Burn

Classification and pathophysiology of burn

1. BURNS (CLASSIFICATION AND PATHOPHYSIOLOGY) Ms. SAHELI C 1 ST M. Sc NURSING RAMAIAH COLLEGE OF NURSING, BANGALORE

2. INTRODUCTION :- Burns is a result from the direct contact with or exposure to any thermal, chemical, electrical or radiation injury on the skin and other tissues. Human skin can tolerate up to 40c temperature, but above that, the higher the temperature, more severe the tissue destruction. In >40c temperature, protein damage exceeds the capacity of cell to repair. Majority of burn cases in India are due to domestic cases and a small percentage accounts for occupational burns.

3. DEFINITION :- Burns is defined as a wound caused by exogenous agent leading to coagulative necrosis of the tissue. It can also be defined as, an injury to tissues of the body caused by direct contact or exposure to thermal, chemicals, electrical current or radiation sources.

4. INCIDENCE :- The estimated annual burn incidence in India is approximately 6-7 million per year. The high incidence is attributed to illiteracy, poverty and low level of safety consciousness in the population and the domestic causes. Quite high in females due to various social factors. Fetal and children burn incidence varies from 6-23 % in different region in India. Overall mortality due to burn injuries is 3.5 per 100,000 population.

5. COMMON PLACES AND CAUSES OF BURN INJURY :- Occupational hazards: Tar Chemicals. Steam pipes. Fertilizers / pesticides. Electricity from power lines. Sparks from live electric sources. Home and Recreational hazards: Pressure cookers. Microwave food. Hot water heater set in higher temperature. Hot liquids from cooking. Multiple extension cords per outlet. Carelessness with smoking or match boxes. Wood burning. Stoves. Cloth catching fires during routine meal time. Suicide. Intentional causes to murder.

6. BURN INJURY CLASSIFICATION :- There are 6 types of burn injury can explain: 1. According to exposure time to heat to heat source: The primary injury. The secondary injury. 2. According to the etilogy of burn: Thermal burn. Chemical burn. Electrical burn. Radiation burn. Inhalational burn. 3. According to the burn depth: Superficial partial thickness Deep partial thickness Full thickness

7. 4. According to the degree of burn: First degree Second degree Third degree Fourth degree 5. According to the severity of burn: Minor Moderate Severe 6. According to the estimation of body surface area injured/ Assessment of burn: The Rule Of Nine. Lund and Browder method. Palm method. Jackson’s Burn model.

8. ACCORDING TO EXPOSURE TO HEAT SOURCE : This classification is based on the immediate damage to the skin and its deleterious effects because of the exposure time to heat source .This includes the following types: a) The primary injury: It is the immediate damage caused by the burn. Prompt removal of the heat source and rapid cooling of the burn limits the extent of primary injury. b) The secondary injury: It is deleterious effects resulting from the primary injury. A major burn can results in loss of fluid, secondary infection and release of toxins by microbes, inflammatory response, fluid shifts, coagulopathy , edema , constriction caused by eschar .

9. ACCORDING TO ETIOLOGY : THERMAL BURN Most common cause of burn, about 95% of the causes. Intensity of burn varies accordingly to the temperature of the affector and time of contact or exposure. Flame : clothing ignited with fire. Flash: Flame burns associated with explosion of fuels. Scald : form of thermal burn resulted from hot liquids and steam, spilled hot beverages. Contact : hot metal , hot sticky tar. ELECTRICAL BURN It causes an array of injuries if current passes through the body Most of damage is beneath the skin surface and therefore the actual injury can easily be underestimated called as ‘ice-berg’ effect.

10. Pathway of current is unpredictable but in general, current passes from a point of entry through the body to a grounded site. Extremely high voltage sources usually exist in multiple areas in an explosive fashion Current passing from hand to hand or hand to thorax has high risk of producing cardiac fibrillation compared to hand to foot passage. Electric current can cause muscle contractions strong enough to cause fracture of long bones and vertebrae. Myoglobins from injured muscle tissues and hemoglobin from damaged RBC released to circulation are then transported to kidney where they mechanically block renal tubules causing Acute Renal Tubular Necrosis (ATN) and ARF.

11. CHEMICAL BURN : Commonly seen in home or workplace, chemicals like acid and alkali can produce local tissue injury and some have potential to be absorbed resulting in body poisoning Chemical injury is usually deeper than it looks as skin is destroyed mainly by chemicals Severe persistent pain is often present, indicative of ongoing skin damage.

12. SMOKE AND INHALATIONAL INJURY :- Exposure to asphyxiants and smoke commonly occurs with flame injuries, particularly if the victim is trapped in enclosed, smoke filled space. Death, if occurs, usually is due to hypoxia and carbon monoxide poisoning. RADIATION BURN INJURY :- Caused by exposure to a radioactive souce . Eg , nuclear radiation accidents, use of ionizing radiation in industry, sunburn,

13. DEGREES and DEPTH OF BURN INJURY

14. FOURTH DEGREE BURN: Involves skin, fat muscles and sometimes bone also Skin appears charred or may be completely burnt away. Areas of fourth degree burn require extensive surgical debridement and grafting.

15. ACCORDING TO SEVEIRITY

16. METHODS FOR ASSESSMENT WALLANCE’S RULE OF NINE RULE OF PALM LUND AND BROWDER CHART JACKSON’S BURN MODEL

17. RULE OF NINE :- Rule of nine was introduced by Alezander Wallace. The system of rule of 9 , divides the body into multiples of 9. The sum total of these parts equals the Total Body Surface Area (TBSA) and it is an important measurement in the severity of injury.

18. PALM METHOD: Used to estimate percentage of scattered burns, using the size of the patients palm ( about 1 % of body surface area ) to assess the extent of burns.

19. CLINICAL MANIFESTATIONS: PAIN: Pain is immediate, acute and intense with superficial burns. It is likely to persist until strong analgesia is administered. With deep burns there is less pain. ACUTE ANXIETY: The patient is often severely distressed at time of injury. It is frequent for patients to run about in pain or an attempt to escape and secondary injury may result

20. FLUID LOSS AND DEHYDRATION Fluid loss commences immediately and, if replacement is delayed or inadequate, patient may be clinically dehydrated. There may initially be tachycardia from anxiety and later a tachycardia from fluid loss. LOCAL TISSUE EDEMA Superficial tissue will blister and deep burns develop oedema in subcutaneous spaces. This may be marked in the head and neck with severe swelling which may obstruct the airway. Limb edema may compromise the circulation.

21. ALTERATION IN RESPIRATION Client may exhibit tachypnea following burns injury. CO exposure can lead to progressive and permanent cerebral dysfunction. In case if upper airway is effected, stridor , dyspnea , increased work of breathing and cyanosis may be noticed. DECREASED CARDIAC OUTPUT Following a major burn injury, heart rate, peripheral vascular resistance increase in response to the release of catecholamines and to the relative hypovolemia , but initial cardiac function and output decreases. Approximately 24 hours after burn injury in client receiving adequate fluid

22. resuscitation, cardiac output returns to normal and increases (2 to 2.5 times normal) to meet hypermetabolic needs of body ( hyperfunction ) ALTERED LEVEL OF CONSCIOUSNESS : Burn injured clients rarely suffer from neurologic damage. When an alteration in level of consciousness is present, it is most often related to neurologic trauma ( e.g fall, motor vehicle accident), impaired perfusion to brain, hypoxemia (as from closed space fire), inhalation injury (as from exposure to asphyxiants or other toxic materials from fire)

23. PSYCHOLOGICAL ALTERATIONS: 1) Period of impact: begins immediately after injury, characterized by shock, disbelief. 2) retreat: characterized by repression, withdrawl , denial, suppression 3) acknowledgement: client accepts injury and resultant change in body image. Mourning of actual or perceived losses may be apparent 4) Reconstructive period: begins when the client and family accept the limitations imposed by the injury and begin to plan realistically for the future