ABGs

Question 1

Kidneys compensate in respiratory acidosis by

Answer 1

retaining Bicarbonate (HCO3) - Metabolic alkalosis

Question 2

Kidneys compensate in respiratory alkalosis by retaining

Answer 2

excreting Bicarbonate (HCO3) - Metabolic acidosis

Question 3

The lungs compensate for metabolic acidosis by

Answer 3

hypoventilating (increasing CO2) - Respiratory acidosis

Question 4

The lungs compensate for metabolic alkalosis by

Answer 4

hyperventilating (decreasing CO2) - Respiratory alkalosis

Question 5

Normal PCO2 levels

Answer 5

4.7 - 6 kPa

35 - 45 mmHg

Question 6

Normal BE levels

HCO3 levels

Answer 6

Be: (-2) - (+2) mol/L
HCO3: 22 - 26 mEq/L

Question 7

Normal pH levels

Answer 7

7.35 - 7.45

Question 8

Normal PaO2 levels

Answer 8

9.3 - 13.3 kPa

Question 9

Steps of interpreting ABGs

Answer 9

1. Look at pH = acidosis/alkalosis
2. Look at pCO2 = agrees with pH (high pCO2) = respiratory problem
3. Look at HCO3 = agrees with pH (high HCO3) = metabolic problem
4. If both pCO2 and HCO3 agree with pH = Mixed (no compensation)
5. If metabolic but pCO2 doesn’t agree = partial compensation
6. If respiratory but HCO3 doesn’t agree = partial compensation
7. If pH is normal but there is a problem + compensation = full compensation

Question 10

Very high HCO3 suggests

Answer 10

Chronic acidosis

Question 11

Low pH + High PaCO2 =

Answer 11

Respiratory Acidosis

- Respiratory opposite

Question 12

High pH + Low PaCO2 =

Answer 12

Respiratory Alkalosis

- Respiratory opposite

Question 13

Low pH + Low HCO3 =

Answer 13

Metabolic Acidosis

- Metabolic equal

Question 14

High pH + High HCO3 =

Answer 14

Metabolic Alkalosis

- Metabolic equal

Question 15

ROME stands for

Answer 15

Respiratory opposite (low pH + high PaCO2)
Metabolic equal (low pH + low HCO)

Question 16

Normal anion gap =

Answer 16

8 - 14 mmol/L

Question 17

Anion gap =

Answer 17

(Na + K) - (HCO3 + Cl)

Question 18

Low pO2 + High pCO2

Answer 18

Type 2 Respiratory Failure (non-compensated)

- CO2 retention

Question 19

Low pO2 + Normal pCO2

Answer 19

Type 1 Respiratory Failure (hypoxia without hypercapnia)

- Increased RR to maintain 02

Question 20

Type 2 Respiratory failure

Answer 20

Non-compensated

Hypoxia with hypercapnia

Question 21

Type 1 Respiratory failure

Answer 21

Compensated

Hypoxia without hypercapnia

Question 22

Causes of Type 1 respiratory failure

Answer 22

Damage to lung tissue

• Pulmonary oedema
• Pneumonia
• Pneumothorax
• Pulmonary fibrosis
• ARDS

Question 23

Causes of Type 2 respiratory failure

Answer 23

Inadequate ventilation of alveoli

• Asthma
• COPD
• Resp muscle weakness

Question 24

Anion gaps are to do with

Answer 24

Metabolic acidosis

Question 25

Causes of a normal anion gap acidosis

Answer 25

HARD AF ``` Hyperchloraemia Addinson's Renal tubular acidosis Diarrhoea Acetazolamide Fistulas ```

Question 26

Causes of a raised anion gap acidosis

Answer 26

KUMAL ``` Ketones (DKA, alcohol) Urate (renal failure) Methanol poisoning Aspirin poisoning (late stage) Lactate (shock, hypoxia, sepsis) ```

Question 27

Causes of Respiratory Acidosis

Answer 27

Not being able to breathe properly ``` Pneumonia COPD Neuromuscular disease Obesity Pulmonary oedema Asthma (severe) Opiate OD Benzodiazepines ```

Question 28

Causes of Respiratory Alkalosis

Answer 28

CAPHA ``` CNS: Stroke, SAH, encephalitis Anxiety (hyperventilation) Pregnancy High altitude Aspiring poisoning (early stage) ```

Question 29

Causes of Metabolic Alkalosis

Answer 29

DANG CAP HV Diuretics Antacids NG suction Cushing's syndrome Congenital adrenal hyperplasia Aspiration Primary hyperaldosteronism Hypokalaemia Vomiting

Question 30

3 pillars of anaesthesia

Answer 30

Hypnosis Analgesia Muscle relaxation