Hypoxemia mechanisms — Flashcards

Flashcard 1: Patients with cyanide poisoning have a _____ of the venous-arterial PO2 gradient

Answer: narrowing

Flashcard 2: In exercise, O2 exhibits _____-limited gas exchange

Answer: perfusion

Extra: O2 is perfusion-limited in both resting and exercise states in healthy individuals at sea level. It becomes diffusion-limited in conditions like pulmonary fibrosis or during exercise at high altitude where the partial pressure gradient is reduced.

Flashcard 3: Carboxyhemoglobin causes _____ O2-binding capacity

Answer: decreased

Flashcard 4: Clinical features of ARDS include hypoxemia and cyanosis with respiratory distress due to a _____ diffusion barrier

Answer: thickened

Flashcard 5: Increased ventilation (e.g. high altitude) causes _____ Paco2

Answer: decreased

Flashcard 6: Is the A - a gradient normal, increased, or decreased, in response to diffusion defects (e.g. fibrosis, pulmonary edema)? _____

Answer: Increased

Flashcard 7: What is the secondary regulator of cerebral perfusion?

Answer: PO2 - only takes effect during severe hypoxia

Flashcard 8: What is the primary regulator of cerebral perfusion?

Answer: PCO2

Flashcard 9: How long can the brain withstand hypoxia before sustaining irreversible damage?

Answer: 5 minutes

Flashcard 10: In the _____, HCO3- enters the red blood cells in exchange for Cl-

Answer: lungs

Extra:  Watch associated Bootcamp video [https://app.bootcamp.com/med-school/pulmonology/videos/blood?index=12] https://onlinemeded.org?ref=anki