Effects of low and high fractions of inspired oxygen on ventilation in ducks anesthetized with isoflurane.
High fractions of inspired oxygen are commonly used during general anesthesia in birds. Observations in ducks anesthetized with halothane or pentobarbital indicated that high fractions of inspired oxygen depress ventilation. The purpose of this study was to test the hypothesis that ducks hypoventilate when breathing high fractions of inspired oxygen, compared with the same ducks breathing low fractions of inspired oxygen. Respiratory variables were recorded in 7 ducks anesthetized with 1.4% isoflurane in oxygen. Four concentrations of oxygen (21, 40, 70, and > 90%) were used for each duck. Respiratory rate decreased as the fraction of inspired oxygen increased, but not significantly. There was a significant decrease in tidal volume as PaCO2 increased. Hyperoxia was observed to contribute to hypoventilation in ducks anesthetized with isoflurane in oxygen.
Seaman
G C
GC
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
Ludders
J W
JW
Erb
H N
HN
Gleed
R D
RD
D000768:Anesthesia, General; D000818:Animals; D001639:Bicarbonates / Q000097:blood; D002245:Carbon Dioxide; D004372:Ducks / Q000502:physiology*; D001239:Inhalation; D007530:Isoflurane; D010100:Oxygen / Q000097:blood / Q000494:pharmacology*; D010313:Partial Pressure; D012119:Respiration / Q000187:drug effects / Q000502:physiology*
D001639:Bicarbonates; D002245:Carbon Dioxide; D007530:Isoflurane; D010100:Oxygen