title: Changes in lung function and pulmonary capillary permeability after cardiopulmonary bypass.
abstract: OBJECTIVE
  To assess the possibility that changes in lung function following cardiopulmonary bypass are associated with increased pulmonary capillary permeability.
  
  
  METHODS
  A prospective, descriptive study.
  
  
  METHODS
  Adult cardiothoracic ICU in a post-graduate teaching hospital.
  
  
  METHODS
  Ten sequential patients undergoing cardiac surgery requiring cardiopulmonary bypass.
  
  
  METHODS
  Arterial blood gas tensions, helium dilution end-expiratory lung volume, and carbon monoxide transfer were measured by a rebreathing technique preoperatively and 2 hrs postoperatively. Lung extravascular protein accumulation index was measured by a double-isotope technique 2 hrs postoperatively and in a group of normal controls.
  
  
  RESULTS
  Mean +/- SEM alveolar-arterial PO2 gradient increased from 77 +/- 14 torr (10.3 +/- 1.8 kPa) to 138 +/- 24 torr (18.5 +/- 3.2 kPa) (p less than .01). Functional residual capacity decreased by 20.2 +/- 5.6% (p less than .01). Carbon monoxide transfer decreased by 26.7 +/- 5.3% (p less than .01) for the lung as a whole and by 17.9 +/- 3.2% (p less than .01) per liter of accessible gas volume. Protein accumulation index ranged from 0.03 to 3.2 x 10(-3) (median 0.6) postoperatively (median for normal subjects 0.4; p less than .05), although only one patient had a value indicative of clinically important endothelial injury.
  
  
  CONCLUSIONS
  Cardiac surgery involving cardiopulmonary bypass results in a deterioration in lung function characterized by a loss of lung volume, a reduction in carbon monoxide transfer, and an increase in the alveolar-arterial PO2 gradient. These changes do not appear to be mediated by an increase in pulmonary endothelial permeability.
authors.affiliation: Department of Clinical Physiology, Anaesthesia, and Intensive Care, Royal Brompton National Heart and Lung Hospital, London, UK.
authors.forename: P D
authors.initials: PD
authors.lastname: Macnaughton
authors.forename: S
authors.initials: S
authors.lastname: Braude
authors.forename: D N
authors.initials: DN
authors.lastname: Hunter
authors.forename: D M
authors.initials: DM
authors.lastname: Denison
authors.forename: T W
authors.initials: TW
authors.lastname: Evans
mesh_terms: D000368:Aged; D002199:Capillary Permeability / Q000502:physiology*; D002315:Cardiopulmonary Bypass / Q000295:instrumentation / Q000379:methods; D004727:Endothelium / Q000503:physiopathology; D005260:Female; D006801:Humans; D007204:Indium; D007205:Indium Radioisotopes; D016018:Least-Squares Analysis; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011877:Radionuclide Imaging; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D013667:Technetium; D014001:Tin; D017971:Tin Compounds
chemical_list: D007205:Indium Radioisotopes; D017971:Tin Compounds; D007204:Indium; C023599:stannous chloride; C020758:indium trichloride; D013667:Technetium; D014001:Tin