147.1 🎓 醫孞生版

147.1.0.1 📌 䞀頁重點

  • HAI 四倧:
    1. CLABSI (Central Line-Associated Bloodstream Infection)
    2. CAUTI (Catheter-Associated UTI)
    3. VAP (Ventilator-Associated Pneumonia)
    4. SSI (Surgical Site Infection)
  • 病原 MDR 為䞻: MRSA, VRE, CRE, ESBL, MDR Pseudomonas, Acinetobacter, C. difficile, Candida
  • Prevention bundles:
    • CLABSI: hand hygiene + max barrier + chlorhexidine skin + femoral avoid + daily reassess
    • CAUTI: catheter only if indicated + sterile insertion + daily eval for removal
    • VAP: head of bed 30-45° + sedation interruption + daily SBT + oral chlorhexidine + DVT/stress ulcer prophy
    • SSI: pre-op antibiotic 1 hr before incision + chlorhexidine skin + normothermia + glycemic control
  • MDR 䞊升嚁脅: stewardship + surveillance + decolonization

147.1.0.2 1⃣ CLABSI (Central Line-Associated BSI)

147.1.0.2.1 Diagnosis
  • BSI in patient with central line in place ≥ 48 hr without other identified source
  • Differential time to positivity: blood culture from line + peripheral; line +ve > 2 hr earlier = line source
147.1.0.2.2 病原
  • CoNS (S. epidermidis) #1 (skin flora)
  • S. aureus (incl MRSA)
  • Enterococci (incl VRE)
  • Gram - (Pseudomonas, Klebsiella, Acinetobacter)
  • Candida (parenteral nutrition, prolonged use)
147.1.0.2.3 Treatment
  • Remove the line (if possible) for severe / Candida / fungal / S. aureus
  • Salvage line + abx + lock therapy for stable + CoNS or selected GN
  • Empirical: Vancomycin + Pip-tazo or Cefepime (cover MRSA + GN); + Echinocandin (caspofungin/micafungin) for Candida risk
  • Duration: 7-14 d (uncomplicated GN); 14 d (CoNS, ampicillin Enterococcus); 4-6 weeks (S. aureus, Candida) — longer if endocarditis / metastatic
147.1.0.2.4 Prevention Bundle
  1. Hand hygiene before insertion
  2. Maximum sterile barrier (full body drape, sterile gown/gloves, mask, cap)
  3. Chlorhexidine skin prep
  4. Optimal site: avoid femoral; subclavian > IJ > femoral (infection risk)
  5. Daily review of need; remove ASAP
  6. Chlorhexidine bath in ICU

147.1.0.3 2⃣ CAUTI

147.1.0.3.1 颚險
  • Catheter ≥ 2 days
  • Daily risk: 3-7% bacteriuria per day
  • 20-50% of catheterized → bacteriuria, 2-4% → CAUTI
147.1.0.3.2 病原
  • E. coli #1
  • Klebsiella, Proteus, Pseudomonas, Enterobacter, Enterococcus
  • Candida (immunocompromised, broad antibiotic)
147.1.0.3.3 Diagnosis
  • Symptomatic + positive culture (≥ 10^3 CFU)
  • Asymptomatic bacteriuria → NO treatment (except pregnant, pre-urologic)
147.1.0.3.4 Treatment
  • Remove or replace catheter + culture-directed antibiotic
  • Empirical: pip-tazo or cefepime (covers Pseudomonas + ESBL); + vanco if MRSA risk
  • 7-14 days
147.1.0.3.5 Prevention
  • Catheter only when indicated: incontinence alone NOT indication
  • Sterile insertion
  • Closed drainage system
  • Daily reassess for removal
  • Bladder scanner to assess retention before catheter
  • Bedside reminders / nurse-driven removal protocols

147.1.0.4 3⃣ VAP (Ventilator-Associated Pneumonia)

  • Pneumonia in patient ventilated ≥ 48 hr
147.1.0.4.1 病原
  • Pseudomonas aeruginosa #1
  • MRSA
  • ESBL Enterobacteriaceae
  • Acinetobacter baumannii (some ICUs)
  • Stenotrophomonas maltophilia
147.1.0.4.2 Diagnosis
  • New / progressive infiltrate + clinical (fever, leukocytosis, purulent secretions, hypoxia)
  • Bronchoscopy with BAL or mini-BAL — quantitative culture
  • Endotracheal aspirate (less specific)
147.1.0.4.3 Treatment
  • Empirical: Pip-tazo OR Cefepime OR Meropenem + Vancomycin OR Linezolid (MRSA cover if prevalence > 15-20%); ± aminoglycoside if MDR risk
  • De-escalate by culture 48-72 h
  • Duration: 7 days (most), 8-14 days if Pseudomonas / MDR
147.1.0.4.4 Prevention Bundle
  1. Head of bed 30-45°
  2. Daily sedation interruption + spontaneous breathing trial (SBT) → extubation ASAP
  3. Subglottic suctioning (specialized ETT)
  4. Oral chlorhexidine 0.12% (controversial in newer studies — focus on oral hygiene)
  5. DVT prophylaxis (LMWH)
  6. Stress ulcer prophylaxis (PPI or H2 — selective)
  7. Hand hygiene
  8. Closed suctioning system

147.1.0.5 4⃣ SSI (Surgical Site Infection)

147.1.0.5.1 Classification
Type Description
Superficial Skin / subcutaneous only
Deep incisional Fascia + muscle
Organ / space Deep cavity
147.1.0.5.2 病原
  • S. aureus (incl MRSA) #1
  • CoNS, Enterococcus, Pseudomonas, GN
  • Specific by surgery type (e.g., GI surgery → polymicrobial + anaerobes)
147.1.0.5.3 Prevention
  • Pre-op antibiotic within 60 min of incision (vancomycin within 2 hr)
  • Specific to surgery:
    • Clean (cardiac, orthopedic prosthetic): cefazolin
    • Clean-contaminated (GI, hysterectomy): cefazolin + metronidazole OR ampicillin-sulbactam
    • GU: cefazolin OR ciprofloxacin
    • Colorectal: mechanical bowel prep + oral neomycin/erythromycin + IV cefazolin + metronidazole
  • Chlorhexidine skin prep (better than povidone-iodine)
  • Hair clipping (NOT shaving) immediately before
  • Glycemic control (BG < 180-200)
  • Normothermia intraoperative
  • Sterile draping + technique
147.1.0.5.4 Treatment (Established)
  • I&D + culture
  • Empirical: vancomycin (MRSA risk) + pip-tazo (broad)
  • De-escalate by culture

147.1.0.6 5⃣ C. difficile (HCAI)

  • See Ch 139 detailed
  • ~ 25% of all HAI in inpatient
  • Prevent: stewardship + isolation + soap-water hands (not alcohol gel) + bleach cleaning