Hospital-acquired infections

🏥 Hospital-acquired infections (HAIs), also called nosocomial infections, occur ≥48 hours after admission and are a major cause of morbidity, mortality, and cost in healthcare. They prolong recovery, drive antimicrobial resistance, and are key targets for NHS patient safety initiatives. 💡 The “big 5” HAIs: UTI, SSI, BSI, VAP, and C. difficile colitis.

🦠 Common Hospital-Acquired Infections

• 💧 Urinary Tract Infection (UTI) – Commonest HAI, usually catheter-associated. – Pathogens: E. coli, Klebsiella, Pseudomonas. – Risk factors: prolonged catheterisation, diabetes, dehydration, poor hygiene. – Prevention: Aseptic insertion, closed drainage, daily review → “If you don’t need it, don’t leave it.”
• 🔪 Surgical Site Infection (SSI) – Occurs within 30 days (or 90 if prosthesis). – Pathogens: skin flora, esp. S. aureus. – Risk factors: long/emergency surgery, obesity, diabetes, immunosuppression. – Prevention: Antibiotic prophylaxis, sterile technique, normothermia, glycaemic control, meticulous wound care.
• 💉 Bloodstream Infection (BSI) – Often from central lines, cannulae, TPN, dialysis. – Pathogens: coagulase-negative staphylococci, S. aureus, Gram-negatives. – Prevention: Full sterile precautions at insertion, chlorhexidine skin prep, daily line review, early removal.
• 🌬️ Ventilator-Associated Pneumonia (VAP) – Usually >48h after intubation. – Pathogens: Pseudomonas, Acinetobacter, MRSA, Enterobacteriaceae. – Prevention (“VAP bundle”): Head up 30–45°, daily sedation breaks, early extubation, chlorhexidine oral care, subglottic suction tubes if long-term ventilation expected.
• 🧻 Clostridioides difficile Colitis – Follows broad-spectrum antibiotics (esp. cephalosporins, clindamycin, fluoroquinolones). – Risk factors: age >65, PPIs, immunosuppression, recent hospitalisation. – Prevention: Antibiotic stewardship, soap & water hand hygiene (alcohol gel ineffective vs spores), isolation, chlorine-based cleaning.

📋 Assessment of Suspected HAI

• 🔎 History: Recent procedures, device use (catheter, central line, ventilation), prior antibiotics, immunosuppression.
• 🩺 Examination: Sepsis screen: fever, tachycardia, hypotension, altered mental status. Inspect wounds, lines, drains.
• 🧪 Investigations: Blood/urine/wound cultures, CXR if pneumonia, stool PCR/toxin assay for C. diff.
• 🧤 Infection control: Hand hygiene, PPE, patient isolation, notify infection control team.
• 💊 Antibiotic stewardship: Culture before antibiotics, de-escalate promptly.

🧭 Diagnostic & Management Pathway

1. ⚠️ Clinical suspicion: New fever, raised CRP/WCC, localising signs (dysuria, wound erythema, new infiltrates, diarrhoea).
2. 🧪 Investigations: Take cultures before antibiotics (blood, urine, sputum, wound, stool).
3. 💊 Empiric therapy: – Start within 1 hr if sepsis suspected. – IV piperacillin–tazobactam or meropenem if resistant risk. – Add MRSA cover (vancomycin/linezolid) if indicated. – Fluids, oxygen, and source control (remove line, drain abscess).
4. 🔬 Targeted therapy: Narrow spectrum once cultures return. Shortest effective course (5–7d uncomplicated).
5. 🛡️ Prevention: Catheter, line, and ventilator “bundles”. Daily device review. Antimicrobial stewardship ward rounds. HAI surveillance + reporting for QI.

📊 Key NHS Prevention Bundles

• 💧 Catheter Care Bundle: aseptic insertion, daily review, prompt removal.
• 💉 Central Line Bundle: full sterile barrier, chlorhexidine, documented line necessity review.
• 🌬️ Ventilator Bundle: head elevation, sedation breaks, oral hygiene, extubation as soon as possible.

💡 Pearls:
– Culture before antibiotics. 🧪 – “Device out is as important as antibiotic in.” 🚫💉 – HAIs = ≥48 hrs after admission (exclude community-acquired). – Surveillance + multidisciplinary prevention are as important as treatment.

📖 References

• NICE Quality Standard: Infection Prevention & Control
• CDC – Healthcare-Associated Infections
• WHO Core Components of Infection Prevention