Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
40 Cards in this Set
- Front
- Back
|
Normal values for pH, pCO2, venous pCO2, HCO3?
|
7.35-7.45, 36-44, 46, 24
|
|
|
net daily acid generation has to equal?
|
net daily acid secretion
|
|
|
what is the most important buffer system?
|
bicarbonate
|
|
|
most important physiological buffering pair?
|
CO2 and HCO3
|
|
|
normal amount of free acid in blood vs amount produced by a 70 kg man?
|
.00004 mEq H+ in blood and 70 mEq H+ produced. that is why buffers are so important
|
|
|
2 major roles of kidneys in regards to acid/base balance?
|
reabsorption of bicarb, excretion of acid and ammonium
|
|
|
where is most of the bicarb reabsrobed?
|
proximal tubule
|
|
|
carbonic acid exists in equilibrium with?
|
dissolved CO2
|
|
|
called titratable acid?
formula? |
phosphate buffer
HCl + Na2HPO4 -> NaH2PO4 + NaCl |
|
|
where is the concentration of PO4 high?Why?
|
tubular fluid and cells. It helps to attach up excess acid
|
|
|
up to 60-70% of the total hm buffering capacity is ___ via the ___ system?
|
inside the cell via the protein buffering system
|
|
|
a rise in pCO2 causes?
|
respiratory acidosis
|
|
|
A diabetic patient who is hyperventilating may be going into ____ and will react to this state by ___?
|
DKA, resp compensation
|
|
|
where is ammonia generated and why?
|
proximal tubule, because it needs to attach to hydrogen to excrete it. This will occur when excess H+ is taken on and binds up bicarb. New bicarb must be freed up so H+ will be excreted with NH3
|
|
|
how much acid and CO2 need to be cleared per day in avg american?
|
15,000 mmoles of CO2 and 1-2 mmoles/kg of acid (70-100 mEq) meaning you have to produce this much HCO3
|
|
|
sources of acid?
|
oxidation of methionine, cystine, cationic AA. incomplete oxidation of carbs and fat. non-metabolized organic acids (uric, oxalic)
|
|
|
sources of base?
|
lactate, acetate, oxidation of amino acids
|
|
|
response to HCO3 load?
|
increased filtration of HCO3 and decrease reabsorbtion. inhibition of H+ secretion
|
|
|
maximal acid/base renal response?
|
Base: >1000 mEq/day happens within hours
Acid: 400-500 mEq/day takes a few days to respond |
|
|
slide 36
|
helpful
|
|
|
process causing inappropriate elevation of plasma HCO3?
|
metabolic alkalosis
|
|
|
how do you compensate for metabolic alk?
|
decrease resp
|
|
|
causes of metabolic alk?
|
GI: VOMITTING, antacids in renal fail
Renal: loop/thiazides DIURETIC cell shift of k+>hypokalemia sweat loss in cystic fibrosis |
|
|
why might it be difficult for a heart failure pt who has metabolic alk to compensate?
|
it is associated with hypervent and decreased CO2
|
|
|
preferred method for assessing renal response to circulating volume in metabolic alk?
|
urinary Cl-
|
|
|
3 factors for the result in net bicarbonate reabsorbtion?
|
effective circulating vol depletion (3rd space: HF)
cloride depletion and hypochloremia hypokalemia |
|
|
how does the body maintain metabolic alk, Na depletion?
|
impaired flitration of bicarb
im of bicarb resorp stim of net acid secretion (high aldo, w Cl- delivery) |
|
|
Maintaining metabolic alk with K depletion?
|
Stim bicarb reaborbtion, stimulate Na+H+ exchanger, increased NH4 production and secretion, net acid secretion
|
|
|
therapy for metabolic alkalosis?
|
correction of volume depletion, correction of K+ depletion, correction or Cl- depletion (must give Na,K with it)
|
|
|
Major causes of metabolic acidosis with increased anion gap?ingestion?
|
Increased acid production (DM, keto, lactic)
methanol, ethylene glycol, aspirin, toluene |
|
|
metabolic acidosis with normal anion gap?
|
GI loss (diarrhea), renal failure, decreased renal acid secretion (type 1 and 4 RTA)
|
|
|
normal plasma anion gap?
|
7-13
|
|
|
winters formula?
|
differs between pure metabolic acidosis and and mixed acid/base.
pCO2=1.5 x HCO3 + 8 +/- 2 if correct than metabolic acidosis |
|
|
Elevated anion gap
|
retained acid may be HCl but could be other anions like Lactate. understanding which anion is important diagnostic tool
|
|
|
anion gap acidosis causes?
|
ketoacid, lactic acid, renal failure, drugs: methanol, glycol, salicylates, toluene
|
|
|
Hypercholremic acidosis (norm anion gap)?
|
2 drugs: acetozolamide, acidifying salts,
2 GI issues: diarrhea, uterosigmoid 2 renal issue: nephritis and RTA (distal/prox) |
|
|
Dx of DKA?
|
you want to measure ketones. In severe disorder ketones will exist as beta-hydroxybuterate. As therapy starts may see rise in ketones but that is just the shift
|
|
|
anion gap formula?
|
Na - (Cl + HCO3)
|
|
|
Mudpiles vs AADUIR
|
methanol, urea, dka, paraldehyde, INH, lactic acid, ethanol, salicylicate acid
Acetozolamide, acidifying salts, diarrhea, uterosigmoidostomy, nephritis, RTA |
|
|
what to know about morphine and acidosis?
|
it depresses resp making acidosis worse
|
