Suzy is a 10 year old with pulmonary fibrosis. This disease causes progressive scarring of the lungs and therefore, reduced inspiratory volumes and chronic hypoxemia. Suzy is very inquisitive. Due to her disease, she knows that when she breathes in, her lungs help to bring oxygen into her blood, and when she breathes out, she gets rid of carbon dioxide from her blood. At her appointment today, you note that she has cyanosis (blue coloration) and clubbing in her fingers and toes – symptoms of hypoxemia. When Suzy asks why her fingers and toes look the way they do, you tell her that she is not getting enough oxygen to them. This answer does not satisfy Suzy! She then asks:
1. “How EXACTLY does oxygen get into my blood and carbon dioxide get out when I breathe?”
2. “And how does the oxygen get into my toes and fingers so they won’t be blue?”
Be thorough (or Suzy will just keep asking “how…why?” She is annoying like that!)
Be sure to include partial pressures of the gases, the carriers in the blood, and dissociation of the gases from their carriers (the Bohr Effect)
Finally, you treat Suzy by giving oxygen via a mask.
3. Explain why this would be helpful even though her inspiratory volumes are reduced.
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