Partial pressure of end-tidal CO2 sampled via an intranasal catheter as a substitute for partial pressure of arterial CO2 in dogs
Article first published online: 10 MAY 2007
Journal of Veterinary Emergency and Critical Care
Volume 17, Issue 2, pages 143–148, June 2007
How to Cite
Pang, D., Hethey, J., Caulkett, N. A. and Duke, T. (2007), Partial pressure of end-tidal CO2 sampled via an intranasal catheter as a substitute for partial pressure of arterial CO2 in dogs. Journal of Veterinary Emergency and Critical Care, 17: 143–148. doi: 10.1111/j.1476-4431.2007.00213.x
- Issue published online: 10 MAY 2007
- Article first published online: 10 MAY 2007
- expired carbon dioxide;
- nasal catheter;
- nasal oxygen
Objective: To demonstrate correlation and clinical usefulness of the partial pressure of end-tidal CO2 (ETCO2) measurement by nasal catheter placement in sedated dogs with and without concurrent nasal oxygen administration as a substitute for partial pressure of arterial CO2 (PaCO2).
Design: Prospective, cross-over trial.
Setting: University of Saskatchewan veterinary research laboratory.
Animals: Six cross-breed dogs with a mean (±SD) weight of 29.1±4.03 kg.
Interventions: All dogs were sedated with 5 μg/kg medetomidine intravenously (IV) and an arterial catheter was placed in a dorsal pedal artery for removal of blood for gas analysis. A nasal catheter was placed in the ventral meatus and connected to a capnometer for ETCO2 measurements in all dogs. Dogs receiving supplemental nasal oxygen had a second nasal catheter placed in the contralateral naris.
Measurements and main results: In the group without nasal oxygen supplementation, the ETCO2 measurement underestimated (negative bias) the PaCO2 by −2.20 mmHg with limits of agreement (95% confidence interval) of −5.79, 1.39 mmHg. In the group receiving oxygen supplementation, ETCO2 measurement underestimated (negative bias) the PaCO2 by −2.46 mmHg with limits of agreement (95% confidence interval) of −8.42, 3.50 mmHg.
Conclusions: The results of this study demonstrate that ETCO2 monitoring via a nasal catheter provides a clinically acceptable substitute to arterial blood gas analysis as a means of monitoring ventilation in healthy, sedated dogs. The limits of agreement were within acceptable limits with and without concurrent insufflation of oxygen.