Chapter 17: Burns Flashcards
Burn: sunburn (epidermis)
First degree
Burn: painful to touch; blebs and blisters; hair follicles intact; blanches (do not need skin grafts)
2nd degree burn: superficial dermis (papillary)
Burn: decreased sensation; loss of hair follicles (need skin grafts)
2nd degree burn: deep dermis (reticular)
Burn: leathery (charred parchment); down to subcutaneous fat)
3rd degree burn
Burn: down to bone; into adjacent adipose or muscle tissue
4th degree burn
How do first and second degree burns heal?
By epithelialization (primarily from hair follicles)
Can cause rhabdomyolysis with myoglobinuria
- Tx: hydration, alkalinize urine
Extremely deep burns, electrical burns, or compartment syndrome
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
Burn assessment: patient population with highest death
Deaths highest in children and elderly (trouble getting away)
MCC burns
Scald burns
Burns: more likely to come to hospital and be admitted
Flamer burns
Assessing percentage of body surface burned
- Head
- Arms
- Chest
- Back
- Legs
- Perineum
- Head: 9
- Arms: 18
- Chest: 18
- Back: 18
- Legs: 36
- Perineum: 1
When do you use Parkland’s formula?
Use for burns > 20% only
What is the Parkland’s formula?
4cc/kg x % burn in first 24 hours, give 1/2 the volume in the first 8 hours
What type of fluids should you use in burn resuscitation?
Lactated ringer’s solution (in the first 24 hours)
Best measurement of resuscitation
Urine output
- Adults: 0.5 - 1.0 cc/kg/hr
- Children
What are the disadvantages of the Parkland formula?
Can grossly underestimate volume requirements with inhalational injury, ETOH, electrical injury, post-escharotomy
What can colloid (albumin) cause in first 24 hours of burn resuscitation?
Increased pulmonary / respiratory complications -> can use colloid after 24 hours
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
What if compartment syndrome is suspected after escharotomy?
May need fasciotomy
Risk factors for burn injuries
Alcohol or drug use, age (very young / very old), smoking, low socioeconomic status, violence, epilepsy
Accounts for 15% of burn injuries in children
Child abuse
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
What primarily causes lung injury in burns?
Lung injury caused primarily by carbonaceous materials and smoke, not heat.
Risk factors for airway injury in burns
ETOH, trauma, closed space, rapid combustion, extremes of age, delayed extrication
Signs and symptoms of possible airway injury
Facial burns, wheezing, carbonaceous sputum
Indications ofr intubation after burn
Upper airway stridor or obstruction, worsening hypoxemia, massive volume resuscitation can worsen symtpoms
MC infection in patients with > 30% BSA burns
Pneumonia
MCC death after > 30% BSA burns
Pneumonia
Tx: acid and alkali burns
Copious water irrigation
Produce deep burns due to liquefaction necrosis
Alkali burns
Produce coagulation necrosis
Acid burns
Tx: hydrofluoric acid burns
Spread calcium on wound
Tx: powder burns
Wipe away before irrigation
Tx: tar burns
Cool, then wipe away with lipophilic solvent (adhesive remover)
Burns: need cardiac monitoring
Electrical burns
Complications of electrical burns
- Can cause rhabdomyolysis and compartment syndrome
- Polyneuritis, quadriplegia, transverse myelitis, cataracts, liver necrosis, intestinal perforation, gallbladder perforation, pancreatic necrosis.
Cardiopulmonary arrest secondary to electrical paralysis of brainstem
Lightning
1st week: early excision of burned areas
- Caloric Need
25 kcal/kg/day + (30 kcal x 30% burn)
1st week: early excision of burned areas
- Protein need
1 g/kg/day + (3g x %burn)
Best source of nonprotein calories in patients with burns
Glucose
- Burn wounds use glucose in an obligatory fashion
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
What is burn viability based on after excision?
Color, texture, punctate bleeding after removal.
When do you treat burn wounds to face, plans, soles and genitals?
Deferred for the first week
What are the goals for each burn wound excision?
- Want
When are skin grafts contraindicated?
If culture is positive for beta-hemolytic strep or bacteria > 10^5.
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])
What regenerates the donor skin site with autografts?
Donor skin site is regenerated from hair follicles and skin edges on STSGs
Vascularization of autografts
- Days 0-3
- Day 3
- Days 0-3: Imbibition (osmotic)
- Day 3: neovascularization
Sites: poorly vascularized beds are unlikely to support skin grafting
Includes tendon, bone without periosteum, XRT areas
Measurements of split-thickness grafts
12-15mm (includes epidermis and part of dermis
- Not as good as autografts
- Can be a good temporizing material; last two to four weeks
Homografts (allografts; cadaveric skin)
Vascularize and are eventually rejected at which time they must be replaced
Allografts (ex of Homografts)
Not as good as homografts; last 2 weeks; these do not revascularize
Xenografts (porcine)
Not as good as homografts or xenografts
Dermal substitutes
Used for back, flank, trunk, arms, and legs
Meshed grafts
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
Most common reason for skin graft loss
Seroma or hematoma formation under graft
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.
- More likely to survive
- Graft not as thick so easier for imbibition and subsequent revascularization to occur
Split thickness skin grafts (STSGs)
- Have less wound contraction
- Good for areas such as the palms and the backs of hands
Full thickness skin grafts (FTSGs)
How can you improve burn scar hypo pigmentation and irregularities?
Can be improved with dermabrasion thin split-thickness grafts.
Treatment 2nd to 5th week:
- Face
Topical antibiotics for 1st week, FTSG for unhealed areas (ngnmeshed)
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
Treatment 2nd to 5th week:
- Palms
Try to preserve specialized palmar attachments. Splint hand in extension for 7 days after FTSG.
Treatment 2nd to 5th week:
- Genitals
Can use STSG (meshed)
Usually applied immediately after burns
Bacitracin or Neosporin
Is there a role for prophylactic antibiotics in burns?
No.
MC organism in burn wound infections
Pseudomonas (followed by Staph, E. coli, enterobacter)
When are burn wound infections more likely to happen?
> 30% BSA
Have decreased incidence of burn wound bacterial infections
Topical agents
Have increased incidence secondary to topical antimicrobials
Candida infections
Impaired in burn patients (leaves them more susceptible to infection)
Granulocyte chemotaxis and cell-mediated immunity
- Do not use in patients with sulfa allergy
- Limited eschar penetration; can inhibit epithelialization
- Ineffective against some Pseudomonas; effective for Candida
Silvadene (silver sulfadiazine)
Adverse effects: silvadene (silver sulfadiazine)
Can cause neutropenia and thrombocytopenia
- Discoloration
- Limited eschar penetration
- Ineffective against Pseudomonas species and GPCs
Silver nitrate
Adverse effects: silver nitrate
- Electrolyte imbalances (hyponatremia, hypochloremia, hypocalcemia, and hypokalemia)
- Methemoglobinemia (contraindicated in patients with G6PD deficiency)
- 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)
ADRs: sulfamylon (mafenide sodium)
- Painful application
- Can cause metabolic acidosis
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
Organism: burn wound sepsis
Pseudomonas
MC viral infection in burn wounds
HSV
Number of organisms: NOT a burn wound infection
Best way to detect a burn wound infection (and differentiate from colonization)
Biopsy of burn wound
Best way to detect a burn wound infection (and differentiate from colonization)
Biopsy of burn wound
Complications after burns (x10)
Seizures, peripheral neuropathy, ectopia, corneal abrasion, symblepharon, heterotopic ossification of tendons, fractures, curling’s ulcer, marjolin’s ulcer, hypertrophic scar
Why seizures after burns?
Usually iatrogenic and related to sodium concentration
Why peripheral neuropathy after burns?
Second to small vessel injury and demyelination
Why ectopia after burns?
From progressive contraction of burned adnexa (Tx: eyelid release)
How do you detect eye injury with burns?
Fluorescein staining to find injury (Tx: topical fluoroquinolone or gentamicin)
Tx: corneal abrasion (s/p burn)
Tx: topical antibiotics
What is a symblepharon and treatment?
Eyelid stuck to conjunctiva.
- Tx: release with glass rod
Tx: heterotopic ossification of tendons
Tx: physical therapy; may need surgery
How do you treat fractures with burn injury?
Tx: often need external fixation to allow for treatment of burns
Gastric ulcer that occurs with burns
Curling’s ulcer
Highly malignant squamous cell CA that arises in chronic non-healing burn wounds or unstable scars
Marjolin’s ulcer
- 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
What is the mechanism of hypertrophic scars?
Usually occur 3-4 months after injury secondary to increased neovascularity
Do you use steroids in erythema multiforme and variants?
No.
Erythema multiforme
Stevens Johnson syndrome
Toxic epidermal necrolysis
- Erythema multiforme: least severe form (self-limited, target lesions)
- Stevens Johnson syndrome: (more serious) -
What do you see in EM, SJS, and TEN?
Skin epidermal-dermal separation
What causes staph scalded skin syndrome?
Caused by staphylococcus aureus
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
Drugs that cause EM / SJS / TEN
Dilantin, Bactrim, penicillin
