Infection Control, Sterilization and Care of Surgical InstrumentsOne

Investigate and identify source of the infection in each case. The source may be a person, a patient or an employee or may be the practice of one or more employees of poor aseptic technique, or a team member may be harboring a specific disease organism that is transmitted to the patients in his or her care.

To identify need for change in rule book to prevent a future outbreak

Provide effective isolation of infected patients.

Where infection is suspected, a bacterial swab should be taken, this will guide the treating physician to select the correct antibiotic.

Fungal infection on toe-nails and finger-nails may be easily recognized by sending nail clippings or even the complete nail for mycology. Such action may avoid the need for surgery and establish a definitive diagnosis.

Candida infections are easily recognized and treated with any of the antimycotic agents.

Careful aseptic technique in the OT (given in this chapter).

Attention to rules and procedures for sterilization of instruments and dressings (to be defined by the hospital administrators).

However, in addition to problems of common bacterial pathogens, surgeons are now having to address themselves to the problems of viral agents such as hepatitis B, C, and HIV infection, which may have more serious long term consequences (guidelines at the end of this chapter).

Infection is not always a one-way problem of patients infecting doctors and other patients:in a few instances an infected surgeon or his team can infect the patient, or other colleagues. It is therefore important for all members of the surgical team to be aware of the potential danger of their personal infections, and to know how to avoid them by strict personal hygiene and to treat these infections if they occur. They must be freed from OT duties for the duration.

Those that enter the theater must change, in the changing room into OT shoes and OT suit

Masks and caps must be worn before entering OT and gowning

All these items must be available in the changing rooms.

Wet your hands, apply a little soap or detergent, and work up a good foam

Scrub your hands and forearms to 5 cm above your elbows for one complete minute

Wash your forearms

Then take a sterile brush and put soap on it (Fig. 1.2)

Scrub the lateral side of your left thumb, then its medial side, then the lateral and medial aspects of each successive finger

Scrub your nails, and then the back and front of your left hand (Fig. 1.3)

Follow same routine with your right hand. Scrub for 5 minutes in all.

Turn off the taps with your elbows (Fig. 1.5)

Dry your hands with a sterile towel before you put on a sterile gown

Dry your hands first, then your forearms

Grasp the folded towel with the fingers of both hands, then let it drop open, so that you don't touch anything with the open towel

Dry your hands on one corner, then dry your forearms

Try not to bring a wet (unsterile) part of the towel back to a dry area of your arms and hands.

Allow it to open up and put your arms into the arm holes while keeping your arms extended. The inside of the gown is facing you

Then flex your elbows and abduct your arms (Fig. 1.6)

Wait for the nurse to help you. She will hold the inner sides of the gown at each shoulder and pull them over your shoulders (Fig. 1.7) and will tie the tapes of the gown at the back (Fig. 1.8).

Be careful to touch only the inner surface of the gloves.

Grasp the inner aspect of the turned down cuff of a glove, and pull it on to your opposite hand (Fig. 1.9)

Leave its cuff for the moment

Put the fingers of your already gloved hand under the inverted cuff of the other glove, and pull it on to your bare hand (Figs 1.10 to 1.11A and B)

It is a good routine to wash your gloved hands in sterile water to remove the powder.

Shave the area on the morning of the operation, or as part of operation.

Start with a soap solution, and follow this with spirit

If there is a low sensitivity to iodine in the community, use alcoholic iodine

Take a sterile swab on a holder start in the middle of the operation site, and work outwards

Discard both swab and holder, and repeat the process with a second swab (some surgeons use a third)

The last is spirit which will evaporate to leave the skin dry

Be sure to prepare a wide enough area of skin

In an abdominal operation this should extend from the patient's nipple line to below his groin.

Place the first towel across the lower part of the operation site (Fig. 1.13A)

Place another towel at right angle on the nearer edge of the operation site (Fig. 1.13B)

Apply a towel clip at the point of crossing of the two towels (Fig. 1.14).

Place another towel at the far edge of the operation site

The final towel goes across the top end of the site. All the corners should have towel clips to prevent them from slipping, they can go through the skin if the operation is under GA

In an abdominal operation an abdominal sheet covers the abdomen on top of the towels. This sheet has an opening in its middle to provide access to the operation site [double toweling]

If any area close to the operation site becomes contaminated at any time during the operation, place another sterile towel over the contaminated site.

The room itself and its furniture and fixed equipment can be cleaned and disinfected

All equipment and furniture used during a surgical procedure are thoroughly cleaned

Floors should be cleaned using a wet-vacuum system. This can be a centralized built in system or a portable wet-vacuum. If neither is available, the following procedure may be used:

The pads of the operating table are removed to expose the undersurface of the table. All surfaces of the table and pads are cleaned with particular attention to hinges, pivotal points, and castors

Doors and walls are spot cleaned with disinfectant.

Surgical lights and slide tracks

All ceiling-mounted equipment

All furniture including castors or wheels

All shelves, counters, work tables and autoclave cabinet tops

All floor surfaces in the department the surfaces are corbo-lised

Scrub sinks

Soap dispensers.

Ventilation and air conditioning/heating duct grills must be vacuumed to prevent the release of bacteria-laden dust into the surgical environment.

Utility rooms, including those used to store house keeping supplies, sewer hoppers, and linens, must be cleaned.

OT Fumigation is utilized after occurrence of infection.

An item may only be sterile or nonsterile.

It cannot be nearly sterile.

Disinfection, on the other hand is the reduction of a population of pathogenic microorganisms without achieving sterility.

In these cases not all bacterial spores are destroyed.

Alcohol (ethyle + isopropyle) 70 percent was the solution most widely used

Recently of 0.5 percent chlorhexidine is widely used for emergency disinfection of surgical instruments requiring only 2 minutes immersion.

Where instruments are left for longer periods or stored continuously, the addition of one tablet of sodium nitrite 1 g will prevent rusting. As the tablet dissolves over several days, another is added.

The aldehydes (formaldehyde + glutaraldehyde) are powerful disinfectants and sterilizers. A solution containing 2 percent glutaraldehyde will disinfect instruments if they are soaked for 10 minutes, and sterilize if left soaking for 10 hours. The disadvantages are that the solution needs to be fresh, and it can cause staining if left on the skin.

It is simple, quick and reasonably effective

Will not destroy certain bacterial spores (tetanus, gas-gangrene) and certain viruses

Normally, instruments are cleaned, and then boiled for 5 minutes (100 degree C or 212 degree F)

A boiling water ‘sterilizer’ is badly named, because at a height of 3000 meters water boils at 90 degree C and is thus much less effective

This method is obviously not suitable for dressings or drapes.

Instruments to be sterilized are heated to 160 degree C (320 degree F) for 1 hour

Sterilization is achieved, but it is not suitable for rubber or plastic instruments

In hospital has been used for sterilizing powders and petroleum products and sharp delicate instruments.

‘Quick’ cycle would heat the water to 134 degree C (273 degree F) for 3.5 min under a pressure of 30 lb/in².

Slower cycle, more suitable for plastics, would heat the water to 121 degree C under a pressure of 15 lb/in² 15 minutes.

In practice, instruments are placed in the trays or in packs, the autoclave turned on, and left for the desired time.

At the end of the cycle, the instruments are ready for use.

The main disadvantage of the smaller autoclave is that instru-ment packs cannot be sterilized as there is not a vacuum cycle to extract air and dry the packs. However, most materials including rubber, plastics and metal can be readily sterilized, the only exception being sealed containers.

It must be at an appropriate temperature (which implies an appropriate pressure).

It must be saturated with steam.

Thus not be mixed with air, so it must displace all the air in the chamber of the autoclave.

And, it must reach all parts of the load. If it contains droplets of water, it will soak into porous materials.

Stage-1 Pre-vacuum—Air removal. The air is removed from the chamber by a vacuum pump and controlled steam pulsations. The vacuum achieved should be in the order of 0.5 mm Hg absolute (0.066 to 0.132 kPa).

Stage-2 Sterilization— Hold period at operating temperature. Steam is admitted to the chamber and when all parts of the load have reached a temperature of 134 degree C this is maintained for 3.5 minutes

Stage-3 Drying— Achieved by an adequate post vacuum, checked periodically by a test pack of towels which when removed from the sterilizer, unfolded and allowed to cool are not damp

Stage-4 Breaking the vacuum— Air replacement. This should be completed within 3 minutes, through a glass fiber or ceramic type filter

134°C (30 lb/in²) for a hold time of 3 minutes

121°C (15 lb/in²) for a hold time of 15 minutes.

A chemical monitor is an object that is treated with material that changes its characteristics when sterilized. This may be in the form of special ink that is impregnated into paper strips or tape and placed on the outside of the package, or it may be a substance that is incorporated into a pellet contained in a glass vial

The chemical responds to conditions such as extreme heat, pressure, or humidity but does not take into consideration the duration of exposure, which is critical to the sterilization process

Another monitoring method used to evaluate the steam sterilizer is the combined temperature time graphs that are installed within the control panel of the sterilizer. These graphs provide a permanent written record of all loads that have been processed

The surest way to determine the sterility of given items is with the use of biologic controls. A strain of a highly resistant, nonpathogenic, spore-forming bacteria contained in a glass vial or a strip of paper is placed in the load of goods to be sterilized. For steam sterilization, the dry spores of the bacteria 22Bacillus stearothermophilus are used. The gas sterilization process uses the bacterium Bacillus subtilis. The vial or strip is recovered at the end of the sterilization process and cultured. This process is time consuming and the results method of testing the efficacy of a sterilization process. Biologic controls should be administered at least once weekly. If feasible, they should also be used whenever an artificial implant or prosthesis is sterilized and the item withheld from use until the results are known to be negative.

It may be transmitted from patient to patient by as little as 0.0001 ml of infected blood.

The virus remains active for up to 6 months in dried blood, consequently instruments which have been poorly cleaned or disinfected may be responsible for infecting other patients, whilst poor surgical technique may result in the doctor becoming infected from the patient, or vice versa

It has been estimated that there are possibly 200 million carriers of hepatitis in the world, representing up to 20 percent of the population in African, Pacific, and other Tropical countries, and 0.5 percent of the population in Northern Europe. The current prevlance in the population is from 1 to 15.8 percent

Thus, statistically the doctor has a 1 in 200 chance of treating a hepatitis B carrier

If the doctor becomes accidentally infected with the hepatitis B virus, not only may the disease develop but the doctor may become a hepatitis B carrier and be an unacceptable risk to patients and may have to give up surgery. The transmission role in case of needle stick is 6 to 37 percent.

In 1983 the receptor cell for the virus was identified as the CD-4 of T-helper cell

Antibody tests were developed which revealed the HIV status of the individual

In 1986 a second strain, HIV 2, was isolated

Like hepatitis B, the virus is present in blood and body fluids, but unlike hepatitis B is relatively easily destroyed outside the body, and is not as infectious as the hepatitis B virus

Infection of the surgeon can occur from contamination from infected blood or body fluids, either through an open wound, or from a puncture wound like a needle-stick injury

Following infection there is an asymptomatic period during which antibody to the virus is not yet present in the blood, and thus HIV tests will be negative

After approximately 6 months the infected individual may seroconvert, and the HIV antibody be detected

A high proportion will then progress to develop AIDS

A common presenting feature of AIDS sufferers is the Kaposi sarcoma, with an incidence of between 25 and 50 percent. Biopsy of such lesions may be the first contact the surgeon has with this disease

Kaposi sarcomas present as pink to purple blotches like a bruise or blood blister. They may be flat or raised. They are skin cancer arising from the endothelial cells such as those lining blood vessels. Histologically, malignant transformation causes the endothelial cells to become stippled with spindle-shaped tumor cells; lymphatic obstruction may occur, but they do not metastasize, and remain multifocal both on the skin and in the alimentary tract. Despite the worry of surgeons about risks of infection, these risks are small

The prevalance rate of HIV 0.3 to 7 percent in our country. Surgeons have been shown to contaminate themselves with blood in 8.7 percent cases, and sustain penetrating injuries in 1.7 percent cases the transmission rate is 0.3 to 0.4 percent, yet statistically the risk of seroconversion for a surgeon is one infection every 8 years in a high-risk area with a case-load of 15000 patients per year, and as small as one infection every 80 years in a low risk area. Thus the risk to surgeon is exceptionally low.