ONEcleaner four Enzyme Surgical Instrument Detergents can significantly improve your decontamination process. Your first-line-of-defense against Preventing Corrosion is the passive oxide layer of Surgical Instruments. Stainless steel surgical instruments are made of corrosion resistant high-grade specialty steels. Corrosion resistant does not mean corrosion proof. One of the special characteristics of these steels is that the manufacturer forms a passive oxide layer on the surface, which protects them against corrosion. This makes surgical instruments as corrosion resistant as possible. It is imperative that you maintain the passive oxide layer to prevent corrosion and maintain your surgery instruments in optimal condition. If this is not done the stainless steel will be more susceptible to corrosion, pitting and stains.This will reduce the life of the surgical instrument and/or render it useless.
Initially, all stainless steel surgical instruments have the same corrosion resistance. When strength and hardness requirements are important factors for instrument function, corrosion resistance is generally lower. Increasing the corrosion resistance would soften the stainless steel. Manufacturers of surgical instruments and surgical instrument containers recommend the use of neutral pH cleaning concentrates. Neutral pH all-in-one or combination enzyme detergent cleaning concentrates have been shown to be effective in optimizing the efficacy of the passive oxide layer. This will provide a longer life for stainless steel surgical instruments. Cleaning concentrates with a high or low pH have been shown to erode the passive layer. The most common of these cleaning concentrates utilize an alkaline detergent with an acid neutralizer. Virtually all manufacturers of surgical instruments and surgical instrument containers recommend against using these detergents and recommend using a neutral ph detergent. The use of cleaning concentrates that deliver an acid rinse will release nickel from the stainless steel and decrease the efficacy of the passive layer. This is most critical on initial reprocessing events of stainless steel surgical instruments. Measurable levels of nickel have been detected. It was also shown that, as the number of subsequent uses increased, the level of nickel release diminished and reached a steady state (measured in the order of μg/l). These observations reflect the changes that occur in the passive oxide layer on first immersion of stainless steels in aqueous media.
What is a Stainless Steel Surgical Instrument?
Stainless steel is essentially a low carbon steel which contains chromium at 10% or more by weight. It is this addition of chromium that gives the steel its unique stainless, corrosion resisting properties. The chromium content of the steel allows the formation of a rough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanically or chemically, this film is self-healing, providing that oxygen, even in very small amounts, is present. The corrosion resistance and other useful properties of the steel are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel and nitrogen. Stainless steel has a passive film created by the presence of chromium and often other alloying elements, nickel, molybdenum that resists this process. When exposed in air, stainless steels passivate naturally due to the presence of chromium. But the time required can vary. In order to ensure that the passive layer reforms rapidly after pickling, a passivation treatment is performed using a solution of nitric acid and water.
How is the passive oxide layer Manufactured and Maintained?
The passive layer or stainless steel is intended to prevent or resist corrosion. Surgical Instruments are polished because the passivation process leaves microscopic pits where the carbon molecules were removed. Polishing also builds a layer of chromium oxide on the surface of the surgical instrument. Proper cleaning, handling, and sterilization will build up the layer of chromium oxide and protect the Surgical Instrument from corrosion and pitting. In some circumstances older instruments have higher resistance to corrosion than new ones. The newer instruments have not had the time to build up the chromium oxide layer. Improper cleaning and sterilization can cause the layer of chromium oxide to disappear or become damaged thus increasing the possibility of corrosion and/or pitting. Proper cleaning and sterilization can cause the layer of chromium oxide to improve over time thus decreasing the possibility of corrosion and pitting. Second only to the financial asset value of the working staff, the surgical instrument and scope inventory is the single most financially valuable asset of the healthcare facility. It is important to properly clean, sterilize, handle, and store your instruments.
To maintain moving parts and protect instruments from staining and rusting during sterilization and storage, they should be lubricated with a water-soluble, lubricant after each cleaning. Most automated washer decontaminators provide the option for lubrication at the end of the final rinse treatment. Since effective ultrasonic cleaning removes all lubricant, re-lubrication is important. The all-in-one cleaning concentrates will provide lubrication. The lubricant should contain a chemical preservative to prevent bacterial growth in the lubricant bath. The bath solution should be made with de-mineralized water. A lubricant containing a rust inhibitor helps prevent electrolytic corrosion of points and edges. Immediately after cleaning, instruments should be immersed or rinsed for 30 seconds and allowed to drain off, not wiped off. A lubricant film will remain through the sterilization to protect instruments during storage.
Prevent Staining and Spotting
Staining and spotting may result if residual chemicals are not completely rinsed from surgical instruments that are subjected to steam sterilization. Following the manufacturer’s recommendations for the proper sequence of treatments (cold water pre-wash, enzyme-detergent wash, purified water rinse/lubrication, and drying) is critical to prevent stains and spots. Cleaning Concentrates that will avoid spotting are free-rinsing.