Non-invasive forced expiratory flow-volume curves to measure lung function in cats.
Forced expiratory flow-volume curves were performed in 15 cats using the non-invasive thoracic compression techniques developed for use in human infants. Cats breathed through a face mask and pneumotachygraph from which flow and volume were obtained. Thoracic compression was applied from an inflatable bag in a non-expandable jacket surrounding the animal. Bag inflation at end inspiration was initiated by a computer pulse to a pressurized chamber. Processed signals from the pneumotachygraph determined maximum-forced expiratory flow at lung volume equivalent to functional residual capacity (FRC), termed V'maxFRC. Different compression pressures were used, and the highest value from a technically satisfactory flow-volume loop was taken as the result. Mean (+/- 95% CI) V'maxFRC was 422 (369-475) ml/s. Compared with infants of similar weight (V'maxFRC approximately 180 ml/s), cats had a much higher V'maxFRC. Tests repeated another day showed a mean (+/-95% CI) percentage difference between paired tests to be 2.8 (-12.6, +18.3)%. Non-invasive forced expiratory flow-volume measurements can be reliably obtained in sedated cats.
Bark
Hylton
H
School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel. hylton.bark@huji.ac.il
Epstein
Ana
A
Bar-Yishay
Ephraim
E
Putilov
Alex
A
Godfrey
Simon
S
D000399:Air Pressure; D000818:Animals; D002415:Cats; D005540:Forced Expiratory Flow Rates / Q000502:physiology*; D005652:Functional Residual Capacity / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics / Q000502:physiology; D013990:Tidal Volume / Q000502:physiology*