Sux vs Roc

Suxamethonium should at most times be used in RSI as it gives the best intubating condition.
Sux is depolarizing. Short acting (dose 2mg/kg)
Roc (Rocuronium) is non depolarizing. Long acting, may not be good if you want to test neuro (dose 1-1.2mg/kg)

Always use Sux except
1. Known hyperkalemia level prior to RSI (eg ECG monitor, known level of 5.5 mmol/L)
2. Unknown last dialysis of renal patient (eg patient with shunt and uncommunicative)
3. Day 2 of Burn patient
4. Crushed injury with extrication after 2 days (eg earthquake victims)

5. Neuro patients (eg Paraplegic/Hemiplegic/Motor neuron disease) prone to denervation
6. Immobilization*
7. Recent known seizure (especially status epilepticus which causes rhabdomyolysis)or rhabdomyolysis
8. recent sepsis who are confined to bed increases K by 2.3 mmol/L

Denervation explained:
1. Patients with cerebrovascular events with known decrease myogenic activity = suggests denervation of affected muscles
2. Denervation causes upregulation of acetylcholine receptors in skeletal muscles = sensitizes muscle response to sux
3. Giving sux rapidly depolarizes these upregulated acetylcholine receptors, leading to massive efflux of ICF potassium

Take note that acute cerebrovascular event with not lead to upregulation rapidly, it has to be days.

*Suxamethonium-induced hyperkalemia may occur from 7 days to 6 months after immobilization

(link: http://www.google.com.sg/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.anzca.edu.au%2Fjficm%2Fresources%2Fccr%2F2006%2Fseptember%2Fccr_08_3_0906_213.pdf&ei=WxxySpPyLpCVkAXb4o3_Cw&usg=AFQjCNEAEC2_L_mq9xmOi67YK_wnu4EcEA&sig2=P1DHpT0K0269A9FOX9UlxQ)
- Crit Care Resusc 2006; 8: 213–21