Clinical non-invasive measurement of effective pulmonary capillary blood flow.
Since traditional pulmonary function testing is centered on measurements of air flow and lung volume, a method to assess the pulmonary circulation might improve our ability to evaluate diseases that impact upon pulmonary hemodynamics. We have developed a PC based application that rapidly calculates pulmonary blood flow. Subjects rebreath a mixture of 10% argon and 3.5% freon for 20 seconds. Gas concentrations at the mouth are monitored by a clinical mass spectrometer and signals are acquired and processed with off-the-shelf hardware. To test the accuracy and reproducibility of this technique, patients with pulmonary artery catheters were assessed by standard thermodilution methods and the rebreathing test. Measurements using this non-invasive technology closely corelate with invasive thermodilution methods (r = 0.980) and show equivalent reproducibility (average standard error = 2.5%). This application of signal processing technology can extend the role of pulmonary function testing to include routine evaluation of the pulmonary circulation.
Winter
S M
SM
Section of Pulmonary and Critical Care Medicine, Norwalk Hospital, CT, USA.
D001128:Argon / Q000493:pharmacokinetics; D001834:Body Water / Q000378:metabolism; D002302:Cardiac Output; D002407:Catheterization, Swan-Ganz; D005617:Chlorofluorocarbons, Methane / Q000493:pharmacokinetics; D003199:Computer Systems; D006801:Humans; D008168:Lung / Q000378:metabolism; D008176:Lung Volume Measurements; D013058:Mass Spectrometry / Q000295:instrumentation; D008838:Microcomputers; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods*; D011652:Pulmonary Circulation; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013815:Thermodilution
D005617:Chlorofluorocarbons, Methane; D001128:Argon