Chapter 17: Burns Flashcards Preview

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Flashcards in Chapter 17: Burns Deck (104):
1

Burn: sunburn (epidermis)

First degree

2

Burn: painful to touch; blebs and blisters; hair follicles intact; blanches (do not need skin grafts)

2nd degree burn: superficial dermis (papillary)

3

Burn: decreased sensation; loss of hair follicles (need skin grafts)

2nd degree burn: deep dermis (reticular)

4

Burn: leathery (charred parchment); down to subcutaneous fat)

3rd degree burn

5

Burn: down to bone; into adjacent adipose or muscle tissue

4th degree burn

6

How do first and second degree burns heal?

By epithelialization (primarily from hair follicles)

7

Can cause rhabdomyolysis with myoglobinuria
- Tx: hydration, alkalinize urine

Extremely deep burns, electrical burns, or compartment syndrome

8

Admission criteria for burns

- 2nd and 3rd degree burns: > 10% BSA in patients aged 50 years. > 20% BSA. To significant portions of hands, face, feet, genitalia, perineum or skin overlying major joints.
- 3rd degree > 5%
- Electrical and chemical
- Concomitant inhalational injury, mechanical trauma, preexisting medical condition.
- Injuries in patients with special social, emotional or long-term rehabilitation needs
- Suspected child abuse or neglect

9

Burn assessment: patient population with highest death

Deaths highest in children and elderly (trouble getting away)

10

MCC burns

Scald burns

11

Burns: more likely to come to hospital and be admitted

Flamer burns

12

Assessing percentage of body surface burned
- Head
- Arms
- Chest
- Back
- Legs
- Perineum

- Head: 9
- Arms: 18
- Chest: 18
- Back: 18
- Legs: 36
- Perineum: 1

13

When do you use Parkland's formula?

Use for burns > 20% only

14

What is the Parkland's formula?

4cc/kg x % burn in first 24 hours, give 1/2 the volume in the first 8 hours

15

What type of fluids should you use in burn resuscitation?

Lactated ringer's solution (in the first 24 hours)

16

Best measurement of resuscitation

Urine output
- Adults: 0.5 - 1.0 cc/kg/hr
- Children

17

What are the disadvantages of the Parkland formula?

Can grossly underestimate volume requirements with inhalational injury, ETOH, electrical injury, post-escharotomy

18

What can colloid (albumin) cause in first 24 hours of burn resuscitation?

Increased pulmonary / respiratory complications -> can use colloid after 24 hours

19

Escharotomy indications (perform within 4-6 hours)

- Circumferential deep burns
- Low temperature, weak pulse, decreased capillary refill, decreased pain sensation, or decreased neurologic function in extremity
- Problems ventilating patient with significant chest torso burns

20

What if compartment syndrome is suspected after escharotomy?

May need fasciotomy

21

Risk factors for burn injuries

Alcohol or drug use, age (very young / very old), smoking, low socioeconomic status, violence, epilepsy

22

Accounts for 15% of burn injuries in children

Child abuse

23

History and exam findings that suggest child abuse

- History: delayed presentation for care, conflicting histories, previous injuries
- Exam: sharply demarcated margins, uniform depth, absence of splash marks, stocking or glove patterns, flexor sparing, dorsal location on hands, very deep localized contact injury

24

What primarily causes lung injury in burns?

Lung injury caused primarily by carbonaceous materials and smoke, not heat.

25

Risk factors for airway injury in burns

ETOH, trauma, closed space, rapid combustion, extremes of age, delayed extrication

26

Signs and symptoms of possible airway injury

Facial burns, wheezing, carbonaceous sputum

27

Indications ofr intubation after burn

Upper airway stridor or obstruction, worsening hypoxemia, massive volume resuscitation can worsen symtpoms

28

MC infection in patients with > 30% BSA burns

Pneumonia

29

MCC death after > 30% BSA burns

Pneumonia

30

Tx: acid and alkali burns

Copious water irrigation

31

Produce deep burns due to liquefaction necrosis

Alkali burns

32

Produce coagulation necrosis

Acid burns

33

Tx: hydrofluoric acid burns

Spread calcium on wound

34

Tx: powder burns

Wipe away before irrigation

35

Tx: tar burns

Cool, then wipe away with lipophilic solvent (adhesive remover)

36

Burns: need cardiac monitoring

Electrical burns

37

Complications of electrical burns

- Can cause rhabdomyolysis and compartment syndrome
- Polyneuritis, quadriplegia, transverse myelitis, cataracts, liver necrosis, intestinal perforation, gallbladder perforation, pancreatic necrosis.

38

Cardiopulmonary arrest secondary to electrical paralysis of brainstem

Lightning

39

1st week: early excision of burned areas
- Caloric Need

25 kcal/kg/day + (30 kcal x 30% burn)

40

1st week: early excision of burned areas
- Protein need

1 g/kg/day + (3g x %burn)

41

Best source of nonprotein calories in patients with burns

Glucose
- Burn wounds use glucose in an obligatory fashion

42

Excise burn wounds in > 72 hours (but not until after appropriate fluid resuscitation for)...

- Used for deep for 2nd, 3rd, and some 4th degree burns

43

What is burn viability based on after excision?

Color, texture, punctate bleeding after removal.

44

When do you treat burn wounds to face, plans, soles and genitals?

Deferred for the first week

45

What are the goals for each burn wound excision?

- Want

46

When are skin grafts contraindicated?

If culture is positive for beta-hemolytic strep or bacteria > 10^5.

47

Decreased infection, desiccation, protein loss, pain, water loss, heat loss, and RBC loss compared to dermal substitutes

Autografts (split-thickness [STSG] or full-thickness [FTSG])

48

What regenerates the donor skin site with autografts?

Donor skin site is regenerated from hair follicles and skin edges on STSGs

49

Vascularization of autografts
- Days 0-3
- Day 3

- Days 0-3: Imbibition (osmotic)
- Day 3: neovascularization

50

Sites: poorly vascularized beds are unlikely to support skin grafting

Includes tendon, bone without periosteum, XRT areas

51

Measurements of split-thickness grafts

12-15mm (includes epidermis and part of dermis

52

- Not as good as autografts
- Can be a good temporizing material; last two to four weeks

Homografts (allografts; cadaveric skin)

53

Vascularize and are eventually rejected at which time they must be replaced

Allografts (ex of Homografts)

54

Not as good as homografts; last 2 weeks; these do not revascularize

Xenografts (porcine)

55

Not as good as homografts or xenografts

Dermal substitutes

56

Used for back, flank, trunk, arms, and legs

Meshed grafts

57

Reasons to delay autografting

Infection, not enough skin donor sites, patient septic or unstable, do not want to create any more donor sites with concomitant blood loss

58

Most common reason for skin graft loss

Seroma or hematoma formation under graft

59

How do you prevent seroma or hematoma formation under skin graft?

Need to apply pressure dressing (cotton balls) to the skin graft to prevent serum and hematoma buildup underneath the graft.

60

- More likely to survive
- Graft not as thick so easier for imbibition and subsequent revascularization to occur

Split thickness skin grafts (STSGs)

61

- Have less wound contraction
- Good for areas such as the palms and the backs of hands

Full thickness skin grafts (FTSGs)

62

How can you improve burn scar hypo pigmentation and irregularities?

Can be improved with dermabrasion thin split-thickness grafts.

63

Treatment 2nd to 5th week:
- Face

Topical antibiotics for 1st week, FTSG for unhealed areas (ngnmeshed)

64

Treatment 2nd to 5th week:
- Hands

- Superficial: ROM exercises, splint in extension if too much edema
- Deep: immobilize in extension for 7 days after skin graft (need FTSG), then physical therapy. May need wire fixation of joints if unstable or open

65

Treatment 2nd to 5th week:
- Palms

Try to preserve specialized palmar attachments. Splint hand in extension for 7 days after FTSG.

66

Treatment 2nd to 5th week:
- Genitals

Can use STSG (meshed)

67

Usually applied immediately after burns

Bacitracin or Neosporin

68

Is there a role for prophylactic antibiotics in burns?

No.

69

MC organism in burn wound infections

Pseudomonas (followed by Staph, E. coli, enterobacter)

70

When are burn wound infections more likely to happen?

> 30% BSA

71

Have decreased incidence of burn wound bacterial infections

Topical agents

72

Have increased incidence secondary to topical antimicrobials

Candida infections

73

Impaired in burn patients (leaves them more susceptible to infection)

Granulocyte chemotaxis and cell-mediated immunity

74

- Do not use in patients with sulfa allergy
- Limited eschar penetration; can inhibit epithelialization
- Ineffective against some Pseudomonas; effective for Candida

Silvadene (silver sulfadiazine)

75

Adverse effects: silvadene (silver sulfadiazine)

Can cause neutropenia and thrombocytopenia

76

- Discoloration
- Limited eschar penetration
- Ineffective against Pseudomonas species and GPCs

Silver nitrate

77

Adverse effects: silver nitrate

- Electrolyte imbalances (hyponatremia, hypochloremia, hypocalcemia, and hypokalemia)
- Methemoglobinemia (contraindicated in patients with G6PD deficiency)

78

- Can cause metabolic acidosis due to carbonic anhydrase inhibition (decreased renal conversion of H2CO3 -> H2O + CO2)
- Good eschar penetration; good for burns overlying cartilage
- Broadest spectrum against Pseudomonas and GNRs

Sulfamylon (mafenide sodium)

79

ADRs: sulfamylon (mafenide sodium)

- Painful application
- Can cause metabolic acidosis

80

Signs of burn wound infection

Peripheral edema, 2nd to 3rd degree burn conversion, hemorrhage into scar, erythema gangrenosum, green fat, black skin around wound, rapid eschar separation, focal discoloration

81

Organism: burn wound sepsis

Pseudomonas

82

MC viral infection in burn wounds

HSV

83

Number of organisms: NOT a burn wound infection

84

Best way to detect a burn wound infection (and differentiate from colonization)

Biopsy of burn wound

85

Best way to detect a burn wound infection (and differentiate from colonization)

Biopsy of burn wound

86

Complications after burns (x10)

Seizures, peripheral neuropathy, ectopia, corneal abrasion, symblepharon, heterotopic ossification of tendons, fractures, curling's ulcer, marjolin's ulcer, hypertrophic scar

87

Why seizures after burns?

Usually iatrogenic and related to sodium concentration

88

Why peripheral neuropathy after burns?

Second to small vessel injury and demyelination

89

Why ectopia after burns?

From progressive contraction of burned adnexa (Tx: eyelid release)

90

How do you detect eye injury with burns?

Fluorescein staining to find injury (Tx: topical fluoroquinolone or gentamicin)

91

Tx: corneal abrasion (s/p burn)

Tx: topical antibiotics

92

What is a symblepharon and treatment?

Eyelid stuck to conjunctiva.
- Tx: release with glass rod

93

Tx: heterotopic ossification of tendons

Tx: physical therapy; may need surgery

94

How do you treat fractures with burn injury?

Tx: often need external fixation to allow for treatment of burns

95

Gastric ulcer that occurs with burns

Curling's ulcer

96

Highly malignant squamous cell CA that arises in chronic non-healing burn wounds or unstable scars

Marjolin's ulcer

97

- Usually occur 3-4 months after injury seconds to increased neovascularity.
- More likely to be deep thermal injuries that take > 3 weeks to heal, heal by contraction and epithelial spread, or heal across flexor surfaces
- Tx?

Hypertrophic scar

Tx: steroid injection into lesion (best), silicone, compression; wait 1-2 years before scar modification surgery

98

What is the mechanism of hypertrophic scars?

Usually occur 3-4 months after injury secondary to increased neovascularity

99

Do you use steroids in erythema multiforme and variants?

No.

100

Erythema multiforme
Stevens Johnson syndrome
Toxic epidermal necrolysis

- Erythema multiforme: least severe form (self-limited, target lesions)
- Stevens Johnson syndrome: (more serious) -

101

What do you see in EM, SJS, and TEN?

Skin epidermal-dermal separation

102

What causes staph scalded skin syndrome?

Caused by staphylococcus aureus

103

Tx: EM / SJS / TEN

Fluid resuscitation and supportive; need to prevent wound desiccation with homografts / xenograft wraps; topical antibiotics, IV antibiotics if due to Staphylococcus

104

Drugs that cause EM / SJS / TEN

Dilantin, Bactrim, penicillin