Lecture 10 - Acid Base Disorders

Question 1

When calculating Anion Gap (AG), add ____ for every 1mg/dL that Albumin is < _____.

Answer 1

2.5

for every 1mg/dL albumin < 4.5

Question 2

Winter’s formula for predicting pCO2:

pCO2 = ?

Answer 2

pCO2 = 1.5 [HCO3-] + 8

This value should be within +/- 2 of the measured pCO2.

If pCO2 is HIGHER than predicted –> superimposed respiratory acidosis

If pCO2 is LOWER than predicted –> superimposed respiratory alkylosis

Question 3

Appropriate Respiratory compensation for Metabolic Alkalosis:

pCO2 should increase by _____mmHg for every 1 unit increase in serum [HCO3-].

Answer 3

0.6mmHg

Question 4

Metabolic compensation for Resp. Acidosis occurs in two ways:

1. ______ ______ from Bone
2. Kidney resorption of HCO3-, titratable acids, and NH4+

Which occurs in about 3 hours, and which occurs in about 24 hours?

Answer 4

1. Calcium Carbonate

Calcium Carbonate from bone in 3 hours

Kidney mechs in about 24 hours

Question 5

Acute (about 24 hours) Renal compensation for Resp Acidosis can be determined as an increase of ____ in [HCO3-] for every ____mmHg increase in pCO2.

Chronic Renal compensation = increase of ____ in [HCO3-] for every ___mmHg increase in pCO2.

Acute renal comp for Resp Alkalosis = decrease of [HCO3-] by ____ for every decrease of _____mmHg pCO2.

Chronic = decrease of [HCO3-] by ____ for every decrease of ____mmHg pCO2.

Answer 5

1

10

4

10

2

10

5

10

Question 6

AG acidosis or alkylosis is METABOLIC. So, _____ should be appropriately low or high, respectively. If it is NOT –> superimposed acidosis or alkalosis, depending on how it’s skewed.

Answer 6

HCO3-

Question 7

What is the Acronym for causes of AG ACIDOSIS (AG > 12)?

Answer 7

G - Glycols (antifreeze)
O - Oxoproline (acetominophen metabolite)
L - L-lactate
D - D-lactate (from commensal bacteria)
M - Methanol
A - Aspirin
R - Renal Failure
K - Ketones

Question 8

Generation of Alkalosis –> ingestion of _____ (think antacids or Milk _____) OR loss of _____ (think vomiting or Chloridorrhea typically from villous adenoma).

Answer 8

Alkali

Alkali

loss of acid

Question 9

Maintenance of Alkalosis –> refers to disturbance in kidney function causing Alkalosis. The two big causes are LOW _____ and/or HIGH ______ effect.

Keep in mind Excretion of HCO3- is _____ and _____ dependent.

Answer 9

Low Cl-

High Aldosterone effect

Flow and K+ dependent –> a decrease in either causes a decrease in HCO3- excretion –> more in serum –> alkalosis

Question 10

First thing to measure once Metabolic Alkalosis is determined –> Cl-

If Cl- is low ( < ___ ), it is considered a Cl-responsive Alkalosis –> the kidney will be reabsorbing HCO3- bc Cl- is low, so you can give Cl- to treat, and the kidney will preferentially reabsorb Cl- (remember these anions are co-transported with Na+).

Common causes of the above scenario with depleted Cl- include 4 main things: 1. ____ 2. ___ 3. _____ 4. _____

Answer 10

< 10

1. Dehydration
2. Vomiting
3. Diuretics
4. Villous Adenoma (Chlorideorrhea)

Question 11

A good way to determine Renal Tubular Acidosis (RTA) is Type ____ (PCT issue) is if patient presents with Glycosuria with normal Serum Glucose.

Answer 11

Type 2 (PCT issue)

Question 12

Type 1 RTA (DCT) patients never have a urine pH < ____. Some patients may present with kidneystones and/or hematuria.

Answer 12

5.5

Question 13

Fanconi’s syndrome is a Type ____ RTA in which there is decreased reabsorption of not only HCO3-, but ___, ___, and ___ as well.

Answer 13

Type 2 (PCT issue)

Glucose, AAs, and Phosphate

Question 14

Treat Type 1 RTA with ______ _____.

Answer 14

Baking soda

Question 15

Non-AG metabolic acidosis with HYPOkalemia is generally one of 3 things:

1. ____
2. ____
3. ____

Answer 15

1. Type 1 RTA
2. Type 2 RTA
3. Diarrhea

Question 16

Type 4 RTA is caused by LOW ____/_____ effect. Look for patients to present with HYPER_______ along with their metabolic acidosis (which can separate this from Type 1 and 2 RTA).

Answer 16

Low Renin/Aldosterone

HYPERkalemia