Arterial blood gas control in the upright versus recumbent Asian elephant.
In the elephant, there is concern that lateral recumbency (LR) impairs respiratory muscle and lung function resulting in clinically significant arterial hypoxemia. Using healthy adult female Asian elephants (Elephas maximus, n=6), the hypothesis was tested that, given the O(2) binding characteristics of elephant blood, substantial reductions in arterial O(2) pressure (Pa(O(2))) in LR could be tolerated without lowering arterial O(2) content appreciably. Fifteen minutes of LR decreased Pa(O(2)) from 103+/-2 (upright, U) to 77+/-4 mmHg (P<0.05) and hemoglobin O(2) saturation (U, 97.8+/-0.1, LR, 95.3+/-0.5%, P<0.05). However, due to a recumbency-induced hemoconcentration, arterial O(2) content was unchanged (U, 18.2+/-2.4, LR, 18.3+/-2.1 ml O(2) per 100 ml). In addition, there was a mild hyperventilation in LR that reduced arterial CO(2) pressure (P(CO(2))) from 39.4+/-0.3 to 37.1+/-1.0 mmHg (P<0.05). These data indicate that the Asian elephant can endure at least short periods of LR without lowering arterial O(2) content.
Isaza
Ramiro
R
Departments of Clinical Sciences and Anatomy and Physiology, Kansas State University, Manhattan 66506-5802, USA.
Behnke
Brad J
BJ
Bailey
Janet K
JK
McDonough
Paul
P
Gonzalez
Norberto C
NC
Poole
David C
DC
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000818:Animals; D001158:Arteries; D001784:Blood Gas Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000502:physiology*; D004606:Elephants / Q000502:physiology*; D005260:Female; D000860:Hypoxia / Q000097:blood / Q000662:veterinary*; D011187:Posture / Q000502:physiology*