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Updated: Jul 27, 2026
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Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 3. Aerobiology
Published on: October 3, 2016
Environmental bacteriology in the unidirectional (vertical) operating room.
Archives of Surgery (Chicago, Ill. : 1960)
|July 1, 1979
Summary
This study shows vertical unidirectional airflow operating rooms significantly reduce airborne and surface contamination compared to horizontal flow systems. This improves surgical site infection control by minimizing microbes and particulates.
Area of Science:
- Healthcare Engineering
- Infection Control
- Microbiology
Background:
- Operating room (OR) contamination poses a significant risk for surgical site infections (SSIs).
- Previous studies evaluated horizontal flow/body exhaust systems for contamination control.
- Optimizing OR airflow is crucial for enhancing patient safety and reducing infection rates.
Purpose of the Study:
- To evaluate an integrated vertical unidirectional airflow and body exhaust system for microbiologic and particulate contamination control.
- To compare the effectiveness of vertical airflow versus horizontal airflow in reducing contamination at the wound site.
- To identify key factors contributing to reduced contamination in the OR environment.
Main Methods:
- Assessed an integrated clean air unit with vertical unidirectional airflow and high-efficiency particulate air (HEPA) filters.
- Utilized a body exhaust system including a surgical mask, faceplate, and microbe-retentive gown/hood.
- Measured airborne and surface contamination at the wound site and microbial burden of the surgical team.
- Employed sampling techniques comparable to a prior horizontal flow system study.
Main Results:
- The vertical flow operating room demonstrated significantly lower (P < .05) airborne and surface contamination levels compared to the horizontal flow enclosure.
- Microbial burden associated with the surgical team was also reduced in the vertical flow system.
- Key factors identified for reduced contamination included surgical light design, draping techniques, and optimal positioning of personnel/materials.
Conclusions:
- Vertical unidirectional airflow systems offer superior microbiologic and particulate contamination control in operating rooms compared to horizontal flow systems.
- The integrated design effectively minimizes airborne and surface microbes, thereby reducing the risk of SSIs.
- Strategic OR design elements, including airflow patterns and personnel/material management, are critical for effective infection control.
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