OnlineMedEd: Nephrology - "Acid Base" Flashcards
Discuss the difference between acidosis and acidemia (and alkalosis and alkalemia).
Acidemia referes to low pH in the blood, while acidosis refers to how it got there. Note: you can have an acidosis without an acidemia.
Normal pCO2 is ___________.
40
List the differential for respiratory acidosis.
- Hypoventilation (such as from decreased drive –opiate overdose or neuromuscular disorders –or obstructed airways –OSA)
- Severe asthma
The most common causes of respiratory alkalosis are _________________.
hyperventilation (from anxiety, pain, or hypoxemia)
A person has metabolic alkalosis. What is the first test you should do?
Urine chloride
In contraction alkalosis, the kidneys pull NaCl from the collecting duct (via aldosterone). Thus, urine chloride will be low.
Caveat: you should also be able to tell from the history and physical if they are dehydrated. If that is the case, then you can also give IVF and monitor for resolution of the alkalosis.
What is a differential for contraction alkalosis?
- Diuretics
- Dehydration
- Vomiting
If a person does not seem to be volume-depleted and has metabolic alkalosis (or if they have a normal urine chloride), then you should determine ________________.
whether they have HTN or not
HTN and metabolic alkalosis = hyperaldosteronism
Hypotension and metabolic alkalosis = Barter and Gettelman.
If a person has metabolic acidosis, then you need to assess their _________________.
anion gap
AG greater than 12 = MUDPILES
AG less than 12 = check the urine anion gap for RTA
What is the formula for urine anion gap?
Na + K - Cl
Urine anion gap should not be greater than ________________.
20
Negative anion gap, negative urine anion gap metabolic acidosis?
Diarrhea
You might think volume loss with diarrhea would make you develop contraction alkalosis, but the loss of bicarb in the stool leads to acidosis.
