Acid Base Disorders

Question 1

What is acidemia and acidosis

Answer 1

Low blood pH

Acidosis - disorder tending to make blood more acid than normal

Question 2

What is alkalosis and alkalemia

Answer 2

Alkalosis - disorder tending to make blood more alkaline than normal
Alkalemia - high blood ph

Question 3

What is standard bicarbonate

Answer 3

Measures of metabolic component of any acid base disturbance
It’s the [bicarbonate] standardised to pCO2, 5.3kPa and temp 37 degrees

Question 4

What 2 components effect absolute bicarbonate

Answer 4

Respiratory and metabolic components

Question 5

What is the base excess

Answer 5

Quantity of acid required to return pH to normal under standard conditions

Question 6

What level of Hb is base excess standardised against

Answer 6

50g/L

Question 7

Is base excess negative or positive in acidosis

Answer 7

Negative - base deficit

Question 8

What drives the respiratory component of blood pH

Answer 8

CO2 excretion

Question 9

What drives the metabolic component of blood pH

Answer 9

Changes in acid load, H+ secretion and bicarbonate recycling

Question 10

What causes a metabolic acidosis

Answer 10

Dilutional
Failure of H+ excretion
Excess H+ load
HCO3- loss

Question 11

What is the compensatory mechanism seen with acidosis

Answer 11

Hyperventilation to increase CO2 excretion

Question 12

What is the normal anion gap range

Answer 12

10-16

Question 13

What conditions would cause a wide anion gap

Answer 13

Lactic acidosis
Ketoacidosis
Ingestion if acid
Renal failure

Question 14

What condition would cause a narrow anion gap (high Cl-)

Answer 14

Renal tubular acidosis

GI bicarbonate loss

Question 15

What is the anion gap

Answer 15

Difference between measured anions and cations

[Na+] + [K+] - [Cl-] - [HCO3-]

Question 16

What are some causes of metabolic alkalosis

Answer 16

Alkali ingestion
Vomiting
Renal acid loss

Question 17

What’s the compensatory mechanism for metabolic alkalosis

Answer 17

Hyperventilation - limited by hypoxic drive

Renal bicarbonate excretion

Question 18

What is respiratory acidosis and what causes it

Answer 18

CO2 retention leading to increased carbonic acid dissociation
Any cause of respiratory failure

Question 19

Compensatory mechanism for respiratory acidosis

Answer 19

Increased renal H+ excretion and bicarbonate retention

Question 20

What is respiratory alkalosis and what causes it

Answer 20

CO2 depletion due to hyperventilation

Cause: type 1 respiratory failure, anxiety/panic