13.4.1 Infection Management and Aseptic Technique

Infection management is the control of infection sources from the environment, common vehicles (medical supplies and instruments), medical personnel (hands, nasopharynx, and body), and the patients themselves at every stage—preoperative, intraoperative, and postoperative.

(1) Sources of infection.

The pathogens of operating room infections mostly come from:

1) Skin and hair. Anyone entering the operating room is a source of environmental contamination; the skin, hair follicles, sweat glands, and sebaceous glands are full of microbial colonies, most abundantly on the head and neck, axillae, perineum, hands, and feet. On average, each person's skin sheds 4 000～10 000 microorganisms per minute; the most common cause of infection is Staphylococcus aureus, and the degree of infection is related to the cleanliness of the skin and hair and the length of the hair.

2) Nasopharynx. Microorganisms in the nasopharynx can be dispersed by talking, coughing, and sneezing, and transmitted to patients through direct contact; the most common is group A streptococcus.

3) Unclean air-conditioning systems. Both air and dust carry microorganisms and serve as vehicles for spreading germs; due to gravity, microorganisms tend to settle on the floor, so the floor is the most heavily contaminated place and should therefore be cleaned promptly. 4) In addition, the growth and reproduction of microorganisms depend on specific environmental factors, including:

① Temperature. Most microorganisms reproduce most rapidly at 20–37°C; a few bacteria with spores or capsules can tolerate high or low temperatures.

② Humidity. Bacteria easily proliferate in moist environments.

③ pH value. Most bacteria prefer to grow in neutral or slightly alkaline environments; once the pH of the environment changes, it will affect the growth or reproduction of bacteria.

(2) The patient's resistance.

The factors affecting the patient's resistance are the body's three major defense mechanisms:

1) Skin and mucous membranes. Substances secreted by the sebaceous glands can inhibit bacterial growth, while sweat can wash away bacteria; gastric mucosal secretions maintain an acidic pH environment, which can inhibit the growth of pathogens; the ciliary activity of the nasal cavity and respiratory tract promotes the removal of foreign matter. Therefore, when the skin and mucous membranes are damaged, ciliary activity is reduced, or the pH of secretions changes, the body cannot defend against the invasion of pathogens.

2) Inflammatory response. When antigens such as foreign matter or pathogens invade the body, blood flow to the injured area increases, and white blood cells move to the damaged site to phagocytize, dissolve, and destroy bacteria, while dead white blood cells, bacteria, and destroyed tissue form pus.

3) Cellular immunity and humoral immunity, accomplished by T lymphocytes and B lymphocytes respectively, constitute the body's third line of defense.

(3) Infection management.

Rational and effective infection management is the basic guarantee for the prevention and control of infection. Every hospital should establish an infection control team. The ultimate goals of infection control are:

1) To reduce infections, thereby eliminating the spread of infectious diseases and preventing the occurrence of epidemics.

2) To promote wound healing, shorten hospital stays, and increase the bed turnover rate.

3) To reduce the morbidity and mortality rates and decrease medical costs.

4) To improve the quality of medical care and improve methods of infection control.

5) Individual patient factors. When the body's three major defense mechanisms are compromised, the patient becomes a high-risk, susceptible individual. In addition, age, health status, and the use of medications and special treatments also affect the patient's resistance. Therefore, before surgery, the patient's health status should be adjusted to an optimal level, including nutrition, control of blood pressure and blood glucose, and treatment and control of existing infections.

6) Preoperative preparation. This includes: preparation of the patient's surgical skin before surgery; staff attire, environmental cleanliness of the operating room, and preparation of supplies, such as the maintenance of instruments and dressings—all of which must comply with aseptic principles.

7) Surgical procedures. Members of the surgical team must strictly adhere to aseptic technique protocols.

(4) Principles of aseptic technique.

1) Only sterile items may be used within the sterile field; if there is any doubt about the sterility of an item, it should be regarded as contaminated.

2) For a sterile surgical gown, only the front from below the shoulders to above the waist and the sleeves are considered sterile.

3) For a sterile table, only the table surface level is considered sterile, and the surface should be kept dry.

4) Scrubbed personnel may only touch sterile items and sterile areas, while unscrubbed personnel may only touch non-sterile items and non-sterile areas. Unscrubbed personnel should avoid entering the sterile field as much as possible; scrubbed personnel should avoid leaning against non-sterile areas and should face the sterile field.

5) The sterile field should be set up as close as possible to the time the surgery begins.

6) When opening a sterile package or container, attention should be paid to the expiration date and whether sterilization is complete, and care must be taken to ensure that the wrapper is not damp.

7) When handing sterile items to the scrub nurse, one should not reach across the sterile field.

8) After donning the sterile gown and gloves, the hands should be kept and operated in front of the body, below the shoulders and above the waist.

9) During surgery, when two scrubbed personnel change positions, they should follow the principle of rotating back-to-back or face-to-face.

(5) Operating room cleaning.

1) Keep the operating room floor clean at all times; do not use a broom to sweep the floor, so as to prevent dust from dispersing into the air. If equipment or the floor If blood stains adhere to the board, they should be wiped off immediately with a cloth soaked in disinfectant.

2) Before daily surgery, 75% alcohol or other chemical disinfectants may be used, and the dust on furniture and equipment in the room should be wiped clean with a dampened cloth.

3) After each operation is completed, the used instruments, dressings, and supplies must be removed from the operating room; sterile packs for the next operation must not be brought in before cleanup is finished.

4) After daily operations are completed, wipe the floor, furniture, and equipment clean with chemical disinfectant, and arrange the equipment in the room neatly.

5) A thorough cleaning should be carried out at least once a week, covering doors, windows, air duct inlets and outlets, storage rooms, cabinets, etc., and their performance should be checked.

(6) Prevent air contamination.

1) Operations involving special infections should be performed in a negative-pressure clean operating room; if performed in a general clean operating room, the purification air-conditioning system of that operating room must be shut down before the operation can proceed. After the operation, the operating room should undergo thorough terminal disinfection, and the air should be disinfected by fumigation.

2) Staff entering the operating room should first change into surgical gowns and shoes, and wear caps and masks properly.

3) Shaking of various dressings in the operating room should be minimized.

4) Personnel with upper respiratory tract infections should avoid entering the operating room as much as possible.

5) Staff in the operating room should avoid talking and laughing loudly, so as to prevent microorganisms in the respiratory tract from dispersing into the air.

6) Movement of personnel back and forth in the operating room should be minimized.

13.4.2 Quality Management of Items

(1) The sterilization process of items shall be strictly carried out in accordance with the Technical Standard for Disinfection issued by the Ministry of Health, with measures for monitoring sterilization effectiveness in place.

(2) The storage of sterile items shall strictly follow the Technical Standard for Disinfection issued by the Ministry of Health; they should be placed by category on shelves, carts, or cabinets in the clean area and issued for use in order. Designated personnel are responsible for regularly checking the sterilization indicators, sterilization dates, expiration dates, packaging integrity, and operator signatures of sterile items. The head nurse and quality control personnel should regularly inspect this work.

(3) Sterile items should be opened, prepared, and transferred in a manner that maintains their sterility and integrity. Sterile items should be retrieved directly by scrubbed personnel or placed safely within the sterile field. Once opened, sterile items must be kept within a person's line of sight to ensure their sterility.

(4) The flow of clean items and contaminated items should be strictly separated, and contaminated items should be sorted and handled strictly in accordance with relevant national regulations.

13.4.3 Quality Management of Floors

(1) Clarify the detailed rules for cleaning work.

1) Cleaning workers complete the cleaning work daily according to strict work procedures, with designated personnel checking daily to ensure work quality.

2) All wrapping cloths used on the operating table should be promptly discarded into the soiled linen bag, the bag opening tied tightly, and sent for washing by designated personnel; dressings and wrapping cloths that have not contacted patients may be placed in another bag for sorted disposal.

3) All infectious waste should be discarded into red garbage bags, and non-infectious waste into ordinary garbage bags.

4) If blood splashes onto instruments or the floor during surgery, it should be wiped promptly with a cloth soaked in disinfectant solution.

(2) Ensure the quality of cleaning tools, and strictly assign cleaning tools by area.

(3) Regularly monitor mops and floors.

13.4.4 Quality Control of Basic Operating Room Equipment

(1) For surface cleaning of basic operating room equipment, see the section on operating room cleaning.

(2) Ensure that basic operating room equipment is in good working condition.

1) The positions of basic equipment in each operating room should be fixed, and equipment should be returned to its original place promptly after use.

2) The circulating nurse should keep informed at all times of the operation status of the water, electricity, gas, negative-pressure suction, and purification air-conditioning systems used in the operating room, and promptly report inspection, and establish a regular inspection and maintenance system.

3) Clarify the usage standards for medical devices used during surgery, such as electrosurgical units, ultrasonic scalpels, endoscopes, and pneumatic tools, and assign dedicated personnel to clean, maintain, and regularly inspect the equipment.

13.4.5 Safety Management

(1) Preventive measures against potential injuries in the environment.

1) Precautions during patient transport and escort are as follows:

① Pay attention to the patient's reactions at all times during transport.

② Transport equipment should be equipped with braking devices, protective restraint devices, adjustable IV poles, fixing devices for oxygen cylinders, adjustable positioning devices, and devices for stabilizing the mattress; it should be easy to maneuver, appropriately sized, and have easy-to-clean surfaces.

③ Transport personnel should be proficient in the use of transport equipment.

④ There should be sufficient auxiliary equipment and personnel when moving patients.

⑤ During transport, all parts of the patient's body should be properly positioned, an appropriate posture maintained, and the patient kept warm.

⑥ During transport, the patient's feet should be at the front, with the transport personnel at the head side, for ease of control.

⑦ Maintain the patency of intravenous infusion and drainage systems, as well as the function of monitoring equipment.

⑧ Patients with special diseases should be escorted with a physician accompanying them.

⑨ Transport equipment should be regularly inspected and maintained.

2) Monitoring of body temperature during surgery. Age, physical condition, anesthesia method, surgical procedure, room temperature, etc. can cause changes in the patient's body temperature. Nursing staff should monitor the patient's temperature changes at all times and implement preventive measures according to specific circumstances, such as: providing warming blankets for protection after entering the operating room; minimizing unnecessary exposure of the patient's body; shortening the time between skin disinfection and draping; avoiding wetting the abdominal drape; adjusting room temperature; warming infusion and irrigation fluids; and assessing the integrity of the patient's skin before, during, and after using items such as ice bags and warming blankets.

3) Sterilizing and disinfecting agents, environmental cleaning agents, tissue preservatives, and certain cytotoxic therapeutic agents used during surgery in the operating room must comply with relevant national regulations and standardized usage methods, so as to reduce patients' exposure to cytotoxic substances; preliminary treatment should be carried out according to regulations to reduce the spread of cytotoxic substances.

4) Electrical equipment used in the operating room should be tested by the hospital's relevant technical department; during daily use, the power supply, wiring, and wear of output devices should be checked at all times; the length of electrical cords should meet the needs of the electrical equipment; and a regular inspection and repair system should be established.

5) Maintenance of the operating room environment. The floor should be kept clean, dry, and free of obstacles; the operating room should ensure an adequate air exchange rate and sufficient lighting.

6) The operating room should refine operating procedures that pose potential harm to patients, such as detailed rules for electrosurgical unit use and disinfection and sterilization systems, and establish corresponding supervision and inspection systems.

(2) Selection and control of medical products in the operating room.

1) Medical products must be safe, meet specific needs, and be able to improve the quality of patients' surgery. Manufacturers should provide product usage instructions and complete, reliable certification documentation.

2) Approval of medical products should be carried out by a committee composed of multiple departments, including hospital materials management, infection control, surgery, the operating room, anesthesiology, and pharmacy, to ensure reliability in all aspects of performance and avoid the waste of duplicate purchases of resources.

3) Evaluation criteria should include at least the following aspects: performance, safety, efficiency, cost, product compatibility, benefits, specifications, sterilization standards and methods, environmental friendliness, after-sales service, and impact on patients.

4) Before selecting products and medical equipment, a preliminary clinical trial evaluation should be conducted after understanding the usage methods and precautions, in order to verify their effectiveness.

5) For the purchase of products and medical instruments, detailed rules for selection, evaluation, testing, and personnel training should be established and revised regularly for reference. [Reference] Chemical disinfectants can be classified, according to their disinfection action, into sterilants and high-, intermediate-, and low-level disinfectants, as shown in Table 13.1.

Table 13.1 Chemical Disinfectants

Category Name Dosage/Usage Scope of Application
Sterilant Glutaraldehyde 2% sterilization: immersion 10h; disinfection: vegetative bacteria 10min, hepatitis viruses 30min Medical devices and precision instruments that cannot be autoclaved
Peracetic acid 0.1% disinfection: immersion or wiping 15min; 0.2%–0.4% spraying, action 30–60min; 0.5% disinfection: immersion 30min, spraying action 30–60min; 1% disinfection: immersion 5min; sterilization: immersion 30min Medical items that cannot be autoclaved but can be immersed in water and are acid-resistant; items contaminated with vegetative bacteria; items contaminated with hepatitis viruses or tubercle bacilli; items contaminated with bacterial spores
Ethylene oxide 450mg/L disinfection; 6h; 800–1 000mg/L sterilization; 6h Various precision instruments, endoscopes, catheters, metal and rubber products, etc.; items contaminated with hepatitis viruses or tubercle bacilli, and items contaminated with bacterial spores
Formaldehyde Formalin: aqueous solution containing 36%–40% formaldehyde; 4%–10% formalin immersion 30min; 8% formaldehyde solution prepared with 70% ethanol, immersion 5min; formaldehyde gas fumigation disinfection, immersion 18min Items contaminated with vegetative bacteria; items contaminated with vegetative bacteria; items contaminated with bacterial spores; disinfection of air and medical items that cannot withstand heat and humidity
High-level disinfectant Hydrogen peroxide 3% irrigation Surgical wounds
Chlorine-containing disinfectant Available chlorine: 200mg/L immersion 10min or wiping; 1 000mg/L immersion 30min Environment, appliances, and surfaces of objects; vegetative bacteria contaminating object surfaces; items contaminated with hepatitis viruses, tubercle bacilli, or bacterial spores
Intermediate-level disinfectant Ethanol 75% immersion 5min; immersion 10min; wiping Surgical hand antisepsis; medical devices that do not enter sterile tissues or organs; skin iodine removal
Iodophor Available iodine: 250mg/L, action 3–5min; 500mg/L immersion 30min; 300–500mg/L, action 3–5min; apply by rubbing twice, action 2min; wiping 3min Irrigation of wounds and vaginal mucosa; immersion of items; wiping of oral wounds and mucosa; skin at injection sites; surgical hand antisepsis
Low-level disinfectant Benzalkonium bromide (i.e., Bromogeramine) 0.1%–0.2% apply by wiping 2–3 times; 0.01%–0.05% wipe 2–3 times Skin disinfection; mucosal disinfection