A 46 year old lady presents following collapse. She has compensated shock and blood tests which show:

Severe compensated metabolic alkalosis with severe hypokalaemia/ hypochloraemia, moderate hyponatraemia and elevated lactate.

All suggest chronic diuretic abuse (Frusemide/Thiazide).

ECG findings of hypokalaemia include ST segment sagging, T wave depression, and U wave – changes which get more pronounced as the K falls. Starts at K<3

• Increased amplitude and width of the P wave
• Prolongation of the PR interval
• T wave flattening and inversion
• ST depression
• Prominent U waves (best seen in the precordial leads)
• Apparent long QT interval due to fusion of the T and U waves (= long QU interval)

With worsening hypokalaemia…

• Frequent supraventricular and ventricular ectopics
• Supraventricular tachyarrhythmias: AF, atrial flutter, atrial tachycardia
• Potential to develop life-threatening ventricular arrhythmias, e.g. VT, VF and Torsades de Pointes

Treatment priorities:

manage in resusc

Full cardiac monitoring

Prepare for unstable arrhytyhmia

Fluid and K replacement – req central access and arterial BP monitoring

ICU admission

Treat cause