Thermal Injuries Flashcards
Highest age group incidence of thermal burns
20-29 years old
Most common cause of thermal burns in children less than four years old
- contact with hot surfaces
- liquid scalds
Three types of burns
- scalds
- contact burn
- fire burns
Subcategories of scalds? Fire burns?
Scalds:
- spill burns
- immersion burns
Fire burns:
- flash burns
- flame burns
What does the severity of a burn relate to
the rate of heat transfer to the skin
A full thickness burn has how many zones of tissue injury
3 concentric zones
What are the 3 zones in a full thickness burn
- coagulation- dead or dying cells d/t coagulation necrosis and absent blood flow
- Stasis- red and may blanch with pressure, becomes avascular and necrotic by day 3
- Hyperemia- blanches on pressure, healing by day 7
SIRS aka
systemic inflammatory response
When does SIRS happen? Why?
occurs in burns greater than 30% of TBSA due to the systemic release of cytokines and immune mediators
What does SIRS cause
- increased vascular permeasbility
- hypovolemia
- end organ damage
- long lasting hypermetabolic response
What does burn survival depend on?
- burn size/depth
- patient age
- inhalation injury
- comorbidities
What burns are fist degree burns
- flash burns
- sunburns
Characteristics of a first degree burn
- minor epithelial damage to epidermis
- redness, tenderness, pain
- no blisters
- healing occurs over several days without scaring
- metabolic response and infection risk are minimal
Two subcategories of second degree burns
- superficial partial thickness
- deep partial thickness
Characteristics of superficial partial-thickness burns. Healing time?
- thin walled, fluid filled blisters
- pink, moist, soft and tender to touch
- healing over 2 to 3 weeks, usually no scarring
Characteristics of deep partial thickness burns. Healing time?
- burns of deeper dermis
- red and blanched white skin, slow cap refill
- thick walled blisters
- some decline in 2 point discrimination
- healing over 3 to 6 weeks, scaring likely
Examples of third degree burns
- immersion scalds
- flame burns
- chemical burns
- high voltage electrical injuries
Characteristics of third degree burns
- full thickness of dermis and epidermis
- white or leathery appearance with underlying clotted vessels
- no sensation
- burns larger than 1cm require grafting to heal
Characteristic of fourth degree burns
- full thickness
- destruction of skin/subcutaneous tissues including fascia, muscle, bone
- requires surgical debridement and repair
Treatment of inhalation injury
typically occurs withing 12 to 24 hours, intubate if signs of upper airway compromised
Fluid resuscitation in burn pts
- oral and IV fluids for <20% TBSA
- 1 large bore IV for moderate burns, 2 for severe
When does maximal edema occur in burn patients
24 to 48 hours
Goal for fluid resuscitation in burn patients
urine output 2ml/kg/hr in children <2 years
1mg/kg/hr in older children
30-40 ml/hr in adults (0.3-0.5 ml/kg/hr)
Parkland formula
LR 4ml/kg/%TBSA burned
1/2 in first 8 hours
second 1/2 in the next 16
Galveston formula
5% dextrose in LR 5000/mlm2 of TBSA + 2000ml/m2
half in first 8 hours
second half in the next 16 hours
Burns in kids less than 6 months?
- catabolism of brown fat regulates temperature requiring large amounts of oxygen
- prone to metabolic acidosis from lactate production
Cold water for treatment of burns?
-immediate use beneficial
What is the benefit to using cold water for burns
- inhibits lactate production and acidosis
- inhibits wound histamine release, reducing vascular permeability–> minimizes edema and volume loss
- suppresses thromboxane production–> vascular occlusion nd progressive dermal ischemia
Wound care for burns
- debridement
- irrigation
- daily dressing changes
- topical anti microbials or occlusive dressings-surgery if burn not healed in 3wks
When should you send a patient with burns to a burn center
- partial thickness of >25% TBSA in adults
- partial thickness of >20% in children <10 or adults >50
- full thickness burn of >10%
- burns involving face, eyes, ears, hands, feet, perieum
- burns from caustic agents, high voltage electrical injury, complicated by inhalation injury or major trauma, high risk patients
When should you hospitalize a burn patients
- partial thickness 15 to 25% in adults
- partial thickness 10 to 20% in children or older adults
- full thickness burns 2 to 10% that do not fit major burn criteria
When can a patient with a burn be managed at home
- partial thickness <15% in adults
- partial thickness <10% in children and older adults
- full thickness burns <2% that do not fit major burn criteria
Complications of burns
- infection
- burn shock
What is typically the cause of low voltage burns
usually hand or mouth due to contact with exposed wire from an extension cord in children 5 years and younger
What does a low voltage electrical burn look like
small, deep burn that can result in need for amputation
+/- LOC
Most common cause of VF
low voltage AC
Initial treatment of a low voltage burn
- clean and dress with topical anti microbial
- splint, elevate and reassess in 48 to 72 hours to assess tissue viability
- EKG
Surgical treatment for low voltage electrical burns
skin loss only–> skin graft
deep injury–> amputation or flap coverage
2 mechanisms of oral injury due to low voltage burns. What does each cause?
- electric arc between 2 wires of opposite polarity–> excessive heat and severe tissue damage
- contact burn–> entry and exit wounds, can lead to VF
Pain with oral low voltage burn injuries?
initially painless because all veins/arteries are occluded from injury
Low voltage injuries are voltage less than what
1000 V
What does a direct current cause
causes single muscle contraction–> throws victim from the source
Electric arc burn current course
external to the body from a contact point to the ground