Acid base 2 Flashcards
Normal values (4)
pH = 7.4
CO2 = 40
CHO3 = 24
anion gap = 12
metabolic acidosis
primary effect is drop in pH and HCO3
metabolic alkalosis
primary effect is incr in pH and HCO3
resp acidosis
decrease in pH and incr. in CO2
resp alkalosis
inrce in pH and dec. in CO2
what is metabolic acid/base status determined by
net balance between HCO3- production and loss
3 general causes of met acidosis
- HCO3 loss from buffering
- NaCO3 loss via diarrhea
- failure to general HCO3-
what is compensatory change for met acid
primary: HCO3 down
compensatory: CO2 down
what is compensatory change for met alk
primary: HCO3 up
compensatory: CO2 up
what is compensatory change for resp acid
primary: CO2 up
compensatory: HCO3 up
what is compensatory change for resp alk
primary: CO2 down
compensatory: HCO3 down
does comp. return pH to normal
no, but may return ICF pH to normal
what should compensation be for met acid
change in HCO3 = change in CO2
2 types of met acidosis
- anion gap
2. non-anion gap
what should be equal in serum
anions and cations
what is actually higher
Na always higher
what accounts for anion gap
albumin is about a 12 (polyanion)
what does increase in anion mean
- accumulation of anions
2. almost always due to addition of an acid
why is anion gap importnant
- reliable way of telling if met acid is due to addition of acid or loss of bicarb
- causes of AG are often life threatening
- can ID met acid even if the blood pH is not acid
**4 Causes of AG
- lactic acidosis
- ketoacidosis
- toxins
- renal failure
what is lactic acidosis
from inadequate tissue perfusion - usually shock leads to anarobic resp
what is ketoacidosis
lack of insulin leads to fatty acid metabolism - breakdown releases acids
3 main toxins
- methanol - metabolized to formic acid
- ethylene glycol - car coolant
- ASA
acid in renal failure
very low GFR means retain acids and can’t excrete NH4+
which met acid are reversible
lactic and keto - reversible
meth, eth, ASA - no because anions not metabilized
what happens in normal AG met acidosis
lose NaHCO3+, so losing both anion (HCO3-) and Cation (Na)
2 main causes of normal anion met acid
- diarrhea - lose bicarb
2. urine excretion
treatment of met acid
treat underlying issue
**5 steps to acid base prob
- what is net effect?
- met or resp
- is there adequate comp.
4a. anion gap?
4b. osmol gap? - is there another metabolic process
