Executive Guideline for the Disinfection of Medical Tools and Equipment

This article is written by Ms. Arezoo Pourdad, Zahra Foroughi, and Manijeh Shams, and was submitted to the 10th Infection Control Congress.

Introduction

Every year, hundreds of millions of people around the world are affected by avoidable healthcare-associated infections. The factors contributing to these infections stem from a complex combination of gaps in infrastructure, organization, and knowledge, as well as deficiencies in healthcare workers’ behavior and patient-related factors. Among these, the disinfection and sterilization of medical tools play a critical role in preventing, controlling, or causing hospital-acquired infections. The goal should be to eliminate all living microorganisms; when this is not feasible, efforts must be made to reduce microbial load as much as possible. The most common healthcare-associated infections that arise from the reuse of dangerous tools or improper disinfection include surgical site infections, Hepatitis B and C, HIV, urinary catheter-associated infections, vascular catheter infections, and ventilator-associated infections. To prevent these infections, thorough cleaning and disinfection are crucial. It is essential to have sufficient knowledge about disinfectants and their application methods.

Given the importance of this process, particularly during the COVID-19 pandemic, this guideline has been developed to guide users on how to disinfect medical tools and equipment in emergency and other clinical departments of Alzahra Educational Medical Center. Additionally, the guideline aims to familiarize personnel with the decontamination of medical essentials, the correct use of disinfectants, the preparation of proper concentrations, and precautions for handling different types of disinfectants.

Definitions

Decontamination: The removal of microorganisms from non-living surfaces like environmental surfaces.

Disinfection: The elimination or reduction of pathogenic microorganisms from objects, ensuring their safe handling, use, or disposal.

Cleaning: The removal of visible contamination from surfaces and tools, achieved through manual or mechanical methods. This is done using detergents and is mandatory before disinfection or sterilization.

Contamination: The presence of harmful, potentially infectious, or unwanted substances on living or non-living objects.

Disinfectant: A chemical agent capable of killing most pathogenic microorganisms (sometimes even bacterial spores) on non-living surfaces under specified conditions. Its counterpart, which eliminates microorganisms on skin and mucous membranes, is called an antiseptic.

Classification of Hospital Disinfectants

1. Based on Microbial Spectrum:

• Low-level disinfectants
• Intermediate-level disinfectants
• High-level disinfectants

1. Based on Effectiveness (Spalding Classification):

1. Based on Instrument Levels:
   • Critical
   • Semi-critical
   • Non-critical
2. Based on Environmental Surfaces:
   • High-risk
   • Low-risk

Note: The determination of high-risk or low-risk environmental surfaces is the responsibility of the hospital.

1. Based on Use in Hospitals (Infection Control Committee Classification):

• Disinfectants for sensitive surfaces: e.g., operating rooms, intensive care units, transplant units, immunocompromised wards.
• Disinfectants for semi-sensitive surfaces: e.g., kitchens, restrooms, corridors, laundry areas.
• Skin disinfectants
• Disinfectants for critical, semi-critical, and non-critical instruments
• Sterilizing agents for critical instruments only

Characteristics of an Ideal Disinfectant

• High microbicidal activity
• Rapidly kills a broad range of microorganisms, including spores
• Chemically stable
• Effective in the presence of organic matter
• Compatible with surfaces being disinfected
• Ability to penetrate crevices (desirable)
• Cost-effective

Importance of Disinfecting Medical Equipment

Disinfection protocols vary depending on the type of contamination. Failure to adhere to such processes can lead to contamination of instruments and the spread of fatal infections to patients. Infection control specialists are at the forefront of the fight against infection, and the method used for cleaning and sterilizing instruments is one of the most important and effective tools in protecting both equipment and patients. The reasons for the importance of disinfecting medical equipment include:

• Prevents bacterial growth
• Reduces the risk of mortality
• Protects staff and patients from microbial agents
• Maintains equipment lifespan and enhances service quality

Factors Affecting the Efficiency of the Disinfection Process

1. Number of Microorganisms: As the bioburden increases, the required disinfection time also increases. Therefore, thorough cleaning of all instrument surfaces is essential.
2. Presence of Organic Materials: Organic substances like blood, serum, pus, feces, and other matter reduce the disinfectant’s effectiveness by interfering with its contact with instruments.
3. Microbial Resistance to Chemical Agents: Microorganisms vary in their resistance to different antimicrobial agents.
4. Physical and Chemical Factors: Disinfectants may have optimal activity under specific temperature and pH conditions.
5. Exposure Time: The efficacy of each disinfectant varies, with each requiring a specific contact time to achieve the desired result.
6. Stability: Some disinfectants, like chlorine-releasing agents, lose effectiveness over time and should be discarded according to the manufacturer’s recommendations.

This guideline ensures adherence to proper disinfection protocols, especially in the context of the COVID-19 pandemic, ensuring the safety and health of both healthcare workers and patients.

Conclusion

Since healthcare environments are places where harmful pathogens, microbes, and bacteria live and spread, and medical devices are used in these high-risk settings—some of which are exposed to infectious pathogens or directly enter patients’ bloodstreams—each device requires a different level of sterilization and disinfection. Therefore, it seems that by utilizing knowledge, adopting best practices, having appropriate protocols for sterilizing or disinfecting medical equipment before and after use, improving infrastructure, and educating on infection prevention and control fundamentals, the harm caused by healthcare-associated infections to both patients and healthcare workers can be prevented.