TY - JOUR
T1 - Effects of normobaric and hypobaric hypoxia on ventilation and arterial blood gases in ducks
AU - Shams, H.
AU - Powell, F. L.
AU - Hempleman, S. C.
N1 - Funding Information:
Acknowledgements. We thank the University of California White Mountain Research Station and NIH/HLBI (HL 173301) for financial support and Leslie Byron, Alice Alstatt and Alan Fong for technical assistance.
PY - 1990
Y1 - 1990
N2 - We measured ventilation (V̇I) and arterial blood gases in awake Pekin ducks exposed to normoxia at sea level, normobaric hypoxia achieved by lowering FIO2 at normal barometric pressure (NORMO), and hypobaric hypoxia achieved with a low pressure chamber and 21% O2 (HYPO). Average normoxic values were: V̇I = 0.46 L·(kg·min)-1, PaO2 = 99.7 Torr, PaCO2 = 30.1 Torr. At PIO2 = 90 Torr, NORMO and HYPO measurements were not significantly different (P > 0.05). At PIO2 = 46 Torr, NORMO V̇I was less than HYPO V̇I but blood gases were not significantly different: V̇I = 1.00 vs 1.45 L·(kg·min)-; PaO2 = 31.3 vs 33.0 Torr; PaCO2 = 11.5 vs 10.6 Torr. Although both tidal volume (VT) and respiratory frequency (fR) were greater in HYPO, similar blood gases with NORMO and HYPO suggest similar parabronchial ventilation. The results suggest increased physiologic dead space, caused by reduced efficacy of aerodynamic valving, with reduced gas density in hupobaria.
AB - We measured ventilation (V̇I) and arterial blood gases in awake Pekin ducks exposed to normoxia at sea level, normobaric hypoxia achieved by lowering FIO2 at normal barometric pressure (NORMO), and hypobaric hypoxia achieved with a low pressure chamber and 21% O2 (HYPO). Average normoxic values were: V̇I = 0.46 L·(kg·min)-1, PaO2 = 99.7 Torr, PaCO2 = 30.1 Torr. At PIO2 = 90 Torr, NORMO and HYPO measurements were not significantly different (P > 0.05). At PIO2 = 46 Torr, NORMO V̇I was less than HYPO V̇I but blood gases were not significantly different: V̇I = 1.00 vs 1.45 L·(kg·min)-; PaO2 = 31.3 vs 33.0 Torr; PaCO2 = 11.5 vs 10.6 Torr. Although both tidal volume (VT) and respiratory frequency (fR) were greater in HYPO, similar blood gases with NORMO and HYPO suggest similar parabronchial ventilation. The results suggest increased physiologic dead space, caused by reduced efficacy of aerodynamic valving, with reduced gas density in hupobaria.
KW - Aerodynamic valving
KW - Airflow, airways of birds
KW - Airway, airway in
KW - Altitude, bird respiration
KW - Animal, birds
KW - Hypoxia, bird respiration
KW - bird lungs
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U2 - 10.1016/0034-5687(90)90080-I
DO - 10.1016/0034-5687(90)90080-I
M3 - Article
C2 - 2218098
AN - SCOPUS:0025316126
SN - 0034-5687
VL - 80
SP - 163
EP - 170
JO - Respiration Physiology
JF - Respiration Physiology
IS - 2-3
ER -