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Medical and surgical asepsis: Clinical skills notes



Infection control

Medical and surgical asepsis


Asepsis is defined as the absence of pathogens. Now, there are two basic types of asepsis: medical asepsis and surgical asepsis.
  • Medical asepsis (a.k.a. “clean technique”): practices that kill some microorganisms to prevent them from spreading. 
  • Surgical asepsis (a.k.a. “sterile technique”): practices that completely kill and eliminate microorganisms.

Figure 1: The differences between medical and surgical asepsis. 

Medical Asepsis

Medical asepsis includes sanitization, antisepsis, and disinfection.


Sanitization refers to cleaning practices and techniques that physically remove microorganisms. These include hand washing and cleaning of clients’ personal equipment, clothing, and linens.

There are several things that you should know in order to maintain a sanitary environment. The most important one is hand hygiene, which includes hand washing and use of alcohol-based hand sanitizer.
  • Always wash your hands before meals, after using the bathroom, and before and after any contact with your clients. 
  • Wash your hands after touching your own or your client’s body fluids, such as urine, feces, blood, saliva, vomitus, or genital discharge. 
  • When coughing or sneezing, always cover your nose and mouth with a tissue or your elbow. Teach your clients to do the same.

Next up are personal items.
  • Each client should have their own soap, cups, toothbrushes, and towels. 
  • Personal equipment should be regularly cleaned to prevent the growth of microorganisms. 
  • When cleaning the room and objects, make sure to not stir up the dust (i.e., avoid shaking dirty linens, and use a moistened cloth or mop to wipe dust). 
  • When disposing of dirty linens to laundry bins, keep them away from your uniform. This will prevent the contamination of your uniform, and subsequently, the spread of microorganisms. 
  • Regularly empty the garbage because trash is a perfect environment for pathogen growth. 
  • Finally, maintain good personal hygiene and assist your clients to achieve the same!

Figure 2: Sanitization includes hand washing and cleaning of clients’ personal equipment, clothing, and linens.


Antisepsis is the process of killing microorganisms or limiting their growth on the skin and non-living objects. Chemicals used in antisepsis are called antiseptics, and the most common ones include rubbing alcohol and iodine. Antiseptics can be used for hand scrubbing; treating cuts, wounds, and burns; and preoperative skin cleaning.

Figure 3: Antiseptics, like rubbing alcohol and iodine, kill microorganisms or limit their growth on the skin and non-living objects. 


Disinfection refers to the process of killing microorganisms on objects that are commonly in contact with your clients, such as overbed tables, wheelchairs, stretchers, urinals, bedpans, and blood pressure cuffs. It’s important to note that disinfection cannot destroy spores, which are highly resistant forms of microorganisms that develop in conditions that are inconvenient for their growth.

Chemicals used in disinfection are called disinfectants. In contrast to antiseptics, disinfectants are much stronger; therefore, they are not used on the skin! Moreover, in order to prevent skin irritation, you should always wear household or utility gloves while handling disinfectants. 

Figure 4: Disinfectants kill microorganisms, except spores, on objects and should be handled with gloves. 

Surgical Asepsis

Examples of surgical asepsis include the use of disposable sterile supplies, such as syringes, needles, and surgical gloves; and the use of reusable sterile equipment, such as surgical instruments (Fig. 5a).

Most commonly, surgical asepsis is acquired through a process known as sterilization. You can think of sterilization as the highest level of asepsis because it kills both microorganisms and spores. Just like disinfection, sterilization is not used on people; instead, it is used on equipment and instruments that must be totally free of microorganisms. For example, a commonly used device to sterilize surgical instruments is the autoclave, which uses high pressure and temperature to kill microorganisms and their spores (Fig. 5b).

Finally, it’s important to note that before something can be disinfected or sterilized, organic materials, such as blood, feces or urine, must be removed using sanitization practices and techniques.

Figure 5: Surgical asepsis is ensured by using A. sterile supplies and B. devices to sterilize instruments, such as an autoclave.