ischemia hypoxia hypoxemia differences

• related: pathophysiology of hypoxia and hypoxemia
• tags: #permanent

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Definitions

• hypoxemia is decreased oxygen saturation in the blood ($SaO_2$)
• hypoxia is decreased oxygen delivery to tissues
• ischemia is decreased blood flow to tissues¹

Hypoxia without hypoxemia

You can have hypoxia without hypoxemia: normal $O_2$ sat but decreased $O_2$ to the tissues. Hypoxia is oxygen delivery to tissues and rely on also cardiac output and hemoglobin concentration (oxygen delivery is dependent on cardiac output and oxygen content). Patients with heart failure or are severely anemic can have normal O2 sat but decreased delivery.

Links to this note

• pathophysiology of hypoxia and hypoxemia
  • ischemia hypoxia hypoxemia differences

Footnotes

1. 05 Hypoxia - Boards and Beyond ↩