The reprocessing of medical instruments begins immediately after a procedure with pre-cleaning. Instruments are considered “grossly soiled” when covered in visible organic material, such as blood, tissue, or bodily fluids. This initial decontamination is fundamental because the success of the final sterilization process relies entirely on thorough cleaning. Without effective pre-cleaning, sterilization methods cannot guarantee the instrument’s safety for reuse.
The Purpose of Initial Decontamination
The primary objective of soaking grossly soiled instruments is to prevent the drying of bioburden, the organic material left on the surface. Dried bioburden, especially blood and tissue, creates a protective barrier that shields microorganisms from the chemical and thermal effects of later disinfection and sterilization. Immediate soaking also prevents the formation of biofilm, a protective matrix of microorganisms notoriously difficult to remove once established.
Allowing organic material to dry on the instrument surface also increases the risk of damage, such as pitting and corrosion, which can shorten the instrument’s lifespan. Furthermore, dried bioburden can become “fixed” to the surface, making manual or mechanical cleaning significantly less effective. Cleaning removes the soil, while sterilization destroys all microbial life forms, including bacterial spores.
The act of soaking helps loosen and dissolve the organic contaminants, preparing the instruments for the next stage of the reprocessing cycle. Using plain water is often insufficient because it lacks the chemical agents necessary to break down complex organic compounds like proteins and fats. Specialized solutions are required to chemically degrade the soil without damaging the delicate instrument surfaces.
Recommended Soaking Solutions
The preferred solution for the initial soaking of grossly soiled instruments is a neutral pH enzymatic detergent. These cleaning agents are specifically formulated to break down the main components of bioburden before the instruments undergo automated washing. The neutral pH is chosen because it is compatible with the various metals and materials used in surgical instruments, minimizing the risk of corrosion.
Enzymatic detergents contain specific enzymes that act as catalysts to digest organic soil. Proteases break down proteins (a large portion of blood and tissue), lipases target fats and lipids, while amylases break down starches, ensuring a broad spectrum of soil removal. These enzymes work by hydrolyzing the long, complex organic molecules into smaller, water-soluble components that can be easily rinsed away.
A secondary, acceptable option is a non-enzymatic neutral pH detergent, especially when enzymatic agents are not immediately available. These detergents rely on surfactants to lower the surface tension of the water, helping it penetrate tight spaces and suspend soil particles for removal. However, they lack the specific digestive action of enzymes on organic matter.
Avoid using harsh disinfectants, such as glutaraldehyde, for the initial soaking or cleaning phase. Glutaraldehyde is a tissue fixative; when it contacts organic protein, it coagulates and hardens the soil onto the instrument surface. This protein fixation creates a barrier that makes the soil nearly impossible to remove and dramatically hinders the effectiveness of subsequent sterilization. Always use a cleaning solution specifically labeled by the manufacturer for instrument pre-soak or cleaning.
Safety and Procedural Guidelines
The soaking process requires strict attention to safety and procedural guidelines to protect personnel and prevent instrument damage. Personnel handling soiled instruments must always wear appropriate Personal Protective Equipment (PPE), which includes heavy-duty, puncture-resistant utility gloves, fluid-resistant gowns, and eye protection. This PPE protects against contact with biohazardous material and the risk of sharps injuries.
The temperature of the soaking solution is a critical procedural detail. The water used to dilute the cleaning agent should be lukewarm or at room temperature, typically below 45°C (113°F). Using hot water is counterproductive because heat causes the proteins in blood and tissue to coagulate, or “cook,” onto the instrument surface.
Instruments must be fully submerged in the solution, and hinged instruments (such as clamps or scissors) should be opened to expose all surfaces to the detergent. The soaking time must strictly follow the solution manufacturer’s instructions, typically a short duration like 5 to 10 minutes. Prolonged soaking beyond the recommended time can damage the instrument’s finish or its working parts.
After the initial soak, the instruments are rinsed to remove the detergent residue before proceeding to the final cleaning phase. This phase may involve manual scrubbing or automated washing in an ultrasonic cleaner or washer-disinfector. The preliminary soaking step is a precondition that ensures subsequent thorough cleaning and sterilization steps are successful.