Study Of Local Anaesthetic Property By Foot Withdrawal Method

Aim: To study the local anaesthetic property of procaine HCL using nerve block anaesthesia by
frog foot withdrawal method.

Principle: Local anaesthetics reversibly block impulse conduction along nerve axons and excitable membranes. Their action is used to produce local or regional anaesthesia and for blocking pain sensation. the local anaesthetic property can be easily studied by using

• Nerve block anaesthesia
• Surface anaesthesia
• Infiltration anaesthesia

Requirements:

Animal: Frog
Drugs: Procaine HCL (1%w/v)
Equipment: Frog board surgical instruments

Procedure:

1. Decereb the frog and Place the frog (100-150 gm) and destroy the upper part of the spinal
   cord with the help of pithing needle.
2. Cut open the abdomen and remove all the abdominal organs , so that a pouch is made of
   abdominal walls.
3. Expose the spinal nerves in the cavity
4. Put the frog on the frog board with two of its hind legs hanging free from the board.
   Alternatively the frog may be pinned to the board placed vertically so that its hind legs
   hang free
5. Immense the right hind leg in the beaker containing 0.1N HCL.
6. Note the brisk reflex withdraw of the leg
7. Wash the immerse leg with flowing water or normal saline.
8. Repeat the same with the left hind leg.
9. Wash the immersed left.
10. Place about 10 ml of 1% w/v procaine Hcl in the abdominal pouch. The sciatic nerve flex is exposed to the local anaesthetic actions of the drugs. allow the drug to act for 5 min.