Effects of normobaric and hypobaric hypoxia on ventilation and arterial blood gases in ducks

H. Shams, F. L. Powell, S. C. Hempleman

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)163-170
Number of pages8
JournalRespiration Physiology
Issue number2-3
StatePublished - 1990


  • Aerodynamic valving
  • Airflow, airways of birds
  • Airway, airway in
  • Altitude, bird respiration
  • Animal, birds
  • Hypoxia, bird respiration
  • bird lungs

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine


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