• Frostbites

• Chemical burns

• Electrical injury

• Commisure burns

Frostbites

Frostbites

• Military injury in the past– “Trench foot”– “Tropical immersion foot"

• Rise in homelessness

• Rise in outdoor activities and sports

Frostbites - Epidemiology

• Ages 30-49

• Male : Female 10 : 1

• Predisposing factors -– Alcohol consumption (46%)– Motor vehicle trauma (19%) or

failure (15%)– Psychiatric illness (17%)

Other comorbidities:– Homelessness – Improper clothing– Atherosclerosis– Diabetes– Smoking– Wound infection

Frostbites - Epidemiology

Cold Injury – Hypothermia

• Can occur in any weather.

• Mechanisms of heat loss :– Radiation (55-65%)– Evaporation– Respiration – Conduction and convection (3-15%)

)20-30%(

Hypothermia - Treatment

• Field – passive rewarming• Hospital – active rewarming

– Surface rewarming– Warm IV fluids, peritoneal irrigation, warm air

inhalation• CBC, PT/PTT, Chem7, ABG ,Tox. Screen• Arrhythmias

“No patient is dead until warm and dead”.

Frostbites – Where?

Most commonly affected sites

Hands and feet (90%)

Ears

Nose

Cheeks

Penis

Frostbites - Pathophysiology

• Tissue freezing

• Hypoxia

• Release of inflammatory mediators

Frostbites – PathophysiologyFreezing

• Extracellular ice crystal formation.

• Intracellular ice crystals.

• Intracellular dehydration.

• Denaturation of membrane lipid-protein complexes.

• “The hunting reaction”

• Local vasoconstriction

• Acidosis

• Increased blood viscosity

• Thrombosis

Frostbites – PathophysiologyHypoxia

• Release of PGF2 and TXA2

• Cycles of warming and freezing increase mediator release

• Cell death

• Exacerbation of dermal vasoconstriction, aggregation, thrombosis, hypoxia…

Frostbites – PathophysiologyInflammation

Frostbites

Degree of irreversability is related to the length of time the tissue remains frozen more than to absolute temperature

Frostbites – Clinical ManifestationsPost Rewarming!!!

I White plaque + erythema

II Clear/milky fluid blisters

III Hemorrhagic blisters

IV Necrosis – non blanching

cyanosis, wooden feeling

Superficial

Deep

Frostbite - Symptoms

• Numbness pain (48-72 h) tingling and electric currents (1wk- 6mo)

• Sensory loss, increased cold sesitivity, hyperhydrosis

• Rare – growth plate disturbences, osteoarthritis, chronic pain, heterotopic calcifications

Frostbites - Radiology• X-Ray

– fragmantation, distraction, disappearence– Epiphyseal fusion

• Arteriography – Early flow slowing– Residual occlusion after rewarming– Vasodilatior addition – better predictor

• Tc scan – Assess tissue viability– Allows earlier debridment

• MRI/MRA– Visualization of occluded vessels– Demarcation line of ischamic soft tissue

Frostbites - Radiology

Frostbite – TreatmentField Care

• Rapid transport to care center

• Warm only if refreezing can be prevented or hospital arrival > 2 hours

• Splint, bulky and loose padding

• DO NOT rub extremity

• NO alcohol and smoking

Frostbite – TreatmentAcute Hospital Care

• Admit to hospital

• Warm water immersion 40–42ºc, 15-30 min

• Debridment of clear blisters, aloe vera cream

• Splint, elevation, loose dressing

• Ibuprofen 12 mg/kg/d, 400 mg q12h

• IM dT

• IV PCN 5x105 U q6h, for 72 hours

• IV MO

Frostbite – TreatmentAcute Hospital Care

• Hydrotherapy, physiotherapy• Medical tx

– Dextran, anticoagulation, vasodalation - not proven

– Thrombolysis, delayed sympathectomy– promising

• Compartment syndrome escharotomy, fasciotomy

• Infection control limited debridment• Amputation only after 22-45 days

Frostbite – TreatmentLong Term Hospital Care

Frostbites – early treatment

• Minimize expectant duration

• Maximize tissue saved

• 48 hrs triple-phase bone scan identifies areas of bony nonperfusion.

• Early debridmant of “high metabolizing” tissue

• Transfer of vascularized tissue to supply “low metabolizing” tissues

Frostbites – early treatment

Frostbite – early treatment