Residual biological surrogate aerosol risk reduction during disrobing litter-bound manikin patients using two dry air treatments for cold regions.

OBJECTIVE

Determine relative effectiveness of two dry air decontamination methods to reduce residual airborne surrogate biological agent on litter-bound manikin patients during disrobing.

DESIGN

Fluorescent 1 µm polystyrene latex (PSL) spheres were applied as a biological agent surrogate to a litter-bound manikin dressed in cold weather outer gear (parka and snow pants) representing the contaminated patient. Two dry air personal decontamination treatments were compared to that involving no -decontamination.

SETTING

Cold region mass casualty biological aerosol contamination event.

PARTICIPANTS

A litter-bound manikin.

INTERVENTIONS: Two treatments were applied independently; high-efficiency particulate air (HEPA) filtered vacuum, and air-knife decontamination were compared to that involving no decontamination. After contaminating the manikin, a treatment was applied and the manikin disrobed. The disrobing process created the highest risk of re-aerosolization of the PSL spheres surrogate biological agent which could be inhaled by the attending medical personnel or the patient.

MAIN OUTCOME MEASURES: Aerosolized PSL sphere quantification was sampled in the breathing zone of medical personnel and analyzed with ultraviolet microscopy.

RESULTS

Analysis of variance revealed that treatment means of log-transformed data differed -significantly (p < 0.001). Tukeys Honestly Significant Difference test revealed a significant difference only between air-knife decontamination and no decontamination (p < 0.05). The HEPA vacuum reduced airborne contamination by 71 percent compared to no decontamination (not significantly different), while the air-knife reduced it by 91 percent (significantly different), after background correction.

CONCLUSIONS

Considering ease of use and significant significance, air-knife decontamination was superior to HEPA vacuum in reducing airborne inhalational risk to attending medical personnel when disrobing the manikin.