| Author: | To, Yuk Ling |
| Title: | An investigation of air dispersion pattern and the environmental influence of open airway suctioning and identification of a practical enclosure device for open airway suctioning in general ward |
| Advisors: | Ngai, Pui Ching Shirley (RS) |
| Degree: | DHSc |
| Year: | 2025 |
| Department: | Faculty of Health and Social Sciences |
| Pages: | xvii, 193 pages : color illustrations |
| Language: | English |
| Abstract: | Open nasopharyngeal suctioning is commonly practiced in airway clearance techniques, not solely at hospital but also at community settings. Suction, however, may trigger coughing which promotes the generation of aerosols. Nonetheless, the pattern of aerosol dispersal and whether or not enclosure device during open nasopharyngeal suctioning would be beneficial remained unknown. This thesis aimed to study the air dispersion pattern, to examine the environmental influence of nasopharyngeal suctioning and to identify a practical enclosure device for mitigating the transmission risk. The first study examined the aerosol dispersion pattern of coughing and open nasopharyngeal suctioning performed in a simulated setting; and to evaluate the protective effect of the surgical mask and plastic tent as the practical barrier device. Number and size of air particles of 0.3 µm, 0.5 µm, 1 µm, 2 µm, 5 µm and 10 µm were measured in four conditions including simulated cough; suction without enclosure device, with surgical mask covered and with plastic tent. The air particle counts at size of 0.3 µm to 2 µm in post-intervention were statistically significantly higher from that in pre-intervention in all conditions except in the group of suction with plastic tent covered. Summing up all six air particle sizes, there was an overall statistically significant differences in air particle counts among the three suction groups (Chi-square = 14.00, p = 0.001). Post-hoc analysis showed that the differences in suction with plastic tent covered group was significantly lower than that of the suction with surgical mask covered group (adjusted p = 0.002) and the air particle counts of the suction with plastic tent covered group was significantly lower than that of the suction without enclosure device group (adjusted p=0.014). The results indicated that a significant aerosol dispersion during both simulated coughing and nasopharyngeal suctioning procedures. The second study assessed the droplet contamination pattern during nasopharyngeal suctioning and evaluated the protective effects of the surgical mask and plastic tent against the environmental contamination. The spreading distance of the fluorescent dye during suction without an enclosure device, suction with a surgical mask covered, and suction with plastic tent were measured and used for statistical analysis. An overall significant difference was found (p<0.001). Post-hoc analysis revealed that maximum distance of fluorescent dye spread in suction without barrier (median 103cm) was statistically significantly higher than that of suction with mask (median 10cm) (adjusted p<0.001) and that in suction without barrier was statistically significantly higher than suction with plastic tent (median 14.5cm) (adjusted p=0.005). The third study evaluated qualitatively how physiotherapists experience in performing nasopharyngeal suctioning without and with different enclosure devices and explored the barriers and enablers in using the innovative enclosure devices for performing nasopharyngeal suctioning. All physiotherapists in the interview experienced that the enclosure device could provide protection to certain extent in performing suctioning. Apparently, the plastic tent was commented to be practical and highly adoptable barrier device. Significant aerosol and droplet contamination during simulated nasopharyngeal suctioning procedures were demonstrated in this study. A plastic tent was found to be a potential enclosure device in reducing aerosol and droplet contamination. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 8646.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 4.88 MB | Adobe PDF | View/Open |
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