Contamination: a comparison of 2 personal protective systems

Abstract

Background: The purpose of this study was to examine the difference in self-contamination rates and levels of contact and droplet protection associated with enhanced respiratory and contact precautions (E-RCP) and a personal protective system that included a full body suit, personal protective equipment and a powered air-purifying respirator (PAPR).

Methods: In this prospective, randomized, controlled crossover study, 50 participants donned and removed E-RCP and PAPR in random order. Surrogate contamination consisted of fluorescein solution and ultraviolet (UV) light- detectable paste, which was applied after each ensemble was donned. A blinded evaluator inspected participants for contamination using a UV lamp after removal of each ensemble. Areas of contamination were counted and measured in square centimetres. Donning and removal violations were recorded. The primary end point was the presence of any contamination on the skin or base clothing layer.

Results: Participants wearing E-RCP were more likely to experience skin and base-clothing contamination; their contamination episodes measuring > or = 1 cm2 were more frequent, and they had larger total areas of contamination (all p < 0.0001). The anterior neck, forearms, wrists and hands were the likeliest zones for contamination. Participants donning PAPR committed more donning procedure violations (p = 0.0034). Donning and removing the PAPR system took longer than donning and removing E-RCP garments (p < 0.0001).

Interpretation: Participants wearing E-RCP were more likely to experience contamination of their skin and base clothing layer. Those wearing PAPR required significantly more time to don and remove the ensemble and violated donning procedures more frequently.

Fig. 1: Enhanced respiratory and contact precautions (E-RCP), familiar to most health care workers. The towel used for neck protection was omitted for illustrative purposes.

Fig. 2: The other system studied, named for its powered air-purifying respirator (PAPR), has 2 protective layers, shown above. The outer layer (left panel) consists of a hood, fluid-resistant surgical gown, shoe covers and 2 pairs of fitted surgical gloves. The inner (right) includes a hooded coverall and shoe covers, PAPR power unit, N95 mask, goggles, bouffant hair cover, and 1 pair of fitted surgical gloves. Contamination assessment for this layer was performed with the PAPR power unit and fitted surgical gloves removed. The towel worn to protect the neck has been omitted for illustrative purposes.

Fig. 3: Examples of contamination of the forearm, wrist and hand (left panel) and neck of a study participant wearing enhanced respiratory and contact precautions (E-RCP).