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Published on: January 22, 2013
Optimization of air application duration for biopsy channel drying during endoscope reprocessing: a prospective study
Kai Xuan1, Runshan Duan2, Youjian Zhang1
1Department of Hospital Infection Management, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, Henan, China.
Objective:
The aim of the present study was to explore how different compressed air application durations influence biopsy channel drying of flexible endoscopes via borescope visualization and determine the optimal drying parameters for hospital endoscope reprocessing workstations.
Methods:
Seventy-six flexible endoscopes were randomly allocated into four equal groups receiving 35 s, 40 s, 45 s and 50 s of air application at 0.25 MPa air pressure. A 30 s air application group following national Chinese guidelines was set as baseline. We used a borescope to observe residual droplets inside biopsy channels and quantified drying quality with a self-developed drying defect weighted score (DDWS), where lower scores represent superior dryness.
Results:
The 30 s baseline group presented massive residual droplets, with a median DDWS of 430 and 0% complete drying rate, failing to reach qualified drying. DDWS decreased markedly with prolonged air application (Z=-9.218, P < 0.001). The 45 s group (median DDWS=0) achieved significantly better drying than the 40 s group (median DDWS=29, P=0.001), while no difference existed between the 45 s and 50 s groups (median DDWS=0, P=1.000). Adenosine triphosphate (ATP) bioluminescence detection showed all endoscopes in 45 s and 50 s groups met the < 200 relative light unit (RLU) standard, with 100% passing rate and no intergroup discrepancy (P=0.243).
Conclusion:
Borescopic objective evaluation indicates that the air application time of workstation under 0.25 MPa pressure should be no less than 45 s to obtain satisfactory biopsy channel drying efficacy.

