Performance of hydrogen peroxide gas plasma and vaporized hydrogen peroxide sterilizers under long narrow lumen challenge conditions.

BACKGROUND

Long narrow lumens remain challenging for low-temperature sterilization because sterilant must reach the distal lumen endpoint. We compared hydrogen peroxide gas plasma and vaporized hydrogen peroxide systems under matched lumen challenge conditions.

METHODS

Polytetrafluoroethylene process challenge devices combined lumen lengths of 2, 4, and 8 m with internal diameters of 0.8, 1.0, and 1.5 mm. Each condition was tested in 5 standard cycles per system, yielding 90 biological indicator observations. Success proportions and between-system percentage-point differences are reported with 95% confidence intervals (CIs).

RESULTS

Overall success was 33/45 (73.3%; 95% CI 59.0-84.0) for ASP/STERRAD 100NX and 36/45 (80.0%; 95% CI 66.2-89.1) for STERIS V-PRO Max; the difference was 6.7 percentage points (95% CI -10.8 to 23.7). At 8 m, success was 6/15 (40.0%) and 8/15 (53.3%), respectively; the difference was 13.3 points (95% CI -20.2 to 43.1). The 8 m × 0.8 mm condition was most challenging. Chemical and biological indicator results diverged in the vaporized hydrogen peroxide system.

DISCUSSION: Distal biological indicator results varied mainly with lumen geometry.

CONCLUSIONS

Local validation should consider combined lumen length and diameter and include distal biological monitoring for challenging lumen configurations.