Week 10- Environmental Emergencies Flashcards
1
Q
Who does drowning most likely impact?
A
- Youth <5 yrs of age
- Males w drug or alcohol intoxication
- Disorders that cause LOC
2
Q
Drowning is the process of what?
A
The process of experiencing respiratory impairment from submersion or immersion in a liquid
3
Q
Submersion
A
The act of being completely covered by a liquid
4
Q
Immersion
A
Being partly covered by a liquid
5
Q
What is the patho of drowning?
A
- Starts with breath holding, most victims lose consciousness within 2 mins
- Occurs due to hypercapnia overriding the voluntary urge to hold breath (55mmHg CO2)
- Prior to LOC, gasping, coughing can occur causing swallowing large amounts of water
- Once water enters the pharynx and/or trachea the pt will suffer from laryngospasm, can be permanent or temporary
- If the spasm is permanent there will be no aspiration (dry drowning)
- When temporary, fluid begins to enter the lungs further compounding hypercapnia & hypoxia causing cardiac arrest
- Brain damage occurs between 4-6 mins after LOC
- Progression is normally tachy, brady, PEA, & asystole
6
Q
Aspiration of fluid can lead to,
A
- Decrease compliance, and
- Pt’s can present with non-cardiogenic pulmonary edema (due to fluid overload) on initial presentation
- With ARDS in later stages due to surfacant washout
7
Q
What does cold water drowning trigger?
A
- Triggers the mammalian diving reflex causing bradycardia, peripheral vasoconstriction, & reduced O2 demand
8
Q
What is dry drowning/ secondary drowning?
A
- Described as laryngospasm stating that no water ever made it to the lungs
- Can be immediate or delayed
- Gets worse within time, can lead to infection
9
Q
Smalls amount of aspirated water can be…
A
- Reabsorbed in vasculature or
- Can cause decrease in lung compliance
- Loss of surfacant
- Atelectasis and
- Hypoxia
10
Q
Acute Respiratory Distress Syndrome
A
- Cascade of processes impacting avelio/ capillaries causing increase capillary permeability, leading to non-cardiogenic pulmonary edema (from loss of protein)
- The 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
11
Q
What is the drowning management?
A
- Need to know the duration of submersion
- Condition of water
- Cold water
- Manage A, B, C’s
- Treat as general cardiac arrest (unless hypothermic)
12
Q
What is boyle’s law?
A
- At constant temp, volume of gas is inversely proportional to its pressure
- Pulling up increases volume and decreases pressure
- Pushing down decreases volume and increases pressure
13
Q
What is Dalton’s law?
A
- The total pressure of a mixture of gases is the sum of the partial pressures of each gas
14
Q
What is henry’s law?
A
- At constant temp, the amount of gas dissolved in a liquid is proportional to the partial pressure of gas above the liquid
15
Q
What is barotrauma?
A
- When on decent it is sometimes referred to as the “squeeze” and on ascent a “reverse squeeze”. This all occurs bc of Boyle’s Law
- If there is a blockage in ear for instance this can lead to barotrauma
16
Q
What can barotrauma cause?
A
- Tympanic membrane rupture
- Tinnitus
- Vertigo
- Nausea, vomiting
17
Q
Pulmonary Overpressurization Syndrome (Pops) and Air Embolism
A
- When a diver makes his ascent there can be air trapped within the lungs from:
- breath holding
- bronchospasm
- mucus plugs
- Can cause alveolar rupture
18
Q
What will the pt present with pulmonary overpressurization syndrome and air embolism?
A
- Dyspnea
- Pleuritic pai
- SubQ emphysema
- Pneumo
19
Q
Decompression Sickness
A
- It occurs when nitrogen that is compressed in tissues/ blood from increase pressure when diving turns back into gas bubbles when surfacing (henry’s law) bc it can’t be exhaled fast enough
- Surfacing too quickly
20
Q
What can decompression sickness cause?
A
- Due to poor tissue perfusion
- It can cause joint pain and also affect the spinal cord.
- Can be minor or cause embolism or CVA type symptoms
21
Q
Treatment for decompression sickness?
A
- High flow O2
- Tranport to hyperbaric chambers if possible
22
Q
What is nitrogen narcosis?
A
- Due to increased pressures, normally with deeper dive (75-100 ft) nitrogen becomes dissolved in blood and passes the blood brain barrier
23
Q
What is the affect of nitrogen?
A
- Nitrogen acts similar to alcohol cause the diver to make poor decisions during the dive
- This can cause injury or death if impairment is enough to remove respirator
24
Q
What is the prehospital treatment for diving injuries?
A
- High flow O2 as per BLS
- Left lateral position
25
Q
Why should you put a pt in left lateral position with diving injuries?
A
- The embolism would stay lodged in the right atrium
- Recommended in BLS to reduce aspiration
26
Q
What is thermoregulation?
A
- The body’s thermoregulatory center is located in the anterior hypothalamus and receives info from both peripheral and central temp receptors
- Respiration also plays a role in thermoregulation as warm air is expelled during exhalation
27
Q
Peripheral receptors (cold)
A
- Skin muscles and mucus membranes; there is more cold than warm receptors peripherally
28
Q
Central receptors (warm)
A
- Great veins, spinal cord, hypothalamus and viscera; there are more warm receptors than cold
29
Q
Internal and External Factors
A
- Metabolism= chemical rxn produce heat
- Radiation= transfer of heat via electromagnetic waves
- Conduction= transfer of heat from hotter to colder object
- Convection= loss of heat from moving air
- Evaporation= conversion of liquid to gas
30
Q
What is thermogensis?
A
- Production of heat for the body via the sympathetic nervous system
- 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 contain mitochondria, and burn fat to produce heat when signaled
31
Q
What is thermolysis?
A
- Release of stored heat from the body, via the parasympathetic nervous system via peripheral vasodilation, allowing more heat to be released, and thus causes diaphoresis
32
Q
What can hyperthermia occur from?
A
- environmental causes
- physical exertion
- failure of the hypothalamus
33
Q
What are the 4 main conditions of hyperthermia?
A
- Heat syncope
- Cramps
- Exhaustion
- Heat Stroke
34
Q
Heat Syncope
A
- Occurs as a result of hypovolemia from volume depletion, and vasodilation
- In heat syncope that is orthostatic hypotension causing decreased brain perfusion causing a LOC
35
Q
Heat Cramps
A
- Mild to severe muscle cramps that are fatigued
- Causing an imbalance between Na and water loss, and can be avoided by electrolyte replacement during extreme exercise or exercise in hot environments, person sweat are replacing fluid and Na
36
Q
How will a pt present when experiencing heat cramps?
A
- Hot flushed skin
- Diaphoresis
- Normotensive
- Tachycardia
37
Q
Heat Exhaustion
A
- More serious than heat cramps, and pt’s will be hyperthermic with <39C.
- May have evidence of poor perfusion, evidence of volume loss with orthostatic BP assessment, and can also have mild confusion/ irritability
38
Q
What may pt who are experiencing heat exhaustion complain of?
A
- Dizziness
- Headache
- Nausea
39
Q
What is tx for heat exhaustion?
A
- Removal from hot environment and supportive care with fluid replacement
40
Q
Heat Stroke
A
- Most dangerous temp be 40C or even higher (proteins will begin to denature at 41C)
41
Q
What can heat stroke occur from?
A
- Environment
- Intracranial hemorrhage
- Overdose
42
Q
What is heatstroke subdivided into?
A
- Classic heat stroke
- Exertional heat stroke
43
Q
Classic Heat Stroke
A
- Impacts young, elderly due to prolonged heat exposure and can be compounded by comorbidities and their meds
- Can also occur from OD/ increased ICP
44
Q
Exertional heat stroke
A
- Athletes/ military who operate in hot/ humid environments, and can’t disperse heat fast enough to maintain normal temps
45
Q
What is the presentation of heat stroke?
A
- Fever greater than 40C
- Decrease LOA
- Coma (decrease CPP)
- Seizure
- Diaphoresis will most likely be absent, except in exertional cases
- Tachycardia
- Hypotension
- Skin flushed indicating vasodilation or pale due to circulatory collapse
46
Q
What is tx for heat stroke?
A
- Remove clothing
- Withhold oral fluids
- Cover with wet sheets
- Apply cold packs to the axillae, groin, neck and head
- Manage seizure, hypotension, airway compromise as per BLS/ ALS
- If LOA improves or temp improves d/c cooling process
47
Q
What is frostbite?
A
- Freezing of the tissue from ice crystals forming in tissue; most often unprotected body parts
48
Q
Frostnip
A
- Mild blanching, mild pain
49
Q
Superficial Frostbite
A
- 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
50
Q
Deep Frostbite
A
- Cold, hard skin
- Affects subdermal layers, and perfusion is not restored
- Non-viable skin mummify and most often require amputation
51
Q
What is the BLS management for frostbite?
A
- Wrap the pt’s body/ affected parts in a blanket or foil rescue blanket
- Cover and protect the part
- Do not rub or massage the skin, leave blisters intact
- If dressing digits, dress digits separately
52
Q
What is hypothermia?
A
- Most often due to exposure to cold, with body temp <35C
- Body attempts to compensate with thermogenesis, but shivering stops at 3 at which point hypothermia progresses quickly
53
Q
What is hypothermia subdivided?
A
- Mild
- Moderate
- Severe hypothermia
54
Q
Pt Presentation Mild Hypothermia
A
- Oriented, may be slightly fatigues.
- Temp <35C, but >34
55
Q
What is tx for mild hypothermia?
A
- Supportive management is required
- Remove cold wet clothing and provide a warm environment
56
Q
Pt presentation for moderate hypothermia?
A
- Confused, difficult making coordinated muscle movements
- Temp <34C, may or may not loose ability to shiver
57
Q
Tx for moderate hypothermia?
A
- May require supportive care for ABCs
58
Q
Pt presentation for severe hypothermia?
A
- Unconscious
- Temp <30C
- May have stiff limbs, bradycardia as a protective measure
59
Q
What are the ECG changes in Hypothermia?
A
- In addition to bradycardia you may see a J wave (osborn wave) which can occur in hypothermia especially when <30C
60
Q
What is the focus on hypothermic cardiac arrest?
A
- The focus of these arrests are preventing further heat loss, and 1 analysis and early transport
- Almost all pt’s will be transported, except in rare circumstances where there is a airway obstruction from ice or chest compression are not possible, as pt is throughly frozen
