Transdiaphragmatic pressure measurement in cattle: technical data.
Techniques and methods required for accurate and reproducible measurements of transdiaphragmatic pressure (Pdi), were studied in seven-week and five-month-old calves. Since reliable pleural pressure measurement in cattle has already been described, separate experiments were conducted to compare retrodiaphragmatic pressures measured (i) with balloon-catheters and needle catheters, (ii) before and after eructation and (iii) in the ruminal and in the peritoneal cavities. Whereas respiratory-induced pressure changes were equally transmitted throughout the rumen content, a marked anteroposterior damping was observed as the recording site in the abdominal cavity was moved away from the diaphragm (P < 0.0001). It was concluded that the most appropriate and accurate way to measure Pdi changes in polygastric animals is to measure the pressure changes existing in the mid-thoracic portion of the oesophagus and in the liquid content of the rumen with balloon-tubing units. Neither growth- and diet-related rumen enlargement nor eructation, which are two typical characteristics of ruminants, altered the reliability of retrodiaphragmatic pressure measurements in the two age groups studied.
Desmecht
D
D
Laboratory for Functional Investigation, Faculty of Veterinary Medicine, University of Liège, Belgium.
Rollin
F
F
Lekeux
P
P
D000005:Abdomen / Q000502:physiology*; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003964:Diaphragm / Q000502:physiology*; D008297:Male; D011312:Pressure; D012129:Respiratory Function Tests / Q000662:veterinary; D015656:Respiratory Mechanics / Q000502:physiology*; D012417:Rumen / Q000502:physiology