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Hospital-acquired and ventilator-associated pneumonia (HAP and VAP)
Pneumonia starting 48 hours or more after admission (HAP) or after intubation (VAP) is treated with antibiotics covering Pseudomonas, with MRSA cover added only for risk factors; treatment lasts 7 days and is narrowed by the cultures.
Why it matters in the exam
The question presents an inpatient or ventilated patient who develops fever, purulent sputum, a new infiltrate and worsening oxygenation, and asks about antibiotics. The difference from community pneumonia lies in the organisms: Pseudomonas, resistant Gram-negative bacteria and Staphylococcus aureus. In HAP without high mortality risk one antipseudomonal beta-lactam is given (piperacillin-tazobactam, cefepime or meropenem). Vancomycin or linezolid is added when intravenous antibiotics were given in the last 90 days, when local MRSA prevalence is above 20% or unknown, or at high mortality risk (septic shock, need for ventilation).
Two antipseudomonal drugs from different classes are added only at high mortality risk or after intravenous antibiotics in the last 90 days, and narrowed as soon as susceptibility is known. In VAP a culture is taken from the airway (endotracheal aspirate). The recommended duration is 7 days for most patients. VAP prevention: bed head elevated 30–45 degrees, daily sedation interruption and weaning trials, oral care and subglottic suction. A well-known distractor: continuing broad treatment for 14 days "to be safe" — it increases resistance and side effects without benefit.
Key points
- HAP or VAP: 48 hours or more after admission or intubation.
- Antipseudomonal beta-lactam; MRSA only with risk factors.
- Double antipseudomonal cover in shock, ventilation or after antibiotics within 90 days.
- Duration 7 days and narrowing by cultures.
- Prevention: head of bed 30–45 degrees, daily sedation interruption.
Summary table
| Situation | Criterion | Treatment | Exam note |
|---|---|---|---|
| Definition | 48 hours or more after admission (HAP) or intubation (VAP) | Cultures before treatment | Hospital organisms |
| HAP at ordinary risk | No shock or ventilation | One antipseudomonal beta-lactam | Piperacillin-tazobactam, cefepime or meropenem |
| MRSA cover | IV antibiotics within 90 days, MRSA above 20%, high risk | Add vancomycin or linezolid | Not routine for every patient |
| Double antipseudomonal | Shock, ventilation or antibiotics within 90 days | Two drugs from different classes | Narrow by susceptibility |
| Duration | Most patients | 7 days | Not 14 days routinely |
| VAP prevention | Every ventilated patient | Head of bed 30–45 degrees, daily sedation interruption, oral care | Subglottic suction |
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Sources
- IDSA/ATS Clinical Practice Guidelines: Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia, 2016 — Empirical therapy, MRSA and Pseudomonas risk, duration
- ERS/ESICM/ESCMID/ALAT International guidelines for the management of HAP and VAP, 2017 — Diagnosis and prevention
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Health Care-Associated Infections; Pneumonia
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.