Direct E-test on Bronchoalveolar Lavage From Patients With Ventilator-acquired Pneumonia

Rapid Bacterial Antibiograms Determined by Direct E-test on Bronchoalveolar Lavage From Patients With Ventilator-acquired Pneumonia: a Prospective Comparison With Standard Culture Methods

• Background: Ventilator-acquired pneumonia (VAP) is the most prevalent nosocomial infection in intensive care units (ICUs). Early microbiological diagnosis and initial administration of appropriate antimicrobial therapy are associated with a better outcome. Broad-spectrum antibiotics should therefore be administered initially. However, inconsiderate antibiotic use can increase the prevalence of multi-resistant bacteria.
• Purpose: A rapid antimicrobial susceptibility method is required to decrease the unnecessary use of empirical broad-spectrum antibiotics. The aim of this study is to compare the efficiency of a rapid antibiogram, provided by E-test strips directly applied to bronchoalveolar lavage (BAL) samples and analysed at 24 h, to that obtained with standard methods of culture which provide a later result.
• Study design: This will be an open-label, prospective cohort study of consecutive patients with VAP, conducted in a medical ICU. In addition to standard culture methods, an E-test will be performed directly on BAL samples and analysed at 24 h. Each standard BAL culture will be used as a control for the E-test method.
• Primary outcome: The occurrence of major errors, defined as isolates determined to be susceptible by the E-test but resistant by standard culture methods.
• Secondary outcomes: The occurrence of minor errors (defined as isolates determined to be resistant by the E-test and susceptible by the standard method), and a comparison of two methods of seeding BAL samples on Mueller Hinton agar plates (swabbing method, flooding method).

• Eligibility criteria:

  • Inclusion criteria: all patients with suspected VAP (defined by a Clinical Pulmonary Infection Score ≥5) undergoing BAL will be eligible.
  • Exclusion criteria: contraindications for BAL (PaO2/FIO2 <100, risk of bronchoscopy-related haemorrhagic complications), secondary exclusion of patients with negative cultures, defined by a threshold of bacteria <104 CFU/ml.
• Interventions:

BAL samples will be cultured by standard methods and the minimal inhibitory concentration (MIC) of bacteria to the usual antibiotics will be determined using standard procedures. At the time of BAL collection, a rapid antibiogram will be performed by placing E-test antibiotic strips (AB Biodisk) directly onto Mueller-Hinton agar plates seeded with the BAL specimen (both by flooding and swabbing). E-test strips will be impregnated with cefoxitin, piperacillin-tazobactam, cefepime, imipenem, ciprofloxacin and amikacin. At 24 h, the E-test plates will be photographed and then examined separately by both a bacteriologist and a medical ICU physician following a consensus method. The final E-test results will be compared with the standard MIC cultures.

Study Overview

• Status: Completed
• Conditions: Ventilator Acquired Pneumonia
• Intervention / Treatment: Procedure: E test; Procedure: standard culture method

• Study Type: Interventional
• Enrollment (Anticipated): 20
• Phase: Phase 4

Contacts and Locations

Study Locations

• France
  • Bordeaux, France, 33000
    • CHU Bordeaux

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• all patients with suspected VAP (defined by a Clinical Pulmonary Infection Score ≥5) undergoing BAL will be eligible.

Exclusion Criteria:

• contraindications for BAL (PaO2/FIO2 <100, risk of bronchoscopy-related haemorrhagic complications), secondary exclusion of patients with negative cultures, defined by a threshold of bacteria <104 CFU/ml.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: E test	Procedure: E test; At the time of BAL collection, a rapid antibiogram will be performed by placing E-test antibiotic strips (AB Biodisk) directly onto Mueller-Hinton agar plates seeded with the BAL specimen (both by flooding and swabbing). E-test strips will be impregnated with cefoxitin, piperacillin-tazobactam, cefepime, imipenem, ciprofloxacin and amikacin. At 24 h, the E-test plates will be photographed and then examined separately by both a bacteriologist and a medical ICU physician following a consensus method. The final E-test results will be compared with the standard MIC cultures.
Active Comparator: standard culture method	Procedure: standard culture method; BAL samples will be cultured by standard methods and the minimal inhibitory concentration (MIC) of bacteria to the usual antibiotics will be determined using standard procedures

What is the study measuring?

Primary Outcome Measures

Outcome Measure
The occurrence of major errors, defined as isolates determined to be susceptible by the E-test but resistant by standard culture methods.

Secondary Outcome Measures

Outcome Measure
The occurrence of minor errors (defined as isolates determined to be resistant by the E-test and susceptible by the standard method), and a comparison of two methods of seeding BAL samples on Mueller Hinton agar plates (swabbing method, flooding method).

Collaborators and Investigators

• Sponsor: Université Victor Segalen Bordeaux 2
• Investigators: Principal Investigator: alexandre Boyer, MD, Université Bordeaux 2

Publications and helpful links

General Publications

• Boyer A, Medrano J, Mzali F, Balick-Weber CC, Bessede E, Picard W, Clouzeau B, Bebear CM, Vargas F, Hilbert G, Rogues AM, Gruson D. Direct testing of bronchoalveolar lavages from ventilator-associated pneumonia patients. Diagn Microbiol Infect Dis. 2012 Jun;73(2):107-10. doi: 10.1016/j.diagmicrobio.2012.02.017. Epub 2012 Apr 5.

Study record dates

Study Registration Dates

• First Submitted: January 4, 2010
• First Submitted That Met QC Criteria: January 4, 2010
• First Posted (Estimate): January 5, 2010

Study Record Updates

• Last Update Posted (Estimate): January 5, 2010
• Last Update Submitted That Met QC Criteria: January 4, 2010
• Last Verified: January 1, 2010

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Respiratory Tract Infections; Respiratory Tract Diseases; Lung Diseases; Disease Attributes; Cross Infection; Iatrogenic Disease; Healthcare-Associated Pneumonia; Pneumonia; Pneumonia, Ventilator-Associated
• Other Study ID Numbers: CHU BDX réa med