acid base balance Flashcards
how do you find out if someone is acidotic?
history, physical exam, ABG
what are the 4 options for pH problems in a patient
resp. acidosis
metabolic acidosis
resp alkalosis
metab. alkalosis
what is it called when the blood is acidic
acidemia
what are the normal pH, O2, CO2 and HCO3 levels
pH 7.35-7.45
O2 >11kPa
C02: 4.7-6kPa
HCO3: 22-26mEq/L
what is a bufffer system
can absorb or release H+ due to being a weak acid + its conjugate base
give an example of a buffer
amino acid NH2 and COOH ends can both gain or lose a H+
describe the buffer systems of the ICF and ECF
Phosphate, Protein x 3, Carbonic acid
what are the 4 things that could go wrong in blood
bicarb increase
bicarb decrease
co2 increase
co2 decrease
how do you analyse ABG results
Look at the pH
is the primary problem acidosis (low) or alkalosis (high)
2. Check the CO2 (respiratory indicator)
3. Check the HCO3 (metabolic indicator)
4. Which is primary disorder (Resp. or Metabolic)?
* If the pH is low (acidosis), then look to see if CO2 or
HCO3 is aligned with acidosis (which ever is acidosis will
be primary). * If the pH is high (alkalosis), then look to see if CO2 or
HCO3 is aligned with alkalosis (which ever is alkalosis is
the primary)
how is the anion gap measured? what is the normal range?
([K+] + [Na+]) - ([Cl-] + [HCO3-] )
8-12mmol/l
what is a noticeable feature of diabetic acidosis
fast breathing (trying to get the CO2 out)
what can hyperventilation lead to
resp. alkalosis
what is pH
-log10(H+]
what are the 3 main ways the body maintains pH balance
chemical (quick) buffering
respiratory (medium seconds-minutes) excretion of acid
renal (minutes- hours) excretion of acid/resorption of carbonate
why is the Hb - HHb (deoxyhaemoglobin) buffer inportant
mobile. Can carry H+ away to be excreted
