• 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%)
Frostbites - Epidemiology
Other comorbidities:
–
–
–
–
–
–
Homelessness
Improper clothing
Atherosclerosis
Diabetes
Smoking
Wound infection
Cold Injury – Hypothermia
• Can occur in any weather.
• Mechanisms of heat loss :
–
–
–
–
Radiation (55-65%)
Evaporation
(20-30%)
Respiration
Conduction and convection (3-15%)
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 – Pathophysiology
Freezing
• Extracellular ice crystal
formation.
• Intracellular ice crystals.
• Intracellular dehydration.
• Denaturation of membrane lipidprotein complexes.
Frostbites – Pathophysiology
Hypoxia
•
•
•
•
•
“The hunting reaction”
Local vasoconstriction
Acidosis
Increased blood viscosity
Thrombosis
Frostbites – Pathophysiology
Inflammation
• Release of PGF2 and TXA2
• Cycles of warming and freezing increase
mediator release
• Cell death
• Exacerbation of dermal vasoconstriction,
aggregation, thrombosis, hypoxia…
Frostbites
Degree of irreversability is related
to the length of time the tissue
remains frozen more than to
absolute temperature
Frostbites – Clinical Manifestations
Post Rewarming !!!
I White plaque + erythema
Superficial
II Clear/milky fluid blisters
III Hemorrhagic blisters
IV Necrosis – non blanching
cyanosis, wooden feeling
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
Frostbites - Radiology
• Tc scan
– Assess tissue viability
– Allows earlier debridment
• MRI/MRA
– Visualization of occluded vessels
– Demarcation line of ischamic soft tissue
Frostbite – Treatment
Field 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 – Treatment
Acute Hospital Care
• Admit to hospital
• Warm water immersion 40–42ºc, 15-30
min
• Debridment of clear blisters, aloe vera
cream
• Splint, elevation, loose dressing
Frostbite – Treatment
Acute Hospital Care
•
•
•
•
Ibuprofen 12 mg/kg/d, 400 mg q12h
IM dT
IV PCN 5x105 U q6h, for 72 hours
IV MO
Frostbite – Treatment
Long Term 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
Frostbites – early treatment
• Minimize expectant duration
• Maximize tissue saved
• 48 hrs triple-phase bone scan identifies
areas of bony nonperfusion.
Frostbites – early treatment
• Early debridmant of “high
metabolizing” tissue
• Transfer of vascularized tissue to
supply “low metabolizing” tissues
Frostbite – early treatment