1. Hypercarbia and Hypoxemia 11.7.11

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

3. Cannot make ATP

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

5. CO2 is not bad by itself but can combine with H2O in the blood  makes carbonic acid  change in pH can cause structure changes in proteins  if 3D structure can lead to loss in function.

6. Why is P I O 2 150 mmHg if atmospheric PO 2 is 160 mmHg?

7. Why is P I O 2 150 mmHg if atmospheric PO 2 is 160 mmHg? Saturation with H 2 O in the lung space decreases the PO 2

8. Causes of Hypoxemia 1. 2. 3. 4.

9. Causes of Hypoxemia 1. Diffusion Impairment 2. V/Q Abnormalities 3. Shunt 4. Hypoventilation

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

11. 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?

12. 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? Slow -Decreased surface area, ie pneumonia? Slow -Decreased P cap O 2, less O 2 in the capillary blood? fast, increased diffusion

13. 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.

14. 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.

15. 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.

16. 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.

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

18. Shunt Definition: When blood passes from the right heart to the left heart without becoming oxygenated?

19. 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

20. 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

21. 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

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

23. Shunt What happens with these two? Foreign object (ie. Peanut) Pneumonia or abundant pus Blood goes through the lungs but does not come into contact with the gas exchange region.

24. Does hypoventilation cause hypoxemia or hypercarbia?

25. BOTH!!

26. Hypoventilation What things can cause hypoventilations? 1. 2. 3. 4.

27. Hypoventilation What things can cause hypoventilations? 1. Problems with nerves 2. Problems with muscles 3. Drugs that suppress resp. drive (morphine) 4. Problems with central resp. drive (CCHS, Ondine’s)

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

29. How to calculate alveolar ventilation?

30. V A = (V T ‑ V D ) x f

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

32. What happens when you increase dead space? V A = (V T ‑ V D ) x f Incr. dead space  decrease alveolar ventilation  increase P a CO 2 = hypercarbia if above 40 mmHg

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

34. Equipment -Snorkel -Gas Mask -Ventilator

35. Deep Vein Thrombosis How does DVT cause dead space?

36. Deep Vein Thrombosis How does DVT cause dead space? Sedentary  blood clot travels to lung  embolus creates dead space  decreased gas exchange  air in and out is unchanged

38. Air can get in but gas exchange surface is destroyed.