Arterial oxygenation associated with portopulmonary hypertension

Chest. 2002 Jun;121(6):1869-75. doi: 10.1378/chest.121.6.1869.


Study objectives: To characterize arterial oxygenation in patients referred to Mayo Clinic for liver transplantation with a diagnosis of portopulmonary hypertension (portoPH).

Design: Prospective study.

Setting: Liver transplantation program and pulmonary hypertension clinic in a tertiary referral center.

Participants: Twenty consecutive patients with abnormal pulmonary hemodynamics documented by right-heart catheterization (mean pulmonary artery pressure [MPAP] > or = 25 mm Hg, pulmonary vascular resistance [PVR] > or = 120, and pulmonary capillary wedge pressure [PCWP] < or = 15 mm Hg). Liver transplant candidates with normal pulmonary hemodynamics via screening Doppler echocardiography (n = 40) served as control subjects. A subgroup of patients underwent postural and inspired 100% oxygen blood gas analysis, contrast echocardiography, and technetium-labeled macroaggregated albumin ((99m)TcMAA) lung/brain scanning to identify and quantitate the degree of intracardiac or intrapulmonary shunting.

Measurements and results: portoPH was moderate to severe (MPAP > 35 mm Hg) in 18 of 20 patients (90%). Arterial-alveolar oxygen pressure gradient (P[A-a]O(2)) was abnormal (> or = 20 mm Hg) in 16 of 20 patients (80%). PaO(2) was abnormal (< or = 70 mm Hg) in 3 of 20 patients (15%). Pa0(2) was significantly less and P(A-a)O(2) was significantly greater compared to control subjects (p < 0.001). All patients had normal (99m)TcMAA brain uptake (< 6%) and negative transthoracic contrast echocardiographic findings. No significant correlations were found between oxygenation and hemodynamic variables (MPAP, PVR, PVR index, and transpulmonary gradient).

Conclusions: Arterial oxygenation associated with portoPH was frequently abnormal and significantly worse when compared to patients with normal pulmonary hemodynamics by Doppler echocardiography. Hypoxemia, as measured by PaO(2) and P(A-a)O(2), was usually mild even in the setting of moderate-to-severe portoPH.

MeSH terms

  • Adult
  • Aged
  • Blood Gas Analysis
  • Female
  • Hemodynamics
  • Humans
  • Hypertension, Portal / metabolism*
  • Hypertension, Portal / physiopathology
  • Hypertension, Pulmonary / metabolism*
  • Hypertension, Pulmonary / physiopathology
  • Male
  • Middle Aged
  • Oxygen / metabolism*
  • Prospective Studies
  • Pulmonary Circulation


  • Oxygen