title: Evaluation of the CO2 rebreathing cardiac output method in seriously ill patients.
abstract: The CO2 rebreathing cardiac output method is a totally noninvasive Fick procedure needing validation in various disease states to become clinically applicable. Simultaneous measurements of cardiac output by CO2 rebreathing and dye-dilution or direct Fick techniques were performed in 53 patients. In nine patients with pulmonary disease rebreathing cardiac output averaged 4.85 L/min compared to 5.18 L/min by dye-dilution or Fick (r = 0.16). In 14 instances of acute myocardial infarction cardiac output was 5.53 L/min by rebreathing and 5.87 L/min by dye-dilution (r = 0.95), while in nine shock cases it averaged 3.98 L/min by dye-dilution or Fick and 3.75 L/min by CO2 rebreathing (r = 0.94). In five heart failure cases with mitral insufficiency, which may distort dye durves, correlation between standard and rebreathing methods was r = 0.09, but in 16 cases without mitral regurgitation, r = 0.89. Acute interventions in ten patients increased dye-dilution cardiac output by 0.92 L/min and rebreathing outputs by 0.60 L/min (r = 0.87). The data suggest that the CO2 rebreathing cardiac output method may be useful in the CCU-MICU setting.
mesh_terms: D002245:Carbon Dioxide; D002302:Cardiac Output; D004395:Dye Dilution Technique; D005069:Evaluation Studies as Topic; D006331:Heart Diseases / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D008171:Lung Diseases / Q000503:physiopathology; D008722:Methods; D009203:Myocardial Infarction / Q000503:physiopathology; D012770:Shock, Cardiogenic / Q000503:physiopathology
chemical_list: D002245:Carbon Dioxide