Environmental Flashcards

This deck covers Chapters 131-138 in Rosens, compromising all of environmental medicine.

1
Q

What is Henry’s Law?

A

Henry’s Law

  • ep = ekc
  • Henry’s hovers

The amount of gas in solution is proportional to the pressure of the gas above the solution

Relevant in:

  • DCS I/II
  • Coca cola!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are heat cramps? Name 4 professions at risk for this.

A

Cramps of most worked muscles after exertion

Copious sweating during exertion, then hypotonic replacement

Treat with salt solutions (Gatorade, IV NS)

At-risk professions:

  • Athletes
  • Roofers
  • Steelworkers
  • Coal miners
  • Field workers
  • Boiler operators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List 5 indications for active rewarming

A
  1. Cardiovascular instability
  2. Moderate hypothermia
  3. Failure of passive rewarming
  4. Endocrinologic insufficiency
  5. Trauma/Toxicologic vasodilation
  6. Secondary hypothermia impairing thermoregulation
    * This is when illness sets a lower set temperature
    * Opposite of fever, when higher set point set
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List 10 factors that predispose you to HYPOTHERMIA

A

Decreased Heat Production

  • Endocrine (DM, Hypothyroidism, Hypoglycemia)
  • Inactivity
  • Extremes of age (limited muscle to shiver)

Increased Heat Loss

  • Environmental exposure
  • Skin damage
  • Ethanol (vasodilation)
  • Iatrogenic (active cooling vs no blankets)

Impaired Thermogenesis

  • Toxins (TCAs, SSRIs, Antipsychotics)
  • CNS lesions
  • Spinal cord injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What changes are made in ACLS with hypothermic arrest?

A
  • Pulse checks last 30 seconds
  • Max 3 shocks until >30 degrees
  • Avoid medications until >30 degrees
  • Some give Epi x3 max
  • Actively rewarm patient
  • Continue CPR/Rewarming until 32 degrees
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Dalton’s Law?

A

Dalton’s Law

  • Ptotal = P1 + P2 + P3 + P
  • Dalton’s divides

The pressure in a mixture of gases is equal to the partial pressure of the proportion of gases in the mixture

Relevant in:

  • Altitude medicine
  • O2/N2 toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List 10 risk factors for heat illness

A

Increased Heat Production

  • Exercise
  • Sympathomimetics
  • Fever
  • Delirium
  • Hyperthyroidism

Decreased Heat Loss

  • Drugs
  • Skin disease
  • Occlusive clothing

Impaired Heat Sensing

  • Hypothalamus injury
  • Atherosclerosis
  • Diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List tissues in the order of increasing resistance to electric current:

A
  • Nerves
  • Blood
  • Mucous membranes
  • Muscle
  • Dry skin
  • Tendon
  • Fat
  • Bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is Charle’s Law?

A

Charles’s Law

  • V1/T1 = V2/T2
  • Charles is Colder

At constant pressure, as volume increases, temperature increases.

Relevant in:

  • Altitude medicine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does High Altitude Pulmonary Edema (HAPE) present? Treated? Prevented?

A

High Altitude Pulmonary Edema

Symptoms

  • SOB at rest, cyanosis
  • Cough, Rales
  • Tachypnea, Tachycardia

Treatment

  • Mild - bed rest
  • Moderate - oxygen
  • Severe - descent/HBOT + Nifedipine 30mg q12h
  • Consider sildenafil/tadalafil if can’t leave
  • Consider Dex/Acetazolamide

Prevention

  • Gradual ascent (500 m/day)
  • Nifedipine 30 mg q12h
  • Acetazolamide (Not evidence-based)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

List two effects of temperature on ABG results

A

Sample warmed before analyzed in lab

Warming causes increased partial pressure of gases (Charles)

  1. Higher O2 than patient
  2. Higher CO2 than patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is malignant hyperthermia? How do you treat it?

A

Ryanodine receptor mutation

  • Autosomal dominant
  • Causes an uncontrolled increase in skeletal muscle metabolism
  • Hypercatabolic
  • Hyperthermic
  • Tachypneic
  • Tachycardia
  • Rigidity
  • Rhabdo
  • HyperK
  • Acidosis

Treatment

  • Dantrolene 2.5 mg/kg
  • 100% oxygen
  • Cool
  • Treat rhabdo, hyperK, acidosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define:

  • Frostnip
  • Frostbite
  • Trench foot/Immersion Foot
  • Chilblains
A
  • Frostnip
  • Superficial cooling injury without tissue loss
  • Frostbite
  • Cold injury with tissue loss
  • Trench foot/Immersion Foot
  • Cold injury from near freezing in wet environment
  • Chilblains
  • Cold injury from chronic dry cold
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are 6 factors that determine electrical burn severity?

A
  • Type of Circuit (AC/DC)
  • Duration
  • Resistance of tissue
  • Voltage
  • Amperage
  • Pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much water do you need to aspirate to interfere with surfactant integrity?

How much water do you need to aspirate to cause intravascular abnormalities?

A
  • Surfactant = 1-3 mL/kg
  • Vascular = 11 mL/kg
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the body physiologically adapt to altitude?

A
  1. Hypoxic ventilatory response
    * Medullar chemoreceptors sense lower PaO2 and stimulate hyperventilation. Resp alkalosis causes bicarb diuresis.
    * Takes 1 week
  2. Cardiovascular
    * Increased CO/HR/SVR
  3. Hematologic
    * Increased EPO causes more RBC mass
  4. Increased 2,3-DPG
    * Causes rightward shift in oxygenation curve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

List 8 indications for prolonged telemetry in electrical injury

A
  1. Cardiac arrest
  2. ECG changes
  3. Arrhythmia
  4. LoC
  5. Chest pain
  6. Hx cardiac disease
  7. Cardiac risk factors
  8. Hypoxia
  9. Severe injuries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Pascal’s Law?

A

Pascal’s Law

  • Delta P = pg(delta H)
  • Pascal’s pushes (equally)

A pressure applied to any part of a liquid is transmitted equally throughout. Think tube of toothpaste.

Relevant in:

  • Inner/Middle ear barotrauma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

List 5 poor prognostic factors in drowning victims

A
  1. Hypoxia
  2. Age <3
  3. Submersion >5 min
  4. GCS 3
  5. Unreactive pupils
  6. Asystole
  7. Ongoing CPR
  8. CPR delay >10 min after rescue
  9. Severe acidosis
  10. Hypothermia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is Joule’s Law?

A

Joule’s Law: P = VI

  • P = Power (Watts)
  • V = Potential (Volts)
  • I = Current (Amps)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

List 10 factors that predispose you to frostbite

A

Physiologic

  • Acclimatization
  • Dehydration
  • Over-exertion
  • Trauma
  • Skin diseases
  • Hypoxia
  • Diaphoresis

Mechanical

  • Wet clothing
  • Immobility
  • Inadequate insulation

Psychological

  • Mental status
  • Fear
  • Attitude
  • Fatigue
  • Peer pressure
  • Hunger
  • Drugs/Alcohol

Environmental

  • Temperature
  • Humidity
  • Wind Chill
  • Duration of contact
  • Altitude

Cardiovascular

  • Hypotension
  • Raynaud’s
  • Anemia
  • Sickle Cell
  • Diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List 4 diving disorders requiring HBOT

A
  1. DCS I
  2. DCS II
  3. AGE
  4. CO poisoning
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

List 5 mechanisms of heat loss

A
  1. Convection
  2. Conduction
  3. Radiation
  4. Evaporation
  5. Respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name 5 indications to terminate resuscitation in hypothermic arrests.

A
  1. DNR
  2. Obvious death (other injuries, decapitated, etc.)
  3. Conditions unsafe (EMS)
  4. Temp >32 degrees + Asystole
  5. Avalanche burial >35 min
  6. K >12 mmol/L
25
Q

What is the most effective method of cooling in the ED?

A

Tepid water fanning (Evaporative)

Ice water immersion

26
Q

What is the earliest indicator of significant radiation exposure following whole-body radiation?

A

Vomiting within 1 hr

Lymphocytes <500 at 48h

27
Q

List 5 mechanisms for lightning strike injury

A
  • Ground current (50%)
  • Side flash (30%)
  • Upward streamer (10%)
  • Direct strike (5%)
  • Contact injury (5%)
  • Blunt injury (unknown)
28
Q

Outline the freezing injury cascade

A

Pre-freeze Phase

  • Loss of sensation
  • Increased blood viscosity

Freeze-Thaw Phase

  • Intracellular dehydration
  • Extracellular ice crystal formation

Vascular Stasis and Progressive Ischemia

  • Microvascular thrombosis
  • Tissue ischemia
29
Q

Differentiate DCS from AGE

A

DCS

  • Dependent on the dive profile
  • Progressive onset
  • Spinal symptoms
  • Limb weakness
  • Paresthesias
  • Urinary retention
  • Headache

AGE

  • Independent of dive profile
  • Caused by rapid ascent
  • Rapid onset
  • Cerebral symptoms
  • Headache
  • LOC
  • Seizures
  • Cardiac arrhythmia/arrest
30
Q

Define:

  • Drowning
  • Submersion Victim
  • Immersion syndrome
A

Drowning

  • Respiratory impairment from submersion in liquid

Submersion Victim

  • Submersion distress requiring transport to hospital

Immersion Syndrome

  • Cardiac syncope after contact with water >5 degrees colder than you
31
Q

What are the 2 types of heat exhaustion? How do you diagnose these? Treatment?

A

Types

  • Water depletion (dehydration/hypovolemia)
  • Salt depletion (hypotonic replacement of sweat)

Diagnosis

  • NORMAL ALERTNESS (otherwise heatstroke)
  • Fatigue, headache
  • Tachycardia/Hypotension
  • Rule out other illness (sepsis, etc.)

Treatment

  • Rest, cool, IVF
32
Q

What is the pathophysiology of DCS?

A
  • Nitrogen bubbles form in blood during ascent
  • Bubbles cause an inflammatory response
  • Bubbles cause obstruction leading to ischemia/hypoxia
  • Nitrogen is very fat-soluble = CNS vulnerable (myelin)
33
Q

What is the minimum observation time for submersion victims?

List 4 discharge criteria that must be met.

A

6 hours

  1. Normal SpO2
  2. Normal CXR
  3. Normal ABG
  4. No symptoms
34
Q

Outline a rewarming protocol to use in the ED for frostbite

A

Pre-thaw

  • Assess pulses
  • Avoid friction massage
  • Stabilize core temperature
  • Rehydrate

Thaw

  • IV Ketorolac/Opiates PRN
  • Advil 600 mg q6h
  • Immerse in 37-39 degree water, gentle circles

Post-Thaw

  • Dry and elevate
  • Aspirate clear vesicles
  • Leave hemorrhagic vesicles
  • Consider tPA/Td/ABx
35
Q

Compare/Contrast DCS I and DCS II

A

DCS I

  • MSK/Skin/Lymphatics involved
  • Periarticular pain in UE/LE (diagnostic if gone with BP cuff)
  • Cutis marmorata (patchy cyanotic marbling of skin)
  • Extremity edema from lymphatic obstruction

DCS II

  • Any organ system involved
  • Any of the above plus:
  • Spinal Cord
  • Patchy motor/sensory deficits
  • Brain
  • H/A, diplopia, inappropriate behavior
  • Inner Ear
  • Vertigo, Nystagmus, N/V
  • Lung
  • SOB, CP, cough
36
Q

List 4 types of radiation and their degree of penetration

A
  1. Alpha particles - Epidermis
  2. Beta particles - 8 mm
  3. Gamma rays - deep
  4. Neutrons - deep
37
Q

How does High Altitude Cerebral Edema (HACE) present? Treated? Prevented?

A

High Altitude Cerebral Edema

Symptoms

  • Severe H/A, Ataxia, N/V, Seizures, Altered LOC

Treatment

  • Immediate descent
  • Dexamethasone
  • HBOT
  • Oxygen
  • ICP management

Prevention

  • Gradual ascent (500m/day)
  • Acetazolamide
38
Q

Differentiate the following:

  • Middle ear barotrauma
  • Inner ear barotrauma
  • Alternobaric vertigo
A

Middle ear barotrauma

  • Ear pain during DESCENT
  • Slight transient vertigo
  • Hearing loss (CONDUCTIVE)
  • Unilateral facial paralysis

Inner ear barotrauma

  • Ear pain during DESCENT
  • Vertigo/Nausea
  • Hearing loss (NEURAL)
  • Nystagmus, Ataxia, Romberg +

Alternobaric vertigo

  • Ear pain during ASCENT
  • Nausea
  • TM injury with transient hearing loss
  • Nystagmus
39
Q

What is ‘let go’ current for men/women/children? What current causes respiratory arrest from diaphragm tetany?

A

Let Go

  • 9 mA = Men
  • 7 mA = Women
  • 4 mA = Children

Respiratory Arrest

  • 20-50 mA
40
Q

When do most cases of AGE become symptomatic?

A

Within 10 minutes of surfacing

41
Q

What are three options for the internal decontamination of radioactive poisoning?

A
  1. Chelating
    * DTPA, Prussian blue, D-Penicillamine
  2. Blocking
    * Potassium iodide
  3. Bronchopulmonary lavage
    * For inhaled exposures
42
Q

List 6 risk factors for drowning

A
  1. Age
  2. Male
  3. Black
  4. Alcohol
  5. Time (Weekends/Summer/Daytime)
  6. Seizure disorder
  7. Long QT
  8. Autism
43
Q

List 5 types of electrical burn

A
  1. Direct contact
  2. Indirect contact
  3. Electrothermal heating
  4. Arc (most destructive)
  5. Flame
  6. Flash
44
Q

Compare exertional and classic heat stroke

A

Exertional

  • Usually younger, healthier people who exercised
  • Diaphoresis
  • Sicker
  • Rhabdo, DIC, AKI, Lactic acidosis

Classic

  • Older, sedentary, comorbid
  • Anhidrosis
  • Mild coagulatopathy, CK, oliguria, mild acidosis
45
Q

What are the recommendations for flying after diving?

A
  • <2h diving = wait 12 hours
  • Multiple day/Unlimited diving = wait 24 hours
  • Patients post-HBOT = wait 72 hours
46
Q

List the signs/symptoms of mild/moderate/severe/profound hypothermia

A

Mild (32-35 degrees)

  • Shivering
  • Ataxia

Moderate (28-32 degrees)

  • Less shivering
  • Stupor
  • Bradycardia/Hypotension
  • Atrial fibrillation

Severe (20-28 degrees)

  • VF
  • Acidemia
  • Severe hypotension/bradycardia
  • No motor response or reflexes

Profound (<20 degrees)

  • Flat EEG
  • Asystole
  • ~14 degrees is lowest survival
47
Q

Define active vs passive rewarming.

A

Passive rewarming - providing insulation and changing the ambient temperature of the environment to preserve and encourage heat generation.

  • Eg. blankets, increasing ambient temperature

Active rewarming - adding heat directly to the patient to increase the temperature of tissues.

  • Eg. warmed oxygen, warm IVF, warm lavage, HD, ECMO
48
Q

List 4 chronic conditions which are contraindicated to climb to altitude

A
  1. CHF
  2. COPD
  3. Pulmonary HTN
  4. Sickle cell
49
Q

What is heat stroke?

A
  • Exposure to heat stress
  • Severe CNS dysfunction
  • Temp usually >40 degrees
  • LFTs markedly elevated
50
Q

Give a DDx of three things depending on diving illness:

  • On Descent?
  • At Depth?
  • On Ascent?
A

On Descent

  • Middle ear barotrauma
  • Inner ear barotrauma
  • External ear barotrauma
  • Facial barotrauma
  • Sinus barotrauma

At Depth

  • Nitrogen narcosis
  • Oxygen toxicity
  • CO poisoning
  • Hypothermia

On Ascent

  • DCS I
  • DCS II
  • AGE (Arterial gas embolism)
  • ABV (Alternobaric vertigo)
  • GI barotrauma
  • Barodentalgia
  • Pneumothorax
  • Pneumomediastinum
  • Pulmonary hemorrhage
51
Q

List 6 risk factors for DCS and 3 for AGE.

A

DCS

  • Fatigue
  • Dehydration
  • Fever
  • Hypothermia
  • Obesity
  • Strenuous exercise

Obese people Exercise, which makes them fatigued, dehydrated, and febrile.

  • Dive profile
  • Diving at altitude
  • Flying after diving
  • PFO
  • Smoking
  • Alcohol

AGE

  • COPD (less lung surface to absorb bubbles)
  • Emphysema
  • Mucus plugging
  • PFO
52
Q

What is Boyle’s Law?

A

Boyle’s Law

  • P1V1 = P2V2
  • Boyles get Bigger (under pressure)

At a constant temperature, as volume increases pressure decreases

Relevant in:

  • Scuba diving
  • Air transport
53
Q

How does Acute Mountain Sickness (AMS) present? Treated? Prevented?

A

Acute Mountain Sickness

Symptoms

  • Headache, nausea, fatigue, insomnia
  • HACE if cerebellar symptoms
  • HAPE if SOB at rest

Treatment

  • Stop ascending
  • Acetazolamide for moderate cases
  • Dexamethasone for severe cases
  • Symptomatic control for headache

Prevention

  • Gradual ascent (500m/day)
  • Avoid alcohol/smoking
  • High carb diet
54
Q

Name 3 extracorporeal rewarming methods

A
  1. Venovenous circuit
    * No oxygenation support
    * 2-3 degrees/hour
  2. Hemodialysis
    * Stabilizes electrolyte/toxicologic issues
    * 2-3 degrees/hour
  3. Continuous AV rewarming circuit
    * Femoral catheters
    * No perfusionist needed
    * 3-4 degrees/hour
  4. Cardiopulmonary bypass (ECMO)
    * Full Circulatory/Oxygenation support
    * Requires anticoagulation/perfusionist
    * 9-10 degrees/hour
55
Q

List 5 treatment priorities in managing heat stroke

A
  1. ABCs, MOVID
  2. Rapid cooling
  3. Fluids
  4. Benzos to stop shivering
  5. Urine alkalinization for rhabdo
  6. Avoid shocks until myocardium cooled, if possible
56
Q

List 10 sequelae of frostbite

A

Pain

  1. Phantom pain
  2. Chronic pain

Sensation

  1. Hypesthesia
  2. Dysesthesia
  3. Paresthesia
  4. Anesthesia
  5. Cold intolerance
  6. Heat intolerance

Autonomic Dysfunction

  1. Raynaud’s syndrome
  2. Hyperhydrosis

MSK

  1. Atrophy
  2. Rhabdomyolysis
  3. Compartment syndrome
  4. Stricture
  5. Necrosis
  6. Amputation

Dermatologic

  1. Edema
  2. Lymphedema
  3. Chronic ulcers
  4. Cancer
  5. Hair/Nail deformities

Miscellaneous

  1. Core temperature after drop
  2. ATN
  3. Electrolyte abnormalities
  4. Gangrene
  5. Sepsis
57
Q

Define mild, moderate, severe, and profound hypothermia

A
  • Mild = 32-35 degrees
  • Moderate = 28 -32 degrees
  • Severe = 20-28 degrees
  • Profound = <20 degrees
58
Q

What is the General Gas Law?

A

General Gas Law

P1V1/T1 = P2V2/T2

Combination of Boyle’s and Charle’s Law