1. Thermal Injury
Mohan K. Rao MD FACS

2. Thermal Injury Objectives To identify types of burns and their causes
To understand the pathogenesis of burn injury
To describe the principles of managing a patient with burns
To explain proper wound management techniques for treating burns

3. Thermal Injury Introduction
2.2 million people per year sustain burns in the U.S.A.
75-80% occur in homes
Major causes: flames, scalds, heat, chemicals and electricity
Under age 6, major cause is scalding, In adults, the major cause is flame
75% of burns could be avoided

4. Thermal Injury Introduction Extremely labor intensive patients
Not enough burn beds available to accommodate a major disaster
Often a disease of persons with few means
Very high cost of care

5. Thermal Injury

6. Thermal Injury Introduction 1st half of the 20th century
Resignation to the inevitability of shock and infection
Treatment directed to the relief of complications of skin injury and not to the repair of the skin itself
Therapies to hold the fort until the host defenses allowed the patient to survive

7. Thermal Injury Introduction 2nd half of the 20th century
Critical care expertise
Understanding of the pathophysiology of burn shock
World Wars
Coconut Grove fire
Development of topical antimicrobial therapy

8. Thermal Injury Pathophysiology Multiple functions of skin
Thermal regulation
Prevention of fluid loss by evaporation
Hermetic barrier against infection
Contains sensory receptors that provide information about environment

9. Thermal Injury Pathophysiology
Histological assessment of the burn wound
Zone of coagulation (necrosis)
Zone of stasis (injury)
Zone of hyperemia

10. Thermal Injury
Pathophysiology
Evaluation
Depth
Size

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19. Thermal Injury Burn Size Rule of nines works well in adults
Head size makes it work
less well in children
Palm of the hand is ~1%
of total body surface injury
1o burns do not count

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21. Thermal Injury Transfer Criteria
1. Partial thickness burns >= 20% TBSA in patients aged years old.
2. Partial thickness burns >=10% TBSA in children aged 10 or adults aged 50 years old.
3. Full-thickness burns >= 5% TBSA in patients of any age.
4. Patients with partial or full-thickness burns of the hands, feet, face, eyes, ears, perineum, and/or major joints.
5. Patients with high-voltage electrical injuries, including lightning injuries.
6. Patients with significant burns from caustic chemicals.
7. Patients with burns complicated by multiple trauma
8. Patients with burns who suffer inhalation injury.
9. Patients with significant ongoing medical disorders.
10. Hospitals without qualified personnel or equipment for the care of children.
11. Burn Injury in patients who will require special social/emotional and /or long-term rehabilitative support, including cases involving suspected child abuse, substance abuse, etc.

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Don't be so intimidated by the burn wound that you don't treat the associated trauma.

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24. Thermal Injury Management Primary survey Airway Breathing Circulation
Disability
Exposure/Enviornment

25. Thermal Injury Management Resuscitation phase
2 large bore peripheral IV’s
Labs
T/C, CBC, CMP, ABG’s, CO, Drug/EtOH screen
NG tube
Foley catheter
CXR, C-spine, Pelvis
Fluid administration of LR

26. Thermal Injury Management Secondary survey (AMPLET) A - Allergies
M - Medications
P - Past medical history/previous illness
L - Last meal or beverage consumed
E - Events preceding injury/history of present illness
T- Tetanus

27. Thermal Injury Airway management
Statistically, more people will die from inhalation injury than from the actual burns
Any victim, burned in a closed area should be presumed to have an inhalation injury

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30. Thermal Injury Airway injury- carbon monoxide
Most common type of airway injury is carbon monoxide poisoning, which may often present with very few symptoms.
Carbon monoxide has a 200 times greater affinity for hemoglobin than oxygen.
As carbon monoxide binds to the hemoglobin molecule, it prevents the red blood cell from transporting oxygen, resulting in a shift of the hemoglobin oxygen dissociation curve to the left.

31. Thermal Injury Airway injury-carbon monoxide
As the levels of carboxyhemoglobin increase the patient may develop myocardial and cerebral hypoxia.
The most common signs are central nervous system complications: confusion, loss of memory and headache.
The skin may become cherry red.
Anyone unconscious at the scene of a fire should be presumed to have a carbon monoxide injury.

32. Thermal Injury Airway injury-carbon monoxide
The only way to treat a carbon monoxide exposure is with immediate application of high flow oxygen at the scene of the fire
1/2 life of carboxyhemoglobin is 30 minutes
? Use of hyperbaric chambers

33. Thermal Injury Airway injury- above the glottis
Quite common due to the capacity of the nasopharynx to dissipate heat to the nose, throat and mouth.
The resulting thermal injury can cause edema which can present within minutes to hours. These are the types of injuries that can progress to airway obstructions.

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35. Thermal Injury Airway injury- below the glottis
Heat injury is less common due to the effective heat removal of the upper airway
Lower airways can be directly burned by hot steam
Injury to the lower airways can be caused by the products of combustion in particular the aldehydes

36. Thermal Injury Airway injury- tests
ABG’s, CXR are often normal acutely
Bronchoscopy
Xenon I131 lung scan

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38. Thermal Injury Airway injury- treatment
Early intubation with positive pressure ventilation
High concentrations of oxygen
Aggressive management of secretions
THERE IS NO VALUE AND POTENTIAL GREAT HARM THAT CAN OCCUR WITH STEROID OR ANTIBIOTIC ADMINISTRATION

39. Thermal Injury Fluid replacement
Biphasic capillary leak to fluid, high density molecular weight proteins (but not red cells), electrolytes
1st phase is histamine dependent
2nd phase related to the release of TNF, leukotrienes, interleukins
Repair begins at 12 hours, complete at 24h

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Fluid replacement

41. Thermal Injury
Fluid replacement

42. Thermal Injury Fluid replacement Example of fluid management
A 70kg patient with 50% body surface area burn would require:4 x 50 x 70 = mls of Ringers Lactate solution over 24h hours.Therefore 7 litres should be given in the first 8 hours and 7 over the following 16 hours
Initial IV rate should be ~ cc/hour

43. Thermal Injury
Fluid replacement

44. Thermal Injury Fluid replacement
Criteria to judge whether or not fluid resuscitation is adequate is measured by urine volume.
Other criteria include appropriate sensorium, pulse, and blood pressure

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Fluid replacement
Why Lactated Ringers solution?

46. Thermal Injury Complications of edema formation Airway edema
Extremity edema limiting circulation
6 p’s of circulatory insufficiency
Torso edema limiting ventilation
High peak ventilatory pressures

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49. Thermal Injury Wound care Goals
If the patient is to be transferred, then simply cover the wounds with a clean dressing
Burn creams are unnecessary in this circumstance

50. Thermal Injury Wound care Goals Cosmesis Comfort
Decrease wound flora to less than 105 organisms/gram of tissue

51. Thermal Injury Wound care Topical antibiotics
Agent Advantages Disadvantages
0.5% AgNO Broad spectrum Electrolyte abn’s,
inconvenient
Silvadene Broader spectrum Leukopenia
(silver sulfadiazine)
Sulfamylon Broadest spectrum Painful,metabolic (mafenide) acidosis

52. Thermal Injury Wound care 1st degree- Keep clean, moisturize
2nd degree
Debride blisters
Keep clean
Topical antibiotic cream
Biologic dressings
Grafting if no healing in 3 weeks

53. Thermal Injury Wound care 3rd degree Topical antibiotic cream
Will need skin grafting
Aggressive vs. non- aggressive treatment
Prompt excision and immediate physiologic wound closure decreases morbidity and hospital stay but increases the likelihood of blood transfusion

54. Thermal Injury Wound care Skin grafting
In general, desirous to graft areas of function first
Split thickness vs. full thickness grafts
Epidermis and variable depths of dermis
The thinner the graft, the greater likelihood of graft take but the greater risk of contraction.
The thicker the graft, the less the likelihood of graft take but the less the risk of contraction.

55. Thermal Injury Complications Curling’s ulcers
85% of all major burn victims have stomach or duodenal inflammation at endoscopy
Best treated with prevention
Perforation, obstruction, hemorrhage

56. Thermal Injury Complications Pneumonia
Infection of thermally injured cartilage
Invasive catheter infection
Invasive burn wound infections

57. Thermal Injury Complications Pneumonia
More likely in intubated patients, especially those with inhalation injury
Need to distinguish between pneumonia and colonization

58. Thermal Injury Complications Infection of thermally injured cartilage
Often requires cartilage removal
Very disfiguring

59. Thermal Injury Complications Invasive catheter infections
Frequent line changes necessary
Gram + or Gram - possible

60. Thermal Injury Complications Invasive burn wound infections
More likely if >105 organisms/gram of tissue
Ecthyma gangrenosum indicates metastatic pseudomonas
Treatment with IV antibiotics and burn debridement
Gram + (staph or strep) or Gram - (pseudomonas)

61. Thermal Injury Electrical injury
With high voltage current, the skin resistance is lowered and the victim can get profound injuries from the electricity.
Electricity does not travel over the surface of the skin, because the surface tension of the skin is very high.
The current tends to enter the body through a relatively small opening, travels deep through the body then exits through a small opening.

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63. Thermal Injury Electrical injury Early complications
Cardiac dysrhythmia
Spine fractures
Bowel necrosis
Seizures
Renal failure

64. Thermal Injury Electrical injury Late complications Cataracts
Gallstones
Neuropsychiatric changes

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Electrical injury

66. Thermal Injury Electrical injury
Renal failure secondary to myonecrosis and the release of myoglobin
Myoglobin causes renal failure by two mechanisms
Direct nephrotoxin
Causes an obstructive uropathy due to the precipitation of myoglobin in the tubules

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68. Thermal Injury Electrical injury Compartment syndrome
The muscles of the lower leg are wrapped with fascia that divides them into four groups called compartments. Two such compartments exist in the forearm.
These fascial envelopes are unable to stretch to accommodate swollen muscles.

69. Thermal Injury Electrical injury
Severe fractures, trauma, vascular injuries and electrical injuries can all produce muscle damage.
As the injured muscle swells the internal pressure rises so high that local circulation is disrupted and the affected muscle dies

70. Thermal Injury Electrical injury- management
Primary survey, resuscitation, secondary survey
Cardiac monitoring
Fluid replacement to assure greater than 100 cc/hour of urine
Alkalinization of the urine with HCO3

71. Thermal Injury Electrical injury- management
Fasciotomy to relieve elevated muscle pressure.

72. Thermal Injury New topics on the horizon
Enhancement of dermal and epidermal regeneration using gene transfer technology
Use of monoclonal antibody to decrease the zone of stasis
Use of laser Doppler imaging to assess depth of injury
Recognition of relative hypoadrenalism is a small population of severely burned individuals
Recognition of the DVT risk in immobilized burn patients

73. Thermal Injury New topics on the horizon
Currently, problems with less than good answers include
Burns in the elderly
Patients with inhalation injury
Patients with high percentage TBSA injured
Long term cosmetic and quality of life issues

74. Thermal Injury
Conclusions