Potential Risk for Bacterial Contamination in Ventilator Systems

Potential Risk for Bacterial Contamination in Conventional Reused Ventilator Systems and Disposable Closed Ventilator-Suction Systems

Background: Few studies have investigated the difference of bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilation systems, and the association between system disconnection and bacterial contamination of ventilator systems.

Methods: The enrolled patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilators' internal system to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study.

Results: The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable system. The inspiratory and expiratory limbs of disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier (HH) of the reused system was significantly higher than that in the disposable system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia.

Conclusion: Both the reused and disposable ventilation systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation for decreasing the risks of environmental pollution and human exposure, especially for the disposable system.

Study Overview

• Status: Completed
• Conditions: Contaminated Medical or Biological Substances; Environmental-Pollution-Related Condition
• Intervention / Treatment: Device: Disposable ventilator system; Device: Conventional reused ventilator system

Detailed Description

The intubated and mechanically ventilated patients were enrolled from the Intensive Care Unit of Chang Gung Memorial Hospital, Taiwan. The experimental study group was assigned to a disposable ventilator system combined with an auto-filled heated humidifier (HH), a closed suction catheter, and a closed aerosol therapy procedure with a valved T-adaptor. According to clinical commonly used system, the control study group was assigned to use with conventional reused ventilator system, combined with a manually filled HH, an open suction catheter, and a conventional aerosol therapy procedure. Every patient was use above both ventilator systems.

• Study Type: Observational
• Enrollment (Actual): 27

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 91 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

A total of 16 patients (10 men and 6 women, aged between 20 and 91 years) were included for the final analysis. Patients had been on a mechanical ventilator for 17-46 days, and had a primary diagnosis of sepsis, septic shock, cardiac arrest, pneumonia (CAP or HAP), chronic obstructive pulmonary disease, respiratory failure, acute respiratory distress syndrome, or lung contusion.

Description

Inclusion Criteria:

• the mechanically ventilated patients in the ICU

Exclusion Criteria:

• the sputum culture results of the patients indicated the presence of drug-resistant bacteria, influenza virus, and early extubation.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Disposable ventilator system; The experimental study group will be assigned to a disposable ventilator system combined with an auto-filled heated humidifier (HH), a closed suction catheter, and a closed aerosol therapy procedure with a valved T-adaptor.	Device: Disposable ventilator system
Conventional reused ventilator system; According to clinical commonly used system, the control study group will be assigned to use with conventional reused ventilator system, combined with a manually filled HH, an open suction catheter, and a conventional aerosol therapy procedure.	Device: Conventional reused ventilator system

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
bacterial concentration	comparison of the two ventilator systems	7 days later

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
bacterial detection rate	comparison of the two ventilator systems	7 days later

Collaborators and Investigators

• Sponsor: Chang Gung University
• Collaborators: Chang Gung Memorial Hospital
• Investigators: Principal Investigator: GWO-HWA WAN, Ph.D., Chang Gung University

Publications and helpful links

General Publications

• Li YC, Lin HL, Liao FC, Wang SS, Chang HC, Hsu HF, Chen SH, Wan GH. Potential risk for bacterial contamination in conventional reused ventilator systems and disposable closed ventilator-suction systems. PLoS One. 2018 Mar 16;13(3):e0194246. doi: 10.1371/journal.pone.0194246. eCollection 2018.

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 2, 2015
• Primary Completion (ACTUAL): July 1, 2016
• Study Completion (ACTUAL): July 31, 2016

Study Registration Dates

• First Submitted: November 21, 2017
• First Submitted That Met QC Criteria: November 30, 2017
• First Posted (ACTUAL): December 2, 2017

Study Record Updates

• Last Update Posted (ACTUAL): December 2, 2017
• Last Update Submitted That Met QC Criteria: November 30, 2017
• Last Verified: November 1, 2017

More Information

Terms related to this study

• Keywords: Bacterial contamination; Nosocomial infection; Ventilator system; Closed suction system; Open suction system
• Other Study ID Numbers: CMRPD1D0251

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No