Processing and sterilization of equipment

Cleaning and storage of endoscopic equipment

Due to the high risk of patient and medical staff infection with virulent microorganisms, the endoscope handling algorithm requires a strict sequence. The complete cycle includes six mandatory steps: mechanical cleaning, flushing, pre-sterilization cleaning, sterilization, drying, and storage.

Preliminary (mechanical) cleaning starts immediately after the procedure ends. This is essential for the reliable removal of biological fluids: blood, mucus, gastric, or intestinal juice.

• Outer surface: thoroughly cleaned mechanically using conventional fabric wipes.
• Internal channels (biopsy and operating): cleared using a specialized brush.
• Flushing: a sufficient amount of air, clean water, or neutral soap solution is supplied into the channels. Special cleaning solutions are also used.
• Features of rigid models: before starting cleaning, rigid endoscopes must be disassembled into individual component parts.

Work-ready sterile devices are placed in special cabinets strictly in a vertical position. To protect against contamination, they are stored in sterile bags made of dense cotton fabric.

Infection prevention during mechanical ventilation and anesthesia

Anesthesia machines and mechanical ventilation (MV) systems represent a significant vector for healthcare-associated infection transmission. Without proper disinfection, cross-infection occurs.

The main goal of processing is the prevention of contact and inhalation contamination of the respiratory tract. Ignoring these rules provokes the development of severe purulent-inflammatory complications of the respiratory tract, such as:

• Pneumonia
• Bronchitis
• Tracheitis
• Pharyngitis

It should be strictly remembered that endotracheal tubes are not subject to reprocessing. They are intended exclusively for single use and undergo factory cold sterilization.

Chemical processing of anesthesia and respiratory equipment

Processing of the respiratory circuit (including the humidifier, vaporizer, and the anesthesia machine itself) in an assembled state after standard procedures is carried out using chemical antiseptics.

Option A: Alcoholic chlorhexidine solution (0.5%) To prepare the working mixture, combine 1 ml of a 20% aqueous chlorhexidine solution and 40 ml of 96% ethanol. The resulting mixture is poured into the humidifier or vaporizer. Ventilation is then initiated in a semi-closed circuit for 1 hour at a gas flow rate of 2 L/min. After removing the antiseptic residues, the system is aerated in a semi-open circuit for 15 minutes.

Option B: Formalin (40% aqueous formaldehyde solution) Pour 100 ml of formalin into the vaporizer or humidifier. The ventilation process continues for 20 minutes. After removing the formalin, an ammonia solution is poured into the system for chemical neutralization. Final ventilation is carried out until the characteristic odor of ammonia completely disappears.

Option C: Gas method and radiation An alternative approach for disinfecting assembled devices is the use of ethylene oxide (gas sterilization) or exposure to $\gamma$-radiation.

Class and exam questions

What else to study on this topic

• Compositions of special cleaning solutions for channel processing
• Ventilation mechanisms in semi-open and semi-closed circuits
• Physics of gamma radiation during the sterilization of assembled devices
• Chemical reaction of formaldehyde neutralization with ammonia

Other topics in the section "CHAPTER 2. ASEPSIS AND ANTISEPSIS"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.