Effect of high PaCO2 and time on cerebrospinal fluid and intraocular pressure in halothane-anesthetized horses

L. K. Cullen From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by L. K. Cullen in
Current site
Google Scholar
PubMed
Close
 MVSc, PhD
,
E. P. Steffey From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by E. P. Steffey in
Current site
Google Scholar
PubMed
Close
 VMD, PhD
,
C. S. Bailey From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by C. S. Bailey in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
G. Kortz From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by G. Kortz in
Current site
Google Scholar
PubMed
Close
 DVM
,
J. da Silva Curiel From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by J. da Silva Curiel in
Current site
Google Scholar
PubMed
Close
 DVM
,
R. W. Bellhorn From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by R. W. Bellhorn in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
M. J. Woliner From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by M. J. Woliner in
Current site
Google Scholar
PubMed
Close
 BS
,
A. R. Elliott From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by A. R. Elliott in
Current site
Google Scholar
PubMed
Close
 PhD
, and
K. A. Jarvis From the Department of Surgery (Cullen, Steffey, Bailey, Bellhorn, Woliner, Elliott, Jarvis) and the Veterinary Medical Teaching Hospital (Kortz, da Silva Curiel), School of Veterinary Medicine, University of California, Davis, CA 95616.

Search for other papers by K. A. Jarvis in
Current site
Google Scholar
PubMed
Close
 MSN

Click on author name to view affiliation information

SUMMARY

The effects of different arterial carbon dioxide tensions (PaCO2) on cerebrospinal fluid pressure (csfp) and intraocular pressure (iop) were studied in 6 male halothane-anesthetized horses positioned in left lateral recumbency. Steady-state anesthetic conditions (1.06% end-tidal halothane concentration) commenced 60 minutes following anesthetic induction with only halothane in oxygen. During atracurium neuromuscular blockade, horses were ventilated, and respiratory rate and peak inspiratory airway pressure were maintained within narrow limits. The csfp and iop were measured at 3 different levels of PaCO2 (approx 40, 60, and 80 mm of Hg). The PaCO2 sequence in each horse was determined from a type of switchback design with the initial PaCO2 (period 1), established 30 minutes after the commencement of steady-state anesthesia, being repeated in the middle (period 3) and again at the end (period 5) of the experiment. Measurements taken from the middle 3 periods (2, 3, and 4) would form a Latin square design replicated twice. The interval between each period was approximately 45 minutes.

Data from periods 2, 3, and 4 indicated that csfp (P < 0.05) and mean systemic arterial pressure increased significantly (P < 0.05) with high PaCO2. Mean central venous pressure, heart rate, and iop did not change significantly during these same conditions. Measurements taken during periods 1, 3, and 5 were compared to assess the time-related responses to anesthesia and showed a significant increase in csfp, a significant decrease in mean central venous pressure, and a small (but not statistically significant) increase in mean systemic arterial pressure.

SUMMARY

The effects of different arterial carbon dioxide tensions (PaCO2) on cerebrospinal fluid pressure (csfp) and intraocular pressure (iop) were studied in 6 male halothane-anesthetized horses positioned in left lateral recumbency. Steady-state anesthetic conditions (1.06% end-tidal halothane concentration) commenced 60 minutes following anesthetic induction with only halothane in oxygen. During atracurium neuromuscular blockade, horses were ventilated, and respiratory rate and peak inspiratory airway pressure were maintained within narrow limits. The csfp and iop were measured at 3 different levels of PaCO2 (approx 40, 60, and 80 mm of Hg). The PaCO2 sequence in each horse was determined from a type of switchback design with the initial PaCO2 (period 1), established 30 minutes after the commencement of steady-state anesthesia, being repeated in the middle (period 3) and again at the end (period 5) of the experiment. Measurements taken from the middle 3 periods (2, 3, and 4) would form a Latin square design replicated twice. The interval between each period was approximately 45 minutes.

Data from periods 2, 3, and 4 indicated that csfp (P < 0.05) and mean systemic arterial pressure increased significantly (P < 0.05) with high PaCO2. Mean central venous pressure, heart rate, and iop did not change significantly during these same conditions. Measurements taken during periods 1, 3, and 5 were compared to assess the time-related responses to anesthesia and showed a significant increase in csfp, a significant decrease in mean central venous pressure, and a small (but not statistically significant) increase in mean systemic arterial pressure.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 34 34 12
PDF Downloads 6 6 2
Advertisement