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Updated: Aug 8, 2025

Whole-Body Nanoparticle Aerosol Inhalation Exposures
Published on: May 7, 2013
Aerosol Concentrations During Otolaryngology Procedures in a Negative Pressure Isolation Room
Kachorn Seresirikachorn1,2, Patthrarawalai Sirinara3,4, Napadon Tangjaturonrasme1
1Department of Otolaryngology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Objective:
To evaluate the role of a negative pressure room with a high-efficiency particulate air (HEPA) filtration system on reducing aerosol exposure in common otolaryngology procedures.
Study Design:
Prospective quantification of aerosol generation.
Settings:
Tertiary care.
Methods:
The particle concentrations were measured at various times during tracheostomy tube changes with tracheostomy suctioning, nasal endoscopy with suctioning, and fiberoptic laryngoscopy (FOL), which included 5 times per procedure in a negative pressure isolation room with a HEPA filter and additional 5 times in a nonpressure-controlled room without a HEPA filter. The particle concentrations were measured from the baseline, during the procedure, and continued until 30 minutes after the procedure ended. The particle concentrations were compared to the baseline concentrations.
Results:
The particle concentration significantly increased from the baseline during tracheostomy tube changes (mean difference [MD] 0.80 × 106 p/m3 , p = .01), tracheostomy suctioning (MD 0.78 × 106 p/m3 , p = .004), at 2 minutes (MD 1.29 × 106 p/m3 , p = .01), and 3 minutes (MD 1.3 × 106 p/m3 , p = .004) after suctioning. There were no significant differences in the mean particle concentrations among various time points during nasal endoscopy with suctioning and FOL neither in isolation nor nonpressure-controlled rooms.
Conclusion:
A negative pressure isolation room with a HEPA filter was revealed to be safe for medical personnel inside and outside the room. Tracheostomy tube change with tracheostomy suctioning required an isolation room because this procedure generated aerosol, while nasal endoscopy with suctioning and FOL did not. Aerosol generated in an isolation room was diminished to the baseline after 4 minutes.
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