Term
1. What is hypoxemia?
2. What is hypoxia? |
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Definition
1. Inadequate O2 in blood supply
2. Region or tissues are deprived of adequate O2 supply |
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Term
| What is the equation for O2 Content in the blood? |
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Definition
| = (Hb * 1.34)(%Saturation) + (PO2 * 0.0031) |
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Term
| What is the value of O2 for arterial hypoxemia? |
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Definition
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Term
| What is the value of O2 for Respiratory Failure? |
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Definition
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Term
| Where is the appropriate place to measure values for mixed venous blood? |
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Definition
| In the pulmonary artery PvO2, which ensure adequate mixing. |
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Term
| What is the normal value for PvO2? |
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Definition
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Term
| What will cells do when faced with hypoxemia? |
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Definition
| They will extract more O2 from the blood to compensate for reduced PaO2 |
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Term
| What is the normal level for indexed oxygen delivery? |
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Definition
| Between 500 and 600 ml per minute per square meter of body surface area. |
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Term
| What is the critical level for oxygen delivery per minute per square meter of body surface area? |
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Definition
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Term
| What is the effect of increased tissue extraction of oxygen on the A-V range? |
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Definition
| Since more oxygen is being extracted the range will become broader |
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Term
| What is the equation for Respiratory Quotient? |
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Definition
= Carbon Dioxide Production/Oxygen Consumption
= 200/250 = 0.8 |
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Term
What is the normal (A-a) DO2 difference on room air?
On 100 Saturation O2? |
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Definition
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Term
| When a patient has a normal (A-a) difference, what are some causes of hypoxemia? |
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Definition
Altitude
Low FIO2
Alveolar Hypoventilation |
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Term
| When a patient has a widened (A-a) difference, what are some causes of hypoxemia? |
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Definition
In this instance, patients have a significant gas exchange abnormality:
Diffusion Abnormalities
V/Q mismatch
Shunting |
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Term
| How does altitude cause hypoxemia? |
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Definition
| The reduced barometric pressure despite the normal oxygen fraction leads to an overall lower partial pressure of oxygen to be ventilated. Increased FIO2 can fix the hypoxemia. |
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Term
| How does Alveolar Hypoventilation cause hypoxemia? |
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Definition
Hypoxemia is due to increase in alveolar carbon dioxide partial pressure which reduces the partial pressure of oxygen to decrease. Can be corrected with supplemental oxygen.
PAO2 = (760-47) x (.21) - (80/.8) = 50 mmHg
Increasing FIO2 value will increase PAO2. |
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Term
| What is a cause of hypoxemia that cannot be corrected with increased oxygen saturation? |
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Definition
| Shunt. Since the alveoli are not ventilated, there is no way for oxygen to reach the blood perfusing them. Also, since the hemoglobin is already maximally saturated, any increase will not markedly affect arterial blood oxygen saturation. |
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Term
| What is the effect when there is a reduction on Cardiac Output during hypoxemia produced by a gas exchange abnormality? |
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Definition
| The effect is compounded since cells will automatically increase the amount of oxygen extraction, which will decrease the remaining oxygen in venous blood. This creates a low mixed venous blood and a vicious cycle. |
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Term
| What is the Shunt Equation? |
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Definition
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