When you find someone without a pulse but then hook up the monitor and there is a rhythm, your first thought it probably “CRAP!” But as you start CPR, you need to be thinking about what caused it because not much will help the person except correcting the underlying problem.

So like most of medicine, there is a handy mnemonic for remembering the main causes: The 6 Hs and 5Ts

The 6 Hs

1. Hypoglycemia
2. H+ (acidosis)
3. Hyperkalemia/Hypokalemia (potassium disturbances only get counted once)
4. Hypovolemia
5. Hypoxia
6. Hypothermia

The 5 Ts

1. Trauma
2. Tension pneumothorax
3. Tamponade
4. Toxins
5. Thrombosis

(I’ll make a T doodle at a later date)

The other handy mnemonic for the Hs I learned from this video (so I take no credit for it): Diabetic crashing with a wide QRS

• Diabetic = Hypoglycemia or H+ acidosis
• Crashing = bad vitals
  • Low BP +/- tachycardia (hypovolemia)
  • Low O2 (hypoxia)
  • Low temperature (hypothermia)
• Wide QRS = hyperkalemia