Skip to Main Content

+

  • • Leading cause of death from nosocomial infection

    • Aspiration of gastric contents in patients with impaired airway protective defenses, due to intubation or level of consciousness, plays central role in pathogenesis

    • Diagnosis can be difficult to distinguish from other likely causes of postoperative or post-injury infection

++

Epidemiology

+

  • • Majority of cases occur outside of ICU

    • Incidence 4-7/1000 admissions

    • 13-18% of all nosocomial infections

    • 25% of ICU patients will develop pneumonia

    • 75% of critically ill patients have oropharynx colonized with pathogenic bacteria within 48 hours

    • Gram-negative bacilli predominate (Pseudomonas, E coli, Serratia, H influenzae, Enterobacter, Klebsiella, etc)

    • Risk factors include:

    • -Old age

      -Mechanical ventilation

      -Head injury

      -H2-receptor antagonists or proton pump inhibitors

      -Frequent ventilator setting changes

      -Winter months

      -Large volume aspiration of gastric contents

      -Thoracic surgery

      -Chronic lung disease

    • Intubation increases risk by 6- to 20-fold

++

Symptoms and Signs

+

  • • Fever

    • Increase and change in character of sputum

    • Hypoxia

    • Decreased breath sounds over affected region of lung

    • Tachypnea

++

Laboratory Findings

+

  • • Leukocytosis

    • Hypoxemia

++

Imaging Findings

+

  • • Pulmonary infiltrate on chest film or CT scan

+

  • • Chest film infiltrate has positive predictive value (PPV) of 64% at best

    • Sputum Gram stain is unreliable

    • Protected brush specimen (PBS) has sensitivity of 64-100% when > 1000 CFU/mL detected on culture

    • Bronchoalveolar lavage (BAL) has sensitivity of 72-100% when > 10,000 CFU/mL detected

    • BAL cell count with < 50% polymorphonuclear leukocytes (PMNs) nearly excludes pneumonia

    • Atelectasis

    • Pulmonary embolus

    • Other likely causes of fever in patient's clinical situation

    • Lung tumor, in appropriate clinical circumstance

+

  • • Chest x-ray

    • CBC

    • Sputum Gram stain and culture

    • Blood culture

    • Consider BAL or PBS to improve sensitivity and specificity

    • Serial imaging exams may be helpful to reveal evolution of infiltrate

+

  • • Consider prior antibiotic exposure when choosing therapy

    • Empiric coverage must be appropriate for patient and unit endogenous flora

    • Early and appropriate antibiotic coverage is essential

    • Duration of treatment is 10-14 days with some recommending longer courses for Pseudomonas, S aureus, and Acinetobacter

    • Respiratory therapy to assist patient to clear secretions essential

++

Medications

+

  • • Antibiotics

++

Treatment Monitoring

+

  • • Clinical improvement

    • Resolution of tachypnea, hypoxemia and leukocytosis; radiographic changes often lag behind clinical improvement

++

Complications

+

  • • Empyema

    • Lung abscess

++

Prognosis

+

  • • Associated mortality, 20-50%

    • Excess risk of death, 33%

++

Prevention

+

  • • Avoid supine positioning

    • Prompt extubation

    • Vigorous respiratory therapy and early ambulation to preserve pulmonary clearance mechanisms

++

References

Kozlow AH et al. Epidemiology and impact of aspiration pneumonia in patients undergoing surgery ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessSurgery Full Site: One-Year Subscription

Connect to the full suite of AccessSurgery content and resources including more than 160 instructional videos, 16,000+ high-quality images, interactive board review, 20+ textbooks, and more.

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessSurgery

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.