SimWars
This post is part of a series developed in preparation for participation in ACEP SimWars. It contains a review of several prominent emergency medicine topics which may be relevant for board preparation. Unless otherwise cited, content is based on HippoEM videos.
- Pediatric Emergencies
- Altitude and Dysbarism
- Bites
- Electrical Injuries
- Heat Emergencies
- Hypothermia
- Radiation Exposure
- Submersion Injury
- Hematologic Emergencies
- Bleeding Disorders
- Oncologic Emergencies
- Adrenal/Pituitary Emergencies
- Thyroid Emergencies
- Acid-Base Disturbances
- Dermatologic Emergencies
- Toxicology
Altitude Illness
- Risk factors: altitude, rapidity of ascent, sleeping altitude
- Pathophysiology
- Hypobaric hypoxia
- Pulmonary: vasoconstriction pulmonary hypertension capillary leak
- Cerebral: vasodilation edema
- Acclimatization
- Hyperventilation primary respiratory alkalosis compensatory metabolic acidosis
- Acetazolamide promotes renal bicarbonate excretion and accelerates acclimatization
- Hypobaric hypoxia
- Management: oxygen and descent
Acute mountain sickness (2000m)
- Mild cerebral edema
- Symptoms: headache, nausea/vomiting, fatigue (hangover)
- Management: acetazolamide 250mg PO BID, dexamethasone 4mg q6h
High-altitude pulmonary edema (HAPE, 3000m)
- Non-cardiogenic pulmonary edema
- Symptoms: dyspnea at rest, cough, fever
- Signs: hypoxia, crackles
- CXR: patchy infiltrates
- Management: nifedipine, PDEi (sildenafil), HBO
High-altitude cerebral edema (HACE, 4500m)
- Cerebral edema
- Symptoms: ataxia, altered mental status
- Management: acetazolamide 250mg PO BID, dexamethasone 10mg then 4mg q6h, HBO
- Gamow bag: portable HBO
Dysbarism (diving pathology)
- Principles
- Boyle’s Law: volume = 1/pressure
- Volume changes greatest near surface
- Henry’s Law: increased pressure increases proportion of dissolved gas
- Boyle’s Law: volume = 1/pressure
Barotrauma
- Localized (descent)
- Barotitis media
- Mechanism: unequal pressure between external and middle ear.
- Symptoms: pain, vertigo if ruptured
- Barotitis externa
- EAC edema/hemorrhage
- Barotitis interna
- Bleeding/rupture of round window
- Symptoms: vertigo, tinnitus, hearing loss
- Management: ENT referral
- Sinus squeeze: pain and epistaxis
- Mask squeeze: periorbital petechiae
- Barotitis media
- Localized (ascent)
- Barodontalgia
- Air trapped in filling
- Symptoms: pain, fracture
- Alternobaric vertigo: Unequal ear pressure causing vertigo
- GI barotrauma: belching, flatulence
- Barodontalgia
- Pulmonary overpressurization (ascent)
- Mechanism: rapid ascent without exhalation, focal alveolar rupture leading to pneumomediastinum, rarely pneumothorax
- CXR: continuous diaphragm sign
- Symptoms: dysphonia, neck fullness, chest pain
- Management: supportive
- Air gas embolism (ascent)
- Mechanism: similar to POP, air enters pulmonary venous circulation
- Symptoms: MI, arrest, stroke, seizure within 10 minutes
- Management: IVF, oxygen, HBO
Dissolved Gas Problems
- Nitrogen narcosis
- At >100ft, nitrogen enters nervous system and acts similarly to general anesthetic
- Symptoms: similar to alcohol intoxication, complications arise from poor judgement
- Management: ascent
- Oxygen toxicity
- Setting: industrial dives, deep
- Symptoms: seizure, nausea, muscle twitching
- Decompression sickness
- Mechanism: nitrogen gas dissolves poorly in solution, with ascent forms bubbles, occurs 1-2 hours after ascent
- Types
- Musculoskeletal, integumentary (“bends”)
- Symptoms: arthralgia, cutis marmorata
- Neurological
- Lower spinal cord (thoracic/lumbar/sacral)
- Symptoms: paraplegia, paresthesia, bladder dysfunction
- Cerebellum (“staggers”)
- Symptoms: ataxia
- Pulmonary (“chokes”)
- Symptoms: similar to pulmonary embolus
- Management: IVF, oxygen, HBO
- Lower spinal cord (thoracic/lumbar/sacral)
- Musculoskeletal, integumentary (“bends”)