7. PATHOPHYSIOLOGY
• Zone of coagulation (central)
– The most intimate contact with heat
source
– Dead or dying cells: coagulation necrosis
and absent blood flow
– Depth of tissue destruction determines
the degree of the burn
– White or charred
8. PATHOPHYSIOLOGY
• Zone of stasis (intermediate)
– Usually is red and may blanch on pressure,
appearing to have an intact circulation
– After 24 hours: petechial hemorrhages may be
present
– 3rd
day, becomes white because its superficial
dermis is avascular and necrosis
– Transformation of the zone of stasis
coagulation
– Progressive dermal ischemia
– Edema
9. PATHOPHYSIOLOGY
• Zone of hyperemia (outer)
– A red zone that blanches on pressure,
indicating that it has intact circulation
– 4th
day, deeper red color
10. Burn wound depth
Depends on
• Temperature of the agent
• Duration of contact with the agent
• Skin thickness
– Globrous skin of the palms and soles is
more resistant to full-thickness injury
than is the thinner skin
– Infant skin is also thinner than adult
skin
11. Immersion time to produce full
thickness burns
Time
Temperature
( ํํF)
1 second
158 ํํ (69
ํํC)
2 seconds 150 ํํ
10 seconds
140 ํํ (60
ํํC)
30 seconds 130 ํํ
1 minute 127 ํํ
10 minutes
120 ํํ (48
ํํC)
12. SEVERITY
• Etiology
• Time contact
• Extent or %burn area
• Depth
• Age
• Part of body burned
• Concurrent injuries
13. Determination of burn
EXTENT
• TBSA: partial + full thickness dermal
injury (2rd
+3nd
burn)
– Rule of 9
– Patient’s hand = 1%
– Lund and browder charts
14. Wallace’s ‘Rule of nines’
Body Part %
Head and neck 9
Upper limb Right and Left 9+9
Anterior trunk 18
Posterior trunk 18
Lower limb Right and Left 18+18
Perineum 1
Total 100%
16. Burn depth
1st : superficial
2nd : partial
Superficial partial
thickness
Deep partial
thickness
3rd : full thickness
4th : underlying
subcutaneous tissue,
tendon or bone
17. Superficial burns
• Involve the epidermis only
• Erythematous and painful
• Heal within 3-5 days
• Best treated with topical agents such as
aloe lotion: accelerate re-epithelialization
and soothe the patient
• Oral analgesics
• Sunburns
18. Superficial partial-
thickness burns
• Pink, moist, blister and painful to the
touch
• Heal within 2 weeks
• Generally do not result in scarring, but
could result in alteration of pigmentation
• Treated with greasy gauze with antibiotic
ointment
• Water scald burns
19. Deep partial-thickness burns
• Extend into the reticular portion of the
dermis
• Dry and mottled pink and white, variable
sensation
• Heal within 3-8 weeds, depending on the
number of viable adnexal structures
• Heal with contraction, scarring, and
possible contractures
• Not be completely re-epithelialized in 3
weeks, operative excision and grafting is
recommended
20. Full-thickness burns
• Involve the epidermis and the entirety of
the dermis
• Brown-black (eschar), leathery, and
insensate
• Fixed carboxyhemoglobin in the wound
cherry-red color
• Treated by excision and grafting, unless
they are quite small
21.
22. Classification of burn severity
MINOR BURN 15%TBSA or less in adults (TBSA = total body surface area)
10%TBSA or less in children and the elderly
2% TBSA or less full-thickness burn in children or adults without
cosmetic or functional risk to eyes, ears, face, hand, feet, or perineum
MODERATE
BURN
15-25%TBSA in adults with less than 10% full-thickness burn
10-20%TBSA partial-thickness burn in children under 10 and adults over
40 years of age with less than 10% full-thickness burn
10%TBSA or less full-thickness burn in children or adults without
cosmetic or functional risk to eyes, ears, face, hand, feet, or perineum
MAJOR
BURN
25%TBSA or greater
20%TBSA or greater in children under 10 and adults over 40 years of age
10% TBSA or greater full-thickness burn
All burns involving eyes, ears, face, hand, feet, or perineum that likely to
result in cosmetic impairment
All high voltage electrical burns
All burn injury complicated by major trauma or inhalation injury
All poor risk patients with burn injury
23. Body response to burn injury
• Physiologic response and burn shock
• Metabolic response
• Neuroendocrine response
• Immune response
30. Initial evaluation and
management
• Primary survey
– ATLS: ABCs
• Airway
– Early recognition of impending airway
compromise
– Prompt intubations
• Fluid resuscitation
– Warmed fluid
31. Initial evaluation and
management
• Secondary survey
– Mechanism of injury
– Inhalation injury
– Assessment of burn wound
• Cooling of burned tissue
– No benefit if delayed >30 minutes
– Do not use ice water
• Major burn
– NG tube
– Foley’s catheter
33. Fluid resuscitation
• Early and adequate
• Extent of burn and size, and fluid
replacement should proceed at the same
rate as the loss
• Constant rate, boluses are avoided
• Both peripheral and central lines can be
placed through burned tissue when
required
34.
35. Fluid resuscitation
• Children: Galveston formula
• First 24 hours
– Fluid = 5,000 ml/m2 burned + 2,000/m2 TBSA
– Age > 1 yr.: LRS 950 ml + alb 12.5 gm/L (25% albumin 50
ml)
– Age < 1 yr.: 5% D/N/2 930 ml + alb 12.5 gm/L + NaHCO3
20 ml
• Subsequent day
– Fluid = 3,750 ml/m2 burned + 1,500/m2 TBSA + NG loss
+ diarrhea/24 hr.
– Age > 1 yr.: Na+ 50 mEq/L K+ phosphate 30-40 mEq/L
– Age < 1 yr.: Na+ 35-40 mEq/L + K+ phosphate 30-40
mEq/L
• ½ in first 8 hr. and ½ in 16 hr.
38. Wound management
• Dressings with a moist, antibacterial
covering to minimize microbial growth,
fluid loss, and painful stimuli and to
maximize skin regeneration
42. Early excision and grafting
• Surgical procedures
– In adults, blood loss reaches 100 ml for
every 1% TBSA
– Limit each operative session to
debridement of 10-20% TBSA
– Tangential debridement involves
cutting the skin tissue at the depth of
the dermal and subcutaneous capillary
network
• 1 cm2 of burn causes 1 ml of blood loss
43. Early excision and grafting
• Autologous split-thickness skin grafts
– Gold standard for burn wounds if
enough donor sites are available
44. Nutrition
• Increase basal metabolic rate 50-100% of the
normal resting rate
– Increase glucose production, insulin
resistance, lipolysis, and muscle protein
catabolism. Without adequate nutritional
support
– Delayed wound healing, decreased immune
function, and generalized weight loss.
• Increase intake of both total calories and protein
(1.5-3 of protein/kg/day)
45. Nutrition
• Measuring weight loss and gain during treatment
is not useful because of the large fluid shifts
• Carbohydrate 65-80%
• Protein 15-20%
• Lipid 5-15%
46. Modification of the Harris-
Benedict Equation
Men
BMR = [66.47 + (13.75 x W) + (5.0 x H) - (6.76 x A) ] x (Activity
factor) x (injury factor)
Women
BMR = [665.1 + (9.56 x W) + (1.85 x H) - (4.68 x A) ] x (Activity
factor) x (injury factor)
BMR = basal metabolic rate W = weight in kg, M = height in cm, A =
age in years
Activity factor
Confined to bed = 1.2
Out of bed = 1.3
Injury factor
Minor operation = 1.2
Skeletal trauma = 1.35
Major sepsis = 1.6
Severe thermal burn = 1.5
47. Nutrition
Caloric Requirement in burned adult
= (25 x BW) + (40 x %burn) Kcal/day
Modified Curreri ‘junior formula’
1-12 yrs. = (60 x BW) + (30-35 x %burn) Kcal/day
< 1 yrs. = (80 x BW) + (30 x %burn) KCal/day
