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BURNS. Topics to be Covered. Definition Initial management Emergent or shock phase Assessment of inhalation injury Assessment of burn severity and extent Wound management Burn infection Electrical burn Chemical burns Summary. Definition. Burn Thermal Scald Contact Electrical
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Topics to be Covered • Definition • Initial management • Emergent or shock phase • Assessment of inhalation injury • Assessment of burn severity and extent • Wound management • Burn infection • Electrical burn • Chemical burns • Summary
Definition • Burn • Thermal • Scald • Contact • Electrical • Chemical • Radiation
Initial Management I • STOP THE BURNING PROCESS • Water for smoldering clothing • Water for chemical burns • Remove clothing - keep warm • Cool water for small 2° burns only
Initial Management II • ASSURE ADEQUACY OF VENTILATION AND OXYGENATION • Provide oxygen for all burns to treat carbon monoxide • Consider early endotracheal intubation with smoke inhalation injury
Initial Management III • Initiate restoration of HEMODYNAMIC stability systemically & locally • Isotonic crystalloid infusion • Remove any constricting items • Consider escharotomy for circumferential burns
Initial Management IV • Look for other traumatic injuries
Initial Management V • Burn wound last priority
Burn Wound Depth First degree Superficialsecond Deepsecond Thirddegree
Estimating Burn Extent • Rule of Nine's - in increments of 9% BSA • entire upper limb • anterior or posterior surface of one lower limb • 1/2 of the anterior or posterior surface of the trunk • total head and neck (adult) • Lund & Browder Chart emphasizes the relatively larger head size in: • in infancy (largest) • childhood (larger) • adulthood (normal) • Patient's palm size in children represents 1 - 1.25%
Emergent or Shock Phase • Increased Vascular Permeability • Altered microcirculation from direct heat injury and inflammation • Time course: • Peak shift 3-8 hrs • Continuous 2 days • increased proteins permeability leading to large plasma leak • Hypovolemia • Edema formation • Edema increases tissue pressure (need for escharotomy) • Resorption over next 5-7 days (can cause hypervolemia)
After thermal injury Edema • Hypovolemia → Fluid resuscitation • Crystalloid • Crystalloid & colloid
Formula for Fluid Resuscitation I For adult
Formula for Fluid Resuscitation II For adult with extensive deep burn
Formula for Fluid Resuscitation III For child
Monitoring Guidelines • Pulse: young patient • Pulse less than 120, reasonable perfusion; pulse > 130, increase fluid • Elderly or with heart disease : pulse not accurate reflection of perfusion • Electrocardiogram • particularly important for patient more than 45 years old • Urine output • 0.5 to 1 cc/kg/hr is adequate in absence of diuretic such as alcohol • Exception: Myoglobin or hemoglobinuria where over 1cc/kg/hr is indicated • Base deficit • > 5 meq / liter reflects decreased tissue oxygenation. Look for progressive decrease in base deficit as marker of adequacy of resuscitation. • Peripheral perfusion • For systemic circulation • For circumferential arm, leg burns
Vital signs Fluid infusion 1.5ml for adult 1.75ml for children 2.0ml for infant X % burn X kg BW Renal Circulation Urine Output 0.5-1.0ml/kg BW/hr Adjustable
Wound management I • Superficial second degree burns • Do not move the blisters and do try to keep the outer of the blisters intact. • Do not change the dressing too frequently unless the dressing is odor the wound is infected
Wound management II • Deep second degree burns • Apply 1% silver sulfadiazine cream to the wound • Change dressing daily • Apply the 10% sulfamylon cream to the infected wound
Wound management III • Third degree burnsduring the early stage • Admit as edema process may require escharotomies • apply 1% silver sulfadiazine cream with dressing • Change dressing daily • Apply 10% sulfamylon cream to the infected wound Operation • Tangential excision • Fascia excision • Skin grafting
Special Area • Apply topical antibiotic ointment or cream followed by soft gauze dressing • Face treat open • Perineum treat open • Meets criteria for Burn Center due to high risk location
Burn Infection I • Wound infection • Invasive infection • Burn wound sepsis: the quantity of bacteria in the tissue underneath eschar ≥ 105/g • Systemic infection
Burn Infection II • Irritable, disorienting, hallucinating, persecutory delusion, apathy • Shivering High fever or hypothermia • Tachycardia • Tachypnea • Deterioration of the burn wound • The count of WBC higher or lower than that in normal range
Burn Infection III • Excision of deep burn wounds and covering the excised wound during early stage • Antibiotics • Nutrition and systemic support
Electrical Burn I • Resistance • Resistance is a measure of how difficult it is for electrons to pass through a material and is expressed in a unit of measurement termed an ohm. • The amount of heat developed by a conductor varies directly with its resistance.
Ohm’s Law • The relationship between current flow (amperage), pressure (voltage), and resistance is described in Ohm’s law, which states that the amount of current flowing through a conductor is directly proportional to voltage and inversely related to resistance. • Current (I) = Voltage (E)/Resistance (R)
Joule’s Law • Power (watts) lost as a result of the current passage through a material provides a measure of the amount of heat generated and can be determined by Joule’s law • Power (P) = Voltage (E) x Current (I)
Body Resistance I • The callused palm may reach 1,000,000 ohms/cm2, while the average resistance of dry normal skin is 5000 ohms/cm2 decrease to 1000 ohms/cm2 if hands are wet. • The stratum corneum that serves as an insulator for the body Exposure of the skin to 50 volts for 6-7 seconds results in blisters that have a considerably diminished resistance.
Body Resistance II • The dermis offers low resistance, as do almost all internal tissues except bone, which is a poor conductor of electricity. • Bone has a high resistance, thus readily transforms current to heat production, which may result in periosteal necrosis or even melting of the calcium phosphate matrix.
Electric Arc • Contact with high-voltage current may be associated with an arc or light flash • Temperature of the ionized particles and immediately surrounding gases of the arc can be as high as 4000°C (7232°F) and can melt bone and volatilize metal. As a general guide, arcing amounts to several centimeters for each 10,000 volts.
Effects of Electricity On the Body • Effects of electricity on the body are determined by 7 factors: (1) type of current, (2) amount of current, (3) pathway of current, (4) duration of contact, (5) area of contact, (6) resistance of the body, and (7) voltage. Low-voltage electric currents that pass through the body have well-defined physiologic effects that are usually reversible. For a 1-second contact time, a current of 1 milliampere (mA) is the threshold of perception, a current of 10-15 mA causes sustained muscular contraction, a current of 50-100 mA results in respiratory paralysis and ventricular fibrillation, and a current of more than 1000 mA leads to sustained myocardial contractions.
Tetanizing Effect A level of alternating current is reached for which the subject cannot release the grasp of the conductor. This tetanizing effect on voluntary muscles is most pronounced in the frequency range of 15-150 Hz.
Factors Found To Be of Primary ventricular fibrillation is inversely proportional to the square root of the importance are duration of current flow and body weight. The threshold for shock duration and directly proportional to body weight. When the heart is exposed to currents of increasing strength, its susceptibility to fibrillation first increases and then decreases with even stronger currents. At relatively high currents (1-5 amps), the likelihood of ventricular fibrillation is negligible with the heart in sustained contraction. If this high current is terminated soon after electric shock, the heart reverts to normal sinus rhythm. In cardiac defibrillation, these same high currents are applied to the chest to depolarize the entire heart.
High-voltage Accidents In high-voltage accidents, the victims usually do not continue to grasp the conductor. Often, they are thrown away from the electric circuit, which leads to traumatic injuries (eg, fracture, brain hemorrhage). The infrequency with which sustained muscular contractions occur with high-voltage injury apparently occurs because the circuit is completed by arcing before the victim touches the contact.
Low-voltage Electric Burns Low-voltage electric burns almost exclusively involve either the hands or oral cavity. In either injury, hospitalization is recommended to treat the local burn injury and monitor for systemic sequelae.
Current Pathways I Low-voltage current generally follows the path of least resistance (ie, nerves, blood vessels), yet high-voltage current takes a direct path between entrance and ground. The volume of soft tissue through which current flows behaves as a single uniform conductor, thus is a more important determinant of tissue injury than the internal resistance of the individual tissues. Current is concentrated at its entrance to the body, then diverges centrally, and finally converges before exiting.
Current Pathways II Consequently, anatomic locations of the contact sites are critical determinants of injury. Most of this underlying tissue damage, especially muscle, occurs at the time of initial insult and does not appear to be progressive. Microscopic studies of electric burns demonstrate that this initial destruction of tissues is not uniform. Areas of total thermal destruction are mixed with apparently viable tissue. Between the entrance and exit points of the electric current, widespread anatomic damage and destruction may be seen. An electric current can injure almost every organ system.