Capnographic monitoring of end-tidal partial pressure of carbon dioxide in anesthetized cinereous vultures (Aegypius monachus)

Abstract

The relationships between end-tidal partial pressure of carbon dioxide (PETCO2) and arterial partial pressure of carbon dioxide (PaCO2), and between PETCO2 and blood pH in isoflurane-anesthetized cinereous vultures were evaluated. Nine cinereous vultures (weighing 7.3-9.5 kg) were anesthetized via mask with isoflurane, intubated, and connected to a mechanical ventilator. By mechanical ventilator, respiratory rate was altered to achieve a PETCO2 randomly selected among 30 to 35 mmHg. PaCO2 and blood pH were determined in serial arterial samples and compared with concurrent PETCO2measured with a sidestream capnography. Thirty six samples, nine cinereous vultures were tested 4 times each, were used to determine correlations coefficients between PaCO2 and PETCO2, and between PETCO2 and blood pH. Strong correlations were observed between PaCO2 and PETCO2 (r = 0.951, P = 0.000, y = 1.679x ? 30.236, R2 = 0.905) as well as between PETCO2 and blood pH (r = ?0.728, P = 0.000, y = ?0.024x + 8.389, R2 = 0.530) with Pearson’s correlation coefficient and simple linear regression. These results suggest that the capnography used provided a sufficiently accurate estimation of PaCO2 and blood pH. Thus, the monitoring of PETCO2 can be useful method to prevent hypoventilation for cinereous vultures receiving mechanical ventilation. ? 2015 Korean Society of Veterinary Clinics. All rights reserved.