Study to Determine Quicker Methods of Diagnosing Pneumonia Caused by a Breathing Machine in Critically Ill Patients

Ventilator-associated pneumonia (VAP) is a common, life-threatening hospital-acquired infectious complication of prolonged mechanical ventilation (MV). Despite aggressive efforts to prevent VAP, rates remain high because clinical diagnosis is imprecise and microbiological diagnosis is frequently delayed. Diagnosis of VAP depends on clinical signs as well as microbiologic evidence from Bronchioalveolar Lavage (BAL) cultures. Ordinarily, these cultures are only ordered after the patient presents with clinical signs and symptoms of VAP, which can significantly delay diagnosis and effective therapy. This research proposes to implement additional surveillance BAL cultures in order to reduce the time to diagnosis of VAP in mechanically ventilated critically ill adults. To further reduce the time to diagnosis of VAP, this research aims to test part of the BAL cultures using a novel flowcell/surface-capture device that allows direct from specimen visualization of bacteria using multiplexed automated digital microscopy (BACcel™) for rapid bacterial identification and antibiotic resistance testing. Additionally, molecular assays of the BAL sample will characterize lower respiratory tract antimicrobial peptide host-innate immune molecule and local anti-oxidant defenses in mechanically ventilated adults at risk for VAP.

Inclusion criteria

• Written, informed consent (by surrogate if unconscious or if altered mental status)
• ≥ 18 years old
• Admission to a Medical Intensive care unit
• Orally/nasally intubated, evaluable within 72 h of initial intubation
• Expected to remain mechanically ventilated for at least 48 h after the first study procedure

Exclusion criteria

• Previously documented cystic fibrosis
• Diffuse bronchiectasis
• Severe or massive hemoptysis
• Presence of an advanced directive to withhold life-sustaining treatment
• Morbid state or expected to survive less than 14 days because of an advanced co-morbid medical condition
• Participation in a clinical trial of any unlicensed drug or device within 30 days
• Pregnant or Nursing