Burn trauma

BURN TRAUMA اصابات الحروق

Definition Burn:is a localized tissue injury caused by exposure to extreme degrees of temperatures & associated with multiple systemic complications.
TYPES
1. Thermal burns(heat &cold injuries).
2. Electric burns.
3. Chemical burns.
4. Radiation injuries.

Thermal burns ( heat injury) :

Pathophysiology
Mechanism: Exposure of tissues to excessive heat result in coagulative necrosis then carbonization(charring).
Factors affecting severity of burn injury:
1. Temperature:43C is the maximum tolerable temperature by cell &tissues.
-44C-60C Reversible changes in cells & tissues.
-60C-100C Coagultive necrosis.
-More than 100C Carbonization.
2.Duration of exposure: 120sec.(2min.) is enough to cause deep burn.


3. Cause(Type of heat):
Dry heat e.g Flame There three ways of transmission
a -Radiation.
b -Conduction (usually cause deep burn).
c -Convection.
Moist Steam & hot liquids.
Either short exposure as hot liquids fall accidentally on the body
OR long exposure(Emersion) as part of the body fall accidentally in hot liquids.
As the density(specific gravity) of hot liquids increased the depth of burn increased. WaterMilkOil
4. Methods used for extinguishing fire & rapidity.
5. Burn clothes increased duration of exposure.
-type of clothes cotton, nylon, wool.
-thickness of clothes.
-clothes socked with hot liquids.
6. Cooling absorb heat from tissues & reduce severity of injury. There are variable methods used for cooling, the best way is by water.

Severity :

1. Percentage of the surface area of the burn wounds to the total surface of the body(TBSA). There are three rules used for estimation of TBSA of the burn wounds:
a. surface area of the palmer surface of the hand of the patient equal to 1%TBSA.
b. Rule (of Wallace)of 9% :
Head &neck = 9%
RT upper limb = 9%
Lt upper limb = 9%
Anterior surface of trunk = 18%
Posterior surface of trunk = 18%
RT lower limb =18%
LT lower limb =18%
External genitalia = 1%
Total =100%
c. Lund & Browder rule: in this method the body divided into fixed & variable areas according to the age of the patient as the surface area of the head in children is larger in relation to the total body surface area of the body than in adult while the surface area of the thighs & legs is smaller.

Fixed areas :

Neck ant. Surface 1%
Neck post. Surface 1%
Ext. genitalia 1%
Hand (palmer or dorsal surface) 1.25%
Forearm (volar ordorsal surface) 1.5%
Foot (planter or dorsal surface) 1.75%
Arm (voler or dorsal surface) 2%
Buttock(each side) 2.5%
Trunk(anterior or posterior surface) 13%
External genitalia 1%


Variable areas : 0 age adult ----------- --------Head (ant. Or post surface) 7.5% 3.5% Thigh(ant. Or post surface) 2.5% 4.75% Leg (ant. Or post surface) 2.25% 3.5%

2. Depth of the burn wounds :according to the depth of the burn wound through the skin(Epidermis & Dermis).
Partial thickness :
1-First degree burn burn of epidermis only
Clinical feature: painful, red color(erythematous), edema(swollen).
Healing by desquamation & reepitheliazation within 7-10 days.
2 -Second degree burn burn of whole epidermis & part of dermis(variable thickness).
Clinical features: very painful, pink to red in color(according to the depth), wet(moist) surface. Or Blister formation Healing within 21 days, separation of Escher started at 5th-7th day, by healing of partial thickness wound with variable degree of scarring.
Full thickness(Third degree) burn;
-Burn of the whole thickness(epidermis &dermis)of skin.
-Clinical Features:-Painless(due to damage of nerve endings).
-Dry surface.
-Color White to black.
-Texture Waxy, Leathery or Chary.
-Pathogmonic sign Black tortuous lines(thrombosed veins)
-Healing more than 21 days, separation of Escher started at 10th day, needs skin graft otherwise it will heal by secondary intention associated with wound contraction & result in excessive scarring, contructures & deformities.


PROGNOSTIC FACTORS:
1. Age poor prognosis below 2years & over 50years.
2. Percentage more than 30%TBSA is critical|& very poor above 50%TBSA.
3.Depth of the burn wound.
4.Type of burn injury.
5.Inhalation injury.
6.burn wound infection & septicemia.
7.Associated trauma.
8.Presence of medical problems.

INDICATIONS OF ADMISSION OF BURN PATIENT:

1. 2nd&3rd degree burn equal or more than 10%TBSA in age below 2 years & above 50 years.
2. 2nd &3rd degree burn equal or more than 15%TBSA in other age groups.
3. Third degree burn of 5%TBSA & more.
4. Circumferential burn.
5. Burn of specific areas; face, hands, feet, external genitalia, perineum & major joints.
6. Inhalation injury.
7. Electric burn.
8. Chemical burn.
9. Associated traumas.
10. Preexisting medical disorders.
11. For learning purposes


EMERGENCY MEASURES:
1.Ensure patent airways & adequate ventilation.
2. Intravenous line (percutaneous canula or venous cut down).
3.Intravenous fluid as Ringer lactate 200ml in children & 1000ml in adults.
4.Systemic antibiotic i.v Penicillin or cephalosporin.
5.Analgesia narcotic analgesia & should be given by i.v rout.
6.Antitetanous immunization.
7.Folly catheter for collection of urine in burn more than 25%TBSA.
8.Nasogastric tube for gastric decompression in burn more than 25%TBSA.
9.Local wound care as removal of burn clothes, wash with warm sterile isotonic solution(e.g.Normal saline) & bland soap, local antibiotics as 1%silver sulfadizne cream(Flamazine), 1% mefenide cream or 0.5% silver nitrate solution.
10. Escheratomy : inscision of Escher used for relieve of pressure in circumferential burns around chest & limbs.
11. Prevention of hypothermia.

BURN SHOCK

The first problem in burn, within the first 48hours. There are two types of shock in burn patient:
1.Neurogenic shock due to severe pain.
2.Hypovolemic shock, which the most important. The burn injury results in generalized inflammatory response leads to release of mediators that cause vasodilatation & increase in vascular permeability with leakage of fluid as exudates& within the interstitial space. This continues for 36hours & leads to loss of excessive amount of fluids according to the surface area of the burn wound. The type of fluid lost is plasma-like fluid as it contains protein (5gm/100ml). The amount of loss is 4ml/1%/kg/24hrs. The rate of loss is(1/2) 2ml within the first 8hrs, (1/4) 1ml within the second 8hrs, (1/4) within the third 8hrs. The clinical manifestation is that of hypovolemia.
Management:
1. Intravenous line.
2. Intravenous fluid (Parkland' s formula) as in the following:
- Amount 4ml/1%/kg/24hs.
- Rate 2ml (1/2) within the first 8hrs.
1ml (1/4) within the second 8hrs.
1ml (1/4) within the third 8hrs.
-Type Ringer-lactate solution + 2000ml as 5%glucose.
- Hypertonic saline & Dextran (2ml/kg) are added in case of burn more than 50%TBSA, patients with cardiopulmonary insufficiency & in patient with inhalation injuries.
3. I.v. Analgesia. 4.I.v. antibiotic. 5. Prevention of hypothermia. Etc...


Monitoring as:
1. Level of Consciousness*.
2. Pulse rate.
3. Blood pressure.
4. Central venous pressure &Pulmonary artery wedge pressure..
5. Temperature.
6. Urine output* ;as Color, Specific gravity & volume (50ml/1hr in adult patient & 0.5-1ml/kg in children).
7.Arterial blood gases.
*The most practical.

This Lecture Collected By Omer Ahmed Al-Samrrai, 5th Grade of T.U.C.O.M