Effects of posture and intraruminal pressure on the bronchial calibre of cattle during xylazine/halothane anaesthesia.
The effects of changes in body position and intraruminal pressure on the bronchial calibre of anaesthetised, paralysed adult cattle were investigated using a computer-aided forced airflow oscillation technique which enabled the measurement of specific lower airways conductance (sGlaw), expiratory reserve volume (ERV) and residual resistance (RA). sGlaw and RA were highest in dorsal and lowest in sternal recumbency, but ERV was very much greater in sternal recumbency than in other positions. Turning the animals from right to left lateral recumbency resulted in a marked reduction in sGlaw and increase in ERV, providing further evidence of functional impairment of the dependent areas of the lungs of large animals. Changes in intraruminal pressure had little effect on bronchial calibre, suggesting that the respiratory dysfunction resulting from ruminal tympany is primarily caused by a reduction in compliance rather than an increase in airway resistance.
Watney
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GC
D000403:Airway Resistance; D000758:Anesthesia / Q000662:veterinary*; D000818:Animals; D001980:Bronchi / Q000502:physiology*; D002417:Cattle / Q000502:physiology*; D005260:Female; D006221:Halothane; D011187:Posture; D011312:Pressure; D012417:Rumen / Q000502:physiology; D014991:Xylazine
D014991:Xylazine; D006221:Halothane