Anion Gaps, Acid/Base

Question 1

what is the anion gap (how calculated)?

which of the 4 ions can be left out?

Answer 1

• Na – (Cl + HCO3)

K+ has little effect bc value is small and can be left out

Question 2

What is the normal range for anion gap?

Answer 2

~8-16 mEq/L

Question 3

Fill in causes of increased anion gap (MUDPILERS)

Answer 3

Methanol/Metformin
Uremia
DKA/Alcoholic ketoacidosis
Paraldehyde
Iron/Isoniazid
Lactic acidosis (shock, seizure, hypoxemia)
Ethylene glycol
Rhabdo/Renal Failure
Salicylates

Question 4

What are the 2 MCC of non-gap acidoses?

Answer 4

Diarrhea and Renal Tubular Acidosis

Question 5

Why measure arterial blood gases?

Answer 5

Allows assessment of effectiveness of ventilation and overall acid-base

Question 6

What are the 3 ABG values that relate to acid base?

what are normal ranges for these values

Answer 6

– pH 7.35-7.45
– PaCO2 35-45 mm Hg (sea level)
– HCO3- 22-26 MEq/L

Question 7

How does “ROME” acronym help us evaluate acid/base imbalances?

Answer 7

R= respiratory
O–> opposite
M= metabolic
E–> equal

First decide if pH is acidic or basic, then look whether CO2 (respiratory) or bicarb (metabolic) matches that determination best.

Question 8

determine primary disorder with ABG values of:
– pH 7.27
– PaCO2 27 mm/Hg
– HCO3 10mEq/L

Answer 8

acidosis–> matched best by bicarb so metabolic

CO2 is low (basic), so has respiratory compensation

Question 9

common causes of respiratory acidosis

Answer 9

HYPOventilation

drug intoxication, cardiac arrest, COPD [retain CO2, things that make you not breathe]

Question 10

common causes of respiratory alkalosis

Answer 10

HYPERventilation,

asthma, PE, high altitude, ASA overdose [breathing]

Question 11

common causes of metabolic alkalosis

Answer 11

vomiting,

volume loss with chloride depletion, gastric lavage

Question 12

What are the main differences between DKA and Hyperglycemic hyperosmolar non-ketotic (HHNK) syndrome?

Answer 12

HHNK has same precipitants as DKA [but more dehydrated, is non-acidotic, no ketone production bc still small amount of insulin]
HHNK blood glucose can be over 600!
HHNK has higher mortality.
Tx for HHNK is FLUIDS (up to 9L)