The phenolphthalein test helps to determine how well the tools were cleaned of detergents. But this is not the only method for diagnosing the purity of medical instruments.
Necessary cleaning and quality control
All medical instruments must be specially treated. All mechanical, fatty and protein contaminants are removed from them. Also, they should not leave traces of drugs.
The quality of their cleaning is checked using special samples. They allow you to see how well the products are washed from blood and other biological fluids. It is also necessary to control the cleaning of instruments from alkaline substances contained in detergents, from medicines.
After disinfection of instruments, the quality of its conduct is evaluated. In a centralized sterilization unit, this must be done daily, checking 1% of all instruments. Moreover, there should be at least 3-5 units of each type. If at least one of the devices shows traces of poor-quality cleaning, then all tools are sent for re-processing. In medical institutions, azopyramic and phenolphthalein samples are made.
Pre-sterilization treatment
Particular attention in hospitals should be given to cleaning the instrument. It can be carried out manually or mechanically. As a pre-sterilization treatment, a special washing solution is used.
Manual processing is carried out as follows.
Rinse instruments under running water for 30 seconds.
Soaking in a specially prepared washing solution for 15 minutes, the temperature should be at least 50 0WITH.
Wash tools in a solution with a cotton-gauze swab or ruff.
Rinse for 30-60 seconds. running, and then distilled water.
Drying of instruments to the complete disappearance of moisture by hot air, its temperature should be 80-85 0WITH.
Mechanized cleaning is carried out in accordance with the instructions that are attached to each device.
Phenolphthalein test
Instruments that have undergone pre-sterilization treatment should be randomly checked. Phenolphthalein test allows you to see traces of detergents. It is carried out using an alcohol solution of phenolphthalein (1%). In addition, you will need a reagent pipette, a tray with dry tools and cotton swabs.
Phenolphthalein test is carried out as follows.
The solution is applied with a pipette to the instruments, into the gaps of the needles.
The items to be checked are kept over clean cotton and the color of the falling reagent is checked.
The result is evaluated over two minutes. If the color of the reagents remains unchanged, then the sample is considered negative.
After completion of the test (provided that it was negative), rinse the instruments.
With a positive reaction, the color of the reagent changes from pink to raspberry. It is this phenolphthalein sample that is used to determine the degree of purification of all instruments from the washing solution. Thus check the quality of their rinsing.
Azopyram test
There are studies that allow comprehensive monitoring of the quality of cleaning tools. For example, the phenolphthalein test does not allow you to see the remnants of hemoglobin, traces of drugs and rust.
For a comprehensive study, an azopyram reagent is needed. To prepare it, take 100 ml of amidopyrine, mix it in a dry bowl with 1 ml of aniline hydrochloride.The resulting mixture is poured with 96% alcohol to a volume of 1 liter. In addition, cotton swabs, pipettes for a solution of azopyram and 3% hydrogen peroxide are prepared. The prepared active mixture should be stored for no more than 2 hours.
To prepare the reagent, 1% alcohol solution of azopyram and 3% peroxide are mixed. It is applied to the instruments with a pipette. The azopyramic (as well as phenolphthalein) test is carried out to check the product cavity, thread clamps, places of contact with body fluids. If the color of the reagent does not change, then the reaction is considered negative. The color of the reagent is observed for a minute.
Blue-violet staining indicates that blood remains on the instruments. A brown color appears upon contact with chlorine-containing oxidizing agents or rust. A pink hue indicates an alkaline reaction.
