title: Cardiopulmonary effects of positioning pregnant cows in dorsal recumbency during the third trimester.
abstract: The uterine hemodynamic response to maternal positioning in dorsal recombency was evaluated in 7 conscious pregnant cows during the third trimester. Anesthetic or sedative drugs were not administered. Uterine artery flow was measured, using a previously implanted ultrasonic flow probe. Catheters implanted in the uterine artery and vein were used for measurement of blood pressure and for blood sample collections. Heart rate, systemic arterial pressure, uterine arterial blood flow, arterial and venous oxygen and carbon dioxide tensions, and pH were measured in cows in standing position. Cows were cast with ropes and positioned in dorsal recumbency, then measurements were repeated at 15 and 30 minutes. Compared with standing measurements, dorsal recumbency caused 50% increase in heart rate and 44% increase in arterial blood pressure. Uterine artery flow did not change significantly. Despite increased ventilation, arterial oxygenation was reduced during dorsal recombency. There were minimal differences between measurements at 15 and 30 minutes of dorsal recumbency.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523.
authors.forename: C I
authors.initials: CI
authors.lastname: Dunlop
authors.forename: D S
authors.initials: DS
authors.lastname: Hodgson
authors.forename: J A
authors.initials: JA
authors.lastname: Smith
authors.forename: P L
authors.initials: PL
authors.lastname: Chapman
authors.forename: L M
authors.initials: LM
authors.lastname: Tyler
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001798:Blood Proteins / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood; D002417:Cattle; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011187:Posture; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D012119:Respiration; D013045:Species Specificity; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance
chemical_list: D001798:Blood Proteins; D002245:Carbon Dioxide; D010100:Oxygen