Acid Base Balance

Question 1

What is the normal pH balancing acid and base?

Answer 1

7.35-7.45

Question 2

What is this describing?

Low pH, high CO2 on ABG.

Answer 2

Respiratory acidosis

Question 3

What causes a respiratory acidosis?

Answer 3

1. Type 2 respiratory failure due to any lung, neuromuscular or physical cause.
2. COPD, sedatives, cerebral tumours, pneumonia, flail chest.

Question 4

What is this describing?

High pH, low CO2 on ABG.

Answer 4

Respiratory alkalosis

Question 5

What causes a respiratory alkalosis?

Answer 5

Result of hyperventilation:

1. Stroke, subarachnoid bleed, meningitis.
2. Mild/moderate asthma, anxiety, fever, pregnancy, pulmonary embolism, severe anaemia, high altitude.

Question 6

What is this describing?

Low pH, low HCO3 on ABG.

Answer 6

Metabolic acidosis

Question 7

What are the two types of metabolic acidosis?

Answer 7

1. Increased anion gap

2. Normal anion gap

Question 8

What are the causes of an increased anion gap metabolic acidosis?

Answer 8

Increased production, or reduced excretion of organic acids, HCO3 binds and falls:

1. Lactic acidosis - sepsis, shock
2. Urate - renal failure
3. DKA
4. Drugs - salicylates

Question 9

What are the causes of a normal anion gap metabolic acidosis?

Answer 9

Due to loss of bicarbonate or ingestion of H+ ions:

1. Diarrhoea
2. Addison’s
3. Renal tubular acidosis

Question 10

What is this describing?

High pH, high HCO3 on ABG.

Answer 10

Metabolic alkalosis

Question 11

What are the causes of metabolic alkalosis?

Answer 11

Vomiting, diuretics (K+ wasting), mineralocorticoid excess, burns.

Question 12

What condition are these signs and symptoms seen in?

Headache, confusion, fatigue, muscle weakness, tachycardia, Kussmaul breathing, arrhythmias.

Answer 12

Acidosis

Question 13

What condition are these signs and symptoms seen in?

Muscle weakness, muscle cramps, headache, tetany, hypokalaemia.

Answer 13

Alkalosis