frostbites chemical burns electrical injury commisure burns
TRANSCRIPT
• 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