Sydney Bowmaster, MD

Mentor: Kevin Doerschug, MD


·         Hospital-acquired pneumonia (HAP): ≥48 hrs after hospitalization

·         Ventilator-associated pneumonia (VAP): ≥48 hrs after endotracheal intubation

·         Ventilated hospital­-acquired pneumonia: HAP patients who later require intubation


·         Microaspiration of colonized organisms, usually bacterial and from oropharyngeal site

·         Direct contact with contaminated equipment or healthcare personnel

·         Inhalation of infectious aerosols

·         Typical microbiology:

o   Aerobic GNR: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter species, Acinetobacter species

o   GPC: Staph aureus, Strep species

Risk Factors & Prevention: VAP occurs in ~10% of intubated patients


Clinical Features:

·         Signs/symptoms: Fever, tachypnea, increased purulent secretions, hemoptysis, rhonchi/rales, reduced breath sounds, bronchospasm, worsening hypoxemia, leukocytosis/leukopenia

·         Radiographic findings: new/progressive infiltrate

·         Altered ventilator mechanics: reduced tidal volume, increased inspiratory pressures

Diagnosis: New infiltrate + infectious signs + positive culture

Treatment: (See flowchart below)

·         Empiric therapy depends on risk for resistant organisms.

·         Risk for MDR pathogens if ANY of these: Septic shock, IV antibiotics within previous 90 days, ARDS, hospitalization ≥5 days, acute renal replacement therapy, structural lung disease (bronchiectasis, cystic fibrosis)

·         Risk for resistant GNR: local antibiogram shows that >10% of GNR are resistant to agent being considered for monotherapy, or prevalence of resistance is unknown

·         Risk for MRSA: local antibiogram shows >10-20% of Staph aureus isolates are MRSA, or prevalence of MRSA is unknown

·         Narrow based on culture & sensitivity results

o   MRSA swab has high negative predictive value. Use this to guide de-escalation.

·         Total duration of antibiotic treatment: 7 days

Prognosis: Attributable mortality ~13%

·         Adequate antibiotic therapy is important!

·         Factors associated with poor outcomes: shock, coma, ARDS, high APACHE score, bacteremia, severe underlying comorbidities, infection caused by MDR organism, multilobar disease, cavitating lesions, rapidly progressive infiltrates, delay in effective antimicrobial therapy



1.        Berton DC, Kalil AC, Teixeira PJ. Quantitative versus qualitative cultures of respiratory secretions for clinical outcomes in patients with ventilator-associated pneumonia. Cochrane Database Syst Rev 2014; :CD006482.

2.        Dangerfield B, Chung A, Webb B, Seville MT. Predictive value of methicillin-resistant Staphylococcus aureus nasal swab PCR assay for MRSA pneumonia. Antimicrob Agents Chemother. 2014;58:859-864.

3.        Dominedò C, Ceccato A, Torres A. Ventilator-associated pneumonia: new principles guiding empiric antibiotic therapy. Curr Opin Infect Dis. 2020;33(2):182-188.

4.        Garrouste-Orgeas M, Chevret S, Arlet G, et al. Oropharyngeal or gastric colonization and nosocomial pneumonia in adult intensive care unit patients. A prospective study based on genomic DNA analysis. Am J Respir Crit Care Med 1997;156(5):1647-55.

5.        Jones RN. Microbial etiologies of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. Clin Infect Dis 2010; 51 Suppl 1:S81.

6.        Kalil AC, Metersky ML, Klompas M, et al. Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis 2016; 63:e61.

7.        Melsen WG, Rovers MM, Groenwold RH, et al. Attributable mortality of ventilator-associated pneumonia: a meta-analysis of individual patient data from randomised prevention studies. Lancet Infect Dis. 2013;13:665-671.

8.        Mergenhagen KA, Starr KE, Wattengel BA, et al. Determining the utility of methicillin-resistant Staphylococcus aureus nares screening in antimicrobial stewardship. Clin Infect Dis 2019; Epub 2019/10/02. Doi: 10.1093/cid/ciz974.

9.        Muscedere JG, Day A, Heyland DK. Mortality, attributable mortality, and clinical events as endpoints for clinical trials of ventilator-associated pneumonia and hospital-acquired pneumonia. Clin Infect Dis. 2010;51(Suppl1):S120-S125.

10.     Muscedere JG, Shorr AF, Jiang X, et al. The adequacy of timely empiric antibiotic therapy for ventilator-associated pneumonia: an important determinant of outcome. J Crit Care 2012;27(3):322.e7-14.

11.     Sievert DM, Ricks P, Edwards JR, et al. Antimicrobial-resistant pathogens associated with healthcare-associated infections: summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2009-2010. Infect Control Hosp Epidemiol 2013;34(1):1-14.

12.     Weber DJ, Rutala WA, Sickbert-Bennett EE, et al. Microbiology of ventilator-associated pneumonia compared with that of hospital-acquired pneumonia. Infect Control Hosp Epidemiol 2007;28(7):825-31.

13.     Wu D, Wu C, Zhang S, et al. Risk Factors of Ventilator-Associated Pneumonia in Critically Ill Patients. Front Pharmacol 2019;10:482.