Acid Base II Flashcards
What is the modified henderson hasselbach equation?
pH = 6.1 + log (HCO3/ .03 X PCO2)
What is responsible for the majority of increased renal H secretion during metabolic acidosis?
enhanced NH4+ excretion
What is the primary alteration in metabolic acid base disorders?
blood bicarb composition
what is the primary alteration in respiratory acid base disorders?
blood PCO2
What is another name for non anion gap metabolic acidosis?
hyperchloremic acidosis
Why would a non AG metabolic acidosis not have an AG?
In a pure form of hyperchloremic acidosis, therefore, the increase in chloride above the normal value should be equal to the decrease in bicarbonate.
What are 4 main classifications for normal AG acidosis?
bicarb wastage
impaired H secretion and reduced NH4+ excretion
impaired NH3 formation and reduced NH4 excretion
administration of chloride containing acid
Diarrhea and urinary tract diversions are examples of what kind of normal AG acidosis?
bicarb wasting
distal RTA and aldosterone deficiency are examples of what kind of non AG acidosis?
impaired renal H secretion and reduced NH4 excretion
advanced CKD and hyperkalemia are examples of what kind of non AG acidosis?
impaired NH3 formation and reduced NH4 excretion
In severe diarrhea, what is true of bicarb levels in the urine?
there is none - low urine pH and increased ammonium and titratable acid
What does a large negative UAG suggest about an acidosis?
that NH4 is in the urine and the kidney is appropriately compensating
Diabetes, alcohol and starvation would cause what kind of AG acidosis?
ketoacidosis
shock, tissue hypoxia, and liver failure would cause what kind of AG acidosis?
renal failure/lactate
increased osmolal gap and hyperemic optic disc would cause what kind of AG acidosis?
methanol/formate
Increased osmolal gap;urinary oxalate crystals; acute kidney failure would all suggest what kind of AG acidosis?
ethylene glycol
An AG acidosis with concomitant respiratory alkalosis would suggest what cause?
salicylates
When alkalosis occurs in the setting of decreased ECF, what happens to bicarb excretion? i.e. in vomiting (which causes fluid and H loss)
it is limited, so correcting the alkalosis requires fixing the volume issue before renal compensation can occur
Diuretics, primary hyperaldosteronism, and bartter’s syndrome cause what kind of metabolic alkalosis?
chloride resistant
what is the urine chloride cutoff for chloride resistant metabolic alkalosis?
> 30 mEq
What is the urine chloride cutoff for chloride responsive metabolic alkalosis?
< 15 mEq
Gastric fluid loss would cause what kind of metabolic alkalosis?
chloride responsive
Vomiting, gastric aspiration, bulimia, and pyloric stenosis cause what kind of metabolic alkalosis?
gastric fluid loss leading to chloride responsive metabolic alkalosis
