VAP | Spectrum

Refers to pneumonia occurring ≥ 48h after endotracheal intubation

Diagnostic Pearls

A diagnosis of pneumonia generally requires a demonstration of an infiltrate of chest imaging; X-rays may be negative in immunocompromised hosts or severely dehydrated patients

Fever, dyspnea, cough and sputum production comprise clinically compatible symptoms

VAP is difficult to diagnose; consider clinical signs such as increased WBC, worsening oxygenation, purulent sputum as well as sputum gram stain. Chest X-rays have poor predictive value due to high prevalence of atelectasis

Blood and sputum cultures should be obtained in; noninvasive sampling is preferred

Procalcitonin of > 0.5 mcg/L (>0.25 mcg/L in ICU patients) has a high positive predictive value for bacterial pneumonia. Antibiotics are discouraged when PCT is negative (<0.25mcg/L)

Legionella urine antigen can be ordered on inpatients if interstitial/atypical X-ray findings or risk factors (hot tub exposure, travel)

Serology (IgM) for mycoplasma is no longer indicated

The Respiratory Pathogen Panel (RPP) tests for 22 different respiratory pathogens by PCR, including atypical organisms and viruses, and can be ordered in patients in the ICU or upon approval from Medical Microbiology

In patients with cavitary pneumonia consider TB, fungal pathogens and Nocardia

In immunocompromised patients consider opportunistic pathogens such as PJP, CMV and fungal pathogens

Duration of Therapy

7 days

Guidelines no longer recommend prolonged treatment

Therapy may be extended based on slow clinical improvement, or radiological and laboratory parameters

Pseudomonas, Acinetobacter, Stenotrophomonas and Staph aureus HAP/VAP may require longer duration of treatment

Procalcitonin is useful in determining duration; normalization warrants stopping treatment, a 50% reduction indicates improvement and step-down may be considered

Empiric Therapy

Piperacillin/tazobactam 4.5g IV Q6H

OR, IF Immunocompromised or known ESBL/AmpC

Meropenem 1g IV Q8H

IF AT RISK FOR MRSA ADD

MRSA Risk Factors

Known colonization
Necrotizing pneumonia
Recent influenza
Injection drug use
Broad spectrum antibiotic use in last 90 days

Vancomycin 25mg/kg BOLUS, then use high target trough nomogram

IF at high risk for pseudomonas or resistant GNB, ADD

Known colonization
COPD with FEV1 < 50%
Severe structural lung disease
Recent broad-spectrum antibiotics
Recent hospitalization

Ciprofloxacin 400mg IV Q8H

De-escalate

Stop vancomycin if MRSA absent from culture/screening swabs

If no pseudomonas isolated, can narrow coverage or use non-anti-pseudomonal doses

Therapy Pearls

Cultures are helpful in guiding therapy, especially if organisms are present on the gram stain

Refrain from treating candida in the sputum unless suspecting systemic candidiasis (e.g. neutropenic, transplant patients)

Cultures may continue to be positive despite treatment in ventilated patients; refrain from re-culturing if patient improving

Microbiology

Usual pathogens

Staph aureus

E. coli

Klebsiella pneumoniae

Enterobacter spp

Pseudomonas spp

Early HAP/VAP (< 5 days of hospitalization)

Streptococcus pneumoniae

Haemophilus influenzae