Acid/Base Disorders Flashcards
Rule #1:
Look at pH from ABG:
if > 7.40 = primary alkalosis
Rule #2:
Calculate anion gap
elevated = primary metabolic acidosis OR mixed acid base problem
Rule #3:
If elevated anion gap, calculate osmol gap
(2 x Na) + (Gluc/18) + (BUN/2.8) = 285ish if normal
subtract that value from measured osmolarity
= 10 is normal
abnormal indicates toxin ingestion
Rule #4:
Calculate excess anion gap:
calculated AG - 12… add answer to measured bicarb
should = 24-26
low = non-anion gap acidosis
high = underlying metabolic alkalosis
Rule #5:
Clinical picture!!
Normal ABG with elevated anion gap= ?
metabolic alkalosis AND metabolic anion gap acidosis
Findings of mixed metabolic acidosis and respiratory alkalosis:
lower PCO2 than expected for acidosis
Findings of mixed metabolic alkalosis and respiratory acidosis:
higher than expected HCO3- for acidosis
Mixed resp and metabolic alkalosis?
high bicarb
low PCO2
MUDPILES???
DDx for metabolic acidosis
Methanol
Uremia–Cr over 5, BUN over 60
Dka and Aka (EtOH increases osm gap)
Paraldahyde
Iron
Lactic acid
Ethylene glycol
Salicylates
Primary disturbance in metabolic alkalosis:
increased plasma HCO3-
Primary disturbance in respiratory acidosis:
increased arterial PCO2
Acute compensation for resp acidosis:
HCO3- rises 1 mEq for each rise of 10 pCO2
Chronic compensation for resp acidosis:
HCO3- rises 3 mEq for each rise of 10 pCO2
Primary disturbance in respiratory alkalosis:
decreased arterial CO2
