Week 10- Environmental Emergencies Flashcards
Who is most likely to DROWN?
Youth < 5 years of age
Males with drug or alcohol intoxication
Disorders that cause LOC ex. Seizures
What are the two types of drownings described as?
fatal or non fatal
Define: drowning?
the process of experiencing respiratory impairment from submersion or immersion in a liquid
Define: submersion?
the act of being completely covered by liquid
Define: immersion?
being partly covered by a liquid (in medical terms this usually includes the face)
Define: thrashing?
is depicted often in media but most drownings are silent /motionless
PATHO OF DROWNING
How fast do pts lose consciousness after being underwater holding their breath?
2 minutes
PATHO OF DROWNING
PRIOR to loss of consciousness, what happens underwater to the pt when drowning?
gasping, coughing causing swallowing of large amounts of water
PATHO OF DROWNING
Once waters enters the pharynx and/or trachea, the victim will suffer from _____ and this can be permanent or temporary.
laryngospasm
PATHO OF DROWNING
If the spasm is permanent, there will be NO aspiration. True or FALSE?
TRUE
PATHO OF DROWNING
When fluid enters the lungs, what 2 things happen that cause cardiac arrest?
hypercapnia and hypoxia causing cardiac arrest
PATHO OF DROWNING
When does brain damage occur after LOC?
4-6 mins
PATHO OF DROWNING
What is the progression of electrical heart activity? (heart rhythms)
normally tachy, brady, PEA and asystole
PATHO OF DROWNING
What is the difference between survivability saltwater and freshwater in the case of drowning?
there no difference
What type of water causes PULMONARY INFECTIONS?
What care do they need?
polluted water/sewage water
- they are gonna need ANTIBIOTICS
Aspiration of fluid can lead to…
decrease compliance and hard to ventilate, water in lungs so hard to manage airway
patients can present with non cardiogenic pulmonary edema (due to fluid overload on initial presentation)
ARDS (acute resp distress syndrome) in later stages due to surfactant washout
If someone drowns in COLD water, what does it trigger in the body?
trigger the mammalian diving reflex causing bradycardia, peripheral vasocosntriction and reduced O2 demand, prounced more in peds who have a greater o2 carrying capacity and cool mcuh faster due to large TSBA
Smalls amounts of aspirated water can be…
reabsorbed in vasculature or
can cause decrease in lung compliance,
loss of surfactant,
atelectasis (death of alveoli) and
hypoxia.
What do we do to make ventilations GOOD? In a drowning patient?
PEEP valves keep the alveoli open
Would you let a drowning pt refuse transport?
NO. because it worsens over time!!
What is ARDS?
acute respiratory distress syndrome
What happens to the lungs during ARDS?
A cascade of processes impacting avelio/capillaries causing
increase capillary permeability,
leading to non-cardiogenic pulmonary edema (from loss of protein) decreased surfactant
This transitions to atelectasis,
decreased lung capacity, ventilation/perfusion mismatch (if only one lung is impacted it will not be ventilated but still perfused)
and hypoxia
fluid goes into the alveloi delayes gas exchange
How do you manage drowning patients?
HISTORY GATHERING:
Need to know the duration of submersion.
Need to know TYPE of water
You are not dead until……..
you are warm and dead
What type of cardiac arrest is a drowning?
general medical cardiac arrest (unless hypothermic)
Do we need SMR for drowning pts?
assess the need for it.
When diving, and the person goes DOWN…. pressure goes?
UPPPPPPP
What is BOYLES LAW?
at constant temperature, volume of gas is inversely proportional to its pressure
What is dalton’s law?
the total pressure of a mixture of gases is the sum of the partial pressures of each gas
What is Henry’s Law?
at constant temperature, the amount of has dissolved ina liquid is proptional to the partial pressur of gas above the liquid
ex- soda can!!
What is barotrauma?
physical tissue damage caused by a pressure difference between an unvented space inside the body and surronding gas or fluid. Shear or overstretching of tissues.
it can occur in any gas filled space but often occurs:
- middle ear sinuses,
- GI system
- lungs
As long as a diver is able to equilibrate (pop ears) there should be no tissue, but if there is a blockage in ear for instance this can lead to barotrauma, true or false?
trueeee
What are 4 examples of barotrauma conditions?
typamic membrane rupture
tinnitus
vertigo
nausea and vomit
What is pulmonary overpressurization syndrome and air emolism?
when a diver makes his scent there can be air trapped in the lungs
- breath holding
- bronchospasm
- mucus plugs
What are the dangers of POPS and air emolism?
can cause alevolar rutpure
pts can present with dyspnea, plueritic pain, sub q emphysema or pnuemothroax
What is an air embolism?
when a diver makes his ascent there can be air trapped within the lungs, causing damage to the tissue and forcing air into circulation.
can be arterial or pulmonary circulation and most often are MULTIPLE bubbles varying sizes that can impact cereberal, cardiac or pulmonary blood flow.
What is decompression sickness (the BENDS)?
occurs when nitrogen is compressed in tissues/blood from increase pressure when diving turns back into gas bubbles when surfacing because it cannot be exhaled fast enough.
due to porr tissue perfusion, it can cuase joint pain and also affect the spinal cord
can be minor or cause embolism or CVA type symptoms
can occur within 1-36hours after dive, and is caused when surfacing TOOO QUICKLLLYYY - if you are surfacing slowly, the nitrogen will release slowly and not form bubbles
What do decompression sickness patients need?
high flow O2 and transport hyperbaric chambers if possible
What is nitrogen narcosis?
due to increased pressures, normally deeper dive (75-100ft) nitrogen becomes dissolved in blood and passes the blood brain barrier!!!!!!!!!!!!
What does nitrogen act simarly to?
alcohol causing the diver to make poor decisions during the dive. this can cause injury or death if impairment is enough to remove respirator
What is thermoregulation?
The body’s thermoregulatory center is located in the anterior hypothalamus and receives information from both peripheral and central temperature receptors.
What is the body’s normal core temperature?
37 degrees celcius
What are the two subtypes of thermoreceptors?
cold and warmth
What are peripheral receptors?
skin, muscles and mucous membranes and there is more cold than warm receptors peripherally - COLD!!
What are central receptors?
great veins, spinal cord, hypothalamus and viscera, there are more warm receptors than cold - WARM ONES
Internal and External Factors
Metabolism?
Define it.
chemical reactions produce heat (excerise you produce more heat)
Internal and External Factors
Radiation?
Define it.
transfer of heat via electromagnetic waves (SUN)
Internal and External Factors
Conduction?
Define it.
transfer of heat from hotter to colder object (soaked clothing in cold environement)
Internal and External Factors
Convection?
Define it.
loss of heat from moving air (blowing on hot food to cool it down)
Internal and External Factors
Evaporation?
Define it.
conversion of liquid to gas ie. water is vapourized to skin surface causing sweating
Internal and External Factors:
Respirations:
Define it.
Respirations also plays a role in thermoregulation as warm air is expelled during exhalation
What is thermogenesis?
the prodcution of heat for the body via the sympathetic nervous system
How does thermogensis work?
The body shunts blood from periphery to core via vasoconstriction, and this causes piloerection. (goosebumps)
When hair is upright it traps more air increasing insulation and closes skin pores, limiting sweating.
When maximal vasoconstriction has occurred the body will signal the need for involuntary shivering.
Lastly, the thyroid will release hormones to increase metabolic rate in cells and this includes brown fat that contains many mitochondria, and burn fat to produce heat when signalled.
What is thermolysis?
release of stored heat from the body, via the parasympathetic nervous system via peripheral vasodilation, allowing more heat to be released, and this causes diaphoresis.
In both thermogensis and thermolysis, how is temperature lost or gained?
As you will note in either form, blood is how temperature is lost or gained, therefore any decrease in cardiac output will limit the body’s ability to maintain a constant temperature.
Hyperthermia can occur from…
- environmental causes
- +- physical exertion
- failure of the hypothalamus
What are the four main conditions of heat related injuries?
Heat Syncope,
Cramps,
Exhaustion
Stroke.
What is heat syncope?
occurs as a result of hypovolemia from volume depletion, and vasodilation.
Often occurs to people who are unacclimated to heat, or the elderly who are susceptible to having less vasomotor tone; this can also be compounded by medications in later stages of life.
In heat syncope, why is orthoststic hypotension a concern?
decreased brain perfusion causing LOC
What are heat cramps?
mild-severe muscle cramps that are fatigued
What do heat cramps cause an imbalance of?
This causes an imbalance between Na and water loss, and can be avoided by electrolyte replacement (gatorade) during extreme exercise or exercise in hot environments, so as the person sweats there are replacing fluid and Na.
- Patient will present with hot flushed skin, diaphoresis, normotensive +- tachycardia
What is heat exhaustion?
more serious than heat cramps, and patients will be hyperthermic with < 39°C.
How would a pt with heat exhaustion present?
ay have evidence of poor perfusion, evidence of volume loss with orthostatic BP assessment, and can also have mild confusion/irritability (get an IV before you get them to stand up! If BP tanks, you will have a line before)
Patients may complain of dizziness, headache, nausea etc.
Removal from hot environment and supportive care with fluid replacement
What is heat stroke?
Most dangerous temperature be 40℃ or even higher (proteins will begin to denature at 41℃ ).
What are the two types of heat stroke?
classic and exertional
What is the difference between classic and exertional heat stroke?
classic- impacts young, elderly due to prolonged heat exposure and can be compounded by comorbidities and their medications (beta blocker, psychiatric medications, diuretics, antihistamines). Can also occur from overdose/ increased ICP
exertiional- athletes/military who operate in hot/humid environments, and cannot disperse heat fast enough to maintain normal temperatures
How would our heat related injuries patient present?
Fever greater than 40℃,
Decrease LOA,
coma (Decrease CPP),
seizure.
- Diaphoresis will most likely be absent, except in exertional cases
profound tachycardia/hypotension.
Skin could flushed indicating vasodilation, or pale due to circulatory collapse
How do we treat heat related injuries?
Tx: Remove clothing,
withhold oral fluids,
cover with wet sheets, and
apply cold packs to the axillae, groin, neck and head.
Manage seizure, hypotension, airway compromise as per BLS/ALS.
If LOA improves or temperature improves decrease cooling process
What is frostbite?
Freezing of the tissue from ice crystals forming in tissue; most often unprotected body parts
Whats the patho beind frost bite?
Fluid shifts to extravascular space, blood vessels damaged, edema causing ischemia
When warm blood flow is normally restricted due to numerous microvascular emboli, this causes hypoxia and tissue death
What is frostnip?
mild blanching, mild pain
What is superficial frost bite?
waxy, white skin Cold, numb area becomes painful during rewarming.
Area becomes edematous and blisters. Eschar tissue forms, and then peels away leaving red shiny skin
What is deep frostbite?
Cold, hard skin. Affects subdermal layers, and perfusion is not restored. Non-viable skin mummify and most often require amputation
What is hypothermia?
Most often due to exposure to cold, with body temperature < 35 ℃.
At what temperature does the body stop shivering?
Body attempts to compensate with thermogenesis, but shivering stops at 32 ℃ , at which point hypothermia progresses quickly.
What is mild hypothermia??
Oriented, but may be slightly fatigued. Temperature < 35 ℃, but > 34℃. Only supportive management is required, remove cold wet clothing and provide a warm environment.
What is moderate hypothermia?
Confused, difficult making coordinated muscle movements, <34 ℃, may or may not lose ability to shiver. May require supportive care for A, B, C’s
What is severe hypothermia?
Unconscious, < 30 ℃, may have stiff limbs, bradycardia as a protective measure
In addition to bradycardia during hypothermia what is an ECG change we can see?
a J Wave (Osborn Wave) which can occur in hypothermia especially when < 30 ℃.
Although this is associated with hypothermia the cause is undetermined in the literature; some postulate it’s due to prolonged repolarization.
