Cardiopulmonary effects of positioning pregnant cows in dorsal recumbency during the third trimester

Colin I. Dunlop From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences (Dunlop, Hodgson, Smith, Tyler), and Department of Statistics (Chapman), Colorado State University, Fort Collins, CO 80523.

Search for other papers by Colin I. Dunlop in
Current site
Google Scholar
PubMed
Close
 BVSc
,
David S. Hodgson From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences (Dunlop, Hodgson, Smith, Tyler), and Department of Statistics (Chapman), Colorado State University, Fort Collins, CO 80523.

Search for other papers by David S. Hodgson in
Current site
Google Scholar
PubMed
Close
 DVM
,
John A. Smith From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences (Dunlop, Hodgson, Smith, Tyler), and Department of Statistics (Chapman), Colorado State University, Fort Collins, CO 80523.

Search for other papers by John A. Smith in
Current site
Google Scholar
PubMed
Close
 DVM
,
Phillip L. Chapman From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences (Dunlop, Hodgson, Smith, Tyler), and Department of Statistics (Chapman), Colorado State University, Fort Collins, CO 80523.

Search for other papers by Phillip L. Chapman in
Current site
Google Scholar
PubMed
Close
 PhD.
, and
Liz M. Tyler From the Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences (Dunlop, Hodgson, Smith, Tyler), and Department of Statistics (Chapman), Colorado State University, Fort Collins, CO 80523.

Search for other papers by Liz M. Tyler in
Current site
Google Scholar
PubMed
Close
 DVM

Summary

The uterine hemodynamic response to maternal positioning in dorsal recumbency 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 recumbency. There were minimal differences between measurements at 15 and 30 minutes of dorsal recumbency.

Summary

The uterine hemodynamic response to maternal positioning in dorsal recumbency 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 recumbency. There were minimal differences between measurements at 15 and 30 minutes of dorsal recumbency.

Advertisement