Thermal Injuries Flashcards
1
Q
Highest age group incidence of thermal burns
A
20-29 years old
2
Q
Most common cause of thermal burns in children less than four years old
A
- contact with hot surfaces
- liquid scalds
3
Q
Three types of burns
A
- scalds
- contact burn
- fire burns
4
Q
Subcategories of scalds? Fire burns?
A
Scalds:
- spill burns
- immersion burns
Fire burns:
- flash burns
- flame burns
5
Q
What does the severity of a burn relate to
A
the rate of heat transfer to the skin
6
Q
A full thickness burn has how many zones of tissue injury
A
3 concentric zones
7
Q
What are the 3 zones in a full thickness burn
A
- 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
8
Q
SIRS aka
A
systemic inflammatory response
9
Q
When does SIRS happen? Why?
A
occurs in burns greater than 30% of TBSA due to the systemic release of cytokines and immune mediators
10
Q
What does SIRS cause
A
- increased vascular permeasbility
- hypovolemia
- end organ damage
- long lasting hypermetabolic response
11
Q
What does burn survival depend on?
A
- burn size/depth
- patient age
- inhalation injury
- comorbidities
12
Q
What burns are fist degree burns
A
- flash burns
- sunburns
13
Q
Characteristics of a first degree burn
A
- minor epithelial damage to epidermis
- redness, tenderness, pain
- no blisters
- healing occurs over several days without scaring
- metabolic response and infection risk are minimal
14
Q
Two subcategories of second degree burns
A
- superficial partial thickness
- deep partial thickness
15
Q
Characteristics of superficial partial-thickness burns. Healing time?
A
- thin walled, fluid filled blisters
- pink, moist, soft and tender to touch
- healing over 2 to 3 weeks, usually no scarring
16
Q
Characteristics of deep partial thickness burns. Healing time?
A
- 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
17
Q
Examples of third degree burns
A
- immersion scalds
- flame burns
- chemical burns
- high voltage electrical injuries
18
Q
Characteristics of third degree burns
A
- full thickness of dermis and epidermis
- white or leathery appearance with underlying clotted vessels
- no sensation
- burns larger than 1cm require grafting to heal
19
Q
Characteristic of fourth degree burns
A
- full thickness
- destruction of skin/subcutaneous tissues including fascia, muscle, bone
- requires surgical debridement and repair
20
Q
Treatment of inhalation injury
A
typically occurs withing 12 to 24 hours, intubate if signs of upper airway compromised
21
Q
Fluid resuscitation in burn pts
A
- oral and IV fluids for <20% TBSA
- 1 large bore IV for moderate burns, 2 for severe
22
Q
When does maximal edema occur in burn patients
A
24 to 48 hours
23
Q
Goal for fluid resuscitation in burn patients
A
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)
24
Q
Parkland formula
A
LR 4ml/kg/%TBSA burned
1/2 in first 8 hours
second 1/2 in the next 16
25
Galveston formula
5% dextrose in LR 5000/mlm2 of TBSA + 2000ml/m2
half in first 8 hours
second half in the next 16 hours
26
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
27
Cold water for treatment of burns?
-immediate use beneficial
28
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
29
Wound care for burns
- debridement
- irrigation
- daily dressing changes
- topical anti microbials or occlusive dressings-surgery if burn not healed in 3wks
30
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
31
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
32
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
33
Complications of burns
- infection
| - burn shock
34
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
35
What does a low voltage electrical burn look like
small, deep burn that can result in need for amputation
+/- LOC
36
Most common cause of VF
low voltage AC
37
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
38
Surgical treatment for low voltage electrical burns
skin loss only--> skin graft
deep injury--> amputation or flap coverage
39
2 mechanisms of oral injury due to low voltage burns. What does each cause?
1. electric arc between 2 wires of opposite polarity--> excessive heat and severe tissue damage
2. contact burn--> entry and exit wounds, can lead to VF
40
Pain with oral low voltage burn injuries?
initially painless because all veins/arteries are occluded from injury
41
Low voltage injuries are voltage less than what
1000 V
42
What does a direct current cause
causes single muscle contraction--> throws victim from the source
43
Electric arc burn current course
external to the body from a contact point to the ground
44
What type of lesion is associated with underlying tissue damage in high voltage burns
flexor point "kissing" lesions due to tetanic muscle contractions
45
Course of current in electric current high voltage burns
passes between point of contact on the body and between the patient adn ground
46
What causes the burn in a high voltage electrical burn
electrical energy is converted to thermal energy
47
Tissue complications of high voltage burns
- limb necrosis--> amputation in 2 to 3 days
- periosteal necrosis/melting of the calcium phosphate mix d/t high resistance
- extravasation of fluids into wounds d/t increased vascular permeability
- muscle ischemia d/t increased interstitial pressure
48
Neurologic complications of electricalburns
Central
- transient agitation/confusion
- mild personality and mental capacity changes long term
- hemiplegia, aphasia, epilepsy, HA
Peripheral
- local tissue contact sites more permanent damage
- temporary paraesthesias or numbness
Spinal cord:
- may be delayed 2 years, distal to site of contact
- ALS
- transverse myelitis
- quadripelegi or paraplegia
49
Cardiac complications of electrical burns
- rhythm conduction disturbances
- sinus tach and nonspecific ST changes
- afib after high voltage
50
Vascular complications of electrical burn
inflammation, vascular wall necrosis--> vessel rupture or thrombosis--> progressive muscle fibrosis
51
Pulmonary complications of electrical burn
- pleural damage--> effusions, local lobar pneumonitis
| - infection
52
Prehospital treatment of electrical burns
- scene safety
- ACLS
- trauma
- burns
53
Treatment of electrical burns in the ER
- IVF, foley
- labs, imaging, EKG
- tetanus
- splint after NVF eval
- fetal monitoring
- compartment pressure
- burn specialist for high voltage
54
When do admit patients with electrical burns?
- anything beyond minor low voltage injury
| - pts with mild sxs, minor burns, normal CPK and EKG can be sent home after several hours of obs
55
When should a patient with a electrical burn be transported to a burn center
- high voltage
- significant burns
- oral burns
56
Risk factors for frostbite
- inadequate shelter
- inadequate/constrictive clothing
- wind chill factor
- high altitude
- prolonged cold exposure
- prolonged moisture exposure
- immobilization
- malnutrition and exhaustion
- previous cold injury
57
Symptoms of frostbite
- coldness
- stinging, burning, throbbing
- numbness and complete loss of sensation
- loss of muscle dexterity
- severe joint pain
58
Soft, palpable skin--> ??
superficial frostbite
59
Pitting edema---> ??
more viable underlying tissue
60
Hard to touch---> ??
deeper frostbite
61
Signs of frostbite
- excessive sweating
- joint pain
- pallor/blue skin
- hyperemia
- skin necrosis
- gangrene
62
Characteristic of first degree frostbite
- poor sensation
- central, white plaque qith ring of hyperemia
- epidermal involvement
- erythema
- mild edema
63
Long term characteristics of first degree frostbite
desquamination over several weeks, transient swelling, erythema, and cold sensitivity
64
Characterisitc of second degree frostbite
- full thickness freezing
- clear blister with surrounding erythema
- hard outer skin, resillient tissue underneath
- substantial edema
65
Characteristics of third degree frostbite
- subdermal plexus freezing
- hemorrhagic blister formation
- blue gray discoloration
- deep burning pain on rewarming (lasts 5 weeks)
- thick gangrenous eschar within 2 weeks
66
Characteristic of fourth degree frostbite
- involvement of muscle, bone and tendons
- frozen, hard, avascular skin and tissue underneath
- mottled tissue, non blanching skin becomes dry, black and mummified
- little pain and edema on rewarming
- spontaneous amputation after 2 months
67
What is frostnip
- no ice crystal formation in tissues
- no tissue loss
- blanching of skin with transient numbness and paraesthesias that resolve with rewarming
68
What is trench foot? What causes it?
peripheral neurovascular damage without crystal formation caused by prolonged exposure to wet, nonfreezing cold
69
Symptoms of trench foot
- pain
- paresthesias
- pallor
- pulselessness
- paralysis
70
What is pernio? What causes it?
- painful, inflammatory lesions from chronic repeated exposure to damp, non freezing cold temperatures
- damage to capillary beds
71
Symptoms of pernio
localized edema, erythema, plaques, nodules, vesicles or bullae as long as 12hrs after injury
resolves in 7 to 14 days
72
Timeline of post rewarming injury
- edema withing 3 hours--> lasts one week
- large clear blebs within 6 to 24 hours
- small hemorrhagic blebs after 24hrs
- eschar in 9 to 15 days
- self amputation withing 3 to 6 weeks
73
Complications of cold injuries
- permanent sensory loss
- increased risk of repeated frostbite
- wound infection
- tetanus
- tissue loss
- bactermia, lymphedema
- compartment syndrome
74
Goals of treatment of cold injuries
- salvage tissue
- maximize return of function
- prevent complications
75
Most effective therapy for frostbite?
rapid rewarming
- circulating water at 40 t 42
- continue until thawing is complete
- encourage gentle movement
- avoid too slow or over rewarming
76
What pathogens should you cover after rewarming a cold injury
- staph
- strep
- enterococcus
- pseudomonas
77
Only surgical intervention that shows early benefit for cold injuries?
fasciotomoy
78
Indicative factors of a favorable prognosis after a cold injury
- more superficial
- early sensation to pinprick
- healthy appearing skin after rewarming
- clear blister over hemorrhagic blister
79
Indicative factors of a poor prognosis after a cold injury
- absence of edema
- hemorrhagic blebs
- persistent mottling/violaceous hue and anesthesia after rewarming
- frozen appearance of tissue
80
How long can a cold injury take to heal
6 to 12 months
81
Shivering increases heat production by how much
2 to 5 times
82
Why might CNS injury compromise temperature control
damage to the hypothalamus affects heat conservation and heat production
83
Hypothermia on EKG
J or osborne waves
84
J or osborne waves are due to what
differences in conduction time between endocardium and epicardium
85
How to get an accurate core temperature
- rectal
- esophageal
- bladder
86
body temperature 34-35-->
shivering
87
body temperature less than 34-->
- altered judgement
- amnesia
- dysarthria
- increased RR
88
body temperature 33-->
- ataxia
- apathy
- tachypnea
- tachycardia
- cold diuresis
89
Moderate hypothermia will present with what
- decrease o2 consumption
- CNS depression
- decreased RR
- hyporelexia
- decreased renal flow
- parradoxical undressiing
90
At what temperature does shivering stop
31 degrees
91
What body temperature mimics brain death
29-30 degrees
92
Severe hypothermia presents with what
- Vfib
- pulmonary edema
- oliguria
- coma
- hypotension
- ridgidity
- apnea
- fixed pupils
- decreased or absent EEG activity
93
Labs for patient in hypothermia
- ABG
- CBC
- chemistries
- DIC
94
Prehispital treatment of hypothermia
- prevent further heat loss
- rewarming
- airway establishment
- manage arrhythmias
95
Treatment in ER is body temperature is less than 30 and stupor or dysrhythmia
- CPR
- high flow, warmed, humidified O2
- handle gently
96
Slow rewarming techniques
- warmed IV fluids
- heated humidified O2 by mask
- warmed blankets
97
Moderate rewarming techniques
- warmed gastric lavage
- warmed IV fluids at 65C
- peritoneal lavage
98
Rapid rewarming techniques
- thoracic lavage
- cardiopulmonary bypass
- ECM), AV dialysis
- warm water immersion
99
Warm=
32C
100
Complications of hypothermia
-rewarming shock
-cardiac arrhythmias
-infection
-acute pulmonary edema
-pancreatitis
0GI bleed
-peritonitis
-bleeding diathesis
-bladder atony
-local cold injuries
-rhabdo
-electrolyte imbalance
-compartment syndrome
-iatrogenic hyperthermia
101
Hyperthermia is core temp over what
38.5C
102
What are some causes of hyperthermia
- increased ambient heat
- increased heat production
- decreased heat dissipation
103
Elevate temperature does what to the body
- denatures proteins
- liquefies membrane lipids
- destabilizes phospholipids and lipoprotiens
104
On a microvascular level heat stroke resembles what
sepsis
- inflammation
- translocation of lippolysaccharides from the gut
- activation of coagulation cascade
105
What causes heat cramps
- muscle fatigue
| - electrolyte abnormalities
106
Physical exam for a person with hyperthermia
- temp >40.5 common
- HR >130
- hypotension that corrects with normalization of temp
- CNS dysfunction
- nystagmus
- tachypnea
- hypoxia
- AKI
107
Treatment of heat exhaustion
- noninasive cooling techniques
| - electrolyte and hydration management
108
Treatment of heat stroke
- reduce core temp to <40 within 30 minutes
| - dantrolene if suspect NMS and malignant hyperthermia
