Hypercarbia and Hypoxemia

What happens to our cells if we don’t get enough O 2 ?

What happens to our cells if we don’t remove CO 2 ?

Why is P I O mmHg if atmospheric PO 2 is 160 mmHg?

Causes of Hypoxemia

Diffusion impairment. VO 2 = K x A x (P A O 2 – P a O 2 )/T

Diffusion impairment. VO 2 = K x A x (P A O 2 – P cap O 2 )/T How does the rate of transport change with: -Increased thickness, ie. with fibrosis? -Decreased surface area, ie pneumonia? -Decreased P cap O 2, less O 2 in the capillary blood?

V/Q Abnormalities 0 Upper parts of the lung receive more/less blood supply than the lower parts (gravity). 0 Upper parts of the lung also receive more/ less of the tidal volume.

V/Q Abnormalities 0 The result is that the upper parts of the lung receive relatively more/less ventilation than they do blood flow, while the lower parts of the lung receive relatively more/less ventilation than they do blood flow.

Shunt Definition: Let’s take a short cut! But is it a good short cut?

Shunt Which causes blood to go from the right to left heart without going through the lungs? A. Foreign object (ie. Peanut) B. Bronchial circulation C. Pneumonia or abundant pus D. Foramen Ovale

Shunt Bronchial circulation- only goes through the larger airways and does not reach the alveolar region Foramen Ovale- system established in utero that may not close when the baby is born

Shunt What happens with these two? Foreign object (ie. Peanut) Pneumonia or abundant pus

Does hypoventilation cause hypoxemia or hypercarbia?

Hypoventilation What things can cause hypoventilations?

Hypercarbia In addition to hypoventilation, Think ALVEOLAR VENTILATION Think DEAD SPACE

How to calculate alveolar ventilation?

What happens when you increase dead space? V A = (V T ‑ V D ) x f

Dead Space Name 3 things that cause changes in dead space.

Equipment -Snorkel -Gas Mask -Ventilator

Deep Vein Thrombosis How does DVT cause dead space?

Air can get in but gas exchange surface is destroyed.