Monitoring of the Ventilatory Status of Anesthetized Birds of Prey by Using End-Tidal Carbon Dioxide Measured With a Microstream Capnometer

Abstract

The relationship between end-tidal partial pressure of carbon dioxide (PETCO2), arterial partial pressure of carbon dioxide (PaCO2), and blood pH in isoflurane-anesthetized raptors was evaluated. PaCO2 and pH were determined in serial arterial samples from isoflurane anesthetized birds and compared with concurrent end-tidal partial pressure of carbon dioxide measured with a Microstream sidestream capnograph. Forty-eight paired samples, taken from 11 birds of prey (weighing 416-2,062 g), were used to determine correlations coefficients between PaCO2 and PETCO2, and between PETCO2 and pH. Limits of agreement between PaCO2 and PETCO2 also were calculated. Strong correlations were observed between PaCO2 and PETCO2 (r = 0.94; P < 0.0001) as well as between PETCO2 and pH (r = -0.90; P < 0.0001). However, the level of agreement between PaCO2 and PETCO2 varied considerably. Low values of PETCO2, ranging from 18 to 29 mm Hg, exceeded the concomitantly measured values of PaCO2 by an average of 6.0 mm Hg (6.0 +/- 1.9 mm Hg; mean +/- SD). Conversely, high values of PETCO2, ranging from 50 to 63 mm Hg, were on average 7.6 mm Hg (7.6 +/- 9.8 mm Hg) lower than values of PaCO2. In the 30 to 49 mm Hg range for PETCO2, the difference between PETCO2 and PaCO2 was on average 1.0 mm Hg (1.0 +/- 8.5 mm Hg). These results suggest that the capnograph used provided a sufficiently accurate estimation of arterial partial pressure of carbon dioxide for birds weighing > 400 g and receiving manual positive ventilation with a Bain system. In our study, the linear relationship observed between the pH and the end-tidal partial pressure of carbon dioxide suggested that the monitoring of end-tidal partial pressure of carbon dioxide also can be useful to prevent respiratory acidosis.

Minimum Anesthetic Concentration and Cardiovascular Dose–Response Relationship of Isoflurane in Cinereous Vultures (Aegypius monachus)

“…Thus, severe hypercapnia and hypoxemia did not occur in the birds of this current study, and PaCO 2 and arterial blood pH were maintained constant at near the physiological range of the raptors. 2 Because birds maintain their body temperatures between 40 and 428C, 3 during the experimental procedures, esophageal temperatures between 40 and 418C were maintained by using a supplemental heat source. Lastly, blood samples from all the birds prior to MAC determination were not obtained.…”

Tramadol ou butorfanol: modelo analgésico pós osteossíntese experimental de úmero em galos ( Gallus gallus domesticus )

“…Ao contrário do observado no estudo de Curro, Brunson & Paul-Murphy (1994), os quais não observaram alterações significativas da f em cacatuas anestesiadas com butorfanol e isoflurano. A redução na f está relacionada ainda ao uso do agente inalatório isoflurano, o qual causa depressão respiratória dose dependente através da depressão do centro respiratório central (Desmarchelier et al 2007). Resultado semelhante para f também foi observada por Granone et al (2012) em falcões de cauda vermelha, que receberam como agente de manutenção anestésica o isoflurano.…”

The Value of Endoscopy in a Wildlife Raptor Service

“…14,15 Inhalation anesthesia is generally preferred for many reasons, including faster recoveries. 14 Anesthesia protocols routinely used by the authors include mask induction with isoflurane, followed by intubation and manually assisted ventilation (target End-tidalCO 2 of 35-45 mm Hg).…”

“…14 Anesthesia protocols routinely used by the authors include mask induction with isoflurane, followed by intubation and manually assisted ventilation (target End-tidalCO 2 of 35-45 mm Hg). 15 Butorphanol is used for analgesia.…”