Ross Enviro 2nd Part Flashcards
T/F: Pernio and chilblains are freezing injuries
False - NON-freezing injuries caused by long term intermittent exposure to damp
How will a pt with pernio or chilblains most likely present?
- Pain remains
- Paresthesias, pain with any pressure on foot
- Shoes are intolerable
Does chilblain or pernio result in long term sequelae?
Only Pernio - chronic pain, inability to walk
How do you treat chilblain or pernio?
- Warm
- Dry
- NO massage
- Nicardipine and occassionally steroids
What is trench foot due to?
Prolonged immersion in cold water leading
In trench foot the affected parts are first cold and anesthetic then what occurs?
Hyperemia with burning pain
What are key PE findings in trench foot?
The foot is pale and mottled and ulcers often form
Does Pernio or trench foot have a worse pathology?
Trench foot - can progress to localized cellulitis –> sepsis
Who is at risk for getting trench foot?
Military (majority)
Snowmakers
Raft operators
What are symptoms of trench foot?
- Hyperhidrosis
- Intolerance to cold
- Pain - especially with the rewarming phase
What are sequelae of trench foot?
- dysfunction of extremity
- cold sensitivity
- hyperhidrosis - leading to chronic fungal infx
- Raynaud’s
- swelling, chronic pain
What condition can lead to cryoglobulins forming, leading to hives and rashes?
Trench foot
T/F: frostbite is a freezing injury where tissue actually freezes
True
What is the histopathology of frost bite?
Endothelial damage -> arachidonic acid -> tissue ischemia
- Neurons damaged 1st
- Muscle then
- Endothelial cells
What are the 3 stages of frost bite?
- Pre-freeze
- Freeze-thaw
- Progressive microvascular collapse
In what stage of frostbite is there superficial tissue cooling, increased viscosity, and endothelium damage?
Pre-freeze
In what stage of frostbite is there extracellular fluid ice crystal formation, water diapedisis, and cell-membrane rupture?
Freeze-thaw phase
In what stage of frostbite is there sludge, microthrombi, and tissues are denied nutrients?
Progressive microvascular collapse
Acral skin structures, fingers, toes, ears and nose contain many ___ ___ they are able to constrict to facilitate shunting of blood
arteriovenous anastomoses
What are the 3 zones of cold injury?
- Zone of coagulation
- Zone of stasis
- Zone of hyperemia
In what zone of cold injury is damage irreversible?
Zone of coagulation
In what zones of cold injury is damage reversible?
- Zone of stasis
- Zone of hyperemia
In what degree of frostbite will you see partial skin freezing, mild edema, no blister, and some stinging with rewarming?
First degree (frostnip)
In what degree of frostbite will you see full thickness skin freezing and blisters that extend to the end of the digit forming black eschars?
Second degree
In what degree of frostbite is there injury to subdermal tissues, skin necrosis, and the extremity feels like a “block of wood”?
Third degree
In what degree of frostbite is there extension to subcutaneous tissue, muscle, bone, and tendons, mottled skin, and deep dry black mummified escar?
Fourth degree
What is the treatment for frostbite?
- Avoid thaw and refreeze
- Remove wet, constrictive clothing
- Avoid slow defrost
- Rapid thaw with circulating water at 104 degrees
Your friend was staying overnight in a tent, drinking a lot of alcohol of course, and his hand wasn’t in his sleeping bag and in the snow all night. You see his hand has blisters forming. What do you remember to do with your friend?
KEEP them COLD until you can gurantee warming and STAYING warm
What do you always want to remember to check on with a frostbite patient?
TETANUS!
*tetanus spores can live in freezing cold environments
What are higher level of care treatments for frostbite?
- Vasodilators: Iloprost, Nitroglycerin, Reserpine (decrease amputation)
- local tPA
- LMWD (dextrose) ONLY if the other two options are not available
Over half of frostbite patients will have what sequelae?
- hypersensitvity to cold
- ongoing numbness
T/F: Admit all but most minor frostbite patients
True
A pt presents with strong muscle contractions that occur at rest and electrolyte deficiency. How would you treat this patient?
Pt has Heat Cramps
Tx: give electrolytes (salt)
What is miliaria rubra?
Skin rash occurring in hot temperatures often found in small children (rupture of blocked sweat glands)
What symptoms are characteristic of heat exhaustion?
- Temp <40.5 (104)
- fatigue, weakness
- N/V
- HA
- muscle cramps, myalgia
- irritability
What is heat exhaustion due to?
Either dehydration (primary water loss) or sweating with hypotonic rehydration (primary sodium loss) depletion
What is the treatment for heat exhaustion?
- Minor: check electrolytes, consider CPK check, orally hydrate, send home
- Several Symptoms: check electrolytes, calculate water deficit, replace deficit over 48 hrs, usually admit
What is the hallmark sign of heat stroke?
CNS symptoms (bizarre behavior, hallucinations, AMS)
In what condition is a patient’s temperature >104 degrees?
Heat stroke
Who are at the greatest risk of heat stroke?
- Elderly (due to meds - BBs)
- Neonates (lack thermoregulatory systems)
- Psych pts
- Drug abuse
How do you manage heat stroke?
- Must have core thermomter in place (rectal or foley)
- Cool down by conduction (blanket, ice packs)
- Dec Temp by evaporation - wet them down or water immersion
Are antipyretics helpful in heat stroke?
NO
What is the MCC of hyperthermia?
Neuroleptic Malignant Syndrome
Neuroleptic Malignant Syndrome is characterized by what symptoms?
Extrapyramidal
- catatonia - AMS
- muscle rigidity (lead pipe)
- parkinsonism, masked facies, tremors, akinesia
What does autonomic dysfunction that occurs in Neuroleptic Malignant Syndrome cause?
- Labile BP
- diaphoresis
- urinary incontinence
What is the treatment for Neuroleptic Malignant Syndrome?
- Dantroline or Bromocriptine
- Benzodiazapines - for rigidity
On PE how can you distinguish NMS from heat stroke?
- diaphoresis
- rigidity
- liver function tests (abnl in heat stroke)
Serotonin syndrome presents similarly to Neuroleptic Malginancy Syndrome. What symptoms are characteristic of serotonin syndrome?
- mycoclonus, hyperreflexia
- AMS
- fever, N/V
What is the treament for serotonin syndrome?
Cyproheptadine
If a pt presents with lictenberg figures, dec respiratory rate, and cardiac asystole what injury have they sustained?
Lightning injury
What can form 2-3 years after a lightning injury?
Delayed cataract
What is keraunoparalysis and how do you treat it?
Vascular spasm usually in the lower legs, cold mottled skin, and look pulseless
Usually resolves spontaneously
What is the work up for a lightning injury?
- CBC, BMP, CPK, UA, urine myoglobin, trop, look for DIC
- EKG
- look for blunt trauma, mental status changes, and cardiac arrhythmia
Dispo: asympto w/ nl EKG = d/c
What could you see on an EKG if a patient sustained a lightning injury?
Prolonged QT or elevated ST
