Flashcards in 16. Oxygen deprivation Deck (16):
what is .hypoxemia
decreased arterial PO2
what is ischemia
loss of bloos flow
causes of hypoxemia
normal A-a gradient : a. high altitude , hypoventialation ( eg opiod )
increased A-a gradient : a. V/Q mismatch b. diffusion limitation ( eg fibrosis) c. Right to left shunt
causes of hypoxia
3. decreased cardiac output
4. CO poisoning
causes of ischemia
1. impeded arterial flow
2. decreased venous drainage
• Name five processes that can lead to hypoxemia (decreased arterial oxygen).
High altitude, hypoventilation, ventilation/perfusion ratio mismatches, diffusion limitations, and right-to-left shunting
• Which two processes lead to hypoxemia with a normal A-a gradient?
High altitude and hypoventilation (e.g., opioid use)
• Which three processes can lead to hypoxemia with an increased A-a gradient?
Ventilation/perfusion ratio mismatches, diffusion limitation, and right-to-left shunting
• Name four processes that can lead to hypoxia (decreased oxygen delivery to tissue).
Decreased cardiac output, hypoxemia, anemia, and carbon monoxide poisoning
Name two processes that can lead to ischemia (loss of blood flow).
Impeded arterial flow and reduced venous drainage
• What is the difference between hypoxemia and hypoxia?
Hypoxemia is decreased arterial partial pressure of oxygen, whereas hypoxia is decreased oxygen delivery to tissue
• A patient appears sedated and is breathing slowly after a painful surgical procedure. What is his likely A-a gradient?
The A-a gradient would be normal (he was likely given too much pain control with opioids, causing sedation and hypoventilation)
• A hiker is weak after rapidly ascending a mountain. What is his likely A-a gradient?
The A-a gradient would be normal in cases of hypoxemia caused by high altitudes
• A patient is found to have a diffusion limitation in his lungs. How is his likely A-a gradient affected?
It is increased
• A patient develops a pulmonary embolus. What is his likely A-a gradient?
This is a case of V/Q mismatch, which would cause an increased A-a gradient