Nicole Baier, MD Statistics In US: 1.2 million burns each year 60,000 hospitalizations 6000 deaths 2nd leading cause of unintentional death in children (after MVA) Pediatric incidence by type of burn: Scald burns: 85% Flame burns: 13% Remaining 2%: electrical and chemical burns The Skin Barrier to: Fluid loss Entry of infection Heat loss epidermis dermis Burn Classification 1st degree (superficial) Epidermis only Erythematous, painful No blistering Classification 2nd degree (partial thickness) Injury to epidermis and variable portion of dermis Moist, pink or red, blanches to touch Vesicles and blisters Extremely painful Heal spontaneously Classification 3rd degree (full thickness) Entire epidermis and dermis No residual epidermal cells – require skin grafting Leathery, white or black or brown Not painful (no viable nerve endings) High risk of scarring Classification 4th degree Involve underlying structures (tendons, nerves, muscles, bone, fascia) Reconstructive surgery often necessary Estimation of Burn Size Used to calculate fluids for IVF resuscitation Only 2nd and 3rd degree burns considered Adults: Rule of nines Pediatric: Lund-Brower chart Estimate: palm of patient’s hand = 1% BSA Burn Diagrams Acute Assessment AIRWAY Airway edema caused by inhalational injury Direct thermal injury – supraglottic Suspicion increased if: Facial/ oral burns Soot in mouth/nose Singed nasal hairs Wheezing, stridor, or hoarseness noted Intubation should be performed quickly as edema can progress rapidly (over initial 24-36 hours) Acute Assessment BREATHING– Initial findings Early hypoxia may result from: Airway obstruction Impaired chest wall compliance (circumferential burns) Decreased ambient FiO2 (10-15%) Carbon monoxide Cyanide Produced when wool, silk, nylon, polyurethane burn Disrupts mitochondrial oxygen use by complexing with cytochrome CO and CN are responsible for majority of early mortality at scene Children more susceptible to toxicity of inhaled materials due to higher minute ventilation Carbon Monoxide Affinity for hemoglobin 250x > O2 Decreases oxygen carrying capacity Shifts oxyhemoglobin dissociation curve to left Binds to myoglobin and mitochondrial cytochrome oxidase Interfere with cell oxygen use and energy production Measured with co-oximetry 20-30% = headache, dizziness 40-50% = altered LOC >50% = coma, death Treatment: 100% oxygen ½ life in room air: 4-6 hours ½ life in 100% FiO2: 40-60 minutes Acute Assessment BREATHING – Later findings Chemical irritants injure tracheobronchial tree and lung parenchyma Lower airway edema Respiratory epithelium sloughs - cast formation causes airway obstruction Manifests as: bronchospasm, post-obstructive atelectsis Patients also at risk for: Surfactant deficiency due to damage to type II pneumocytes ARDS After 72 hours: nosocomial pneumonia may develop Restrictive lung disease may develop in survivors Acute Assessment CIRCULATION In 50% BSA burn: 1 minute after burn, cardiac output is ½ of preburn state At 1 hour, cardiac output is 1/3 of preburn state Hypovolemic shock Loss of skin integrity increases evaporative losses 6-7X Increased vascular permeability leads to interstitial edema and intravascular volume loss Maximal at 30 minutes Capillary integrity restored 8-12 hours post-injury Myocardial depression also occurs Thought to be due to TNF release Acute Management CIRCULATION Burns >15% BSA require IV fluid resuscitation to maintain perfusion Time to IV access is a major predictor of mortality in pediatric patients who have burns greater than 80% TBSA IV preferably placed in nonburned tissues Acute Management CIRCULATION Parkland Formula: Used to determine resuscitation fluids = LR 4 mL x weight (kg) x % TBSA burned ½ over 1st 8 hours, ½ over remaining 16 hours Added to maintenance dextrose-containing fluids Monitor hemodynamics, urine output and adjust fluids accordingly Question You have a 14 month old, 11 kg infant who was involved in a house fire and has second degree burns to both of her hands, feet, her right lower arm and both lower legs. What IV fluids should she receive over the 1st 24 hours? Burn Diagrams Answer Calculate % BSA: 1. Both hands: 3 x 2 = 6% Both feet: 3.5 x 2 = 7% Right lower arm = 3% Both lower legs: 5 x 2 = 10% = 26% TBSA Burn Parkland Formula: 2. 4 mL x 11 kg x 26% = 1144 mL fluid resuscitation requirement 572 mL over 1st 8 hours = 61 mL/hr of LR 572 over remaining 16 hours = 35 mL/hr of LR Maintenance Fluid Requirement 3. 44 mL/hr of D5 ½ NS Other initial management Remove all clothing that is hot/ burned/ exposed to chemicals Prevent continued skin damage Wound treatment Clean with mild soap and water Apply cool saline-soaked gauze – decreases pain Do not apply ice – produces hypothermia, worsens damage Covering with a sheet may decrease pain by decreasing environmental exposure Electrical injuries Minor surface burns may hide massive coagulation necrosis of muscle and deep tissues Risk of rhabdomyolysis Risk of cardiac abnormalities Asystole, ventricular tachycardia/ fibrillation Atrial and ventricular ectopy, 1st and 2nd degree heart block, bundle branch blook, prolonged QT Non-specific ST-T changes and interval delays most common Electrical Injuries Tissue injury is directly proportional to resistance Nerves, muscles, blood vessels have lowest resistance Electricity preferentially flows through these structures More severe damage Increased resistance: Skin Tendons Bone Fat Water decreases resistance, therefore moist areas (eg, axillae) tend to sustain more damage Electrical Injuries Type of current AC (household electricity) is more dangerous Continual muscle contraction and relaxation results in muscle tetany Eg, a 60 Hz alternating current changes direction 120x/ second DC (lightning strikes) produces muscle contraction only at beginning and end of current flow Electrical Injuries Current Pathway Current may flow in 1 of 3 pathways: Hand to hand 60% mortality rate due to: Spinal cord transection at C4-C8 Suffocation due to chest wall muscle tetany Myocardial muscle damage Hand to foot 20% mortality rate due to cardiac arrhythmias Foot to foot 5% mortality rate Additional Management for Electrical Injuries Obtain EKG Consider obtaining cardiac enzymes Monitor patients with medium and high-voltage injuries on monitor for 24-72 hours Compartment Syndrome Most common early cause of diminished pulses is inadequate resuscitation High index of suspicion for elevated compartmental pressures in circumferential burn Emergent escharotomy or fasciotomy is indicated for limb salvage in pulseless extremity Thoracic escharotomies are occasionally required to improve chest-wall compliance and facilitate ventilation Ongoing Management Hypermetabolic state Increase in metabolism over 1st 5 days – then plateau through remainder of acute admission and into rehab Due to surge of catecholamines, cortisol, aldosterone, growth hormone Insulin secretion decreased, tissues insulin resistant Degree correlates with extent of injury Hypermetabolic State Manifestations Tachycardia, increased cardiac output Hyperthermia Baseline temp reset to 38.5⁰C Increased gluconeogenesis, protein catabolism, lipolysis Resting energy expenditure 2-3 x normal May be associated with: Impaired wound healing Sepsis Loss of lean body and muscle mass Hypermetabolic State In burn injuries > 40% TBSA: Resting metabolic rate at 33°C is: 180% of basal rate at admission 150% at full healing of the wound 140% 6 months after the injury 120% at 9 months post injury 110% after 12 months Hart DW, Wolf SE, Mlcak R, et al. Persistence of muscle catabolism after severe burn. Surgery 2000; 128: 312–319. Hypermetabolic state Long-term consequences Profound muscle wasting Decreased bone mineral density Retarded linear growth in children In 80 patients with > 40% TBSA burn: Profound growth arrest noted during postburn year 1 Growth improved to normal by postburn year 3 Rutan FL, Herndon DN. Growth delay in postburn pediatric patients. Arch Surg 1990; 125: 392-395. Ongoing Management Feeds started EARLY Within 6 hours of admission Require up to 50% more calories than at baseline Hypermetabolic state Pain and anxiety increase physiologic demands Greater heat loss occurs in young infants with larger surface area-to-mass ratios Reduces bacterial translocation and sepsis TPN avoided due to infectious complications Goal: full feeds by 24-48 hours Infectious Concerns Risk of infection related to: Loss of skin barrier Wound colonization is universal by 1-2 weeks post-injury Presence of inhalational injury - compromises normal clearance mechanisms 5x higher rate of pneumonia Immunosuppression Impaired cellular and humoral immune response Infection now responsible for 50-60% of deaths in burn patients Topical Therapies Bactroban Used for superficial burns, primarily on face Silvadene (silver sulfadiazene) Bacteriocidal Cannot be used in those with sulfa allergies Causes neutropenia and thrombocytopenia Topical Therapies Sulfamylon (mafenide acetate) Better penetration of deep burns, eschars, and cartilage Bacteriostatic Better gram negative coverage (pseudomonas) Causes fungal overgrowth Painful Carbonic anhydrase inhibitor – causes metabolic acidosis Surgical Wound Management Early excision and closure of full thickness burn wound If wound >50% TBSA is totally excised and covered with autograft within 2–3 days: Metabolic rate 40% less compared with wound coverage 1 week post injury Hart DW, Wolf SE and Chinkes D, et al. Determinants of skeletal muscle catabolism. Ann Surg 2000; 233: 455–465. Surgical Wound Management Other benefits of early wound excision Decreases pain Provides barrier to fluid and heat loss, bacterial invasion Decreases length of stay Accelerates recovery Fewer septic complications Decreased morbidity and death Surgical Wound Management Serial wound excision and grafting is the standard of care for full-thickness burns When the burned area exceeds donor site supply (burns >30% BSA), homografts from donors or skin substitutes are used Taken back to OR weekly to replace homografts with autografts as donor sites heal Criteria for Admission >15% BSA 3rd degree burns Electrical burns Inhalational injury Burns to hands, feet, face, genitalia, joint surfaces Suspected abuse or neglect Inadequate home situation Outpatient Treatment Leave blisters intact Dress burns with silvadene Wash wound and change dressings BID Pain control with tylenol or tylenol with codeine Identifying abusive burns 15-20% of burn injuries are the result of abuse Suspicious patterns: Glove or stocking burns of hands and feet Deep burns on trunk or back Small-area full-thickness burns (cigarette) Circumferential burns Burns localized to the perineum or buttocks Symmetric burns Burn Prevention Preset water heaters to max of 120⁰ F Duration of exposure required to produce full-thickness burn: 120⁰ F: 130⁰ F: 140⁰ F: 150⁰ F: 158⁰ F: 10 minutes 30 seconds 5 seconds 2 seconds 1 second Federal Flammable Fabric Act Requires sleepwear to be flame retardant Use of smoke detectors