Saturday, 11 September 2010

MRCP revision battle 8.4: Reversible causes of cardiac arrest

A little bit of a random one to throw into MRCP revision but a quick recap of the reversible causes of cardiac arrest, famously recalled as the 4 Hs and 4 Ts, can never go amiss...

4 H's:
  • hypoxia
  • hypovolaemia
  • hypothermia
  • hypoglycaemia/hyper/hypokalaemia/ other electrolyte imbalance

4 T's:
  • Tension pneumothorax
  • cardiac Tamponade
  • Thombus
  • Toxins

I remember the 4 H's in the format of a little picture of a man standing on top of a snow-covered mountain.  He is struggling to breath as there's not much oxygen up there (hypoxia) and  is shivering as its so cold (hypothermia).  He is looking sad and in one hand is an empty water bottle (hypovolaemia) and in the other an empty lunchbox (hypoglycaemia... then remember the hypo/hyper kalaemia from that).

For the 4 T's I think of the less happy phrase of 'Thomas has Ten Toxic Tampons' (= Thombus, tension pneumothorax, toxins, tamponade)

So after a couple of nice straightforward battles let face a juicier one: pituitary tumours...