Arterial Blood Gas Interpretation

Question 1

The Resuscitation Council (UK) advocate a 5 step approach to arterial blood gas interpretation. What is step 1?

Answer 1

How is the patient?

Question 2

The Resuscitation Council (UK) advocate a 5 step approach to arterial blood gas interpretation. What is step 2?

Answer 2

Is the patient hypoxaemic?

the Pa02 on air should be >10 kPa

Question 3

The Resuscitation Council (UK) advocate a 5 step approach to arterial blood gas interpretation. What is step 3?

Answer 3

. Is the patient acidaemic (pH <7.35) or alkalaemic (pH >7.45)

Question 4

The Resuscitation Council (UK) advocate a 5 step approach to arterial blood gas interpretation. What is step 4?

Answer 4

Respiratory component: What has happened to the PaCO2?

1. PaCO2 > 6.0 kPa suggests a respiratory acidosis (or respiratory compensation for a metabolic alkalosis)
2. PaCO2 < 4.7 kPa suggests a respiratory alkalosis (or respiratory compensation for a metabolic acidosis)

Question 5

The Resuscitation Council (UK) advocate a 5 step approach to arterial blood gas interpretation. What is step 5?

Answer 5

Metabolic component: What is the bicarbonate level/base excess?

1. Bicarbonate < 22 mmol/l (or a base excess < - 2mmol/l) suggests a metabolic acidosis (or renal compensation for a respiratory alkalosis)
2. Bicarbonate > 26 mmol/l (or a base excess > + 2mmol/l) suggests a metabolic alkalosis (or renal compensation for a respiratory acidosis)

Question 6

What does ROME stand for?

(Respiratory)

Answer 6

Respiratory = Opposite

1. low pH + high PaCO2 i.e. acidosis, or
2. high pH + low PaCO2 i.e. alkalosis

Question 7

What does ROME stand for?

(Metabolic)

Answer 7

Metabolic = Equal

1. low pH + low bicarbonate i.e. acidosis, or
2. high pH + high bicarbonate i.e. akalosis