329.4 📋 章末速記 Summary

329.4.1 🔑 一句話總結

High altitude illness (> 2500m)：(1) AMS (HA + GI + fatigue) → acetazolamide；(2) HAPE (pulmonary edema from hypoxic vasoconstriction, 2-4 days post-arrival) → descend + O2 + nifedipine/sildenafil；(3) HACE (life-threatening cerebral edema, AMS + ataxia + altered MS) → descend + dexamethasone；prevention = gradual ascent (300-500 m/day) + acetazolamide 125-250 mg BID prophylaxis；diving emergencies：(1) decompression sickness (DCS) from N2 bubbles → 100% O2 + HBOT；(2) arterial gas embolism (AGE) from pulmonary barotrauma → Trendelenburg + 100% O2 + HBOT；(3) pulmonary barotrauma → pneumothorax;；inhalation injuries：smoke (CO + cyanide + thermal — 100% O2 + hydroxocobalamin Cyanokit + early intubation if airway burn + HBOT for severe CO), chemical (chlorine, ammonia, SO2, NO2 silo filler’s delayed bronchiolitis obliterans, phosgene delayed pulmonary edema 6-24h), thermal；near-drowning → lung-protective ventilation + no routine antibiotics + supportive；HBOT indications：DCS, AGE, severe CO, cyanide adjunct, necrotizing fasciitis, radiation injury。

329.4.2 💊 治療精要

• AMS：rest, hydration, acetazolamide 250 mg BID (also for prevention 125-250 BID 24h before ascent), ibuprofen for HA, O2 if available
• HAPE：descend immediately + O2 + nifedipine 30 mg ER BID + sildenafil alternative；Gamow bag for portable hyperbaric if descent impossible
• HACE：descend + dexamethasone 4-8 mg IV/IM/PO q6h + O2 + supportive
• DCS：100% O2 + IV fluids + HBOT (recompression — gold standard)
• AGE：Trendelenburg or supine + 100% O2 + HBOT
• smoke inhalation：100% O2 (CO half-life 320 → 60-80 min); hydroxocobalamin (Cyanokit) for cyanide; HBOT for severe CO (CO-Hb > 25%, neuro symptoms, pregnancy, MI); early intubation if airway burn
• chemical inhalation：supportive + bronchodilators + steroids if late inflammation；NO2 silo filler observation for delayed bronchiolitis obliterans; phosgene 24h observation for delayed pulmonary edema
• near-drowning：ABC + intubation + lung-protective ventilation + spinal precautions + no routine antibiotics + no routine steroids

329.4.3 🎯 盧醫師的考前提醒

1. high altitude illness 三大類：AMS (mild) → HAPE (pulmonary, life-threatening) → HACE (cerebral, life-threatening)；descend is most important treatment for all
2. AMS Lake Louise criteria：headache + 1 of (GI, fatigue, insomnia, dizziness) at > 2500m
3. HAPE pathophysiology：hypoxic pulmonary vasoconstriction → heterogeneous overperfusion → stress failure of pulmonary capillaries → non-cardiogenic edema；nifedipine + sildenafil as pulmonary vasodilators
4. HACE hallmark：truncal ataxia + altered mental status；treatment dexamethasone 4-8 mg q6h + descend + O2
5. acetazolamide for AMS prevention：125-250 mg BID, start 1-2 d before ascent, continue 2-3 d at altitude；mechanism = induces metabolic acidosis → ↑ respiratory drive
6. DCS vs AGE：DCS minutes-hours post-dive + joint/neuro/pulmonary；AGE minutes after surfacing + stroke-like + cardiac；both → HBOT
7. CO poisoning treatment：100% O2 (half-life 4-5h air → 1-1.5h 100% → 23 min HBOT)；HBOT for CO-Hb > 25%, neurologic symptoms, pregnancy, MI
8. cyanide poisoning：burning synthetics + lactic acidosis + altered MS + cherry-red appearance (unreliable)；hydroxocobalamin (Cyanokit) binds cyanide → cyanocobalamin (vit B12, excreted)
9. silo filler’s disease (NO2)：silage off-gas + delayed bronchiolitis obliterans 2-4 weeks post-exposure；avoid silos for 2 weeks after filling
10. phosgene 延遲性 pulmonary edema 6-24h：WWI chemical weapon + industrial；observation > 24h after exposure（even if asymptomatic initially）