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;
17 Cards in this Set
- Front
- Back
|
What is the primary job of the PT re: acid-base regulation?
|
reabsorb the filtered HCO3-
|
|
|
What are the three primary mechanisms thru which metabolic acidosis occurs?
|
1. loss of bicarb (diarrhea, PT dysfuntion)
2. decreased renal excretion of H+ (distal renal tubular acidosis, acute/chronic kidney injury) 3. Excess acid intake/production (lactic acidosis, ketoacidosis, etheylene glycol, etc.) |
|
|
What is the primary mechanism of respiratory acidosis? alkalosis?
|
primary decrease in minute ventilation --> increase in CO2 i/ the blood --> shifts the equilibrium towards more H+ --> respiratory acidosis
increase in minute ventilation, drop in primary CO2, shift towards consumption of protons --> systemic alkalosis. |
|
|
What are the two primary mechanisms causing metabolic alkalosis?
- Which mechanism is dependent on the copresentation of impaired renal excretion? |
Loss of acid (vomiting, or thru kidney (hyperaldosteronism)
Excess bicarb (NaBiCarb or Citrate admin) --> also requires impaired renal excretion to cause alkalosis |
|
|
In vomiting, do you lose HCl or Bicarb? diarrhea?
|
HCl, Bicarb.
|
|
|
Can renal compensation ever return the pH to completely normal in a pt with a primary acid-base dz?
what is going on if you do see a normal pH in a pt with a primary acid-base dz? |
No.
There must be another primary dz present. |
|
|
What is the a) site and b) method of compensation for the following dz:
Met acidosis Met alkalosis Resp acidosis Resp alkalosis |
- medulla, increase minute Vent.
- medulla, decrease minute Vent. - Type A intercalated cells, increase H+ secretion + also sensed in the PT, which incrase Bicarb reabsorption. - Type B ICs, increased HCO3- secretion |
|
|
What is an equation that can be used to estimate expected pCO2 associated with a given HCO3- decrease?
How about the association worded statement for the same effect for pCO2 < and > 24? |
pCO2 = HCO3 + 15
pCO2 = 1.5 x HCO3 + 8(+/-2) "Winter's equation" ~1.2 mmHg decrease in pCO2 for each 1 meQ/L fall in HCO3- below 24 mEq/L. 0.7 increase in pCO2 for every meQ/L >24 |
|
|
What are the two stages/components of the metabolic response to respiratory alkalosis/acidosis? Timescale for them?
|
Acute and Chronic
Chronic is 3-5 days after event. |
|
|
When we measure venous electrolytes, what are the main things we measure? What is the anion gap? Equation?
***What is the normal value? |
Sodium, Chloride, and bicarbonate
The amount of anions that aren't actually measured (what Cl and bicarb don't account for) AG = Na - (Cl + HCO3) 12 mEq/L --> we have to know this |
|
|
What's on the differential for increased anion gap Metabolic Acidosis?
|
MUD PIES
Methanol Uremia Diabetic ketoacidosis Pyroglutamic acidosis Ischemia-Lactate Ethylene glycol Salicylate toxicity |
|
|
What is the basic pathogenesis of Diabetic ketoacidosis?
|
Insulin deficiency and increase in glucagon --> increased G in blood --> increased liver G production --> adipose tiss breakdown --> met by liver to ketoacids --> metabolic ketoacidosis
|
|
|
What are the types of lactic acidosis and some associated causes?
|
Type A - hypoperfusion / hypoxia (shock, sepsis, CO poisoning, anemia)
Type B - absense of hypoperfusion / hypoxia (drugs, systemic dz) |
|
|
What is the Osmolal Gap? If it is high along with a high AG, which etiologides of MUD PIES should be strongly considered?
|
= MeasuredOsm - CalculatedOsm (the thing about 2xNa(plas) + G/18 + BUN/2.8 from smallgroup)
Methanol & Ethylene glycol |
|
|
What is the tx for metabolic acidosis caused by ethylene glycol and methanol poisoning?
|
hemodialysis + compound to inhibit the metabolism of the offending agent.
|
|
|
If you see a pt with metabolic acidosis with a normal AG, what might you think?
|
renal tubular acidosis
diarrheal state |
|
|
What is the expect pCO2 used to help calculate?
|
If you see something like metabolic acidosis, and you want to figure out if there is a concurrent primary respiratory dz (or if the respiratory compensation is normal), use those equations for expected pCO2. If it's around expected, it's probably just normal compensation.
|
