Cyanosis

Question 1

Definition of Cyanosis

Answer 1

More than 5g pg deoxygenated haemoglobin in cappillaries.

Central cyanosis - bluish of the tongue and oral mucosa

Question 2

Causes of Central Cyanosis

Answer 2

1. Cyanotic Congenital Heart Disease, Eisenmenger complex
2. Persistent fetal circulation seen in newborn at risk:
   Big baby with perinatal asphyxia
   IDM
   Hypocalcaemia
   Hypoglycaemia
   Polycythaemia
   Down’s Syndrome
3. Chronic lung diseas (BPD,CF, Kartageners and Pulmonary fibrosis)
4. Methaemoglobinaemia (High PaO2 but low SaO2)

Ddx - Traumatic facial cyanosis

Question 3

Steps to clinical examination of Cyanosis

Answer 3

1. Demonstrate cyanosis of central origin - Tongue
2. Note if patient is dyspnoeic or not - if +ve —-> Pulmonary origin unless on e is in congestive HF
3. Examine fingers for clubbing, esp the thumb
   Stage I - Fullness of nail bed
   Stage II - Obliteration of angle between nail and nail fold
   Stage III- Convexity of nail longitudinally and Transversely
   Stage IV - Drumstick appearance
4. Look for Pitting Oedema - Ankle and Sacrum
5. Comment about the growth of the patient - Wasted/ FTT
6. CVS exam - also note size of liver and measure BP
7. RS exam - esp if pt is dyspneoic
8. If all -ve —-> Take a drop of blood and expose to oxygen to see the persistence of blueness (Methaemoglobinaemia)

Note:
Differential Cyanosis
Pink UL and Cyanotic LL: COA + PDA
Cyanotic UL and pink LL: TGA + PDA