Prevention of surgical site infections

Routing principles and sanitary regimen

The basis for preventing exogenous infection is a strict separation of patient flows into “clean” and “suppurative”.

Ideally, patients with purulent-inflammatory pathologies are allocated separate surgical departments with their own staff, operating rooms, and dressing rooms. If the hospital has only one department, infected patients are isolated in a special compartment with a mandatory dedicated dressing room.

The prevention process begins already in the admission department:

• Primary triage: instant separation of clean and suppurative flows.
• Sanitary treatment: taking a hygienic shower or bath, changing into hospital clothing.
• Specific treatment: if scabies or pediculosis is detected, linen disinfestation and patient treatment are carried out.

A strict regime is maintained within the surgical department itself. Daily wet cleaning with antiseptics is carried out, and the walls are subjected to wet scrubbing with brushes every three days. A shower before the shift, wearing caps, change shoes, and clothing are mandatory for the staff. The most important step is the identification of bacillary carriers (apparently healthy people who shed pathogenic flora from the pharynx or nose). Such employees are suspended from work, undergo sanitation, and are allowed back only after receiving negative bacteriological culture results.

Combating exogenous infection

Exogenous infection enters the wound from the external environment. The main method of combating it is asepsis (a system of measures to prevent the entry of microorganisms).

Sources of exogenous flora include suppurative patients, bacillary carriers, and, in rare cases, animals. The latter are dangerous for the development of specific infections: anthrax can be contracted when handling infected carcasses, and tetanus or gas gangrene can be acquired through accidental wound contamination with soil containing spores.

Routes of entry:

1. Contact (the main route). Infection is transmitted through transmission factors: the surgeon's hands, surgical linen, dressing material, or surgical instruments.
2. Airborne. Settling of microorganisms from the surrounding air onto the wound surface.
3. Implantation. Infection occurs when suture material, bone fixators, or prostheses are left in the tissues. The cause is either a violation of the implant sterilization rules or its contamination directly during the intervention.

Prevention of endogenous infection

Endogenous infection is located inside the patient's own body. Antisepsis is used to eliminate it.

Sources can include:

• Chronic foci outside the surgical area (carious teeth, tonsillitis, pyoderma).
• Organs on which the intervention is performed (inflamed appendix, gallbladder, osteomyelitis focus).
• Normal saprophytic microflora (respiratory tract, oral cavity, intestines).

Routes of spread within the body:

• Contact. Occurs when surgical technique is violated (iatrogenic factor), when exudate, pus, or intestinal contents get into a clean wound from gloves or sponges.
• Hematogenous. Spreading of bacteria with the bloodstream from a remote focus.
• Lymphogenous. Transfer of microorganisms via lymphatic vessels.

Infection safety in the operating room

A critical level of sterility is maintained in the operating unit. The airborne route accounts for about 10% of wound infections. Despite sterile clothing, the surgical team actively sheds microorganisms. Over 1–1.5 hours of work, the bacterial contamination of the air doubles.

Standards for 1 m³ of air:

• Before starting work: no more than 500 microorganisms.
• During the operation: no more than 1000 microorganisms.
• Pathogenic flora must be completely absent.

During the operation itself, the surgeon must strictly observe the sequence of maneuvers. When opening infected cavities (large intestine, purulent peritonitis), the wound is reliably isolated with sponges. After completing this “dirty” stage, a mandatory change of instruments, gloves, sponges, and, if necessary, surgical linen is performed.

Class and exam questions

What else to study on this topic

• Methods and regimens of surgical instrument sterilization
• Ventilation and air conditioning systems in the operating unit
• Specific prophylaxis of gas gangrene and tetanus
• Algorithms for antiseptic treatment of the surgeon's hands and the surgical field
• Classification of modern antiseptics

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.