Thermal injury (all; including extravasation, XRT)

Question 1

Outline principles for management of hand burns

Answer 1

1. Initial assessment and management of total patient / total burn following ATLS/ABLS protocol including tetanus
2. Proper evaluation of depth and extent of burn wound
3. Consideration for prophylactic (therapeutic) escharotomies
4. Prevention of infection with moist, anti-microbial dressings (ex: SSD)
5. Early wound closure
   
   1. for superficial burns likely to close in 2-2.5 weeks, as above
   2. aim for excision and grafting for burns unlikely to heal in 2-2.5 weeks (all deep partial and full thickness, some intermediate thickness)
6. Use sheet grafts when surgery is necessary
7. Prevent stiffness and maintain/ regain ROM
   
   1. pre-operatively and immediately for non-operative
   2. at POD5 for patients having excision and grafting
   3. using “intrinsic plus” position of safety to prevent claw hand
8. outpatient rehab including OT/PT and silicone therapy, pressure garments
9. Reconstructive surgery for scars, contracture, claw hand, syndactyly @ 12 mos

Question 2

list criteria for prophylactic escharotomy

Answer 2

1. circumferential or near-circumferential deep partial or full thickness burns
2. extensive burns likely to require major fluid resuscitation and limb/digit at risk (at least partially, nearly circumferential)
3. unable to evaluate patient (confounding factors like hypothermia)

Question 3

discuss how and where you will do an escharotomy on an upper extremity

Answer 3

• Technical points
  
  • in tub room
  • use betadine prep
  • 15 blade or needle-tip cautery
  • just through dermis, just proximal and distal to extent of burn
• Arm and forearm:
  
  • medial incision in antebrachial groove, ANTERIOR to elbow, along ulnar border
  • lateral incision lateral arm to radial border, be aware of sensory radial nerve branches
• hand:
  
  • 2 dorsal interMC (btwn 4,5 and 2,3)
  • thenar (radial 1st MC) and hypothenar (ulnar 5th MC)
• Digits
  
  • 1,5 radial border
  • 2,3,4 ulnar border

Question 4

what is approach to upper extremity fasciotomy?

Answer 4

• most common to release is volar (Rowland’s)
  
  • curvilinear incision along volar forearm
  • leaves radially based flap to cover median nerve and brachial artery at AC fossa
  • leaves radially based flap to cover median nerve at wrist
  • release guyon’s canal and carpal tunnel
• Dorsal incision is dorsal longitudeinal to release mobile wad and extensor compartment
• Hand: incisions are same as for fasciotomy
  
  • 2 dorsal incisions: d/v i/o, adductor
  • thenar and hypothenar

Question 5

when would you consider fasciotomy in burn patient? what is another consideration against fasciotomy?

Answer 5

• may want to consider fasciotomy when
  
  • late escharotomy
  • clinical suspision
    
    • pain out of proportion
    • pulseless limb despite adequate resuscitation
    • sensory deficit
    • non-resolving myoglobinuria or lactate
  • limb ischemia > 2 hrs
  • large volume resuscitation expected over short time
• consideration against fasciotomy is taking a sterile wound bed and opening it, exposing it to risk of infection from open wounds, lungs,

Question 6

List common sequellae of hand burn

Answer 6

• all suffer from edema, stiffness, pain
• Hypertrophic scar / scar contracture
  
  • general hypertrophic scars
  • D5 abduction contracture
  • dorsal skin contracture (extension postures)
  • volar skin contract (flexion postures)
  • wrist, elbow, axillary contracture
• Webspace contracture
  
  • syndactyly
  • thumb adduction contracture
  • webspace adduction contracture
• Claw Hand
  
  • MCP hyper/extension
  • PIP (DIP) flexion
  • Boutonneire
  • “intrinsic minus” posture
  • extensor tendon adhesions
• Other
  
  • Compression neuropathy (MN, UN, 10% of burns > 20% tbsa)
  • heterotopic ossification
  • gangrene, amputation

Question 7

List and discuss advantages / disadvantages of different flaps that can be used for burn scar reconstruction in upper extremity

Answer 7

Flap

Technical Considerations

Advantages

Disadvantages

Groin

• SCIA
• Large size, direct closure, hidden scar, reliable
• 2 procedures
• stiffness w/ immobilization

Radial Forearm

• Harvest from other arm
• Thin, supple, potentially sensate, can cover entire dorsum of hand/digits
• Sacrifice major vessel. Donor site deformity

Reverse PIA

• Posterior interosseous artery (pivot @ 3cm proximal to DRUJ)
• Can cover dorsal/volar wrist, dorsal hand, 1^st web
• Does not compromise vascularity to hand

Dorsalis Pedis

• Potentially sensate. Can cover dorsum & proximal digits. Can harvest extensor tendons, 2^nd metatarsal for composite recon.
• Cannot cover entire hand
• Donor site deformity

Temporoparietal Fascia

• Fascial flap then grafted with skin
• Thin, pliable. Minimal donor morbidity (closed primarily). Can cover entire dorsum hand/digits. Potentially sensate (auricular N)
• Variable venous outflow, makes it more tenuous
• Short pedicle

Lateral arm

• Fasciocutaneous
• (PRCA)
• Thin, supple. Potentially sensate (brachial cutaneous nerve). Minimal donor morbidity/primary closure of donor site
• Smaller than RFF or tempoparietal

Local hand flaps

axial

• Homodigital finger
• Heterodigital finger
• DMCA (antegrade, retrograde)
• Local
• Single stage
• Easy and reliable
• (homodigital – do digital allen’s test)
• May not be available
• STSG to defect

Local hand flaps

random

• Z-plasty (2,4 flap)
• Jumping man (5 flap)
• V-M, V-Y
• Reliable, effective, particularly for small or webspace contracture
• Random flap in burned skin - ? increased risk of ischemia

Question 8

Draw a Z-plasty

what % increase do you anticipate?

Draw a classic 4-flap z-plasty - what % increase do you anticipate?

Answer 8

• 30’ – 25%
• 45’ – 50%
• 60’ – 75%
• 75’ – 90%
• 90’ – 120%
• for a 4-flap Z plasty, expect 150% increase length

Question 9

draw a jumping man

how much % increase in length?

Answer 9

150%

Question 10

what is your approach to managing a flexed joint in claw hand?

Answer 10

• first determine if the primary problem is skin scar/contracture or joint contracture (or both)
• decide then if patient requires both soft tissue AND joint release
• undertake appropriate choice of soft tissue procedure
• undertake capsulotomy - volar plate / check-rein ligament release, capsule release, partial accessory liament release, +/- K-wire
• Consider arthrodesis for refractory cases
• Do not consider arthroplasty in this context, given poor soft tissue envelope, premorbid stiffness, risk of chronic pain and extrusion

Question 11

what is heterotopic ossification

Answer 11

bone formation in extra-skeletal soft tissue

Question 12

who is at risk for heterotopic ossification / what are the associations?

Answer 12

• burn
• critical care and immobilization
• CNS injury, spinal cord injury
• trauma; hip surgery

Question 13

what is the suspected etiology of HO?

Answer 13

• BMP triggers dormant osteoprogenitor cells to differentiate into osteoblasts / osteoid

Question 14

treatment of HO

Answer 14

1. prevention in high risk pts: NSAIDS, bisphosphonates (etidronate)
2. treatment:
   
   1. non-operative
      
      1. PT/OT/SPLINTS
      2. NSAIDS, bisphosphonates,
   2. operative
      
      1. be cautious - high recurrence, low resolution of pain (what is the goal?)
      2. joint release and excision at > 12 mos

Question 15

what are the mechanisms of injury during extravasation injury?

Answer 15

1. Pressure: vascular obstruction 2’ pressure in extra-cellular (intersititial) space occludes vessels - early necrosis
2. Chemical: vascular obstruction 2’ inflammatory response to chemical - early necrosis

Question 16

Summarize injection material, typical treatment principle

Answer 16

• high pressure injection injuries are variably defined, but generally administerd from a high pressure gun or hose of some sort
• Toxic injection modalities include: grease (commonest), paint, paint thinner (worst), fuel
  
  • management includes history, physical (including for compartment syndrome), imaging (XR), tetanus administration, analgesia (via PO/IV not local), IV antibiotics, dress/splint/elevate, to OR urgently for decompression and debridement and second look
• Non toxic injection injuries include air and clean water
  
  • management includes history/physical (for compartment syndrome), imaging (XR), tetanus, analgesia, IV antibiotics –> oral antibiotics, dress/splint/elevate
  • non-operative management as above with active surveillance (close fu)

Question 17

what do you wnat to know on history?

Answer 17

• agent, toxicity, viscosity, concentration, estimate of volume? etc
• pressure of unit
• when it happened, what was done immediately
• entry point (flexor = more dissemination)
• symptoms now (pain, paresthesia, skin changes)

Question 18

describe principles of surgical management for high pressure injection injuries

Answer 18

· Removal of all material is often not feasible

· Surgical goals

o Neurovascular decompression

o Decontamination

o Debridement of non-viable tissue

o Prevention of infection

o Delayed reconstruction

· Anaesthesia: general or regional

· Tourniquet, but no exsanguination

Question 19

discuss management of normal pressure injection injuries

Answer 19

• history:
  
  • agent: what was the agent, when injected, how injected, by whom, initial response, response over time, why injected
  • problems: what is the current problem (pustule, draining sinus, inflammation, pain, etc) and how has it been treated so far?
  • usual rest
• Physical: signs of acute or delayed presentation:
  
  • Acute reaction –> chemical irritation, infection or pain, systemic illness/septicemia, embolization
  • Delayed presentation –> abscesses, scar, draining fistula/sinus, bleeding, extrusion, infection, granulomas, beading
• Investigations:
  
  • CT or MRI to image cavity
  • tissue biopsy to rule out fungus, mycobacterium, other atpyical infection
• Superficial localized granulomas may be improved with local or systemic steroids or imiquimod
• Chronic inflammation, induration and sinus formation are usually treated by excision of involved tissue
• Staged recon

Question 20

describe universal interventions for extravasation injuries

Answer 20

o Prevention

o Stop infusion immediately

o Aspiration via in-situ catheter (ie by RN prior to removal; often IV is removed by the time we’re called)

o Remove intravenous and re-start only at different site

o Elevation and splinting +/- cool compress

o Analgesia

o Serial examination

• No prophylactic debridement; follow and treat w/ dsg (vs surg, below) as necessary once fully demarcated
• *Adjunct: clysis with saline irrigation+/- hyaluronidase à not really done

Question 21

during an extravasation injury, describe agents that have an anti-dote

Answer 21

o Vasoconstricting agents (ie epi/norepi etc) –> phentolamine

o Cisplatin, nitrogen mustard (chemotherapeutics) –> sodium thiosulfate

o Doxorubicin (chemotherapeutic) –> DMSO

Question 22

Describe 5 factors determining the cellular response to radiation

Answer 22

• Repair - ability of cell to recover from sublethal damage
• Repopulation - cells ability to repopulate tumor
• Reoxygenation - cell most sensituve to Rtx when oxygenated b/c ROS/free radicals formed
• Reassortment - cell most sensitive to Rtx in mitosis/DNA replication phase
• Radiosensitivity
  
  • sensitive if high oxygenation, reassortment
  • not sensitive if repair and repopulate
  • inherent cell sensitivty is based on frequency of cell division, time between division and life span

Question 23

How does radiation affect wound healing?

Answer 23

impairs all phases of wound healing

• Inflammatory:
  
  • decreased macrophage function/GFs
• Proliferative:
  
  • reduced fibroblast number, collagen production
  • impaired angiogenesis 2’ fibrosis and endoarteritis obliterans
  • delayd epitheliazation: abnormal and fewer keratinocytes
• Maturation
  
  • impaired collagen turnover/ remodelling

RESULTS

• Pre-op Rtx: delay surgery 1wk per wk of radiation prior to surgery - approx 6mths for breast OR
• Post- op Rtx: Should delay rtx until wound healed - approx 3wks

Question 24

What are the phases of radiation dermatitis?

Answer 24

• Acute - erythema phase (hrs-days)
• Dry desqaumation phase (4-5thwk)
  
  • enough basal keratinocytes remain to repopulate epidermis
  • pruritus, scaling, hyperpigment which remains
• Moist desquamation phase (4thwk) - at >40Gy doses
  
  • not enough basal keratinocytes remain
  • at lower Gy doses, re-epi occurs form appendages
  • at high Gy doses, re-epi occurs from edges
• Late phase (1yr post-Rtx)
  
  • atrophic,fibrosis,scarring with latreed pigment, telangiectasia, risk of radiatio ulcer/necrosis

NB: most skin cancers require >40Gy= moist desqaum

<30Gy get dry desquamation

Gy = joule/kg of tissue, 1rad = 0.01 Gy - radiation absorbed dose

Conventional fractionation:

1.8-2Gy/day, 5day/wk, 5-6wks, total 50-70Gy

Question 25

What is your management and treatment options for a radiation ulcer?

Answer 25

* Etiology: fibroblast and endothelial dysfx * Hx: * local trauma/injury, recent infections/systemic illness, Hx of Rx * PE: depth, surrounding itssue involvement * Investigation * BIOPSY * CBC (anemia) Alb,electrolytes (nutritional asx) TREATMENT * wound care dressings w antimicrobials * correct systemic factors (malnutirtion Vit a,c Zn), anemia(Fe) * Hyperbaric Oxygeb (5x/wk) oxygen supplementation stimulates fibroblasts, halts progression of ulcer * Surgery if failed conservative * direct, skin graft, local not advised, regional/free

Question 26

What are geeral principles for reconstruction in a radiated field

Answer 26

* confirm no residual/ de novo malingnacy * debridement: non -viable tissue * bone recon with vascularied BG * ST recon/coverage of prosthesis with non-radiated well vascularized tissue (regional/free) * Pedicle non-radiated and anastomosis not non-radiated

Question 27

What treatment options would you recommend for breast reconstruction in patient with * previous radiation * mastectomy and post-op radiation NOT SURE ON THESE ANSWERS - check wi lipa

Answer 27

* Previous radiation: * autologous tissue (pedicled flap - non radiated, or free tissue with anastomiss in non-radiated field) * NOT alloplastic b/c * poor wound healing, risk implant expousre * capsular contracture * poor cosmetic result * Timing - wait until late phase of radiation changes \>6mths * Mastectomy + post-op Radiation * Delayed autologous recon preferred over immediate recon * less complications of fat necrosis, loss of flap volume