Microbial and Pharmacological Assessment of Chlorhexidine

Study Overview
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Brief Summary
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Ventilator-associated pneumonia (VAP) is the most frequent life-threatening nosocomial infection in the ICU. Oropharyngeal colonization with bacterial pathogens is the first step toward lung infection. Oral hygiene with Chlorhexidine mouth wash (CMW) is among the most widespread preventive measure to prevent VAP. Precise microbial documentation of CMW efficacy on oropharyngeal colonization is lacking. Investigators wish to determine CMW antimicrobial efficacy in ICU ventilated patients and to measure chlorhexidine residual concentration in patients' saliva at the same time-points after CMW.

Detailed Description
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Ventilator associated pneumonia (VAP) is the most frequent life-threatening nosocomial infection in the ICU. Oropharyngeal colonization with bacterial pathogens is the first step toward lung infection. Oral hygiene with Chlorhexidine mouth wash (CMW) is among the most widespread preventive measure to prevent VAP. Although many guidelines and expert opinions recommend oral hygiene with chlorhexidine, optimal conditions of CMW use remain unknown. In addition, precise microbial documentation of CMW efficacy on oropharyngeal colonization is lacking. Investigators wish to determine CMW antimicrobial efficacy in ICU ventilated patients and to measure chlorhexidine residual concentration in the saliva at the same time-points after CMW. In the participanting unit, CMW is performed every 6 hours with a 0.12% chlorhexidine solution. Hence, microbial oropharyngeal sampling will be performed 6h after the last CMW (and just before the next one), to assess oropharyngeal colonization and then 15 minutes, 1 hour, 2 hours, 4 hours, and 6 hours after a new CMW to assess CMW efficacy in terms of bacterial growth. In a subset of patients, 0.5 mL of saliva will be collected with a syringe at the same time points, with an additional T30 time (at 30 minutes) to measure chlorhexidine concentration.

Official Title
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Efficacy of Chlorhexidine Mouth Wash in ICU Ventilated Patients: Microbiological Effects and Antiseptic Residual Concentrations

Conditions
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Oropharynx Abnormality, Pneumonia, Ventilator-Associated, Chlorhexidine, Bacterium; Agent, Infection, Bacterial

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: critically-ill patients admitted to the ICU and receiving invasive mechanical ventilation for more than 48 hours Non-inclusion criteria: cervical or mouth surgery in the last 15 days; history of oropharyngeal neoplasm or of cervical or oropharyngeal radiotherapy, tracheotomy, age under 18 Exclusion Criteria: Patients whose samples retrieved less than 10 to the 3 colony forming unit (CFU)/mL bacteria and those who had two or more missing microbiological samples were secondarily excluded

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| study population<br>Consecutive critically-ill patients admitted to the ICU and receiving invasive mechanical ventilation for more than 48 hours | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes over time of bacterial growth | oropharyngeal colonization (i.e., amount of bacterial growth in each oropharyngeal sample) before and after a mouth wash with chlorhexidine will be measured at different time points (before (H0) and 15 minutes, 60 minutes, 120 minutes, 240 minutes, and 360 minutes after the mouth wash with chlorhexidine) | 6 hours (360 minutes) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes over time of bacterial growth of each bacterial specie | changes over time in bacterial growth of each bacterial species isolated in the oropharynx will be measured before (H0) and 15 minutes, 60 minutes, 120 minutes, 240 minutes, and 360 minutes after the mouth wash with chlorhexidine | 6 hours (360 minutes) | 
| susceptibility of isolates to chlorhexidine | chlorhexidine minimal inhibitory concentration of dominant pathogens of each patient will be determined using the broth microdilution method recommended by the Clinical & Laboratory Standards Institute | 1 hour | 
| salivary concentration of chlorhexidine | salivary concentration of chlorhexidine will be measured 15 minutes, 30 minutes, 60 minutes, 120 minutes, 240 minutes, and 360 minutes after the mouth wash with chlorhexidine using high-pressure liquid chromatography | 6 hours (360 minutes) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oropharyngeal colonization