title: Echocardiographic evaluation of pulmonary venous blood flow and cardiac function changes during one-lung ventilation.
abstract: OBJECTIVE
  The intra-pulmonary shunt induced by one-lung ventilation (OLV), is alleviated by increased pulmonary blood flow by gravitational redistribution and hypoxic pulmonary vasoconstriction. We investigated the changes of pulmonary venous blood flow (PVBF) and biventricular function during OLV with echocardiography. And the correlation between PVBF and intra-pulmonary shunt fraction (Qs/Qt) was evaluated.
  
  
  METHODS
  PVBF of the left upper pulmonary vein and cardiac function were measured with echocardiography in twenty-five patients who underwent elective thoracic surgery in left lateral decubitus. Qs/Qt and PaO2 were measured with blood gas analysis. Data was obtained at 10 min after two-lung ventilation in supine (TLV-S) and lateral decubitus position (TLV-L), and at 10, 20 and 30 min after OLV in lateral decubitus position (OLV-10, -20 and -30).
  
  
  RESULTS
  There were significant changes in PVBF among TLV-S, TLV-L and OLV-10 (959.5±280.8, 1416.9±489.7 and 1999.9±670.5 ml/min; P<0.05, respectively). There were not differences in PVBF, Qs/Qt and PaO2 among OLV-10, -20 and -30. There were an inverse correlation between percent change of PVBF and change of Qs/Qt (r(2) = 0.5; P<0.0001) and positive correlations between the percent change of PVBF and change of PaO2 (r(2) = 0.4; P<0.0001) during OLV over TLV-L. No significant changes in biventricular systolic and diastolic function were observed during positional change and OLV.
  
  
  CONCLUSIONS
  A remarkable change of PVBF relevant to gravitational distribution and hypoxic pulmonary vasoconstriction was proved by echocardiography. And PVBF changes could represent the changes of Qs/Qt and PaO2 during OLV. However, biventricular function was not impaired during OLV.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Su Hyun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Namo
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Hyun Il
authors.initials: HI
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Oh
keywords: One-lung ventilation; arterial oxygenation; cardiac function; echocardiography; hypoxic pulmonary vasoconstriction; intra-pulmonary shunt; pulmonary venous blood flow