Following a burn, charring and insensitivity to pain was found over the entire surface of the right lower limb, entire surface of right trunk and anterior surface of the right upper limb. approximately what percent of the body surface had burns and how would you classify the burn?

The  burn may be classified as a Fourth-degree burn with 31 % of TBSA.

Explanation:

There are 4 types of burn classifications: Superficial burn (first-degree), Superficial partial thickness burn or Deep partial thickness burn (second-degree), Full thickness burn (third-degree), and Fourth-degree burn.

Superficial burn or First-degree burnInvolved layer is epidermisIt appears red without blisters with dry textureWith sensation of pain is presentHealing time within 5 - 10 days and heals well with no complications.Superficial partial thickness burn/Deep partial thickness burn or Second-degree burnIt extends to the dermis. (papillary for superficial, reticular for deep)Blanches with pressure, with or without blistering, red to yellow, white appearance, moist to dry textureIt still presents with pain, superficial and deep.Healing may take 2-3 weeks for superficial, 3-8 weeks for deep. Local infection may occur and scarring may ensue.Full thickness burn (Third-degree)Destroys the entire dermis.Stiff with white-brown appearance, NO blanching, with leathery texture.PainlessLong time needed for recovery. It may need surgical removal of dead tissue.Fourth-degree burnEncompasses the whole layer of skin and underlying fat, exposing the bones and/or muscles.Black and charred (eschar), dry texture.PainlessDefinitely needs surgical removal of dead tissue to allow recovery.It may also cause significant functional disability.Wallace “Rule of Nines”

To determine for the burn percentage, we use the Wallace “Rule of Nines” chart. It estimates the percentage of total body surface area (TBSA) that has been destroyed by burns. The diagram attached shows the body divided into multiple sections which represent 9% of the body surface area.

For the example, we have the following given and corresponding percentages:

Entire surface of the right lower limb - 18% (the whole right leg is affected, front and back, so that's 18%)Entire surface of right trunk - 9% (The trunk is 18% in whole, but in this example, only the right trunk is affected, so that's 9%)Anterior surface of the right upper limb - 4.5% (Only the front surface of the right arm is affected so it's 4.5%)

% TSBA = 18 + 9 + 4.5

% TSBA = 31.5 %