Burn Injuries Dr. Eranda Epaarachchi The layers of the skin Anatomy of the skin Classification of burns – By depth What is shown here? What is the diagnosis? First degree burns Characteristics Epidermis is involved Appearance : Redness (Erythema) Dry & painful Heals within 1 week Complications : Risk of developing skin cancer in later life What are these lesions? Superficial – partial thickness burn (20) Second degree – Partial thickness Characteristics Extends into superficial dermis Red with clear blister & Blanches with pressure Moist & painful Heals within 2-3 weeks Complications : Local infection, Cellulitis What are these lesions? What are these lesions? Deep partial thickness burn Characteristics Extends into deep dermis Red-and-white with bloody blisters & Less blanching Moist & painful May heal in weeks or progress into a third degree burn Complications : Scarring, contractures (May need skin grafts) What are these lesions? Third degree burns (Full thickness) Characteristics Extends through entire dermis Stiff and white/brown Dry, leathery to touch Painless Requires excision Complications : Scarring, contractures, amputation What are these lesions? It’s a fourth degree burn Characteristics Extends through skin, subcutaneous tissue and into underlying muscle and bone Black (charred) Dry Painless Requires excision Complications : Amputation, significant functional impairment, possible gangrene, and in some cases death Classification of burns by causes Chemical Most chemicals that cause burns are strong acids & bases Acids : H2SO4, HNO3, HCl Bases : NaOH Acid burns : Most of the injury occurs at the point of impact Alkali burns : Capable of deep penetration and can cause severe pain NaOH burn after 44 hours from exposure Electrical burns – Causes 1. Workplace injuries 2. Taser wounds 3. Being defibrillated without a conductive gel 4. Lightning Electrical burns Human body is very vulnerable to application of supra-physiologic electric fields Some electrocutions produce no external burns at all, as very little current is required to cause fibrillation of the heart muscle The internal injuries sustained may be disproportionate to the size of the burns seen (if any), and the extent of the damage is not always obvious Such injuries may lead to Cardiac arrhythmias Cardiac arrest Unexpected falls with resultant fractures or dislocations Electrical burns – Low voltage injuries Low-voltage (<500 AC volts) injuries usually doesn’t have skin burns This is sufficient to cause cardiac arrest and ventricular fibrillation VF (Can lead to aystole in minutes) – Defibrillation to save the life Electrical burns – High voltage (> 1000V) injuries Common cause of third and fourth degree burns Explosions caused by electrical faults produce high intensity Ultraviolet radiation which can also cause radiation burns Radiation burn – causes Radiation burns are caused by prolonged exposure to UV light (Sun exposure – the commonest) : Severity UVB > UVA Tanning booths Radiation therapy Radioactive fallout X-rays More severe cases of sun burn result in what is known as "heatstroke“ Microwave burns are caused by the thermal effects of microwave radiation Heatstroke Microwave burn Scalding Caused by hot liquids (water or oil) or gases (steam) Immersion scald is created when an extremity is held under the surface of hot water (Common form of burn seen in child abuse) Scald burns are more common in children Generally scald burns are first or second degree burns, but third degree burns can result, especially with prolonged contact (Diabetic neuropathy) Scald Immersion scald Child abuse? SSSS Inhalation injury Steam, smoke and high temperatures can cause inhalational injury to the airway and lungs Inhalation injury Pathophysiology of burns injuries Burn injury results in a local or systemic inflammatory response (Depends on the size of the burn) The lungs may be doubly compromised by smoke inhalation Following a major burn injury, heart rate and peripheral vascular resistance increase This is due to the release of catecholamines from injured tissues and the relative hypovolemia that occurs from fluid volume shifts Pathophysiology of burns injuries Initially cardiac output decreases At approximately 24 hours after burn injuries, cardiac output returns to normal if adequate fluid resuscitation has been given Following this, cardiac output increases to meet the hypermetabolic needs of the body Pathophysiology of burns injuries The effects of high temperature on tissue include speeding chemical reactions & denaturing proteins Pathophysiology of burns injuries Due to the inflammatory response, permeability of blood vessels is increased in the burn area This causes exudation of proteins and fluid into the adjacent interstitial tissue Red cells are not extravasated This results in increase in the oncotic pressure in the interstitium Pathophysiology of burns injuries The volume of fluid loss is directly proportional to the burn area If burn area is 10% to 15% of the total body surface area (TBSA), then the consequent fluid loss may cause circulatory shock If it is more than 25% of TBSA, then inflammation occurs even in the blood vessels remote to the burn, causing greater fluid loss Diagnosis – By severity By American Burn Association Major burns – Treat in specialized burn units 1. Age 10-50yrs : Partial thickness burns >25% of total body surface area 2. Age <10 or >50 : Partial thickness burns >20% of total body surface area 3. Full thickness burns >10% 4. Burns involving the hands, face, feet or perineum 5. Burns that cross major joints 6. Circumferential burns to any extremity 7. Any burn associated with inhalational injury 8. Electrical burns 9. Burns associated with fractures or other trauma 10. Burns in infants and the elderly 11. Burns in persons at high-risk of developing complications Moderate burns – Treat in hospitals 1. Age 10-50yrs : Partial thickness burns involving 15-25% of total body surface area 2. Age <10 or >50 : Partial thickness burns involving 10-20% of total body surface area 3. Full thickness burns involving 2-10% of total body surface area Minor burns – Doesn’t require hospitalization 1. Age 10-50yrs surface area : Partial thickness burns <15% of total body 2. Age <10 or >50 : Partial thickness burns involving <10% of total body surface area 3. Full thickness burns <2% of total body surface area, without associated injuries Estimating surface area burnt – Rule of 9 Lund & Browder charts (More accurate) The size of a person's hand print (palm and fingers) is approximately 0.8% of their TBSA, but for quick estimates, medical personnel round this to 1%, slightly overestimating the size of the affected area Burns of >/= 10% in children or >/=15% in adults are potentially life threatening injuries (because of the risk of hypovolemic shock) and should have formal fluid resuscitation and monitoring in a burns unit Lund & Browder charts Lund & Browder charts Management Once the injured person is stabilized, attention is turned to the care of the burn wound itself Until then, it is advisable to cover the burn wound with a clean and dry sheet or dressing Early cooling reduces burn depth and pain, but care must be taken as uncontrolled cooling can result in hypothermia IV fluids Children with >10% TBSA burns, and adults with >15% TBSA burns need formal fluid resuscitation and monitoring (blood pressure, pulse rate, temperature and urine output) Once the burning process has been stopped, the injured person should be volume resuscitated according to the Parkland formula This formula calculates the amount of Ringer's lactate required to be administered over the first 24 hours post-burn. Parkaland formula Composition of Ringer’s lactate Hartman’s solution (Very similar, but ionic concentrations are different) Na+ = 131 K+ =5 Ca2+ =4 Cl– = 111 Lactate = 29 IV fluids Parkland formula = 4ml x (percentage of total body-surface-area sustaining non-superficial burns) x (person's weight in kg) Half of this total volume should be administered over the first 8 hours, with the remainder given over the following 16 hours This time frame is calculated from the time at which the burn is sustained, and not the time at which fluid resuscitation is begun IV fluids Children also require the addition of maintenance fluid volume The formula is a guide only and infusions must be tailored to the urine output and central venous pressure Inadequate fluid resuscitation may cause renal failure and death, but overresuscitation also causes morbidity Crystalloid fluids appear just as good as colloid fluids and as colloids are more expensive they are not recommended Other aspects of the management Wound care : Biosynthetic dressings may speed healing Antibiotics Analgesics Surgery : Skin grafts (As early as possible for better results) Alternative therapy : Bee honey Biosynthetic dressing Complications – Infections Risk factors for infections 1. Burn > 30% TBSA 2. Full-thickness burn 3. Extremes in age (very young, very old) 4. Preexisting disease e.g. diabetes 5. Virulence and antibiotic resistance of colonizing organism 6. Failed skin graft 7. Improper initial burn wound care 8. Prolonged open burn wound Complications Burn wounds are prone to tetanus (A tetanus booster shot is required if individual has not been immunized within the last 5 years) Circumferential burns of extremities may compromise circulation. Elevation of limb may help to prevent dependent edema Acute Tubular Necrosis of the kidneys can be caused by myoglobin and hemoglobin released from damaged muscles and red blood cells Prognosis The modified Baux score determines the futility point for major burn injury The Baux score is determined by adding the size of the burn (% TBSA) to the age of the patient In most burn units a score of 140 or greater is a non-survivable injury, and comfort care should be offered In children all burn injuries less than 100% TBSA should be considered a survivable injury. A major concern of a survivor of any traumatic injury is post-traumatic stress disorder (PTSD) Another significant concern for children is coping with a disturbance in body image