why bicarb decreases in aspirin poiosoning ?

[BeitE]

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can anyone explain properly the early and late manifestations?

 

[BurghStudent]

Early you have respiratory alkalosis. Aspirin causes increased respiratory drive. This means high pH, low pCO2. The kidneys excrete bicarb to compensate.

The later phase is metabolic acidosis. Aspirin uncouples the electron transport chain. This causes lactic acidosis, which chews up bicarb.

Overall the picture can look mixed, but a clue is unexpectedly low pCO2, with lowish bicarb.

 

[BeitE]

Early you have respiratory alkalosis. Aspirin causes increased respiratory drive. This means high pH, low pCO2. The kidneys excrete bicarb to compensate.

The later phase is metabolic acidosis. Aspirin uncouples the electron transport chain. This causes lactic acidosis, which chews up bicarb.

Overall the picture can look mixed, but a clue is unexpectedly low pCO2, with lowish bicarb.

amazing but how lactic acidosis chews up bicarb? H combines with HCO3?

 

[BurghStudent]

amazing but how lactic acidosis chews up bicarb? H combines with HCO3?

Yes, any proton donating acid will help bicarb become CO2 and H2O

This is also helpful in remembering anion gap vs non anion gap acidoses:

Anion gap = bicarb was consumed, because of excess acid (MUDPILES are all acids, or cause an acidosis). Therefore Na - (Cl+HCO3) = high
Non anion gap = bicarb was lost any other way and Cl was reabsorbed to compensate (diarrhea, acetazolamide, hypoaldo etc). Therefore Na - (Cl+HCO3) = low

 

[BeitE]

Yes, any proton donating acid will help bicarb become CO2 and H2O

This is also helpful in remembering anion gap vs non anion gap acidoses:

Anion gap = bicarb was consumed, because of excess acid (MUDPILES are all acids, or cause an acidosis). Therefore Na - (Cl+HCO3) = high
Non anion gap = bicarb was lost any other way and Cl was reabsorbed to compensate (diarrhea, acetazolamide, hypoaldo etc). Therefore Na - (Cl+HCO3) = low

amazing thanks a lot