Altitude And Dysbarism Flashcards
3 types of altitude illness
Acute mountain sickness (AMS)
High altitude pulmonary edema (HAPE)
High altitude cerebral edema (HACE)
6 risk factors for altitude illness
Adolescents and elderly Rapidity of ascent Elevation attained Presence of comordibities (neuro or lung) Cold exposure Exercise
Pathophysiology of altitude illness
Decreased partial pressure of oxygen Periodic breathing, (tachypnea and apnea) Pulm hypertension Cerebral hypoxia Fluid retention
Symptoms of acute mountain illness and treatment
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
Pathophysiology of high altitude pulmonary edema
Usually 2-4d post exposure
Pulmonary vasoconstriction, pulm hytertension leading to endothelial damage and capillary leak
Treatment of high altitude pulmonary edema
Descent Supplemental oxygen, hyperbaric oxygen Nifedipine Minimize exertion Role of opioids, diuretics, antibiotics controversial
Highest cause of mortality related to altitude illness
High altitude pulmonary edema
Clinical presentation altitude cerebral edema
Altered mental status, can have seizures
Ataxia most sensitive sign
Third or sixth CN pansies
Treatment of high altitude cerebral edema
Immediate descent
Supplemental O2, hyperbaric
Acetazolamide (carbonic anhydrase inhibitor) – bicarbonate excretion, leads to hyperventilatory response
Dexamethasone
Furosemide and mannitol with caution as will dehydrate
3 phases of dysbarism
Descent dysbarism
Dysbarism at depth
Ascent dysbarism
5 parts of body can have descent dysbarism (the squeeze)
External ear Middle ear Internal ear Sinus Lung
Symptoms and treatment of nitrogen narcosis in descent dysbarism
Altered mental status, poor judgement, hallucination, loss of motor coordination
Ascend slowly to avoid ascent dysbarism, decrease nitrogen mixture for dives over 100ft
Symptoms of alternobaric vertigo
Ear pain, TM rupture
Severe transient nystagmus and vertigo
Hearing loss
N/v
Two presentations of arterial gas embolization
Cerebral embolization (sudden stroke like symptoms, seizure, loss of consciousness) Coronary artery embolization -- looks like acs obviously
Treatment of arterial gas embolism
100%o2
Supine
Ivf
Hyperbaric oxygen chamber
Pathophysiology of decompression sickness
Ambient pressure decreases, nitrogen bubbles precipitate out of solution and coalesce in blood and tissue
Clinical presentation of the bends
Skin, joint and extremity involvement.
Pruritus, erythema, skin marbling, limb and joint pain, lymphedema
Risk factors for decompression sickness
Heavy exertion, dehydration, obesity, increased length of dives, diving at altitude, rapid ascent, flying after diving, older age
What limits amount of water aspirated in 10-15% of submersion events
Laryngospasm and bronchospasm
Define diving reflex and immersion syndrome
Diving is transient protective bradycardia, apnea, peripheral vasoconstriction
Immersion syndrome: vagally mediated asystolic arrest in v cold water
Clinical presentation of submersion injury
Respiratory distress ( wheeze, rales, rhonchi) can be delayed
Cardiac dysrhythmias
Altered mental status
Hypothermia if cold submersion
Poor prognostic factors in submersion injuries
Age <3, delay in cpr start over 5 mins, prolonged submersion time, GCS 3, ongoing need for cpr
How long do you need to monitor asymptomatic submersion injury patients for
4-5 hours
7 complications of submersion injuries
Pneumonia, pulm edema, pneumonitis, ARDS, hemolysis, DIC, hypoxia related cns injury
