KC Environment Flashcards

1
Q

*What are the definitions of mild, moderate, severe and profound hypothermia?

A
  • Mild: 33-35 degrees Celsius
  • Moderate: 29-32 degrees Celsius
  • Severe: 22-28 degrees Celsius
  • Profound: 20 degrees and lower
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

*What are the indications for active external rewarming?

A

Previously healthy patients with acute hypothermia are optimal candidates for AER

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

*What are the indications for active core rewarming?

A
  • Moderate or severe hypothermia (temperature <= 32 degrees Celsius)
  • Cardiovascular instability
  • Inadequate rate of rewarming or failure to rewarm
  • Endocrinologic insufficiency (e.g. adrenal insufficiency, DKA, hypopit)
  • Traumatic or toxicological peripheral vasodilation (e.g. spinal cord transection)
  • Secondary hypothermia impairing thermoregulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

*Temperature doesn’t rise with interventions, why not?

A

(1) Adrenal insufficiency - give methylprednisolone or hydrocortisone.
(2) Myxedema - levothyroxine
(3) Sepsis - Ab
(4) Hypoglycemia - D50

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

*5 methods of heat loss

A
  • Radiation
  • Conduction
  • Convection
  • Respiration
  • Evaporation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

*5 methods of noninvasive rewarming

A

Rewarming options include plumbed garments that circulate warm fluids, hot water bottles, heating pads, forced air warming systems, and radiant sources.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

*2 methods of invasive rewarming

A

Airway rewarming
Peritoneal dialysis
Heated irrigation
Endovascular rewarming
ECMO rewarming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

*4 causes of failure to rewarm and interventions for each

A

(1) Adrenal insufficiency - give methylprednisolone or hydrocortisone.
(2) Myxedema - levothyroxine
(3) Sepsis - Ab
(4) Hypoglycemia - D50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

*In the setting of hypothermia, please provide the temperature at which the following physiologic changes occur
1 Ataxia and apathy develop
2 Extinguishing of shivering thermogenesis
3 At this temperature the body assumes a poikilothermic state
4 Temperature above which ACLS medications are indicated for arrested patient
5 Onset of VF susceptibility; 50% decrease in 02 consumption

A

1 Ataxia and apathy develop -33
2 Extinguishing of shivering thermogenesis -31
3 At this temperature the body assumes a poikilothermic state -30
4 Temperature above which ACLS medications are indicated for arrested patient - 30
5 Onset of VF susceptibility; 50% decrease in 02 consumption - 28

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

*6 EKG changes in hypothermia

A
  • Osborne waves
  • Sinus Bradycardia
  • Prolonged QT, PR, QRS
  • VF
  • Asystole
  • Atrial fibrillation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

*What effect does hypothermia have on the oxy-Hb dissociation curve

A

Left shift

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

*The ABG machine heats the blood to 37 C.
i) The result of the PO2 will appear higher/lower
ii) The result of the pH will appear higher/lower

A

i) Increases the partial pressure of blood gases – higher P02 and higher PC02
ii) Lower ph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

*4 mechanisms of heat loss in the treatment of hyperthermia and list 1 example for each

A
  • Conduction - cool water bath
  • Convection - fan at bedside
  • Radiation - take off clothes (facilitate radiation)
  • Evaporation – spray with normothermic mist
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

*3 immediate treatments for core temp <28

A

Active rewarming, options listed above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

2 end points for termination of resusciation of *hypothermic patient

A

Temp > 32 with asystole on monitor and no cardiac activity on US
Valid DNR order
obvious signs of irreversible death - non compressive chest, decapitation
conditions unsafe for rescuers
avalanche burial 35 min or +, airway packed with snow
serum K+> 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

*Risk factors for Hypothermia in elderly patients

A

-Poly-pharmacy / medications
-Dementia/ cognitive deficits
-Poor (low socioeconomic)
-Endocrine disease
-Malnourished
-Social isolation
-Age (impaired thermoregulation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

*What 3 things can be done in a pre-hospital environment for this patient specifically to lower core temperature?

A

Ice water immersion
Removal from hot environment (move to ac, shade…)
Fan
Remove clothes
ICe packs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

*4 mechanisms of heat loss in the treatment of hyperthermia and list 1 example for each

A

-Conduction - cool water bath
-Convection - fan at bedside
-Radiation - take off clothes (facilitate radiation)
-Evaporation – spray with normothermic mist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

*3 findings that differentiate heat stroke and heat exhaustion

A

Altered mental status
Core temperature >40.5 (loss of compensation)
End-organ damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

*6 pharmacologic causes of this presentation (different classes) (Hot and crazy)

A
  1. Anticholinergic
  2. Sympathomimetics
  3. EtOH withdrawal
  4. Benzo withdrawal
  5. ASA/clopidogrel
  6. NMS
  7. MH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

*What are 3 management points for heat stroke

A

Cooling
Correct electrolyte imbalance/fluid deficit
Control seizure (benzo),
Limit shivering (paralysis and intubation PRN).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

*List two early physiologic responses to heat stress

A
  • earlier onset of sweating (ie at lower core temp)
  • lowered sweat Na
  • increased sweat V
  • Expanded / increased plasma V
  • Lower HR with higher stroke V
  • earlier release of aldosterone (and lower amounts)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

*One lab result most characteristic of heat stroke

A

Transaminitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

*Two ways of quickly cooling patients

A
  1. Evaporative cooling using fans and skin wetting (spraying)
  2. Ice water immersion (conduction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

*8 clinical features of heatstroke

A

• Exposure to heat stress, endogenous or exogenous
• Signs of severe central nervous system dysfunction (coma, seizures, delirium)
• Core temperature usually > 40.5° C (105° F), but may be lower
• Hot skin common, and sweating may persist
• Marked elevation of hepatic transaminase levels
- DIC
- Renal failure
- Rhabdo
- Diarrhea
- Pancreatitis …

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

*8 factors that impair the body’s ability to disperse or dissipate heat and which may predispose to heat stroke

A

No longer a table in new Rosens, but:
Pump: cardiac disease, beta blockers
Thermoregulation: age, chronci illness, CNS bleeding
Fluid: dehydration, inadequate fluid inatke
Evaporation: vaso-occlusive clothing, anticholinergic medication, burns
Increased production: fever, exercise, NMS, drugs, thyroid storm, malignant hyperthermia, seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

*4 complications of heat stroke

A

CNS - cerebral edema, seizures, coma
CVS - peripheral vasodilation and central vasoconstriction
Liver - failure
Kidney - failure
Heme - DIC
Muscles - Rhabdo
Pancreas - itis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

*4 examples of burns from electrical injuries

A

Entrance and exit site burns: deep tissue burns may be more significant than visible tissue burns
Arc burns, kissing burns: due to current jumping across flexed surfaces of the body
Thermal burns: due to fire started by lightning
Flash burns: skin burns caused by brief flashes of electrical current or radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

*6 physical exam findings suggestive of a lightning strike, other than burns

A

CNS: Apnea, LOC, amnesia, peripheral nerve damage/paralysis, keraunoparalysis, seizures, cerebellar ataxia, cognitive dysfunction, facial nerve paralysis,
CVS: Asystole, dysrhythmias, vasospasm
HEENT: Tympanic membrane rupture, hearing loss, tinnitus, vertigo, nystagmus, cataracts
Resp: Respiratory muscle/centre paralysis
GI: Pancreatitis, solid organ injury, hepatitis, rhabomyolysis
MSK: Fracture, dislocation, rhabdomyolysis, compartment syndrome, osteonecrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

*5 potential ECG findings after a lightning injury

A

ST segment elevation
QT interval prolongation
Atrial fibrillation
Inverted or flattened T waves
Myocardial infarction pattern without cardiac sequelae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

*What is EMSs top priority in managing the scene of a lightening strike?

A
  1. Secure the scene
  2. Triage
  3. VSA first ** as pts rarely die from lightning unless present with cardiac arrest “At some point, the intrinsic pacemaker activity of the heart brings about a resumption of cardiac activity. However, if the respiratory center has not been reactivated, hypoxia follows, and the cardiac rhythm will deteriorate into ventricular fibrillation.”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

*Injuries listed – more likely caused by electrical injury or lightning?

A
  • Rhabdo (E)
  • TM perf (L)
  • Keraunoparalysis (L)
  • Vascular thrombosis (E)
  • Pulmonary Contusion (L)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

*5 ways in which lightening can injure a casualty

A
  • Force of the strike
  • Blunt trauma from being thrown
  • Superheating of metallic objects in contact
  • Blast-type effects and barotrauma
  • Shrapnel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

*Fernlike patterns of erythematous streaks

A

Lichtenberg figure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

*6 indications for ECG monitoring in electrical injury

A

Not in new Rosen, but indications are listed for lightning: suspected direct strike, loss of consciousness, focal neurologic complaint, chest pain or dyspnea, associated traumatic injuries, pregnancy, and burns of the cranium or legs or on more than 10% of the total body surface area.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

*4 ddx for chest and shoulder pain and mottling 24 hours post dive

A

DCS I
Lymphatic obstruction
Trauma?
Compartment syndrome?
?PTX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

*3 things that can happen at depth

A

Nitrogen narcosis
Oxgen toxicity
Contaminated air
Hypothermia
Trauma
Drowning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

*6 features of a dive profile

A

Depth
Length of the dive (bottom time)
Speed or time of ascent
Safety stop time and depth
Number of dives
Surface interval time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

*1 thing you can do in the ED

A

100% oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

*Disposition

A

Hyperbaric chamber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

*What are the formulas and descriptions for:
- Boyle’s law
- Dalton’s law
- Henry’s law

A

Boyle’s law: P1V1 = P2V2 (Pressure and volume are inversely proportional)
Dalton’s law: Pt = P1 + P2 + P3 … (Total pressure in a space is equal to the sum of all the gases)
Henry’s law: C=kPgas (The amount of a gas that will dissolve in a liquid at a given temperature is directly proportional to the partial pressure of that gas); this is the law that governs hyperbarics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

*Scuba diver, unconscious, lateralizing to the right… 5 things on the differential

A

o AGE
o DCS II (involves CNS, inner ear, or lungs)
o SAH
o ischemic stroke
o CO toxicity
o post-ictal todd’s paralysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

*3 indications for hyperbaric oxygen after diving

A

o Decompression sickness Type 1
o Decompression sickness Type 2
o Arterial gas embolism
o Contaminated air (CO poisoning)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

*One treatment to start before hyperbaric

A

100% oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

*One resource to consult

A

Diver Alert Network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

*Diving stem: inexperienced divers dive to 130 feet (lost track of time/depth?), presents to ED with headache, malaise, lethargy onset right after surfacing, now neurologically normal. Choose the LEAST likely diagnosis:

A

a) DCS II
b) AGE
c) nitrogen narcosis
d) near drowning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

*True or False
a At least 5% of near submersions have associated c‐spine injuries
b Antibiotics for submersion related aspiration are indicated
c DCS II commonly presents with loss of consciousness

A

a False
b False
c True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

*Risk factors for DCS

A

age, obesity, fatigue, heavy exertion, dehydration, fever, cold ambient temperatures after diving, diving at high altitude, and flying after diving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

*Contraindications for HBO

A

Not in new Rosen
-pneumothorax (untreated)
-pacemaker (can malfunction)
-claustrophobia
-history of seizures (decreases seizure threshold)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

*Treatment options for DCS I

A

Fluids, analgesia, oxygen, HBO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

*Patient is spending time at 4000 m, s/s: headache, fatigue, anorexia, dizziness: What is the diagnosis ?

A

AMS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

*2 physiologic EARLY adaptations and what their mechanism is?

A

Hypoxic ventilatory response: increase in minute ventilation decreases the partial pressure of carbon dioxide in the alveolus and increases the partial pressure of oxygen in the alveolus. This results in a respiratory alkalosis; which limits the response

Hypoxemia also results in an increase in 2,3-diphosphoglycerate, causing a rightward shift of the oxyhemoglobin dissociation curve, which favors a release of oxygen from the blood to the tissues. This is counteracted by the leftward shift of the oxyhemoglobin dissociation curve caused by the respiratory alkalosis from hyperventilation.

Rapid release of catecholamines, increasing cardiac output and elevations in heart rate, stroke volume, blood pressure, and venous tone.

Erythropoietin is secreted in response to hypoxemia within hours of ascent, which in turn stimulates the production of red blood cells, leading to new circulatory red blood cells in 4 or 5 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

*Two ways the Hb-oxygen dissociation curve changes at altitude and why?

A

2,3 DPG to the right to compensated by the decrease in CO2 (alkalosis) which shifts to the left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

*3 non-pharmacologic ways to prevent AMS

A
  1. Slow ascent (gradual introduction of higher altitude)
  2. Allow time for acclimation period (ie, stay at basecamp to acclimate prior to ascent)
  3. Stay well hydrated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

*2 treatments, their class, and mechanism of effect

A

Acetazolamide (carbonic anhydrase inhibitor): increases minute ventilation and enhances renal bicarb diuresis
Dexamethasone (steroid): anti-inflammatory, reduces cerebral blood flow and the release of inflammatoyr growth factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

*you decide to go on a relaxing weekend getaway vacation to the base-camp of K2. At 12,000 ft, a 28 year old male on vacation himself presents to you with headache, nausea, fatigue and malaise.

a. What could prevent this? (3)

A
  1. Gradual ascent
  2. Mild exercise
  3. Maintain hydration (not over hydrate, use balanced solution)
  4. Acetazolamide: 250mg BID 24H before and 1st 2 days
  5. Dexamethasone: 8mg first then at 4mg Q 6H if Acetaz not available
  6. Oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

*you decide to go on a relaxing weekend getaway vacation to the base-camp of K2. At 12,000 ft, a 28 year old male on vacation himself presents to you with headache, nausea, fatigue and malaise. You note that he is desating, has developed crackles and is looking more unwell. Please outline your further management of this patient.

A
  • Immediate descent 1,500-3,000 feet
  • Supplemental oxygen/Gamow Bag/Hyperbaric oxygen
  • Nifedipine*
  • Sildenafil*
  • Acetazolamide**
  • Rx with Abx if cant r/o pneumonia
  • DO NOT give lasix, bc not CHF, and probably already dry

*Lower pulmonary artery pressure, pulmonary blood volume, and pulmonary vascular resistance or enhance alveolar fluid clearance
**Enhances acclimatization by promoting renal bicarbonate diuresis, thus improving renal correction of ventilation- related respiratory alkalosis encouraging enhanced ventilation and arterial oxygenation

58
Q

*How does acetazolamide work to prevent/treat AMS?

A

Increased minute ventilation,
HCO3 diuresis,
decreases nocturnal period breathing
also
It lowers CSF volume and pressure
upregulation of fluid resorption in the lungs

59
Q

*3 drugs that can be used for AMS

A

Acetazolamide, O2, NSAIDs, tylenol, dexamethasone

60
Q

*2 symptoms that would warrant immediate descent

A

ataxia, altered mental status, seizures, slurred speech, hallucination (ataxia is
most specific)

61
Q

*4 physiologic changes involved in acclimatization to altitude

A

● increased RR (HVR)
● increased HR
● Increased EPO and resulting RBC production and blood volume
● Relase of catecholamines resulting in increased cardiac output
● bicarbonate diuresis
● Increase in 2,3-DPG
Hypoxic ventilatory response

62
Q

*6 risk factors for altitude sickness

A

Travel details: rapid ascent, sleeping altitude, duration of stay, weather (ex. low pressure front), seasonal variations (lower barometric pressures during winter, making lower altitude ‘physiologically higher’), durating of stay
Patient details: underlying medical issues, genetic susceptibility (NOT older age), exercise tolerance

63
Q

*4 treatment strategies for HACE

A

Descent
Hyperbarics
Pharmacologic (acetazolamide, dex, O2); caution with diuretics
Evaluate for trauma, CVA, intox

64
Q

*Describe THREE pathophysiological injuries to the lung that contribute to hypoxia post- drowning

A
  • Loss of surfactant due to wash out
  • Alveolar collapse/atelectasis
  • Non-cardiogenic pulmonary edema
  • Intrapulmonary shunting (ventilation:perfusion ratio of 0)
65
Q

*Define immersion syndrome

A

Syncope resulting from cardiac dysrhythmias on sudden contact with water that is at least 5 degrees Celsius lower than body temperature

66
Q

*FIVE of the MOST important factors affecting outcome (ie survival) in drowning/near-drowning.

A

Environmental: water temperature, submersion time
Vitals: hypoxia, hypothermia
Rescue: initial rescue efforts, need for CPR
Patient: neurologic status (GCS), acidosis, pupils

67
Q

*What are three criteria for discharge of a patient after a submersion injury?

A
  • Asymptomatic
  • Normal room air oxygen saturation
  • Normal chest X-ray
  • Normal blood gas
68
Q

*Why should you never hyperventilate before diving?

A

Blackout

69
Q

*Define: drowning, immersion syndrome, diving reflex

A

Drowning: “the process of experiencing respiratory impairment from submersion/immersion in liquid” (WHO)
Immersion syndrome: syncope from cold water + arrhythmia
Diving reflex: Activation of the diving reflex by fear or immersion of the face in cold water shunts blood centrally to the heart and brain. Apnea and bradycardia ensue, prolonging the duration of submersion tolerated without central nervous system (CNS) damage.

70
Q

Describe the stages of freezing injuries

A

Prefreeze 0-10 degrees: superficial cooling and vasoconstriction, plasma leakage
Freeze-thaw (0 degrees): ice crystals form extracellularly -> osmotic diuresis -> intracellular dehydration -> cellular collapse
Vascular stasis and progressive ischemia (>10 degrees): inflammatory reaction leads to stasis coagulation, platelet aggregation, AV shunting, leukocyte immobilization, and damage to the microvasculature

71
Q

List 10 predisposing risk factors

A

[Box 131.2]
Physiologic: poor physical condition, dermatologic disease, EtOH, diabetes, genetics, psychiatric illness, previous cold injury, trauma, dehydration, hypoxia
Mechanical: constrictive wet clothing, inadequate insulation, immobility
Psychological: mental status, fear, panic, peer pressure, attitude, fatigue, hunger, malnutrition, intoxicants
Environmental: temperature, wind chill, humidity, duration of exposure, heat loss through conduction (ex. through water), altitude, exposed surface area,
PmHx: atherosclerosis, arteritis, raynaud’s syndrome, cold-induced vasodilation, anemia, sickle cell disease, diabetes, vasoconstrictors, vasodilators

72
Q

List 3 good prognostic signs in freezing injuries

A

Normal sensation/warm/colour after rewarming, soft pliable tissue, early formation of large blebs with clear fluid

73
Q

What is frostnip

A

Superficial freezing injury with transient numbness and tingling that resolves after rewarming, no tissue destruction, sensory deficits in light tough/pain, temperature

74
Q

How are freezing injuries classified

A

Superficial, deep

75
Q

List 10 sequelae in freezing injuries

A

[Box 131.3]
Neuropathic: pain, complex regional pain, paresthesias, thermal sensitivity, autonomic dysfunction, Raynaud’s
MSK: compartment syndrome, rhabdo, ATN, atrophy, tenosynovitis, necrosis, amputation
Dermatologic: edema, lymphedema, ulcers, hair and nail deformities, squamous cell
Misc: cold temperature after drop, ATN, electrolyte fluxes, psychological stress, gangrene, sepsis

76
Q

What is cold temperature after drop

A

Acute thawing causes cold, hyperkalemia, acidotic blood to rush back to the heart. May cause arrhythmia and Vfib

77
Q

What are the stages of trench foot

A

Occurs without freezing of tissue due to prolonged exposure to wet and cold environments
Stage 1: cold exposure, extremities are white with vasoconstriction, feels numb but no pain or swelling
Stage 2: post cold exposure/rewarming: peripheral blood slowly returns and extremities become mottled and blue
Stage 3: hyperemia weeks-months: increased blood flow, hot and red extremity, severe pain, bullae can form
Stage 4: stabilization of skin, gangrege of tissue
(remember white -> blue -> red -> black)

78
Q

What is pernio

A

Non Freezing injuries that cause cold sores, typically in susceptible individuals (ex. Raynaud’s)

79
Q

List 10 factors that predispose patients to hypothermia

A

Box 132.1
- Decreased heat production
- Lack of fuel: hypoglycemia
- Endocrine failure: hypothyroid, hypoadrenalism, hypopituitarism
- Poor homeostasis: elderly (poor sensation, behavioral reaction, autonomic dysfunction)
- Increased heat loss
- Poor insulation: malnutrition, neonates
- Increased peripheral blood flow(erythroderma): psoriasis, dermatitis, eczema, burns
- Ethanol: less shivering, increased peripheral blood flow, poor adaptive behavior; paradoxical undressing
- Iatrogenic: exposure during resuscitation, cold fluids
- Impaired thermoregulation
- CNS: skull fractures (basal), chronic subdural hematoma, stroke, neoplasm
- Psych meds: antidepressants, antimanic, antipsychotics, anxiolytics
- Spinal cord transection
- Other
- Infection: sepsis, pneumonia, meningitis/encephalitis, atypicals
- Trauma: hypotension jeopardizes thermostability, hypothermic coagulopathy worsens bleeding”

80
Q

List the stages of hypothermia and the clinical features associated with each stage

A

“Stage 1 mild: 33-35 degrees - increased shivering, increased metabolic rate, confusion but conscious i.e. amnesia and ataxia at 33 degrees, blood pressure and HR normal
Stage 2: moderate 29-32 degrees - decreased shivering (31 degrees), afib and other dysrhythmias, decreased LOC/stupor, decreased HR, RR
Stage 3: severe 20-28 degrees - fib, 50% decreased in O2 consumption, decreased LOC, decreased cerebral blood flow, loss of reflexes, major acid-base disturbances, hypotension
Stage 4: profound <20 degrees - asystole, vital signs absent”

81
Q

List 3 cardiac symptoms of hypothermia

A

Bradycardia, J/Osborn waves, T wave inversions, prolonged PR/QRS/QTc, afib, v fib, asystole

82
Q

List 3 CNS symptoms of hypothermia

A

Decreased LOC, decreased reflexes (initially increased), nystagmus, EOM abnormalities

83
Q

List 5 differences in ACLS for the profoundly hypothermic patient

A

Longer pulse checks >1 min, max 1-3 doses of epi (consider withholding if <30), no evidence for other antiarrhythmics, max 1-3 shocks (defib usually unsuccessful if temp <30), transcutaneous is preferred over transvenous pacing, atropine in effective, do not terminate until warm and dead at 32 degrees

“Epi x 3, defib x 3, then no further until 30”

84
Q

List 5 causes of J waves on ECG

A

Hypothermia, hypercalcemia, STEMI, sepsis, increased ICP, Brugada

85
Q

List 3 types of rewarming strategies

A

Passive external (patient must be able to generate their own heat)
Active external: non invasive
Active internal: invasive

86
Q

List 3 ways our body control heat regulation

A

Thermosensors in skin and hypothalamus
Central integrative area that receives info from thermosensors
Thermoregulatory effectors ex. sweat glands, vasodilation

87
Q

4 types of minor heat illness

A

Prickly heat rash, heat cramps, heat syncope, heat edema

88
Q

How does prickly heat rash develop

A

Blockage of sweat glands cause them to fill with keratin plugs, leads to pruritic vesicles

Presents with an intensely pruritic rash without sweating over clothes areas”

89
Q

List 2 treatment strategies for heat rash

A

Chlorhexidine lotion or topical salicylate (avoid in children), wear light loose fitting clothing

90
Q

What is the mechanism for the development of heat cramps

A

Thought to be related to salt content; treated with salt solutions. Usually occurs after exertion with copious sweating and replacement with isotonic fluid

91
Q

What is the mechanism for the development of heat edema

A

Vascular leak due to increased peripheral blood flow and vasodilation

92
Q

What is the mechanism for the development of heat syncope

A

Vasodilation and poor venous return; often from standing outside for long periods in warm weather

93
Q

What are the two types of heat exhaustion

A

Water depletion: inadequate fluid intake with progressive hypovolemia
Salt depletion: large volumes of sweat are replaced with free water but no salt

94
Q

What is the clinical presentation of heat exhaustion

A

Malaise, fatigue, headache, Hyponatremia and hypochloremia with low urine sodium
NO CNS dysfunction temp <40

95
Q

What are the two types of heatstroke

A

Exertional: healthy young patients with exercise. Present with diaphoresis, hypoglycemia, DIC, rhabdo, renal failure, high lactate
Classic: older, sedentary individuals with high environmental temperatures. Present in heat waves with anhidrosis and normal labs in comparison to exertional heat stroke

96
Q

List 7 differentials for the hot and altered patient

A

CNS hemorrhage, tox (ex. anticholinergic poisoning), seizures, malignant hyperthermia, meningitis/encephalitis, serotonin syndrome, NMS, thyroid storm, sepsis

97
Q

What is our cooling target in heat stroke

A

39 degrees

98
Q

List 5 ways to cool the patient

A

Remove clothing, fans + mist with cold water,* ice packs to the neck/groin/axilla*, cooling blankets, ice water immersion, peritoneal lavage/rectal lavage/gastric lavage (low evidence) *preferred

99
Q

List that factors affect the degree of electrical injury

A

Voltage Can Cause ARCs: voltage, current, current type (AC/DC), amps, resistance, contact

100
Q

What is the difference in the pattern of injury between DC and AC electrical exposures

A

DC: single, strong muscular contraction, limited exposure but force of fall can cause other injuries
AC: alternating current, tetany contractions can result in prolonged exposures

101
Q

Compare tissues in terms of their resistance to current

A

Good conductors (low resistance): nerve -> blood vessel -> muscle -> dry skin -> tendon -> fat -> bone -> poor conductors (high resistance)

102
Q

List 5 signs of a lightning strike

A
103
Q

How is ACLS modified for lightning injuries

A

Reverse triage; those who appear dead get medical attention first

104
Q

Compare the presentation of electrical vs lightning burns

A

Electrical: V fib >asystole, skin burns/kissing burns more common, joints and extremities more commonly affected, higher risk of muscle injury/compartment syndrome, may have transient LOC

105
Q

List 4 mechanisms of injury in lightning strikes

A

Direct contact, side flashes, ground strike

106
Q

List 5 injuries that occur on descent

A

Middle ear barotrauma, external ear barotrauma, inner ear barotrauma
Barosinusitis, facial barotrauma

107
Q

What is the mechanism of external ear barotrauma

A

Obstruction of the auditory canal (wax, earplus) traps air, causing relative negative pressure and the tympanic membrane to rupture

108
Q

What is the mechanism of middle ear barotrauma

A

As the diver descends, water exerts pressure on the tympanic membrane. Sx include pain, tinnitus, vertigo. Managed with equalization during descent

109
Q

What is the mechanism of inner ear barotrauma

A

Pressure is transmitted from the middle ear down the oval window of the cochlea and through the ossicles; which can cause the round and oval window to rupture. Clinical similar to middle ear barotrauma; but may present with more vertigo

110
Q

What injuries occur at depth

A

Nitrogen narcosis, oxygen toxicity

111
Q

What gas law is relevant on ascent/descent

A

Boyle’s law

112
Q

What gas law is relevant on depth

A

Dalton’s law

113
Q

What is nitrogen narcosis

A

Increased ambient pressure increased the concentration of nitrogen at depth. Sx include euphoria, confusion, disorientation. This should resolve as the diver ascends and partial pressure of nitrogen increases

114
Q

What is oxygen toxicity

A

Partial pressure of oxygen increases at depth; toxic level is beyond where most sport divers can go >218 feet

115
Q

What gas law explains the pathophysiology of the bends

A

Henry’s law

116
Q

What are 7 injuries that occur on ascent

A

Vertigo
Barodontalgia, GI barotrauma, pulmonary barotrauma
Decompression sickness, arterial gas embolism

117
Q

When is the highest risk of barotrauma

A

Within the first 10 ft of water. As the pressure decreased volume in the alveoli increases; beyond their limit they rupture causing pneumothorax, pneumomediastinum, subcutaneous emphysema

118
Q

What are 6 factors that increase the risk of barotrauma in asthmatics and COPDers

A

Box 135.2
- Bronchospasm and mucus plugging predispose certain area of the lung to injury
- Dense, compressed air results in turbulent airflow
- Breathing capacity is reduced due to the effects of immersion
- Scuba air is chilled and may trigger bronchospasm
- Scuba diving is effortful and exertional
- Compressed air may be contaminated by pollen and other allergens

119
Q

What is decompression sickness

A

As the partial pressure of nitrogen decreases bubbles come out of solution. If this happens too quickly nitrogen accumulates and disrupts body tissues. A slow ascent allows gas to be carried to the vascular bed and exhaled

120
Q

What are risk factors for decompression sickness

A

Dive factors: length and depth of the dive, flying after diving, type of gas used
Patient factors: age, obesity, fatigue, heavy exertion, fever

121
Q

What is the no decompression limit

A

The maximum dive time based on the expected amount of dissolved nitrogen for a dive’s length and depth

122
Q

What are the types of decompression sickness

A

Type 1: MSK (joint pain), skin (cutis marmorata), lymph
Type 2: any other organ system
Vertigo/cochlea: the ‘staggers’
Pulmonary ‘chokes’
CNS: limb weakness, spinal cord injuries (CNS has high limit content and more susceptible to nitrogen)

123
Q

What is an arterial gas embolism

A

Air bubbles precipitate from the alveolar capillary membrane and into the venous system. Sx of cerebral embolism include altered LOC, headache, dizziness. Sx of pulmonary embolism include dyspnea, chest pain, hemoptysis.

124
Q

Patient presents with ear pain during descent. Most likely diagnosis?

A

Middle ear if transient vertigo
Inner ear if more severe vertigo, nausea, nystagmus
Both can have ear pain, hearing loss

125
Q

Patient presents with ear pain during ascent. Most likely diagnosis?

A

Alternobaric vertigo

126
Q

Patient presents confusion after a dive. Most likely diagnosis?

A

“Decompression if delayed onset, longer and deeper dive, joint and neurologic pain
AGE if sudden onset (within 10 mins of ascent) independent of dive profile with more CNS sx”

127
Q

List 5 potential injuries in scuba diving other than dysbarism

A

Environmental exposures: hypothermia, sunburn, trauma
Aquatic exposure: drowning, motion sickness, marine envenomations

128
Q

List 5 risk factors for drowning injuries

A

Infants, men, alcohol, seizure disorder, autism or other behavioural health issues, prolonged QtC

129
Q

How is ACLS modified for a drowning patient

A

No role for compressive only CPR; needs positive pressure ventilation. Intubation if PCO2 >50 or PaO2 <60

130
Q

What is ionizing radiation and how does it cause damage

A

Particle: particles carry an electric charge ex. alpha particles, protons
Electromagnetic: ionizing radiation occurs in the form of high energy particles or rays ex. gamma rays

131
Q

List 3 mechanisms of radiation exposure

A

Particles or high frequency have enough energy to producing ionization of the particles they encounter. This can cause direct damage (ex. damage to the DNA) or indirect (ex. free radical damage)

132
Q

List 4 ways to quantify radiation

A

Irradiation, contamination (exposure to particles), and incorporation (ingestion or absorption)

133
Q

List 4 ways to reduce radiation

A

Time, distance, shielding, quantity

134
Q

What is acute radiation syndrome

A

Syndrome that occurs after exposed to whole body radiation. Includes stages:
Prodromal: non specific nausea, vomiting, fatigue, anorexia, diarrea
Latent: symptom improvement
Manifest: sub systems

135
Q

Describe the hematopoietic syndrome and when does it occur?

A

Bone marrow suppression with lymphocyte suppression, thrombocytopenia, and immunosuppression. Occurs after 1-2 Grays. Treated with supportive care (prophylactic antibiotics), cytokine treatment, bone marrow transplant

136
Q

Describe the GI syndrome and when does it occur?

A

N/V, GI bleeding, malabsorption, fluid losses.hypovolemia. Occurs at 5-7 days. Treated supportively

137
Q

Describe the neurovascular syndrome and when does it occur?

A

Altered mental status with multiorgan failure, seizures, irritability, death. Occurs at 10-12 Grays. Comfort care

138
Q

Describe the manifestations of local radiation injury that occur at the following levels: 3 Gy, 6Gy, 10 Gy, 15Gy, 25 Gy

A

Hair loss, erythema, dry desquamation, wet desquamation, necrosis

139
Q

What is the best predictor of radiation injury

A

Lymphocyte count at 48 hours

140
Q

List the antidotes for each of the following exposures: iodine, uranium, caesium, plutonium

A

Potassium iodide, bicarbonate, prussian blue, DTPA

141
Q

List 6 universal precautions that should be taken by the health care provider when treating a patient with a radiation injury

A

1- Wearing rubber gloves x2
2- Patients outer clothes —> removed—> plastic container
3- wash with water and soap
4- The water to be collected in plastic containers ( radioactive waste)
5- Wound should be decontamination with high pressure irrigation
6- Decontamination should continue until the radiation reading is only 2 times background radiation

142
Q

What score can you use to triage patients with hypothermia who may benefit from ECLS? What are the components and cut-off?

A

HOPE score

Calculates likelihood of survival from 0-100% - using cut off of 10% survivability has NPV of 97%