Measurement of breath-by-breath gas exchange during general anaesthesia using a single pneumotachograph.
A breath-by-breath gas exchange measurement system using a single pneumotachograph suitable for use during general anaesthesia is described. The system's accuracy has been assessed by a combination of error sensitivity analysis, laboratory testing of the component measurements used to calculate gas exchange and measurements on volunteers and patients. The system is shown to have a mean accuracy of +/- 2.6 ml breath-1 for VCO2 measurements, +/- 7.12 ml breath-1 for VO2 and +/- 5.55 ml breath-1 for VN2O measurement. The application of a lung gas stores correction using argon improved between breath variability by 50%.
Beatty
P C
PC
North Western Department of Medical Physics, University Hospital of South Manchester, UK.
D000465:Algorithms; D000768:Anesthesia, General; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005069:Evaluation Studies as Topic; D006801:Humans; D013058:Mass Spectrometry; D008838:Microcomputers / Q000592:standards; D011659:Pulmonary Gas Exchange; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity