Altitude And Dysbarism

Question 1

3 types of altitude illness

Answer 1

Acute mountain sickness (AMS)
High altitude pulmonary edema (HAPE)
High altitude cerebral edema (HACE)

Question 2

6 risk factors for altitude illness

Answer 2

Adolescents and elderly
Rapidity of ascent
Elevation attained
Presence of comordibities (neuro or lung)
Cold exposure
Exercise

Question 3

Pathophysiology of altitude illness

Answer 3

Decreased partial pressure of oxygen 
Periodic breathing, (tachypnea and apnea)
Pulm hypertension
Cerebral hypoxia
Fluid retention

Question 4

Symptoms of acute mountain illness and treatment

Answer 4

Similar to viral syndrome or hangover – anorexia, headache, nausea, insomnia, weakness
Treatment is descent, acetazolamide can speed acclimatization, dexamethasone but can mask symptoms, supplemental oxygen, Tylenol ASA
Avoid sedatives/CNS depressants

Question 5

Pathophysiology of high altitude pulmonary edema

Answer 5

Usually 2-4d post exposure

Pulmonary vasoconstriction, pulm hytertension leading to endothelial damage and capillary leak

Question 6

Treatment of high altitude pulmonary edema

Answer 6

Descent
Supplemental oxygen, hyperbaric oxygen
Nifedipine
Minimize exertion 
Role of opioids, diuretics, antibiotics controversial

Question 7

Highest cause of mortality related to altitude illness

Answer 7

High altitude pulmonary edema

Question 8

Clinical presentation altitude cerebral edema

Answer 8

Altered mental status, can have seizures
Ataxia most sensitive sign
Third or sixth CN pansies

Question 9

Treatment of high altitude cerebral edema

Answer 9

Immediate descent
Supplemental O2, hyperbaric
Acetazolamide (carbonic anhydrase inhibitor) – bicarbonate excretion, leads to hyperventilatory response
Dexamethasone
Furosemide and mannitol with caution as will dehydrate

Question 10

3 phases of dysbarism

Answer 10

Descent dysbarism
Dysbarism at depth
Ascent dysbarism

Question 11

5 parts of body can have descent dysbarism (the squeeze)

Answer 11

External ear
Middle ear
Internal ear
Sinus
Lung

Question 12

Symptoms and treatment of nitrogen narcosis in descent dysbarism

Answer 12

Altered mental status, poor judgement, hallucination, loss of motor coordination
Ascend slowly to avoid ascent dysbarism, decrease nitrogen mixture for dives over 100ft

Question 13

Symptoms of alternobaric vertigo

Answer 13

Ear pain, TM rupture
Severe transient nystagmus and vertigo
Hearing loss
N/v

Question 14

Two presentations of arterial gas embolization

Answer 14

Cerebral embolization (sudden stroke like symptoms, seizure, loss of consciousness)
Coronary artery embolization -- looks like acs obviously

Question 15

Treatment of arterial gas embolism

Answer 15

100%o2
Supine
Ivf
Hyperbaric oxygen chamber

Question 16

Pathophysiology of decompression sickness

Answer 16

Ambient pressure decreases, nitrogen bubbles precipitate out of solution and coalesce in blood and tissue

Question 17

Clinical presentation of the bends

Answer 17

Skin, joint and extremity involvement.

Pruritus, erythema, skin marbling, limb and joint pain, lymphedema

Question 18

Risk factors for decompression sickness

Answer 18

Heavy exertion, dehydration, obesity, increased length of dives, diving at altitude, rapid ascent, flying after diving, older age

Question 19

What limits amount of water aspirated in 10-15% of submersion events

Answer 19

Laryngospasm and bronchospasm

Question 20

Define diving reflex and immersion syndrome

Answer 20

Diving is transient protective bradycardia, apnea, peripheral vasoconstriction
Immersion syndrome: vagally mediated asystolic arrest in v cold water

Question 21

Clinical presentation of submersion injury

Answer 21

Respiratory distress ( wheeze, rales, rhonchi) can be delayed
Cardiac dysrhythmias
Altered mental status
Hypothermia if cold submersion

Question 22

Poor prognostic factors in submersion injuries

Answer 22

Age <3, delay in cpr start over 5 mins, prolonged submersion time, GCS 3, ongoing need for cpr

Question 23

How long do you need to monitor asymptomatic submersion injury patients for

Answer 23

4-5 hours

Question 24

7 complications of submersion injuries

Answer 24

Pneumonia, pulm edema, pneumonitis, ARDS, hemolysis, DIC, hypoxia related cns injury