Medical Device Reprocessing Association of Ontario (MDRAO) Practice Exam

What is the most common cause of staining of instruments?

1. Excessive heat during sterilization

2. Using outdated detergents

3. Insufficient rinsing of detergent residue

4. Improper drying techniques

The correct answer is: Insufficient rinsing of detergent residue

Staining of instruments during reprocessing is frequently attributed to insufficient rinsing of detergent residue. When instruments are not thoroughly rinsed after cleaning, remnants of detergents can remain on the surface. These residues may react with water, heat, or other environmental factors, leading to discoloration or staining of the instruments. It is crucial to ensure that all cleaning agents are completely removed to maintain the integrity and appearance of medical instruments. While excessive heat during sterilization can indeed damage materials, it does not directly cause staining in the same way that detergent residues do. Using outdated detergents may also affect cleaning efficacy or cause issues, but it is not the predominant reason for staining. Similarly, improper drying techniques can lead to water spots or other forms of degradation but is not the primary cause of staining. Thus, insufficient rinsing stands out as the most significant factor contributing to the staining of instruments.