emphysema vs chronic bronchitis

[Oh_Gee]

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emphysema has normal V/Q b/c alveoli and capillaries are destroyed but why does emphysema have lower cardiac output

whereas

chronic bronchitis has mismatch V/Q (mucus blocks ventilation). why does chronic bronchitis have higher cardiac outout?



does emphysema have lower cardiac output b/c of the destroyed capillaries? (no point in sending blood if there's no vessels)

 

[073116]

emphysema has normal V/Q b/c alveoli and capillaries are destroyed but why does emphysema have lower cardiac output

whereas

chronic bronchitis has mismatch V/Q (mucus blocks ventilation). why does chronic bronchitis have higher cardiac outout?



does emphysema have lower cardiac output b/c of the destroyed capillaries? (no point in sending blood if there's no vessels)

Emphysema ---> Mild hypoxia: Despite the “matched” V/Q defect, overtime hyperventilation develops and cardiac output (CO) drops which leads to areas of poor blood flow in relatively well oxygenated areas. Due to this poor CO, the rest of the body suffers from tissue hypoxia.

Chronic bronchitis ---> V/Q mismatch: The physiologic response leads to a drop in ventilation and compensation with the rise in CO. Increased perfusion in the areas of poor ventilation takes place eventually causing hypoxia and secondary polycythemia. [Chronic bronchitis ---> Severe hypoxia and hypercarbia: Chronic V/Q mismatch leads to decreased oxygenation/deoxygenation of the blood resulting in hypoxemia and increased CO2 retention (respiratory acidosis ensues)].

Chronic obstructive pulmonary disease (COPD) | McMaster Pathophysiology Review

 

[Oh_Gee]

Emphysema ---> Mild hypoxia: Despite the “matched” V/Q defect, overtime hyperventilation develops and cardiac output (CO) drops which leads to areas of poor blood flow in relatively well oxygenated areas. Due to this poor CO, the rest of the body suffers from tissue hypoxia.

Chronic bronchitis ---> V/Q mismatch: The physiologic response leads to a drop in ventilation and compensation with the rise in CO. Increased perfusion in the areas of poor ventilation takes place eventually causing hypoxia and secondary polycythemia. [Chronic bronchitis ---> Severe hypoxia and hypercarbia: Chronic V/Q mismatch leads to decreased oxygenation/deoxygenation of the blood resulting in hypoxemia and increased CO2 retention (respiratory acidosis ensues)].

Chronic obstructive pulmonary disease (COPD) | McMaster Pathophysiology Review

why does the cardiac output decrease in emphysema and increase in bronchitis though? what is the physiology behind that?

 

[el_duderino]

why does the cardiac output decrease in emphysema and increase in bronchitis though? what is the physiology behind that?

Hyperinflation, I suppose. Inflated, pressurized alveoli compress capillaries.