INTRODUCTION
Surgical site infections (SSI), are a significant cause of morbidity .This can be attributed to several reasons, the important surgical procedures including the instrumentation, emergence of drug resistant microorganisms, increase in the number of surgical patients with chronic debilitating  diseases and immuno-compromised patients.
Surgical site infections result in delayed wound healing increased hospital stays, unnecessary pain and in extreme cases, death of the patient. The misuse of “surgical prophylaxis” has resulted in an increase in the number of unusual and highly resistant pathogens like methicillin –resistant  staphylococcus aureus and Vancomycin –resistant enterococci. In many parts of our country, even the diagnosis of these infections is difficult due to the lack of laboratory support. Another major limitation in India is the lack of the documentation and data on the prevalence of SSI in different settings.  It is necessary to create awareness that this risk is influenced by the characteristics of the patient, operation, personnel, and hospital environment.

• Practice of aseptic techniques
• Sterilization of instruments and equipment
• Staff and patient skin preparation
• Surgical attire
• Creation and maintenance of sterile field
• Control of the environment
  

Genesis of SSI
Sources of pathogens include:

• The endogenous flora of the patients skin, mucous membranes or hollow viscera
• Seeding of the operative site from a distant focus
• Exogenous sources like surgical personnel, OR environment, instruments or other material brought into the sterile field during an operation

Environmental Issues

I.OR Design and Plan should include the following

• The clean and dirty areas should be separated.
• The scrub or handwash station should be closed to the operating room.
• The sterilizers should be housed in a clean room.
• The OR should not be cluttered with shelves and other crevices for storage.
• All items should be removable.
• The wall of the OR should be smooth and washable.
• The high humidity promotes easy growth of fungus which may be prevented by using antifungal paints.
• Tiles may be used as an alternative.
• The floor should be tiled with non-porous material.
• All natural stone surface like marble etc  are porous and absorb.  
• Fans should not be provided because they create air turbulence.

OR Air-handling is specialized subject. Modern day Ors have complex systems that guarantee air quality. There are four critical parameters that need to be monitored.

• The air should be under positive pressure to ensure that the dirty air from outside does not matter. All air-conditioning systems provide this, doors should be kept closed.
• The temperature should be 20 to 22 degrees Celsius to inhibit bacterial growth.
• Air changes per hour as per international guidelines are a minimum of 15 ACH i.e the entire air in the room is changed 15 times per hour. This is based on the assumption that the occupants in the room are responsible for the most of the contamination and peak efficiency for the removal of particulars takes place at this level of air changes. HEPA filters are recommended only for high risk surgeries involving implants etc. The role of other devices like UV irradiation and ionizers is not proven. However, in India where many surgeons operate with window air-conditioners their role needs to be validated.
• Humidity in the OR needs to be maintained at 30-60% relative humidity to prevent fungal growth. This parameter cannot be controlled without an air handling unit.
• Sources of microorganisms in the OR environment include dust, lint skin squamous (epithelial cells), aerosols and respiratory droplets.
• The microbial level in the OR is directly proportional to the number of people moving about in the room. Efforts should therefore be made to minimize traffic during surgery.
• Movement of  “swinging” doors also creates turbulence and adds to the microbial burden. Sliding doors are thus to be preferred.

• HVAC systems maintain indoor air temperature and humidity, control odours, remove contaminated air and minimize the risk of transmission of air borne microorganisms.
• They consist of air inlets, filter beds, humidity modification mechanisms heating and cooling equipment, fans, ducts and air exhausts.

• Decreased performance of HVAC systems can contribute to the transmission of air borne infections in the OR.

II. Environmental Sampling

• Air Sampling is used to detect aerosols or particles of microorganisms. These may be respirable particles (<5um) or larger particles. This requires counters and is a practical method for evaluating the efficiency of filters.
• Microbiologic sampling may be in the form of settle plates which rely on gravity.

• This selects large particles and lacks sensitivity  for respirable particles. They are commonly used for sampling air for bacteria and fungi.
• The detection of pathogenic microorganisms and or fungi from the operating room environment should thus be an indicator of inadequacy of cleaning / air quality.

• Microbiologic sampling remains controversial since there are no standards for comparison. Interpretation of results by an infection control expert is necessary.

III. OR sanitation and cleaning

Environmental surfaces in Ors are rarely implicated as the pathogens. However, it is important to perform cleaning of these surfaces to reestablish a clean environment after each operation. The choice of disinfectant is important. The ideal disinfectant should have a broad spectrum, be safe and economical. There is a wide choice environmental iodophors , hydrogen peroxide (stabilized with silver), chlorhexidine gluconate combinations etc.

Brooming should not be done in the OR. Cleaning is with wet moping only.

• Beginning of the day i.e. before the first surgery.
• During a procedure.
• Between procedures.
• End of the day
• Weekly / monthly
• Prior to the first case

The furniture, equipment, lights are damp dusted with a detergent germicide, preferably with lint free cloth. Particular attention to be paid to horizontal surfaces because dust and lint transport microorganisms settled on them.

• During the procedure

Spills / blood splashes in the vicinity of the sterile field should be absorbed with a cloth and cleaned with a germicide.

All instruments opened for a procedure whether used or not are treated as contaminated.

• In-between cases

Furniture, operating lights, suctions canisters and other equipment used is wiped with a detergent germicide. Mattress is wiped and bed is remade.
Patient transport vehicles are wiped.

3-4 feet area of the floor around the table be cleaned. Wet mop, fresh for every patient is preferred or wet vacuum cleaner.

Walls, doors, push plates and other areas that have come in contact with the patients’ blood and body fluids are cleaned.

• Days’ End:

OR, scrub utility, corridor, furnishings and floors after evacuation of OR
With a detergent water followed by a disinfectant.

Fumigation / Fogging
This ancient routine is still widely practiced. However, there is no substitute for vigorous washing of surfaces that come in contact with patients.

Fumigation traditionally consisted of a mixture of formalin and potassium permanganate being placed in a bowl. The room would then be sealed and opened 12 – 24 hours later. Later on this changed to formalin sprayed with humidification by a spraying device or automist.

Fogging hastens the process of setting of airborne microorganisms. Mist, generated by a disinfectant or water would achieve the same process. This procedure is no longer recommended in the Western literature. Fogging, however, continues to be a primary method of decontaminating ORs in our country.

It is prudent to mention that this gives a false sense of security. Moreover, formalin has now been identified as a carcinogen.

If this procedure is to be continued the following points need to be considered.

• Replace formalin with a safer agent like hydrogen peroxide stabilized with a silver salt.
• This is not an alternative to mechanical cleaning of surfaces.
• If has no role in ORs with modern day HVACs.
• If surgeries are being performed with window air-conditioners fogging would be required on a daily basis not on weekends alone as is practiced.

IV. Sterilization of instruments

This is one of the most critical procedures requiring stringent monitoring. Surgical instruments should be soaked in a germicidal detergent and thoroughly washed prior to steam sterilization or the use of other approved methods.

Shortcut methods like boiling and chemical decontamination of surgical instruments should be avoided.

Insufficient numbers of surgical instruments sets during “camps” may lead to inadequate sterilization of instrument resulting in grave consequence.

Patients characteristics that may influence the risk of SSI:

• Age
• Nutritional status
• Diabetes
• Smoking
• Obesity
• Coexistent infection
• Colonization with microorganisms
• Altered immune status
• Length of Preoperative stay

Certain studies have shown the above factors to be significant risk factors.
Preoperative colonization of the nares with Staphylococcus aureus has been shown to be one of the most powerful independent risk factors for SSI following cardiothoracic operations.

Preoperative antiseptic bath / shower reduces the microbial load of the skin. Chlorhexidine gluconate achieves a 9 fold reduction when compared with Povidone Iodine product which achieves a 1-2 fold reduction in microbial counts.

Preoperative shaving
Shaving the surgical site the night before an operation is a significant risk factor for SSI. Microscopic skin cuts serve as foci for bacterial multiplication. The recommended practices are shaving immediately before an operation, clipping depilation before an operation.

Patient skin Preparation
The recommended agents are

• Chlorhexidine  gluconate
•  Povidone Iodine
• Alcohol containing products

     Chlorhexidine  gluconate is advantageous because of its residual activity after a single application and the fact it is not in activated by blood or serum proteins, iodophors on the contrary lack both these properties.

Principals for surgical prophylaxis

• Use a safe, inexpensive and bactericidal agent that covers the most likely intra-operative organisms.
• Time the initial dose such that a bactericidal concentration is achieved in the serum and tissues by the time the skin is incised )eg. With induction of anesthesia)
• Simple protocols will ensure proper implementation.

The choice of antimicrobials depends on the endogenous flora likely to contaminate the site. Cephalosrins are the most thoroughly
investigated agents  for surgical prophylaxis.

Anaerobic cover if required, is achieved with Clindamycin or Meteronidazole.

Preparative related to the surgical team

• Hand / Forearm antisepsis:

Surgical team members who came into direct contact with the sterile operating  field, sterile instrument or supplies used in the field must perform a surgical scrub. The most appropriate agents are chlorhexidine gluconate 4% or povidone-iodine 7.5%. the duration of the scrub should be at least three minutes. The first scrub of the day should include thorough cleaning underneath the finger nails. Sterile towels should be used for drying.

• Colonized or Infected Surgical Personnel

Personnel operating with active infections have been linked with outbreaks of SSI. Healthcare organizations should implement policies to prevent the transmission of microorganisms from personnel to patients. Policies will depend on the infectivity of the person, the type of patient contact and when necessary should consists of exclusion from work.

Surgical attire
The use of barriers like scrub suits , caps, masks, gloves and gowns seems prudent to minimize the exposure of the patient to the skin mucous membrane or hair of the surgical team members and to protect the surgical team members from exposure to blood borne pathogens.

All personnel working in the operating rooms must wear claen surgical attire in place of their ordinary clothes should not worn out side this area.

Scrub suits : Surgical attire should be designed for maximum skin coverage since skin is a potential source of microbial contamination.

Caps : head and facial hair should be covered. Hair is a rich source of microbes.

Masks : disposable deflector masks which should be well fitting must worn. Cloth masks, are ineffective barriers for microorganisms particularly once they get moistened during breathing.

Some studies have raised doubt about the efficacy of masks in preventing  SSI risk. Nevertheless, masks are beneficial in protecting the wearer from inadvertent exposure to blood and body fluids. If splashes are anticipated during surgery additional protective  eye wear / face shields are recommended.

Shoes/ Shoes covers: Dedicated footwear is recommended for use in the OR. The footwear should be designed to protect the wearer form spills of blood and body fluids.

Sterile gloves: Sterile gloves are worn by all scrubbed members of the surgical team. They help to minimize the transmission of microorganisms from the hands of the surgical team to the patient. They also protect the surgical team members from contamination with the patient’s blood and body fluids. Double gloving is recommended for protection during operations on patients infected with blood borne pathogens namely, HBV, HCV and HIV.

(Reuse of surgical gloves is not recommended)

Gowns and drapes: sterile surgical gowns and drapes are used to create a barrier between the surgical operative field and potential sources of microorganisms. All surgical team members should wear gowns and draped are placed over the patient.

The gowns and drapes should ideally be made of material that is impermeable to liquids. However, such gowns are uncomfortable and require careful selection.

Gowns and drapes may be disposable or reusable.

It is common practice to use cotton gowns and drapes. A plastic apron should be worn under the gown. The cotton gowns and drapes are laundered following use and steam sterilized for reuse.

Asepsis and surgical technique
All  scrubbed personnel must adhere practices at all times.

Members who work in close proximity of the sterile field auch as anesthesia personnel must also follow the same standards of asepsis.

Invasive procedures like endotracheal intubation, intravascular devices have all been associated with out breaks of post operative infections including SSI.

Additional Issues
Pest Control
It is essential to keep the OR free from pests like flies, which can sometimes gain entry through open doors. There has to be a regular schedule for pest control. Besides, the pesticides used must be safe in case the AHU gets contaminated with these or else the procedure should only be carried out when the AHU is shut down.

Water
This is an important reservoir of microorganisms like Pseudomonas species. Some water sources may also be responsible for outbreaks of legionellosis.

If the OR dose not have a dedicated water tank it is advisable to treat the water at the user end by some means prior to its being used in the OR

There are several commercial gadgets available for this purpose.

Water has been implicated as an important reservoir in outbreaks of post operative infections.

SSI surveillance :

Principles and practice
Surveillance of SSI with appropriate feedback to the surgeon has been shown to be one of the important strategies to reduce the risk of SSI.

Essential clinical data should consists of the following :

• Severity of infection
• Type of operation and extent of bacteriological contamination of the wound (wound classification)
• Time period between the procedure and the appearance of infection

Microbiology  laboratory data should be reliable and include the complete identification of organisms isolated and their antimicrobial susceptibility. Thus the recommended practice is Targeted surveillance. This may use be by site by unit, or by priority.

Surveillance methods

• In-patient SSI surveillance

Direct observation of surgical site by surgeon /Infection Control Nurse. Case finding varies from daily to < 3 times per week

Indirect observation through review of laboratory reports or patient records.

• Post discharge SSI surveillance

Most SSI become evident within 21 day after the operation. This may be by the following means

• Direct examination of wounds during follow up
• Review of clinical records
•  Mail based surveys
• Pharmacy records for the use of antimicrobials

 CONCLUSION:

As is evident from these guidelines the problems of a developing country are unique. This fact is further complicated by resource crunches , poor hygienic standards, non availability of items and irregularity of supplies.

Simples solutions, tailor –made to suit the problem are far easier to implement than reading international standards and being idealistic rather than realistic.