ABG's Flashcards
VBG
VBG can’t tell you about O2 but can tell you about CO2
PO2
expected to be <10 of FiO2
e. g. room air is 21% so expect PO2 to be 11 (21-10)
e. g venturi is 35% so expect PO2 to be 25
nasal cannula
1/Lmin 24%
2L/min 28%
3L/min 32%
4L/min 36%
simple mask
FiO2 30-40% at 5-10L/min
non re-breather mask
85% at 15L/min
venturi mask
bernoulli principle
blue 2L/min 24% white 4L/min 28% yellow 8L/min 35% red 10L/min 40% green 15/ min 60%
respiratory acidosis
COPD / life threatening asthma
OSA- obesity, hyperventilation
neuromuskular (myasthenia gravis, gullian barre)
central depression (opioid toxicity)
respiratory alkalosis
hyperventilation (pain, anxiety)
hyperventilating in response to hypoxia (acute asthma)
PE
pneumothroax
base excess
< -2 more negative (metabolic acidosis) lost base
> 2 metaboic alkalsos (HCO3)
metabolic acidoiss
DKA, alcohol, ethylene glycol, methanol, GI loss, renal tubular acidosis (holding on / not excreting HcO3)
? ocetazzolamide?
metabolic alkalosis
vomiting (loose HCl)
diuretics
endocrine (cushings/conns/ectopic ACTH)
iatrogenic (steroids) (NaHCO3)
anion gap
Na - Cl - Hco3 = anion gap
12 + / -2
a raised anion gap means that there is another negative ion being produced that is not in this calculation e.g. DKA/ lactic acidosis (lactate)