Experimental and Preclinical Anatomy Definition A burn is a type of injury of skin or other tissues caused by heat, electricity, chemicals, friction or radiation. Reminder of Anatomy Electrical burns Electrical burns may cause serious injury that is not readily apparent. Often the entry and exit points for the electrical shock may not be easily found. Electricity flows more easily through tissues in the body that are designed to deal with electricity. Nerves and muscles are "wired" for this task and often are damaged. If significant muscle damage occurs, muscle fibers and chemicals can be released into the bloodstream causing electrolyte disturbances and kidney failure. Electrical burn Chemical burns Burns can also occur when chemicals are spilled onto the body and generate a reaction that creates heat. Chemical burns may be classified by their pH or acidity. • Acids are those with pH less than 7 and include common household compounds like acetic acid, hydrochloric acid, or sulfuric acid. • Bases or alkali compounds have a pH greater than 7. Ammonia is a common alkali found in the home. Chemical burn Radiation burns Radiation burns may be caused by protracted exposure to ultraviolet light (such as from the sun, tanning booths or arc welding) or from ionizing radiation (such as from radiation therapy, X-rays or radioactive fallout). Sun exposure is the most common cause of radiation burns and the most common cause of superficial burns overall. There is significant variation in how easily people sunburn based on their skin type. Radiation burn from cancer treatment. Classification Based upon their depth, burns are classified as follows: First degree burn: superficial, causes local inflammation of the skin (can be caused by sunburns) Signs: • Pain • Redness • Mild swelling Painful erythema and edema recover spontaneously without special treatment, and most of these burns do not scar. Classification Second degree burn: deeper, affecting epidermis and part of the dermis. Signs: • Pain • Redness • Swelling • Blistering of the skin Second degree burns have been subdivided into burn categories: • Superficial • Deep Classification Superficial second degree burns affect the entire epidermis and upper third of the dermis, including papillary layer of the dermis. It may leave slightly rough and weak scars. Deep dermal burn affects most reticular layer of dermis and extends down to about ¾ of the dermis. It leaves severe scars with high possibilities of developing into hypertrophic scars. Superficial second degree burn Deep dermal burn Classification Third degree burn: causes most damage, extending through every layer of skin. The damage can even reach the bloodstream, major organs, and bones, which can lead to death. Signs: • Difficulty breathing • Carbon monoxide poisoning • Other toxic effects, if smoke inhalation also occurred There is also technically a fourth-degree burn. In this type, the damage of third-degree burns extends beyond the skin into tendons and bones In addition to the depth of the burn, the total area of the burn is significant. Burns are measured as a percentage of total body area affected. The "rule of nines" is often used. This calculation is based upon the fact that the surface area of the following parts of an adult body each correspond to approximately 9% of total (and the total body area of 100% is achieved): • Head = 9% • Chest (front) = 9% • Abdomen (front) = 9% • Upper/mid/low back and buttocks = 18% • Each arm = 9% • Each palm = 1% • Groin = 1% • Each leg = 18% total (front = 9%, back = 9%) If more than 15%-20% of the body is involved in a burn, significant fluid may be lost. Shock may occur if an adequate fluid transfusion is not provided intravenously. As the percentage of burn surface area increases, the risk of death increases as well. Patients with burns involving less than 20% of their body should do well, but those with burns involving greater than 50% have a significant mortality risk, depending upon a variety of factors, including underlying medical conditions and age. First aid for burns For minor burns (first degree burns or second degree burns involving a small area of the body) Gently clean the wound with lukewarm water. Though butter has been used as a home remedy, it should NOT be used on any burn. Rings, bracelets, and other potentially constricting articles should be removed (edema, or swelling from inflammation may occur and the item may cut into the skin). The burn may be dressed with a topical antibiotic ointment like Bacitracin or Neosporin. If there is concern that the burn is deeper and may be second or third degree in nature, medical care should be accessed. Tetanus immunization should be updated if needed. For major burns (second and third degree burns) 1.Remove the victim from the burning area, remembering not to put the rescuer in danger. 2.Remove any burning material from the patient. 3.Call 112 if needed. 4.Once the victim is in a safe place, keep them warm and still. Try to wrap the injured areas in a clean sheet if available. DO NOT use cold water on the victim; this may drop the body temperature and cause hypothermia. First aid for burns •Heat burns (thermal burns): Smother any flames by covering them with a blanket or water. If your clothing catches fire, do not run: stop, drop, and roll on the ground to smother the flames. •Cold temperature burns: Try first aid measures to warm the areas. Small areas of your body (ears, face, nose, fingers, toes) that are really cold or frozen can be warmed by blowing warm air on them, tucking them inside your clothing or putting them in warm water. •Liquid scald burns (thermal burns): Run cool tap water over the burn for 10 to 20 minutes. Do not use ice. •Electrical burns: After the person has been separated from the electrical source, check for breathing and a heartbeat. If the person is not breathing or does not have a heartbeat, call 112. •Chemical burns: Natural foods such as chili peppers, which contain a substance irritating to the skin, can cause a burning sensation. When a chemical burn occurs, find out what chemical caused the burn. •Tar or hot plastic burns: Immediately run cold water over the hot tar or hot plastic to cool the tar or plastic. Any questions?
