L50 + 51 Flashcards
What is compensation?
Development of a 2ary AB disorder to help correct the 1ary
Does compensation return the pH to normal?
NO
If back to normal, you should suspect mixed
How do you get rid of H+ in the urine?
Prox tubule
Carbonic anhydrase for bicarb reabsorption
To gain bicarb, you lose H
What does low PaCO2 mean practically?
Hypervent (1ary or 2ary)
CO2 = acid
Name the 4 steps of compensating for high H+ in the blood and the timeframe in which each occurs.
- Buffer with bicarb in blood - immediate
- Resp comp - mins
- Intracell buffering - hrs
- Renal H+ secretion - days
How is H+ secreted in urine?
Ammonium
If you have a metabolic acidosis and your urine is acidic, does that imply a renal or non-renal source of increased H+ produciton?
Non-renal
You’re excreting protons as you should to increase your bicarb
If you have a metabolic acidosis and your urine is basic, does that imply a renal or non-renal source of increased H+?
Renal
- Renal tubular acidosis = H+ secretion impaired so losing bicarb
- Chronic kidney disease = ↓nephron #
What are the effects of metabolic acidosis on the body?
Hb/O2 curve shifts R = dissociation, more O2 delivered to tissues ↓CNS Arrhythmia ↓Cardiac contractility Hyper K ↓Pulm BF
What GI problem would cause a metabolic acidosis?
Diarrhea - losing bicarb
Formula for anion gap
Na - (HCO3 + Cl)
Acid minus the bases
Mudplies for anion gap metabolic acidosis
Methanol (formaldehyde) Uremia (creatinine) DKA (ketones) Propylene glycol Lactate Iron tabs/isoniazid Ethylene glycol (anti-freeze look for oxalate) Salicylates
Heart CCU for non-gap metabolic acidosis
Hyperalimentation (feeding tube) Expansion Acetazolamide Renal tubular acidosis Diarrhea Cholestyramine Carbonic anhydrase inhibitors Utererosigmoidostomy
If you’re normally reabsorbing bicarb in the kidney by excreting H into urine, where are you naturally compensating by doing the opposite?
Colon - bicarb into poop, reabsorb H
Why diarrhea loses bicarb -> acidosis
Describe the metabolic acidosis caused by renal tubular acidosis
- Gap?
- Urine pH
↑Cl metabolic acidosis
Non-gap
Urine pH not max acid (aka should be more acidic to compensate for acidosis)