Place of PSC in the instrument processing cycle
Infection control in healthcare facilities relies on strict adherence to a three-stage processing cycle for reusable instruments that compromise the integrity of the skin. This cycle includes three consecutive stages:
- Disinfection — primary destruction of microorganisms and immersion of instruments in solutions immediately after use.
- Pre-sterilization cleaning (PSC) — removal of protein, lipid, and mechanical contaminants.
- Sterilization — the final stage of destroying all microorganisms.
Mandatory PSC and subsequent sterilization are indicated for devices that come into contact with blood, wound surfaces, injection solutions, or mucous membranes when there is a risk of their trauma.
Algorithm and rules for manual cleaning
The pre-sterilization cleaning process is carried out after disinfection measures are completed at room temperature and includes the following mandatory steps:
- Rinsing instruments under running water for 2–3 minutes.
- Soaking devices in distilled water for 10–15 minutes.
When immersing in the solution, basic technical rules must be followed:
- Modular devices are immersed strictly in a disassembled state.
- Instruments with locking mechanisms are soaked exclusively in the open position.
To effectively remove mechanical contaminants from small instruments, specialized ultrasonic devices such as the «Serga» unit may be used.
Quality control and process completion
To verify cleaning efficiency and detect possible residues of «occult» blood, the azopyram test is used.
Evaluation of test results is carried out according to the following criteria:
- The test is considered positive, indicating ineffective cleaning, if the reagent upon contact with the test area within one minute causes the appearance of a purple color that rapidly changes to pink-lilac or brownish.
- Upon completion of pre-sterilization cleaning, medical instruments must be thoroughly dried before being sent to the next sterilization stage.
PSC consists of three «R»s of manual work: Disassemble (modular parts), Open (locks), and Soak (in distilled water for 10–15 minutes).
Class and exam questions
In what water and for how long is soaking performed during PSC?
Instruments are soaked in distilled water for 10–15 minutes after preliminary rinsing under running water.
How to prepare locking and modular instruments for cleaning?
Modular medical devices are immersed in the cleaning solution strictly in a disassembled state, and instruments with locking mechanisms must be in the open position.
How is the quality control of pre-sterilization cleaning performed?
To detect residues of occult blood, the azopyram test is performed. If a purple color appears within one minute and transitions to pink-lilac or brownish, the cleaning is considered ineffective.
What else to study on this topic
- Modern disinfectants with detergent effect (QACs, surfactants)
- Automated processing devices for handpieces («Assistina», «Terminator»)
- Methods and devices for actual sterilization (dry-heat cabinets, autoclaves)
- Features of using glass bead and chemical sterilizers
- Organization of central sterile services departments (CSSD)
Master the entire topic in the "Hygiene" course
This is a summary. The course covers everything tested in classes and exams.
- Complete manual on «Pre-sterilization cleaning of medical devices» and 530 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 95 video lessons for the subject
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.