title: Arterial to end-tidal CO2 tension difference after bilateral lung transplantation.
abstract: OBJECTIVE
  To assess ventilation/perfusion mismatch with high ventilation/perfusion ratios (i.e., alveolar deadspace) and to assess capnography as a noninvasive method of monitoring ventilation after bilateral lung transplantation.
  
  
  METHODS
  Clinical, prospective study. Repeated-measures analysis of variance was done to assess the time course of the arterial to end-tidal CO2 tension difference.
  
  
  METHODS
  University hospital operating theater and intensive care unit.
  
  
  METHODS
  Seven consecutive patients aged 25 to 64 yrs who underwent bilateral lung transplantation for end-stage lung disease.
  
  
  METHODS
  None.
  
  
  RESULTS
  The arterial to end-tidal CO2 tension difference was determined using infrared absorption capnography during postoperative day 1. Measurements were done at 10 mins, and at 1, 3, 12, and 24 hrs after bilateral lung transplantation (timing of measurements determined from the time when both lungs were perfused and mechanically ventilated). An arterial to end-tidal CO2 tension difference, ranging from 6 to 21 torr (0.8 to 2.8 kPa), mean 16 +/- 5 torr (2.2 +/- 0.7 kPa), was observed immediately after the transplantation. This difference rapidly decreased to 9 +/- 4 torr (1.2 +/- 0.6 kPa; p < .01) after 3 hrs and to 5 +/- 3 torr (0.6 +/- 0.4 kPa; p < .01) after 24 hrs.
  
  
  CONCLUSIONS
  Our data suggest marked alveolar deadspace ventilation immediately after bilateral lung transplantation. The presence and rapid improvement of this ventilation/perfusion mismatch may reflect the presence of ischemia-reperfusion lung injury and its improvement in the first hours of reperfusion. In five of seven patients, capnography was not a good measure of PaCO2 during the first hours after bilateral lung transplantation.
authors.affiliation: Department of Cardiothoracic Anesthesia and Intensive Care, University of Vienna, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Jellinek
authors.forename: M
authors.initials: M
authors.lastname: Hiesmayr
authors.forename: P
authors.initials: P
authors.lastname: Simon
authors.forename: W
authors.initials: W
authors.lastname: Klepetko
authors.forename: W
authors.initials: W
authors.lastname: Haider
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000097:blood / Q000502:physiology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D015427:Reperfusion Injury / Q000503:physiopathology; D012119:Respiration; D012126:Respiratory Dead Space; D014692:Ventilation-Perfusion Ratio
chemical_list: D002245:Carbon Dioxide