Ventilator associated pneumonia (VAP)
Related Subjects:Asthma
|Acute Severe Asthma
|Exacerbation COPD
|Pulmonary Embolism
|Cardiogenic Pulmonary Oedema
|Pneumothorax
|Tension Pneumothorax
|Respiratory (Chest) infections Pneumonia
|Fat embolism
|Hyperventilation Syndrome
|ARDS
|Respiratory Failure
|Diabetic Ketoacidosis
|Intubation and Mechanical Ventilation
About Ventilator-Associated Pneumonia (VAP)
- 🛏️ Most common healthcare-associated infection in intensive care.
- ⚠️ Associated with significant mortality and morbidity.
- 📖 No universally agreed definition, but usually refers to pneumonia developing ≥48 hours after endotracheal intubation and mechanical ventilation.
🧫 Aetiology
- Use of cuffed endotracheal tube (ETT) or tracheostomy.
- Intubated and ventilated >48 hours.
- Early VAP (<5 days): Often community-acquired pathogens (e.g. Haemophilus influenzae, Streptococcus pneumoniae).
- Late VAP (>5 days): Usually multidrug-resistant organisms (e.g. Pseudomonas aeruginosa, Acinetobacter spp., MRSA).
- 🔑 Main pathogenic factor: biofilm formation within the tracheal tube and micro-aspiration of secretions.
📌 Risk Factors
- Age >55 years.
- Chronic lung disease (e.g. COPD).
- Supine nursing position → aspiration risk.
- Recent chest/upper abdominal surgery.
- Previous or prolonged broad-spectrum antibiotic therapy.
- Reintubation after failed extubation or prolonged intubation.
- ARDS, polytrauma, or prolonged paralysis.
- Frequent ventilator circuit changes.
- Premorbid conditions: malnutrition, renal failure, anaemia.
🩺 Clinical Features
- Fever 🌡️.
- Purulent respiratory secretions.
- Rising inflammatory markers (↑ WCC, ↑ CRP).
- Worsening gas exchange (↓ tidal volume, ↑ minute ventilation, hypoxia on ABG).
- Respiratory distress (tachypnoea, increased work of breathing).
🔍 Differentials
- Atelectasis.
- Pulmonary embolism.
- Non-pulmonary sepsis with lung infiltrates.
- Pulmonary oedema.
🧪 Investigations
- 🩸 Bloods: FBC (raised WCC), CRP, U&E, LFTs; ABG → hypoxia, type 1 or 2 respiratory failure.
- 🩻 CXR: New or progressive infiltrates. If normal → consider other diagnoses.
- 🧫 Microbiology: Tracheal aspirates, BAL (bronchoalveolar lavage) if available, before starting antibiotics.
💊 Management
- Prevention:
- ⏳ Avoid unnecessary intubation where possible.
- Head-up positioning (30–45°) → ↓ risk of micro-aspiration.
- 🦷 Strict oral hygiene (chlorhexidine mouth care).
- ❌ Avoid routine H2 blockers/PPIs unless clear indication → ↓ gastric colonisation.
- 💤 Daily sedation breaks + early mobilisation.
- Treatment:
- Ensure adequate oxygenation and ventilatory support.
- Send microbiological samples before starting antibiotics.
- Empirical broad-spectrum IV antibiotics (tailor to local resistance patterns & de-escalate once sensitivities available).
- Consider early extubation if clinically feasible.
📚 References
📝 Revisions
- Last updated: September 2025
3 Clinical Cases — Ventilator-Associated Pneumonia (VAP) 🫁🦠
- Case 1 — Early-onset VAP 🕒: A 59-year-old man intubated for 3 days following a stroke develops new fever, purulent tracheal secretions, and worsening oxygenation. CXR: new right lower lobe consolidation. Teaching: VAP within 4 days of intubation is often due to community-type organisms (e.g. H. influenzae, S. pneumoniae, MSSA). Diagnosis requires clinical, radiological, and microbiological correlation. Broad-spectrum antibiotics should be started promptly then narrowed by culture.
- Case 2 — Late-onset multidrug-resistant VAP 🧫: A 72-year-old man ventilated for 10 days after cardiac surgery develops fever, leukocytosis, and new bilateral infiltrates on CXR. Endotracheal aspirate grows Pseudomonas aeruginosa. Teaching: VAP after >5 days is usually hospital-acquired with higher risk of multidrug-resistant organisms (Pseudomonas, MRSA, Acinetobacter). Empiric therapy must cover resistant Gram-negatives and MRSA until sensitivities return.
- Case 3 — Difficult-to-wean patient with VAP 🔄: A 65-year-old man ventilated for 14 days after severe pancreatitis fails multiple weaning trials due to fever, purulent secretions, and hypoxia. CXR: patchy bilateral infiltrates. BAL confirms Klebsiella pneumoniae. Teaching: VAP prolongs ICU stay and delays extubation. Key strategies = strict infection control, ventilator care bundles (head-up positioning, oral chlorhexidine, subglottic suctioning), and early de-escalation of antibiotics once sensitivities are known.
