title: Effects of head-up tilt on intrapulmonary shunt fraction and oxygenation during 1-lung ventilation in the lateral decubitus position.
abstract: OBJECTIVE
  Hypoxemia is a common problem of 1-lung ventilation. Arterial oxygenation progressively decreases after 1-lung ventilation. The surgical position influences the shunt and arterial oxygenation. Therefore we evaluated the effect of head-up tilt on intrapulmonary shunt and oxygenation during 1-lung ventilation in the lateral decubitus position.
  
  
  METHODS
  Twenty patients requiring 1-lung ventilation were included in this study. During 1-lung ventilation, hemodynamic and respiratory variables were measured 15 minutes after horizontal positioning in the lateral decubitus position (baseline), 5 and 10 minutes after a 10-degree head-up tilt (T5 and T10, respectively), and 10 minutes after the patient was returned to a horizontal position (T20). Arterial and mixed venous blood analyses were performed at the same time points.
  
  
  RESULTS
  Arterial oxygenation was increased, and shunt was decreased significantly during head-up tilt position in 1-lung ventilation. These changes were accompanied by decreases in the mean arterial pressure and cardiac filling pressures without significant changes in cardiac index.
  
  
  CONCLUSIONS
  Head-up tilt during 1-lung ventilation in the lateral decubitus position caused a significant decrease in shunt and an increase in arterial oxygenation that persisted after the patient was returned to the horizontal lateral decubitus position.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Ajou University of College of Medicine, Suwon, Korea.
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Park
authors.forename: Dae Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Hong
mesh_terms: D005260:Female; D006439:Hemodynamics; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D056888:Patient Positioning; D011013:Pneumonectomy / Q000379:methods; D011659:Pulmonary Gas Exchange
chemical_list: D010100:Oxygen