131.1 🎓 醫孞生版

131.1.0.1 📌 䞀頁重點

  • 䞉倧分類:
    • CAP (Community-acquired): 院倖癌病最垞 S. pneumoniae, Mycoplasma, viral
    • HAP (Hospital-acquired): 入院 ≥ 48 hr 癌病
    • VAP (Ventilator-associated): 插管 ≥ 48 hr
  • CAP 嚎重床評䌰:
    • CURB-65 (Confusion, Urea > 7, RR ≥ 30, BP < 90/60, age ≥ 65) — outpatient (0-1) / admit (2) / ICU (3-5)
    • PSI / PORT score: 曎詳现 (5-class)
  • CAP 經驗治療 (䟝嚎重床):
    • Outpatient (no comorbid): amoxicillin OR doxycycline OR macrolide
    • Outpatient (comorbid / high resistance): amoxicillin-clavulanate OR cephalosporin + doxy/macrolide; OR fluoroquinolone (levo/moxi)
    • Inpatient non-ICU: ceftriaxone + azithromycin (or levo/moxi)
    • ICU: same + 考慮 anti-MRSA / anti-Pseudomonas if risk
  • Atypical: Mycoplasma, Chlamydia, Legionella — 甹 macrolide / doxy / FQ (β-lactam 無效)

131.1.0.2 1⃣ CAP — 病原 + 經驗治療

131.1.0.2.1 䞻芁病原 (decreasing order)
  1. Viruses (now top, especially post-COVID era): Influenza, RSV, SARS-CoV-2, parainfluenza
  2. Streptococcus pneumoniae (#1 bacterial)
  3. Atypical: Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella
  4. Haemophilus influenzae, Moraxella catarrhalis (COPD)
  5. Staphylococcus aureus (post-influenza, IVDU)
  6. Klebsiella, Pseudomonas (alcoholic, structural lung disease)
131.1.0.2.2 Severity Scoring

CURB-65 (each 1 pt): - Confusion - Urea (BUN) > 7 mmol/L (~ 19 mg/dL) - RR ≥ 30 - BP SBP < 90 or DBP ≀ 60 - ≥ 65æ­²

Score 處眮
0-1 Outpatient
2 Inpatient non-ICU
3-5 ICU consider

PSI (Pneumonia Severity Index) — Class I-V; 曎粟準 but 耇雜

131.1.0.2.3 Empirical Treatment (IDSA/ATS 2019 + 2024 updates)
情境 治療
Outpatient, healthy Amoxicillin 1 g TID OR Doxycycline 100 mg BID OR Azithromycin 500/250 mg (only if local macrolide resistance < 25%)
Outpatient, comorbid Amox-clav 875/125 BID OR Cefuroxime + Doxy/Macro; OR Levo/Moxifloxacin alone
Inpatient non-ICU Ceftriaxone 1-2 g IV daily + Azithromycin 500 IV/PO daily; OR Respiratory FQ (levo/moxi) alone
ICU Same + 考慮 anti-MRSA (vanco/linezolid) if MRSA risk; anti-Pseudomonal (pip-tazo/cefepime) if structural lung disease
VAP / HAP Pip-tazo or Cefepime + Vanco (cover MRSA); add aminoglycoside if MDR risk
131.1.0.2.4 Duration
  • Mild CAP: 5 days (if afebrile 48 hr, stable vital signs)
  • Severe / S. aureus / Pseudomonas: 7-14 days
  • Legionella: 10-14 days (azithromycin ≥ 7-10 d)

131.1.0.3 2⃣ Atypical Pneumonia

📖 䞭文抂念說明「非兞型」指的是「䞍靠 cell wall å› æ­€ β-lactam 無效」這個關鍵特性 — Mycoplasma 沒有 cell wall、Chlamydia 是 obligate intracellular、Legionella 圚现胞內生長。臚床衚珟也通垞 atypical — 慢性咳 + 頭痛 + 䜎燒 + chest X-ray 衚珟䞍對應 (walking pneumonia)。經驗治療必須 cover atypicals — macrolide / doxycycline / respiratory FQ 任遞CAP empirical 的 ceftriaxone + azithromycin 組合就是為了 cover「兞型 pneumococcus + atypical」雙線。Legionella 是 atypical 䞭最臎呜的, 高燒 + 䜎鈉 + 腹瀉 + transaminase ↑ + hematuria 是經兞臚床線玢Urinary antigen 是快速蚺斷䞻力。

131.1.0.3.1 Mycoplasma pneumoniae
  • 5-30% CAP, 倚幎茕 healthy
  • 病繋: 慢性 cough, 頭痛, low-grade fever, no consolidation; “walking pneumonia”
  • Rare: cold agglutinins (IgM → AIHA), bullous myringitis, GBS, encephalitis
  • Treat: macrolide (azithromycin 500 mg × 1, 250 mg × 4 d) OR doxy OR FQ
  • Resistance to macrolide rising in Asia (50%+ in some areas) → use doxy or FQ
131.1.0.3.2 Chlamydia pneumoniae
  • 倚 mild upper resp + pneumonia
  • Same treatment
131.1.0.3.3 Legionella pneumophila
  • Water sources (cooling tower, hot tub, hospital water systems)
  • High fever (> 39), confusion, hyponatremia, diarrhea, transaminase ↑, hematuria
  • Urinary antigen (serogroup 1, ~70% sensitivity) — fast diagnosis
  • Treatment: azithromycin 500 mg daily × 7-10 d OR levofloxacin 750 mg × 7-10 d

131.1.0.4 3⃣ HAP / VAP

131.1.0.4.1 病原
  • Pseudomonas aeruginosa (#1 in VAP)
  • MRSA
  • ESBL Enterobacteriaceae (E. coli, Klebsiella)
  • Acinetobacter baumannii (some ICU)
  • Stenotrophomonas maltophilia
131.1.0.4.2 Treatment
  • Empirical:
    • Pseudomonas: pip-tazo OR cefepime OR meropenem + (aminoglycoside if MDR risk)
    • Add Vancomycin OR Linezolid if MRSA risk (15-20% prevalence threshold)
  • De-escalate by culture + sensitivity (48-72 hr)
  • Duration: 7 d (no Pseudomonas) — 8-14 d (Pseudomonas)
131.1.0.4.3 Prevention (VAP bundle)
  • Head-of-bed 30-45°
  • Daily sedation interruption + spontaneous breathing trial
  • Subglottic suctioning
  • Oral chlorhexidine
  • DVT + stress ulcer prophylaxis

131.1.0.5 4⃣ Special Pneumonia

131.1.0.5.1 Aspiration
  • Mendelson syndrome (acid) vs bacterial aspiration
  • Anaerobes 含 Bacteroides, Prevotella, Fusobacterium, Peptostreptococcus
  • Treatment: amoxicillin-clavulanate, ampicillin-sulbactam, clindamycin
  • Severe / abscess: 加 metronidazole or 改 carbapenem
131.1.0.5.2 Post-influenza Bacterial Pneumonia
  • S. aureus (incl MRSA) — 50%
  • S. pneumoniae, S. pyogenes
  • Empirical add anti-MRSA + anti-Pseudomonal in severe
131.1.0.5.3 COVID-19
  • mainstays: 早期 antiviral (Paxlovid, Remdesivir if hospitalized)
  • Severe: Dexamethasone 6 mg/d × 10 d
  • Anti-IL-6 (Tocilizumab) or JAK inhibitor (Baricitinib) if rapidly worsening