1- Environmental Emergencies Flashcards
What injury is associated w/ prolonged stationary posture, dehydration, wet clothings, lack of head/hand protection or footwear?
Frostbite
How is a frostbite injury classified?
By depth of injury and amount of tissues damage on appearance AFTER rewarming
Can freezing alone cause tissue death?
No, thawing also causes damage
The formation of arachidonic acid (promoting vasoconstriction), platelet aggregation (V/ATE), and subsequent ischemia, necrosis and gangrene are all part of what?
Thawing process of frostbite
What is the depth of freezing dependent on?
Temperature, velocity, and duration of exposure
Frostbite can occur anywhere is most common where?
Distal extremities (face, noses, ears, fingers, toes)
Pt presents with pale, waxy, hard and cold skin. Why dx are you concerning of and what is the initial tx?
Frostbite (clinical dx), tx w/ rewarming
What are the sx of first degree degree frostbite?
No blisters, numbness, central pallor w/ surrounding erythema, edema, desquamation, dysesthesia
What are the sx of 2nd degree frost bite?
Blisters of the skin w/ surround erythema and erythema
What are the sx of 3rd degree frost bite?
Tissue loss involving entire thickness of the skin, hemorrhagic blisters
What are the sx of 4th degree frost bite?
Tissue loss involving the entire thickness of the part, including deep structures, resulting in the loss of the part
What is the initial tx for frostbite?
Immersion in water b/w 101.5-102.2˚F until erythematous and pliable (20-30 min)
+/- IV opioids for pain (anticipated severe pain w/ rewarming
If pt w/ frostbite w/ cyanosis proximal to ITP joints, what imaging should you consider to assess circulation/tissue viability?
CTA or bone scan
If pt presents w/in 24hrs of frostbite injury w/ high risk of amputation and w/o any C/I what tx should you consider?
tPA followed by lovenox
After rewarming area of frostbite what is the next tx?
- Aloe cream 1 6 hrs w/ non-occlusive dressing
- Ibuprofen
ABX only if signs of infection
Td immunization if needed
What should not be done acutely after rewarming area of frost bite?
No blister or soft tissue debridement acutely
When can a pt w/ frostbite be d/c home?
Superficial frostbite
What are the d/c instructions for pt w/ superficial frostbite?
Ibuprofen, aloe, smoking cessation, close follow up
What is the tx course for deep tissue injuries associated w/ frost bite?
Admission + ortho/hang surgeon consults
Hypothermia is due to an involuntary drop in body temp below what?
95˚F
What are primary causes of hypothermia?
Due to exposure (wind, rain, water, snow)
What are secondary causes of hypothermia?
Lack of thermoregulation (alcoholism, DKA, meds, burns, shock, sepsis, cold IV infusions, newborns, NM disease)
Mild or HT 1 is classified by what body temps and sx?
Core temp 89.6-95˚F
Conscious, tachycardia, increased shivering
Mild or HT 2 is classified by what body temps and sx?
Core tempe 82.4-89.6˚F
Lethargy, bradycardia, loss of pupillary reflexes, decreased shivering
Mild or HT 3 is classified by what body temps and sx?
Core temp < 82.4˚F
Vital signs presents, unconscious, hypotension. pulmonary edema, rigidity
Mild or HT 4 is classified by what body temps and sx?
Core tempe 82.4-89.6˚F
Absent vital signs, cardiac arrests
What tool will assist in the dx of hypothermia?
Low reading thermometer (do not use oral or infrared TM thermometers)
Where should you take the temp in a conscious pt w/ hypothermia?
Rectal or bladder (no accurate if pt in rewarming)
If pt w/ severe hypothermia, what temperature location is recommended?
Esophageal temp probe
If pt w/ moderate to severe hypothermia what Labs should your order?
Insulin, ECG, CXR, BMP, CBC w/ diff
What hormone is ineffective below 86˚F?
INsulin
What impact does hypothermia have on glucose levels?
Initial hyperglycemia followed by normalization or hypoglycemia after rewarming
What will be masked on EKG in pt w/ hypothermia?
Hyperkalemia (masked until pt is rewarmed)
Why do you order a BMP for pt w/ hypothermia?
Lyte abns, cold blood prone to hemolysis
What will increase by 2% for every 1˚C drop in tempe?
HCT
What tests are recommended in pt w/ mod to severe hypothermia?
Coag studies, O2 sat, ABG
What is the tx for Mild HT 1?
Remove wet clothes, passive external warming, (warm drinks, cover w/ blankets), encourage active movements
What is the tx for moderate HT II?
Manage ABCs, avoid rough movements (may induce arrhythmias), active external and internal rewarming, +/- ET intubations, monitor for hypotension from rewarming
Why do pts tx for hypothermia have paradoxical drop in core temp while rewarming?
Cold blood from extremities is returning to core (rewarm core first to minimize risk)
What is th tx for severe HT III?
ABCs, active internal and external rewarming + pleural and peritoneal irrigation w/ warm saline, extracorporeal options, tx any arrhythmias
Extracorporeal options: hemodialysis, CP bypass, continuous AV rewarming
What tx is rarely successful at txing heart arrhythmias for HT II-III pt w/ core temp < 86˚F?
Defibrillation
What is the tx for HT IV?
CPR, prevent further heat loss/extracorporeal options, thoracic lavage w/ NS, ACLS protocol
How many cycles of advanced ACLS are reasonable to attempt before defering until core tempe is increased/pt improved?
3 cycles
Hypotension, lyte abn, rhabdomyolysis/multi organ failure (pulm, renal, neuro) are all complications of what?
Rewarming tx for hypothermia
What causes hypotension sx w/ rewarming?
Fluid shifts and dehydration
What is the 1st line tx for hypotension as a result of rewarming from hypothermia?
Isotonic crystalloid
What is the leading cause of death in young athletes in the US?
Heat emergencies
Cramps are associated w/ what environmental emergency
Heat
The following all result from what and cause what? - Intense muscle pain (w/o other signs of exertional heat stroke)
- “Salty sweater” (sweat w/ high salt concentration)
- Heavy sweating w/ hypotonic fluid replacement
- Lack of heat acclimation
Result from heat exertional illness, cause Heat cramps
What is the tx of heal illness/ cramps?
Rest in cool place, hydrate/replace Na loss (oral or IV), relax/stretch, future preventative measures
What will result secondary to to water and Na depletion?
Heat stress (exhaustion)
Sx of heat stress will include sx of heat cramps + what?
HA, N/V, dizziness, orthostatic hypotension
What + exam findings are concerning for heat stress?
Body temp normal/elevated (<104˚F), NO signs of CNS impairments
What labs should be ordered for pt in heat stress?
BMP (lyte abn), CBC (hemoconcentration common)
What is the tx for pt w/ heat stress?
- Remove from hot enviroment
2. Bolus infusion of IV fluids (1-2 L short term, 1.5 increase in maintenance fluids, NS while waiting for labs)
What is tx for pt w/ CHF or abn lytes heat stress?
Longer fluid replacements, possible admission
If pt is not responding w/in 30 minutes of fluid replacements and removal from hot environments what is the next tx?
External cooling until core temp reaches 102.2˚F
What exam findings are concerning for heat stroke?
Tempe > 104˚F & AMS
What is the progression of heat emergencies from least to most severe?
Heat cramps, heat stress/exhaustion, heat stroke
What is the tx goal for pt w/ heat stroke?
Cool quickly w/o inducing hypothermia (goal 102.2˚F)
Evaporative cooling, ice packs to axilla, neck, groin, immersive cooling, and invasive cooling are tx for what?
Heat stroke
What is evaporative cooling tx?
Remove clothes, spray skin w/ water, direct fan over pt
What is invasive cooling?
Cardiopulmonary bypass
What injury is common, usually accidental, and more common in men and young children?
Electrical injury
What is the effect of direct contact w/ electrical current?
Conversion of electrical to thermal energy along w/ blunt mechanical trauma that can result in tissue or organ damage
The physiological effect of electric shock are dependent on what?
amount, duration, type of current
What current is more common in homes and short distance power lines?
Alternating current (AC)
What current is found in lightning, batteries and long distance power lines?
Direct current (DC)
What type of current will cause repetitive muscle contraction w/ pt can not let go of electrical sources?
AC current
What type of current w/ cause a single muscle spasm that will hurl the victim away from the current source?
DC (shorten duration of exposure vs AC current)
What current will cause an injury w/ an entrance and exit wound?
DC
What current will cause an injury w/ an entrance wound only?
AC
Via what mechanisms does electricity induce injury? (3)
- Direct tissue damage from electrical energy
- Tissue damage from thermal energy
- Mechanical injury from trauma induced by fall or muscle contraction
In what class of electrical injury does the body become part of the circuit w/ entry and exit wounds?
Classic Injury
- Wounds do no predict path of current
- Degree of internal thermal injury can be underestimated
In what class of electrical injury does the current arc strike skin but does not enter the body?
Flash (arc) Injury
In what class of electrical injury does clothing catch fire in the presence of an electrical source?
Flame injury
In what class of electrical injury is a DC current shock wave transmitted through the body resulting in mechanical trauma and Lichtenberg figures (flowers)?
Lightening injury
Electrical injuries can present w/ what cardiac abnormality?
Cardiac dysrhythmias
If pt that has sustained a low voltage electrical injury is asx and has a normal EKG in the ED, will they typically develop a dysrhythmia later?
No
*Fatalities due to Vfib or asystole typically occur prior to arrival in ED
What type of injury is common following a high voltage electrical injury?
Neuro injury (CNS, spinal cord, PNS) & Vascular and muscle injury
*LOC may be followed by seizures, focal neuro deficits may be present
If pt touched the power source resulting in an electrical injury, how might they present?
Cutaneous burns, paresthesias (immediate or delayed)
What are the sx of an electrical burn?
CNS injury (CNS, spinal cord, PNS), cutaneous burns, orthopedic injuries (due to muscle contractions/falls), vascular and muscle injury (risk of compartment syndrome)
What is the tx for pt that has sustained a high voltage (≤600 VAC) electrical injury?
TX as trauma -> ABCs, fast exam, labs, EKG, CT head/spine, XR spine, XR injured extremities
ADMIT (even if no apparent injury/asx)
What is the tx for pt that has sustained a low voltage (<240 V AC) electrical injury?
ECG, thorough exam, no labs or imaging required unless pt is symptomatic or w/ abn finding
D/C home if normal ECG and physical exam
What spider bite will result in pain w/in 3 hrs of bite and systemic effect w/in 4-6 hrs?
Black widow
Is this a mild moderate or sever envenomation by a black widow?
Local wound, +/- spasm adjacent to site?
Mild
Is this a mild moderate or sever envenomation by a black widow?
Spasm and muscle pain in bitten extremity, back, chest, and abd w/ adjacent diaphoresis?
Moderate
Is this a mild moderate or sever envenomation by a black widow?
Severe pain and spam and systemic features (N/V, HA, tachycardia, HTN)
Severe
What spider bite will result in mild to intense pain and itching 2-8 hrs following bite w/ ulcer and necrosis 1+ wk later?
Brown recluse
Pt presents following the bite of a spider. On exam you note, depressed grey macule, pale grey color w/ eroded center and halo of inflammation and hemorrhage. What do you suspect?
Brown recluse bite
T or F: A Brown recluse bite will frequently result in a systemic sx?
FALSE
Infrequent systemic sx (mailse, n/v, fever) and rarely severe systemic sx (rhabdo, DIC, hemolytic anemia)
Are systemic sx of a brown recluse bite more common in children or adults?
Children
What is needed for the dx of spider bite?
- Spider observed inflicting the bite/collected/identified
2. Skin lesion/systemic finding typically associated w/ type of spider bite present
What is the general tx for a spider bite?
Wound cleaning, tetanus PRN, tx secondary skin infection PRN
What is the tx for black widow bite?
Self limited, duration of sx typically 24-48 hrs
Supportive care: analgesics/opioid, muscle relaxants, anti-venom if severe (must consult toxicologist)
Monitor for secondary infection
What is the tx for a brown recluse bite?
Self limited, wound improves w/in 5-10 days
Monitor for secondary infection
Debridement no proven beneficial, no anti-venom in US
What venomous scorpion is common to AZ, NM, and CA?
Bark spider
When treating scorpion sting, what precaution should you take?
Treat all as potentially dangerous until lack of signs/sx indicate otherwise
What are the sx of a bark scorpion bite?
Initial sx = pain and paresthesia to involved area, swelling usually absent, few skin changes
What are the sx of an adult bit by bark scorpion?
Tachycardia, HTN, tachypnea, weakness, muscle spasm/fasciculations and respiratory difficulty is rare
What are the sx of a child bit by a bark scorpion?
Restlessness, anxiety, agitation, muscle spasm, abnormal, random head, neck, eye movements, weakness, diaphoresis, excessive drooling/salivation, respiratory difficult is rare.
Death has resulted in children < 6
What is the tx for a bark scorpion bite?
Supportive care, monitor for 8-12 hrs after sting, antivenom available for severe sx that are unresponsive to supportive care, tetanus prophylaxis
What snake has a triangular shaped head, cat like pupils and foldable fangs?
Rattlesnake
What is the prehospital tx for a rattlesnake bite?
Keep pt relaxed/limit movements, remove tight clothing/jewelry from bitten limb, seek emergency care ASAP
What are the clinical features of rattle snake bite?
Fang marks, local tissue injury, fibrinolysis, thrombocytopenia, systemic effects (unstable vs AMS)
We treat all pts w/ rattlesnake bites that develop progressive signs and sx ASAP. What are the progressing sx?
Worsening of local injury, abnormal lab results (decreasing platelet count, prolonged PPT, decreased fibrinogen), systemic manifestations
What is the initial control of a rattlesnake bite at hospital?
Supportive care, antivenom (given in ICU), clean wound, prevent progression of sx
What is rattlesnake antivenom administered in ICU?
Risk of anaphylaxis and/or develop serum sickness (fever, rash, arthralgia)
What is the tx for pt that develops serum sickness to rattlesnake antivenom?
Oral prednisone 1 mg/kg/d x 1-2 wks
How can you identify a coral snake?
Red, black, yellow rings. Red and yellow rings touch
What is the tx for pt bitten by coral snake?
Admit pt and give antivenom ASAP
Supportive care
Tetanus prophylaxis
What is the concern w/ coral snake venom?
Venom in a neurotoxin that does not cause marked local tissue injury and can take hours for effects to manifest
What lizard requires a prolonged bite for envenomation and has a strong bite grip that can result in fractures and deep tissue injuries?
Gila monster
What is the tx for a gila monster bite?
Remove lizard, clean wound, remove any remaining teeth, XR for fx, Td and ABX prophylaxis, admit
*No anti-venom available
What are the sx of a gila monster envenomation?
Weakness, light-headedness, paresthesia, diaphoresis, HTN
What injuries can result due to pressure changes during descent while diving?
Barotitis, sinus barotrauma, inner ear barotrauma
What barotrauma is a result of the an occluded ear canal (either by cerumen or ear plugs) resulting in an inability to equalize pressure b/w TM and external canal during descent?
Barotitis, aka ear squeeze –> conductive hearing loss, vertigo, ruptured TM
What are the sx of barotitis?
Range of sx
Pain/fullness in ear w/o otoscopic changes to hemorrhage w/in TM or middle ear (hemotympanum)
What is the concern w/ barotitis is TM ruptures?
Water can flow into ear –> pain relief BUT can induce vertigo, panic, drowning/other injury
What is the tx for barotitis?
Decongestant, +/- ABX if TM rupture, secondary infection
What barotrauma is a results if the sinus ostia is occluded and air can’t enter sinuses during descent to equalize pressure?
Sinus barotrauma –> submucosal hemorrhage (blood bleeding into diving mask), stripping of sinus mucosa from bone
What are the sx of sinus barotrauma?
pain over affected sinus, possible epistaxis
What is the tx for sinus barotrauma?
Decongestant, +/- ABX
ENT consult based on severity
What barotrauma is a result of a diver attempting a forceful valsalva maneuver to equalizer pressure in middle ear against an occluded eustachian tube?
Inner ear barotrauma –> rupture of oval window and tearing of vestibular membrane
What are the sx of inner ear barotrauma?
sudden onset f sensorineural hearing loss, tinnitus, severe vertig
What is the tx for inner ear barotrauma?
Stat ENT consult, elevated head of bed, no nose blowing, antivertigo meds
Is barotrauma of descent of ascent for severe?
Ascent
Barotrauma of ascent results in what injuries?
Pulmonary barotrauma, arterial gas embolism
What is the pathophys for barotrauma of ascent?
Secondary to rapid or uncontrolled ascent while diving, w/ rapid ascent, over expansion of air injury can occur, pressure difference becomes so great the tissues rupture and air is introduced into tissues and spaces
What are RF for barotrauma injuries of ascent?
Breath holding while ascending, hx of obstructive airway disease
What barotrauma of ascent will result in pulmonary overinflation or burst lung syndrome?
Pulmonary barotrauma
What are the sx of pulmonary barotrauma?
Dyspnea, chest pain, subQ air, PTX
What is the pt for pulmonary barotrauma?
Pnuemomediastimun requires sx care, if PTX may require further interventions
Any neurologic sx in the setting of documented pulmonary barotrauma must be treated as what?
Arterial gas embolism
What are the sx of arterial gas embolism?
Neurologic sx occurring immediately after an uncontrolled, rapid ascent while diving
What is the tx for arterial gas embolism?
ABCs, high flow O2, IV hydration, hyperbaric oxygen, stat neuro consul
