Changes in the arterial to end-tidal PCO2 differences during coronary artery bypass grafting.
The arterial to end-tidal PCO2 difference, PaCO2-PE,CO2, was measured at four different stages during coronary artery bypass grafting in 43 patients: 1) before sternotomy; 2) after sternotomy, sternum retracted; 3) after bypass, sternum still retracted; 4) sternum closed. Mean PaCO2-PE,CO2 initially was 0.6 kPa and changed scarcely at all during the procedure. There were, however, some moderate individual changes in PaCO2-PE,CO2 during surgery, the range of changes compared to the initial value being from -1.4 to +1.3 kPa. The standard deviations for the changes from stage to stage were 0.3-0.4 kPa. PaCO2-PE,CO2 changed by more than 0.5 kPa on only 12 occasions in ten patients. The limitations of PaCO2-PE,CO2 as an index of the alveolar deadspace fraction and the efficiency of ventilation are discussed.
Fletcher
R
R
Department of Anaesthesia, University Hospital, Lund, Sweden.
Veintemilla
F
F
D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood* / Q000378:metabolism; D006328:Cardiac Catheterization; D001026:Coronary Artery Bypass; D005112:Extracorporeal Circulation; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D011659:Pulmonary Gas Exchange; D015657:Respiratory Transport; D013249:Sternum / Q000601:surgery; D013990:Tidal Volume
D002245:Carbon Dioxide