Acid/Base Disorders

Question 1

What is seen in Renal Failure?

Answer 1

Increase in phosphate, sulfate, and organic anions

Question 2

What is the most common non-anion gap?

Answer 2

Hyperchloremic

Question 3

Is resp compensation fast or slow?

Answer 3

Fast, metabolic is slow

Question 4

What is the 4 step algorithm for Acid Base disorders?

Answer 4

1) Classify Primary Disturbance
2) Compensation
3) Calculate Anion Gap
4) High AG – Calculate Potential Bicarb

Question 5

What is the winter’s formula and what do you use it for?

Answer 5

pCO2=1.5*HCO3 + 8 +/- 2

- Use in primary metabolic acidosis

Question 6

What is the formula to calculate primary metabolic alkalosis?

Answer 6

pCO2=0.8*changeHCO3 + 40

Question 7

What is the rule for primary respiratory acidosis

Answer 7

Up 1 (acute) Up 3 (chronic)

Question 8

What is the rule for primary respiratory alkalosis?

Answer 8

Down 10, Decrease 2 (acute) or 4 (chronic)

Question 9

If high anion gap how do you calculate potential bicarb?

Answer 9

Potential HCO3=HCO3 + ^AG

Question 10

What is have metabolic alkalosis that is saline/chloride Unresponsive. Ucl >20

Answer 10

Hyperaldosteronism

Question 11

What labs to get in acid/base disorder?

Answer 11

Electrolyte panel
ABGs
- HCO3 from BMP and ABG should be within 2 (if not doesn’t work)

Question 12

What if pCO2 is higher than expected in expected CO2 for metabolic acidosis?

Answer 12

Secondary respiratory acidosis

Question 13

If metabolic Alkalosis present check saline responsiveness?

Answer 13

Saline-responsive Urine Cl

Question 14

Calculate the anion gap?

Answer 14

Na-(Cl+HCO3)
Anion gap = unmeasured anions- unmeasured cations
- High: Decrease in HCO3, increased in unmeasured anions

Question 15

What happens if there is a low albumin?

Answer 15

Corrected AG = (2.5-3)(changeAlbumin) - Expected AG= albumin2.5-3
Assume 4 if none is given

Question 16

If high AG calculate potential Bicarb

Answer 16

Potential HCO3: HCO3 + (delta AG)

Question 17

Calculate the Osmolar Gap?

Answer 17

Unmeasured plasma osmolality - calculated plasma osmolality

Gap: Measured plasma osm - calculated plasma osm
Normal: 5-10

Question 18

What is MUDPILES?

Answer 18

AG meta acidosis
M: Methanol
U: Uremia
D: DKA
P: Propylene glycol
I: Iron/INH
L: Lacate
E: Ethylene glycol
S: Salicylates/Aceta

Question 19

Is the AG isopropyl alcohol normal or abnormal?

Answer 19

The AG is NL

Question 20

Non-AG metabolic is HARDASS?

Answer 20

H: Hyperalimentation
A: Addison Disease
R: Renal Tubular
D: Diarrhea
A: Acetazolamide
S: Spironolactone
S: Saline infusion (low aldosterone)

Question 21

WHat are some other Non-Anion gap?

Answer 21

Ingestion: Sevelamer, toluene, cholestyramine

• Early Renal Failure
• Fistulas (pancreatic fistula, uretosigmoid fistula
• Post-hypocapnea

Question 22

What is urine anion gap?

Answer 22

(Na + K) - (Cl): Renal NH4 excretion x (-1)

Question 23

What if you have a positive UAG?

Answer 23

Low NH4 excretion

DDx: RTA (distal, hypoaldosteronism), early renal failure

Question 24

What if you have a negative UAG?

Answer 24

High NH4 excretion

DDx: Vomiting, (RTA prox), ingestions, dilutional

Question 25

What is type 2 RTA?

Answer 25

Decreased PROXIMAL reabsorption of HCO3

• Fanconi Syndrome
• Paraprotein
• Meds (acetazolamide, heavy metals, ifosfamide, NRTIs
• Renal Transplant
• Low vit D

Acidosis: Moderate
UAG: +/-
UpH: 15%
K serum: Low

Question 26

What is type 1 RTA?

Answer 26

Distal type
Defective distal H+ secretion
- Autoimmune
- Nephrocalcinosis
- Meds (ampho, Li, ifosfamide)
- Increased K: SCD, Obstruction, SLE, Renal transplant
Acidosis: Severe
UAG: Positive
UpH: >5.3
FeHCO3:

Question 27

What is type 4 RTA?

Answer 27

Hypoaldosteronism
Low aldo: High K: Low NH3 synthesis/delivery: Decreased urine carrying capacity

• Low renin: Diabetic nephropathy, NSAIDS, chronic interstitial nephritis, HIV
• Norm Renin, Low aldo: Primary aldo disorders, ACEI, ARBs, Hep
• Low aldo response: Meds (k-sparing diuretics, TMP-SMX, pentamidine, calcineurin inh,
• Tubulointerstitial disease (sickle cell, SLE, diabetes)
  Acidosis: Mild
  UAG: Positive
  UpH:

Question 28

What are some Saline Responsive metabolic alkalosis?

Answer 28

Vomiting, NGT, Prior Loop diuretics, Hypovolemia, Post-Hypercapnia

Question 29

What are some Saline Resistant alkalosis?

Answer 29

Hyperaldosteronism (HTN, hypokalemia)

• Antacids
• Hypokalemia
• Current Loop Diuretics (exception euvolemic)