Effect of body position on respiratory system volumes in anesthetized red-tailed hawks (Buteo jamaicensis) as measured via computed tomography

Abstract

In anesthetized red-tailed hawks, positioning in sternal recumbency resulted in the greatest lung and air-sac volumes and lowest lung density, compared with positioning in right lateral and dorsal recumbency. Additional studies are necessary to determine the physiologic effects of body position on the avian respiratory system.

Comparison of air sac volume, lung volume, and lung densities determined by use of computed tomography in conscious and anesthetized Humboldt penguins (Spheniscus humboldti) positioned in ventral, dorsal, and right lateral recumbency

“…Recumbency and anesthesia had a negligible effect on lung volume in the penguins in this study; no significant difference was detected for lung volume in any recumbency or for conscious versus anesthetized penguins. These findings were consistent with a model of nonelastic lungs in birds, but was in contrast with results of studies performed with Pekin ducks (Anas platyrhynchos domestica) 16 and redtailed hawks (B jamaicensis) 18 ; results of those studies indicated significant lung volume changes among positions. Such differences may be species specific, and lungs with low elasticity may be beneficial for aquatic, diving birds.…”

“…[26][27][28] Anesthetized, spontaneously breathing red-tailed hawks (Buteo jamaicensis) have the highest lung and air sac volumes and the lowest lung densities when positioned in ventral recumbency, compared with values for birds in right lateral and dorsal recumbencies. 18 To the author' s knowledge, no studies have been conducted to evaluate air sac volume or lung density in clinically normal penguins. Similarly, no studies have been conducted in which those variables were evaluated in various body positions or sedation statuses of such birds.…”

“…Few studies have been conducted in which air sac volume in birds [16][17][18] and lung volume in turtles 19 have been determined with CT. Computed tomography has been used to determine pulmonary, renal, and hepatic volume and density in humans and other animals. [20][21][22] Avoidance of a long duration of dorsal recumbency during anesthesia for birds has been recommended on the basis of the theory that air sacs can be compressed by internal organs.…”

Analysis of Electrocardiographic Parameters in Helmeted Guinea Fowl (Numida meleagris)

“…Birds positioned in dorsal and right lateral recumbency reportedly have lower lung and air-sac volumes and greater lung density compared with those positioned in sternal recumbency. 22,23 Sternal positioning, as was used for the birds in this study, helps maintain normal cardiopulmonary anatomic and physiologic orientation, which in turn may affect blood pressure, perfusion, cardiac outflow, and function. As is the case among mammalian species, significant differences in most ECG parameters have been described among avian species.…”

Comparison of Computed Tomographic Images of Birds Obtained With Sedation vs General Anesthesia

“…Several studies have been published on the normal tomographic and CT anatomy of birds. [1][2][3][4][5][6][7] Digital radiography is an important imaging technique used for avian patients; however, there are limitations associated with traditional radiography, including the following: (1) general anesthesia is usually required during radiographic procedures owing to the temperament of birds and the difficulties associated with manual restraint, and (2) radiographic evaluations are an insensitive means of detecting pathology in areas with significant superimposition of anatomic structures. 8 One scientific study compared conventional radiographs with CT in imaging of the head in both raptors and psittacines.…”