Surgical site infections (SSIs) are the second most common cause of hospital acquired (Nosocomial) infections. These complications of surgical procedures cause considerable morbidity and, when these occur deep at the site of the procedure, can lead to mortality as high as 77%. The source of SSIs may be endogenous (normal flora of the patient’s skin, mucous membranes, or hollow viscera) or exogenous, which includes surgical personnel (especially members of the surgical team), the operating room environment (including air), and tools, instruments, and materials brought to the sterile field during an operation. By maintaining sterile environment in operation theatre we can control major part of exogenous infections.
To sterilize the operation theatre formaldehyde gas (bactericidal & sporicidal) is widely employed (cost effective) for fumigation. Formoldehyde kills the microbes by alkylating the amino acids and sulfydral group of proteins and purine bases.
- Thoroughly clean windows, doors, floor, walls and all washable equipments with soap and water.
- Close windows and ventilators tightly. If any openings found seal it with cellophane tape or other material.
- Switch off all lights, A/C and other electrical & electronical items
- Calculate the room size in cubic feet (L×B×H) and calculate the required amount of formaldehyde as given in step 3.
Step 2: Precaution
- Adequate care must be taken by wearing cap, mask, foot cover, spectacle ect.,
- Formaldehyde is irritant to eye & nose; and it has been recognized as a potential carcinogen.
- So the fumigating employee must be provided with the personal protective equipments (PPE).
Step 3: Fumigation
- Electric Boiler Fumigation Method: For Each 1000 cu.ft 500ml of formaldehyde (40% solution) added in 1000ml of water in an electric boiler. Switch on the boiler, leave the room and seal the door. After 45 minutes (variable depending to volume present in the boils apparatus) switch off the boiler without entering in to the room (Switch off the main from outside).
- Potassium Permanganate Method: For every 1000 cubic feet add 450gm of Potassium permanganate (KMnO4) to 500 ml of formaldehyde (40% solution). Take about 5 to 8 bowels (heat resistant; place it in various locations) with equally divided parts of formaldehyde and add equally divided KMnO4 to each bowel. This will cause auto boiling and generate fume.
- After the initiation of formaldehyde vapor, immediately leave the room and seal it for at least 48 hours.
Step 4: Neutralization
- After the fumigation process neutralize the formaldehyde vapor with ammonia solution. On inspection (or Surgery) day enter the operation theatre at 7 a.m with 150 ml of 10% ammonia (for 500ml of formaldehyde used, i.e., for 1000 cu. ft).
- Place the ammonia solution in the center of the room and leave it for 3 hours to neutralize the formalin vapor.
Operation Theatre Volume = L×B×H = 20 × 15 × 10 = 3000 cubic feet
Formaldehyde required for fumigation = 500 ml for 1000 cubic feet
= So 1500 ml of formaldehyde required
Ammonia required for neutralization = 150ml of 10% ammonia for 500 ml of formaldehyde
= So 450 ml of 10% ammonia required
Guidelines to be considered for Operation Theatre Sterility Check:
- Construction, carpentry, plumbing, electrical, cleaning and other works should be completed before the initiation of fumigation procedure.
- If exhaust fan is used (instead of A/C) its exterior level fins should be closed.
- Rooms allotted for operation (as shown in the plan) should not be used for other purposes.
- The Construction must have
- Separate dressing room for medical officer and staff nurses
- Patient waiting room
- Operation room
- The entire block should be cleaned and fumigated.
- Entry should be restricted to authorized persons (Label must be pasted on the main door)
- All apparatus such as boils, suction, table, cautery, focus lights, A/C units, exhaust fans should be cleaned completely as per the manufacturer instructions.
- Theatre dress (includes head cap, mask, apron, chapel, ect.,) should be made available for all persons who are entering into the operation theatre (surgeons, anesthetist, microbiologist team, nurses, theatre assistants& helper).
- Surroundings should be clean and free from garbage, open drainage, bushes, shrubs, wastes, ect
- Operation theatre should be cleaned and fumigated once a month periodically.
keywords: operation theatre, OT, operation theater, sterilization, OT sterilization, Fumigation, Operation theater fumigation, Operation theater sterilization, surgery