Acid-Base Disorders Flashcards
(24 cards)
What is the range of urine pH?
4.4-8.0
What is the normal urine pH?
6.0
What falsely elevates urine pH?
Proteus infection (UTI)
How do fruit/veggies affect pH?
citrate is broken down into bicarb, raising pH
In what form is a fixed amount of acid excreted each day?
H2PO4-
What is titrated by the kidneys to excrete acid as needed?
NH3 (traps protons in the lumen)
What are the three mechanisms of developing metabolic acidosis?
loss of bicarb, low H+ excretion, excess H+ production/intake
What is the compensation for metabolic acidosis?
for every 1 decrease in bicarb, PCO2 drops by 1.2
What is the compensation for metabolic alkalosis?
for every 1 increase in bicarb, PCO2 increases by 0.7
What is the compensation for respiratory acidosis?
acute: for every 10 inc in PCO2, bicarb inc by 1
chronic: for every 10 inc in PCO2, bicarb inc by 4
What is the compensaiton for respiratory alkalosis?
acute: for every 10 dec in PCO2, 2 dec in bicarb
chronic: for every 10 dec in PCO2, 5 dec in bicarb
What is an anion gap?
Na-(Cl+HCO3) > 12
What is the differential for anion gap metabolic acidosis?
Glycols Oxoproline (acetaminophen) L-lactate (humans) D-lactate (bacteria) Methanol Aspirin Renal failure Ketoacidosis
What is the differential for metabolic acidosis with anion gap and osmolal gap?
glycols, methanol
What is the differential for osmolal gap without acidosis?
isopropyl alcohol poisoning, mannitol, sorbitol, glycine, dextran
What is the differential for metabolic acidosis without anion gap?
Acute kidney injury Chronic kidney injury Carbonic anhydrase inhibitors Renal tubular acidosis Ureteroenterostomy Expansion of volume Diarrhea/Diuretics (K-sparing)
What is the differential for metabolic alkalosis?
Bartter syndrome Aldosteronism NG suction Gitelman syndrome Excess alkali Renin Emesis Diuretics
What is the relationship between serum K and HCO3 reabsorption
inverse
Describe the generation phase of metabolic alklalosis in vomiting.
Na, HCl, H2O lost in vomit; excess Na, HCO3 generated (alkaline tide); chloride is reabsorbed due to hypovolemia; excess HCO3 is lost in urine with Na, K;
Describe the maintenance phase of metabolic alkalosis in vomiting.
decreased volume increases aldosterone (excrete H+), and promotes reabsorption of Na, Cl, bicarb
How do diuretics cause hypokalemic alkalosis?
loss of NaCl in urine decreases volume, which activated SNS and RAAS, which activates ENaC, leading to a negative lumen and secretion of H+ and K+
What are the urine Na/Cl levels in the generation and maintenance phases of vomiting metabolic alkalosis?
generation: Na>15, Cl<15
maintenance: Na<15, Cl<15
What are the urine Na/Cl levels in current and remote uses of diuretic metabolic alkalosis?
current: Na>15, Cl>15
remote: Na<15, Cl<15
What are the urine Na/Cl levels in the initial and escape phases of hyperaldosteronism metabolic alkalosis?
initial: Na<15, Cl<15
escape: Na>15, Cl>15
