Pulmonary · Topic 22 of 28

Hospital-Acquired & Ventilator-Associated Pneumonia

Pulmonary · nosocomial pneumonia

Hospital-Acquired & Ventilator-Associated Pneumonia

Pneumonia 48 hours into a hospital stay or after intubation: culture, cover S. aureus and Pseudomonas by MDR risk, de-escalate, and stop at 7 days.

Key numbers

HAP or VAP: onset after 48 hours≥ 48 h

IV antibiotics in 90 days: MDR riskIV antibiotics ≤ 90 days

Treat HAP and VAP 7 days7 days

01 · What it isHAP or VAP: onset after 48 hours

HAP is pneumonia not incubating at admission that develops 48 hours or more after admission; VAP is pneumonia developing more than 48 hours after endotracheal intubation. HAP in this guideline excludes VAP.

02 · RiskIV antibiotics in 90 days: MDR risk

VAP MDR risk factors: IV antibiotics within 90 days (the strongest), septic shock at VAP onset, ARDS before VAP, ≥ 5 days of hospitalization before VAP, and acute renal replacement therapy before onset.

03 · The ruleTreat HAP and VAP 7 days

Give a 7-day antibiotic course for both HAP and VAP rather than a longer one; extend only when clinical, radiologic and laboratory improvement is slow.

Diagnosis & monitoring

Work-up

New infiltrate plus fever, purulence or worse oxygenationSuspect HAP/VAP with a new or progressive infiltrate plus new fever, purulent secretions, leukocytosis or worsening oxygenation; atelectasis, pulmonary edema, PE and ARDS mimic it, and no single finding is diagnostic.

Do right now

In this order

First moves

Culture before antibiotics: tracheal aspirate, blood

→

MDR risk: MRSA agent plus 2 antipseudomonals

→

Reassess at 48–72 hours and de-escalate

→

Treat HAP and VAP 7 days7 days

Why each step

Culture before antibiotics: tracheal aspirate, bloodObtain respiratory cultures before antibiotics — for VAP, noninvasive endotracheal aspirate with semiquantitative culture is preferred over bronchoscopic quantitative sampling — plus blood cultures, so therapy can be narrowed.

MDR risk: MRSA agent plus 2 antipseudomonalsVAP with an MDR risk factor, or in a unit with high or unknown resistance: vancomycin or linezolid plus 2 antipseudomonal agents of different classes; otherwise one antipseudomonal agent with MSSA activity (piperacillin-tazobactam, cefepime).

Reassess at 48–72 hours and de-escalateReassess 2–3 days after starting therapy and de-escalate — narrower agent or combination to monotherapy — based on cultures, susceptibilities and clinical response rather than keeping a fixed broad regimen.

Treat HAP and VAP 7 daysGive a 7-day antibiotic course for both HAP and VAP rather than a longer one; extend only when clinical, radiologic and laboratory improvement is slow.

Management

Orders

Low-risk HAP: one antipseudomonal agentHAP without MRSA risk or high mortality risk: a single agent — piperacillin-tazobactam, cefepime, levofloxacin, imipenem or meropenem — covers MSSA and gram-negatives.

HAP: add vancomycin or linezolid for MRSA riskHAP: add vancomycin or linezolid for IV antibiotics within 90 days, unit MRSA > 20% or unknown, or high mortality risk (ventilatory support for HAP, septic shock); the first and last also warrant dual antipseudomonal coverage.

Prevent VAP: less sedation, faster liberation, HOB 30–45°VAP prevention essentials: avoid intubation with high-flow nasal oxygen or NIPPV when safe, minimize sedation (avoid benzodiazepines, daily awakening), use a ventilator liberation protocol, early mobility, and elevate the head of the bed 30–45°.

Oral care with toothbrushing, not chlorhexidineProvide oral care with toothbrushing but without chlorhexidine — chlorhexidine oral care is no longer recommended because it may increase mortality without clearly lowering VAP.

Red flags & don'ts

Avoid harm

No aminoglycoside monotherapy for Pseudomonas avoidNever treat Pseudomonas HAP/VAP with an aminoglycoside alone; avoid empiric aminoglycosides and colistin when other agents with adequate gram-negative activity are available.

The rules

Know these

VAP regimens cover S. aureus and PseudomonasAll empiric regimens for suspected VAP must cover S. aureus, Pseudomonas aeruginosa and other gram-negative bacilli — the leading VAP pathogens.

Start on clinical criteria, not procalcitonin or CPISDecide whether to start antibiotics on clinical criteria alone — not procalcitonin, CRP or the Clinical Pulmonary Infection Score; procalcitonin plus clinical criteria may guide stopping.

HAP or VAP?

Commonly confused

Definition	≥ 48 h after admission, not incubating on arrival
MDR risk factors	IV antibiotics in prior 90 days
Add MRSA coverage when	IV antibiotics in 90 days, unit MRSA > 20% or unknown, or high mortality risk
Respiratory sample	Sputum Gram stain and culture
Mortality	> 20%

More detail

Reference

Show 7 reference facts

Usual empiric doses: vancomycin 15 mg/kg every 12 hours (level-adjusted), linezolid 600 mg every 12 hours, piperacillin-tazobactam 4.5 g every 6 hours, cefepime 2 g every 8 hours, meropenem 1 g every 8 hours.

The 2016 guideline dropped healthcare-associated pneumonia (HCAP) and asks each hospital to keep a regularly updated, ideally ICU-specific, antibiogram to choose empiric therapy.

For VAP from gram-negatives susceptible only to aminoglycosides or polymyxins, add an inhaled antibiotic to systemic therapy.

Known carbapenem-resistant gram-negative colonization: use a newer agent such as ceftazidime-avibactam, ceftolozane-tazobactam, imipenem-relebactam or meropenem-vaborbactam, guided by susceptibilities and ID input.

Mortality is above 20% for HAP and about 35–45% for VAP, partly from comorbidity; inadequate initial coverage and resistant organisms raise it.

Endotracheal tubes with subglottic secretion drainage lower VAP rates, but effects on ventilator days and mortality are unproven — an additional approach since 2022, not essential practice. Change circuits only when soiled or malfunctioning.

Non-ventilator HAP prevention: oral care, head-of-bed elevation, early mobilization, dysphagia screening and incentive spirometry after surgery.

Pearl

Broad and early, then narrow and short: cover by risk on day 1, de-escalate by day 3, stop at day 7.

Sources · Kalil AC et al. Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 IDSA/ATS Clinical Practice Guidelines. Clin Infect Dis 2016;63:e61–e111 · Merck Manual Professional — Hospital-Acquired Pneumonia · Merck Manual Professional — Ventilator-Associated Pneumonia · Klompas M et al. Strategies to prevent VAP, VAE and non-ventilator HAP in acute-care hospitals: 2022 Update (SHEA/IDSA/APIC). Infect Control Hosp Epidemiol 2022;43:687–713 · Metlay JP et al. ATS/IDSA CAP guideline 2019 (Table 4 doses per the 2016 HAP/VAP guideline). Am J Respir Crit Care Med 2019;200:e45–e67 · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).