Environmental emergencies Flashcards
what is Heat Illnesses?
At risk pts?
- one is unable to adequately regulate body temperature
- Young/elderly, Obese, Chronic physical/mental illness, Impaired by drugs/ETOH, Anyone denied access to hydration/nutrition
Mild swelling of dependent extremities due to heat exposure
Results from muscular and cutaneous vasodilation combined with venous stasis
dx?
mgmt?
- heat edema
- self-limiting with elevation, rest, cooling, oral rehydration
- Syncope after exertion in the heat
- results from vasodilation leading to intravascular volume redistribution
- Core temp is normal, skin is cool and diaphoretic, weak pulse, transient hypotension
dx? mgmt?
- Heat Syncope
- R/o other causes of syncope (hypoglycemia, arrhythmias, and fixed myocardial or cerebrovascular lesions)
- supine with legs elevated, remove from heat, (+/-) external cooling, IV/oral rehydration
- DC after tx and pt ed
painful spasms of voluntary muscles of the abdomen and extremities resulting from salt depletion
core temp normal or slightly elevated, (+/-) muscle fasciculations, skin is moist or dry and cool or warm
dx?
w/u?
mgmt?
- Heat Cramps
- w/u rarely needed - possible hemoceoncetration, low-nml Na, +/- low K+ & Mg
- Remove from heat and start external cooling, PO lyte (pedialyte or Gatorade) or IV NS, Replace K+ and Mg if needed
- DC home, Rest x 1-3 d - avoid physical exertion and heat exposure
inability to maintain adequate CO d/t strenuous physical exercise and environmental heat stress
Rapidly evolves to heat stroke if no intervention
dx?
Heat Exhaustion
2 types of Heat Exhaustion
often a combination
- Hypernatremic (water loss): results from lack of water access
- Hyponatremic (sodium loss): fluid loss replaced with water only
- Temperature often mildly elevated - usually will not exceed 40°C (104°F)
- Diaphoresis, HA, N/V, malaise, weakness,
- Muscle cramps, dizziness, (+/-) dark urine
- Tachycardia, hypotension
- No evidence of CNS dysfunction
dx?
heat exhaustion
difference between heat exhaustion vs heat stroke?
Heat exhaustion does NOT have evidence of CNS dysfunction
w/u and mgmt for heat exhaustion
- BMP, UA, additional labs depending on presentation (CK, LFT, ABG, EKG)
- Remove from heat, (+/-) external cooling, PO lytes if tolerable; Alt: IV NS or LR; hypertonic saline if marked hyponatremia d/t water intoxication
criteria to admit for heat exhaustion
- moderate-to-severe symptoms
- comorbid illnesses
- patients at extremes of age
- lab abnormalities - Elevated CPK, creatinine, LFTs, cardiac abnormalities, hyponatremia, persistent acidosis
- social concerns
Home: mild cases who don’t meet criteria below
- dysfunction of the heat regulating mechanism with hyperthermia (core body temp >104°F) and end-organ damage
- Cardiovascular collapse due to vascular volume loss
dx?
heat stroke
what structures are most senstive to heat stress? (4)
- Neural tissue
- hepatocytes
- nephrons
- vascular endothelium
2 types of heat stroke
- exertional (rapid onset)
- non-exertional (slow onset)
after a hot day a pt is now presenting with:
- HA, dizziness, nausea, diarrhea, visual disturbances
- Skin is hot, flushed, usually dry
- CV: rapid, bounding pulse, hypotension indicates CV collapse
- Neuro: confusion, seizure, delirium, ataxia, coma
- hematuria, hematemesis, bruising, petechiae, and oozing at sites of venipuncture
dx?
hematuria, hematemesis, etc are signs of what?
- heat stroke
- signs of DIC
ddx heat stroke
- Infectious: sepsis, meningitis, encephalitis, malaria, typhoid, tetanus
- Endocrine: DKA, thyroid storm
- Neuro: CVA, status epilepticus
- Other: toxin exposure, serotonin syndrome, neuroleptic malignant syndrome, and anticholinergic toxicity
w/u for heat stroke
- CBC, PT/PTT - evidence of hemoconcentration and DIC
- CMP - reassess electrolytes every hour
- hyperkalemia is seen with ARF secondary to rhabdomyolysis - Phosphate (hypophosphatemia)
- UA - concentrated, with protein, myoglobin and tubular casts
- CK
- EKG
- CXR
mgmt heat stroke
- Rapid cooling - Ice water submersion (preferred method)
- severe shivering - IV BZD
- Continuous temp (rectal) - DC when 101.5-102℉
- If unresponsive: internal lavage - peritoneal, gastric, bladder, and/or rectal
- CV support - IV fluids
- 1-2 L bolus NS if hypotension or rhabdo
- fluid rate high enough to maintain UO - Goal UO: 50–100 mL/h
- O2 if needed
- Significant AMS - ventilate/intubate
- Admit to ICU if hemodynamic instability, severe LFT elevation or rhabdomyolysis; All others admit to general floor (med/surg)
frostbite - Initial clinical findings before re-warming
- Mild: Paresthesias, pruritus of tissue involved; loss of sensation and fine motor control
- Mod-Severe: decreased ROM, blister formation, edema, tissue appears white, firm/hard, cool to touch
frostbite - clinical findings after warming
- Stinging, burning, aching, throbbing, tenderness
- Tissue discoloration, loss of elasticity and mobility
- Profound edema, hemorrhagic blisters, necrosis, gangrene
when to assess severity of frostbite?
after rewarming
Degrees of frostbite - describe each
- 1st degree: erythema and edema without blister, skin peeling
- 2nd degree: serous filled blister
- 3rd degree: skin necrosis: hemorrhagic blister with subcutaneous involvement
- 4th degree: full-thickness (includes bone), non-blanching cyanosis; dry, black mummified eschar formation; loss or deformity of body part
mgmt for frostbite
Tx as burn
- tx systemic hypothermia before frostbite
- Avoid partial rewarming/refreezing
-
Rapid rewarming in circulating water at 98.6–102.2°F
- 15-60 min; until red–purple color appears and skin becomes pliable - allow skin to air dry
- can be painful - parenteral NSAID/opiates - Warm oral/IV fluids if evidence of hypovolemia
- Extremity/Wound Care - aloe q6h, consult/refer for superficial dead tissue in a whirlpool BID x 3 wks
- splint + elevate limb
- tetanus
disposition for frostbite
- Home: limited area with only 1st degree injury
- Hospital: extensive area of 1st degree and all 2nd, 3rd, 4th degree
Long-term sequelaes from frostbite
- Cold sensitivity
- loss of sensation
- hyperhidrosis
- loss of digit/limb