Evaluation of gowns and coveralls used by medical personnel working with Ebola patients against simulated bodily fluids using an Elbow Lean Test

Abstract

Gowns and coveralls are important components of protective ensembles used during the management of known or suspected Ebola patients. In this study, an Elbow Lean Test was used to obtain a visual semi-quantitative measure of the resistance of medical protective garments to the penetration of two bodily fluid simulants. Tests were done on swatches of continuous and discontinuous regions of fabrics cut from five gowns and four coveralls at multiple elbow pressure levels (2-44 PSI). Swatches cut from the continuous regions of one gown and two coveralls did not have any strike-through. For discontinuous regions, only the same gown consistently resisted fluid strike-through. As hypothesized, with the exception of one garment, fluid strike-through increased with higher applied elbow pressure, was higher for lower fluid surface tension, and was higher for the discontinuous regions of the protective garments.

Keywords: Ebola; Elbow Lean Test; medical garment; strike-through; synthetic blood.

Figure 1.

ELT process for Gown A1 as an example, which had failed: (a) foam pad saturated with synthetic blood; (b) foam pad covered by “pre-test”fabric, which is then covered by the blotter; (c) elbow lean onto blotter with polyethylene to separate fluid from clothing of elbow; (d) “post-test”fabric, strike-through of fluid observed through blotter; (e) penetration side of fabric showing less fluid than blotter; and (f) side of fabric in direct contact with foam pad.

Figure 2.

Blotter images of blood used to semi-quantitatively estimate amount of fluid strike-through, identified as: (a) very small (v); (b) small (s); (c) medium (m); and (d) high (h).

Figure 3.

Cumulative blot area (amount of fluid strike-through) for a given pressure, calculated as the sum of the visually determined blot sizes of all replicates within a garment model (see Appendix B, Equation B1), and stacked graphically by pressure for a given region and fluid type.

Figure 4.

Difference between strike-through of synthetic blood and colored water, derived from the CBSS (see Appendix B, Equation B2), summed by pressure for each garment model, where only samples tested at all three pressures are plotted. Positive results show greater strike-through of synthetic blood and negative results favor colored water.