Regional Lung Function and Central Haemodynamics during Hypoxia, Hyperoxia, and Breath-Holding

Abstract

In 13 healthy males pulmonary blood flow distribution (PBFD), pulmonary artery pressure (PAP), and cardiac ouptut (Q˙) were measured during 10% and 100% O₂breathing and after maximal breath-holding preceded by breathing air and 100% O₂. The PAP and Q˙ increased and the PBFD became more even during 10% O₂breathing and after maximal breath-holding during air breathing. There were no significant changes in the Q˙and PBFD during 100% O₂breathing nor after prolonged breath-holding during 100% O₂. During the latter experiment PAP increased somewhat.

Key Words:

• Breath-holding
• cardiac output
• hyperoxia
• hypoxia
• pulmonary artery pressure
• radiospirometry
• regional lung function
• Xenon radioactive