Answer
A burn is tissue damage caused by one of several agents:these include fire, electricity, radiation, chemicals, steam, and hot objects. A victim who is burned may be harmed in several ways. First, protection against microbial infection may be lost; second, dehydration may occur; third, pain may be experienced because pain receptors are exposed. In addition, the thermoregulation function of the skin will be impaired
Burns are classified on the basis of two types of criteria both of which are measures of severity of the burn, The depth of the burn lesion and the tissues affected are indicated by degree of the burn. The seriousness of the burn can also be assessed and evaluated by estimating the percentage of body surface burnt. Patients with burns covering more that 70% of body surface seldom survive.
Degree of burn
Burns are usually classified anatomically as first degree, second degree and third degree burns. However, insurance companies, and attorneys also have additional categories of fourth, fifth, and sixth degree burns. In a first degree burn only the epidermis is damaged. Signs and symptoms (SS) may include redness, mild pain, some flaking and peeling, but no blisters. This is called a partial thickness burn Second degree burns are more invasive: the epidermis is destroyed and part of the dermis is damaged at the burn site. Signs and symptoms include redness, pain, and edema. There is also blistering as epidermis separates from the dermis and fluid accumulates between. Sweat glands, sebaceous glands, and hair follicles are usually spared. Second degree burns are also designated partial thickness burns.
Third degree burns are designated full thickness burns because epidermis, dermis, and subcutaneous layers of the skin are all destroyed. Sign and symptoms include numbness and edema.
The burn area usually has a whitish or dark to black coloration. Systemic effects include loss of water, plasma and plasma proteins. The victim may go into shock and bacterial infections may supervene. Other potential deficits that may be experienced include impaired circulation, reduced urine production, and weakened immune responsiveness.
The parameter of size of surface burnt is a vital part of evaluation of burns in hospital burn clinics.
The quantitation of the burnt area is done using the rule of nines. The following surfaces are estimated to account for the indicated percentage of the whole surface area of the body:
a, Head and neck surfaces , anterior and posterior represent 9% of body surface
b.Surfaces of upper limbs--anterior and posterior represent 9% (18% for both)
c.Surfaces of lower limbs--anterior and posterior up to buttocks-- 36%
d. anterior and posterior trunk including buttocks 36%
e. Perineum 1%
The following are considered major burns:
1. A third degree burn over 10% of the body
2. A second degree burn over 25% of the body
4. Any third degree burn on face hands or perineum
If a victim sustains a burn over more than 70% of the body surface the victim usually does not survive. Age and state of health of burn victim are other factors that affect survival.
Work Step by Step
A burn is a tissue injury caused by heat, open flame, hot liquid, steam, radiation ,or corrosive chemicals. A very common form of burn is sunburn.
The severity of a burn may be assessed on the basis of depth of the burn lesion and the layers of tissues affected-- from epidermis to muscle and bone. Another way of assessing the seriousness of a burn is to estimate the percentage of the skin surface area affected by the burn lesion. Burn victims that are burned over more than 70% of the surface area of the body usually do not survive the burn injury.
Degree of the Burn
The burn injury may affect only the epidermis or it may penetrate through the epidermis, dermis subcutaneous layer, muscles and reach bone.
First degree burns affect only the epidermis--heals in 3 to 6 days
Second degree burns destroys the epidermis and do some damage to the dermis ( heals in 3-4 weeks). They are characterized by blistering. First degree and second degree burns are called partial thickness burns
Third degree burns go through skin and reach flesh. These are full thickness burns . They have local effects --numbness, edema, whitish to dark coloration-- but the systemic effects are more serious. Healing is difficult, and skin grafting is usually necessary.
Fourth degree burns damage both muscles and nerves. Sweat glands, sebaceous glands, hair follicle and bone may be destroyed.
Fourth, fifth, and sixth degree burns leave charred, blackened surfaces in the burn wound.. Bone and muscle do not regenerate and the consequences of these kinds of burns are long term loss of function and often eventual amputation of limbs
The evaluation of body surface are burned is done using the rule of nines:
The guidelines are as follows:
1. Head and neck surfaces represent 9% of surface area
2.Surface area of upper limbs anterior and posterior (9+9 )%
3. Anterior and posterior trunk (18+18) %
4 Lower limbs, anterior and posterior surfaces (18+19) %
5. Perineum 1%
Major burns
1. A third degree burn over 10% of body surface
2. A second degree burn over 25% of body surface
3. Any 3rd degree burn on face hands feet or perineum
A burn over more than 70% of body surface is usually fatal.
