Lidocaine

Question 1

Lidocaine side effect

Answer 1

CNS disturbances:
o Sleepiness, dizziness, disorientation, confusion and convulsions

Cardiovascular:
o Hypotension, bradycardia, decreased myocardial contractility and increased AV blocks at toxic levels only

Question 2

Lidocaine class

Answer 2

Antiarrhythmic, Sodium Channel Blocker

Question 3

Lidocaine contraindication

Answer 3

Not used for supraventricular rhythms or bradycardias

Hypersensitivity to any of the “caines”

Question 4

Lidocaine action

Answer 4

• Depresses the automaticity of the Purkinje Fibers therefore raises the depolarization threshold in the ventricular fibers and decreases tendency to fibrillate.
• Little antiarrhythmic effect on atrial muscle at sub-toxic levels

-Cardiovascular effects:
o Decreased conduction rate and force of contraction, mainly at toxic levels
o Prolongs phase 4 depolarization and shortens action potential

-CNS stimulation:
o Tremors, restlessness, clonic convulsions followed by respiratory depression and
respiratory failure at higher doses.

-Onset of action: less than 3 minutes

Question 5

Lidocaine dose

Answer 5

Adult
-1 – 1.5mg/kg IV bolus; may repeat doses every 3 – 5 minutes at 0.5 – 0.75mg/kg to a total dose of 3mg/kg. May then start continuous infusion of 1 – 4 mg/min
Use 4mg/ml concentration for infusion
-For endotracheal administration use 2 – 2.5 the loading dose followed by a 10ml NS flush.

-Pediatric:
1mg/kg IV bolus (not to exceed 100mg), may repeat at 0.5 – 1.0mg/kg every 3-5 minutes as needed to a total dose of 3mg/kg. May then start continuous administration of 20 – 50mcg/kg/min.

For ETT use, increase loading dose by 2 -3 times

Question 6

Lidocaine indication

Answer 6

Ventricular tachycardia or wide-complex tachycardia with pulses

Recurrent or refractory ventricular fibrillation/pulseless v-tach.

Following successful defibrillation

Pre-intubation in head injuries (may minimize the rise in ICP associated with intubation).