clinic visit on record. Patients with SpO(2) measurements at ≥ 2 visits were included.
  
  
  RESULTS
  A total of 22 HPS patients were compared to 32 non-HPS patients (18 with intrapulmonary vasodilation on contrast echocardiography, CE) over a mean duration of 20 months and 4 SpO(2) measurements. HPS patients had lower SpO(2) at baseline (96.8 vs. 98.4%, P = 0.02) and at end of follow-up (95.8 vs. 98.2%, P = 0.02), and were more likely to have a ≥ 2% reduction (P = 0.04) and faster decline in SpO(2) as compared to non-HPS patients (F = 2.2, P = 0.04). HPS patients with lower SpO(2) and/or PO(2) at baseline appeared more likely to worsen over time. There was no difference in SpO(2) over time between the 2 non-HPS subgroups (- or +CE).
  
  
  CONCLUSIONS
  HPS patients have a significant decline in SpO(2) over time compared to non-HPS patients, and therefore, pulse oximetry may be useful for monitoring cirrhotics for development or worsening of HPS. Presence of intrapulmonary vasodilation in the absence of hypoxemia does not appear to affect SpO(2) over time.
authors.affiliation: Division of Gastroenterology, Hepatology and Nutrition, The University of Texas Health Science Center at Houston, 6431 Fannin Street, MSB 4.234, Houston, TX 77030, USA. rajankochar@gmail.com
authors.forename: Rajan
authors.initials: R
authors.lastname: Kochar
authors.forename: Rajasekhar
authors.initials: R
authors.lastname: Tanikella
authors.forename: Michael B
authors.initials: MB
authors.lastname: Fallon
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D020065:Hepatopulmonary Syndrome / Q000473:pathology*; D006801:Humans; D000860:Hypoxia / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D010100:Oxygen