Local anaesthetic

Question 1

mechanism of action of local anaesthetic agent

Answer 1

Na channel blockade

Question 2

List 4 serious clinical complications of LA toxicity

Answer 2

1- decreased GCS , coma
2- seizures 
3-Hypotension 
4- Methaemoglobinaemia 
5- Respiratory depression

Question 3

ECG features of systemic LA toxicity

Answer 3

1-broad QRS 
2- Large terminal R wave in aVr 
3- RAD 
4- prolonged PR intervals 
5- Bradycardia 
6-ventricular dysrhythmias

Question 4

To treat the CV effects of LA toxicity , list 3 pharmacological agents ( from different classes ) that can be used in treating toxicity

Answer 4

1- adrenaline :5 mcg/min , infusion titrated to response
2- Intralipid , 20 % ( 1-2ml/kg ) , 15 mg /kg /hr
3- sodium bicarbonate 8.4 % , 100 ml , every 5 min until QRS normalised .