Theatre practice

Theatre practice

Pip Millard and Jo Hobbs


The management and maintenance of the theatre environment are of prime importance in a situation where patients, already weakened by their existing condition, are further subjected to procedures that may be painful, bewildering and traumatic.

The main focus in running an efficient operating theatre is on maintaining a good aseptic technique. This must be applied not only to the more obvious care of instruments, preparation of the surgical site and scrubbing-up techniques, but also to the daily routine of maintaining the hygiene of the theatre and associated preparation areas and to the personal hygiene of all who work in the area. It takes very little upset in any of the procedures to compromise asepsis and introduce infection which could in turn lead to wound breakdown, systemic infection, reduced surgical success rate and, inevitably, an effect on the reputation of the practice.

It is usually the responsibility of the veterinary nurse to organize all matters concerned with the operating theatre and its efficient function and it is to the nurse and her management routines that the veterinary surgeon will turn if things go wrong.


Sterilization can be defined as the process by which instruments and drapes are rendered aseptic (or sterile) by the destruction or removal of all microorganisms including spores. This can be achieved by various methods, including:

Boiling cannot be considered to be a method of sterilization because it does not reach a high enough temperature to destroy bacterial spores.

Chemical solutions based on chlorhexidine or glutaraldehyde will kill bacteria if items are soaked in them. They may be used for surgical equipment, which cannot be sterilized using any other method. However, they should only really be considered to be a method of disinfection.


Hot-air ovens produce a dry heat. Microorganisms are more resistant to dry heat so high working temperatures are required for a long period of time (Table 7.1). Long cooling periods are also required and the very high temperatures may damage metal items. A safety device should be fitted to the door to prevent accidental opening before the oven is cool. Care should be taken not to overload the oven, as air will be unable to circulate freely.

Use is limited by the long period of time required for sterilization and cooling. However, hot-air ovens are useful for items damaged by moist heat such as glassware, powders, oils and sharp cutting instruments.


This is the most common method of sterilization used in veterinary practice. In normal circumstances, water cannot reach temperatures greater than 100 °C (boiling point) before producing steam. If water is boiled under pressure, the boiling point is raised so the temperature of the steam is greater. This steam produces heat which penetrates to the innermost layer of the packs. The moisture increases the permeability to the heat. Care should be taken to avoid overloading or blocking the inlet and outlet valves. Items to be autoclaved should be free from grease and protein in order to achieve effective penetration of steam.

The majority of autoclaves designed for modern veterinary practice incorporate a drying cycle. Steam is exhausted and replaced by filtered air which dries the packs (Table 7.2).

Autoclaves are used for sterilizing instruments, drapes, gowns, swabs and some rubber or plastic items.


Ethylene oxide gas sterilizes by inactivating the DNA in the cells of the pathogen, thus preventing their replication. It is, however, toxic, irritant to tissues and very inflammable. In order to comply with Control of Substances Hazardous to Health (COSHH) regulations manufacturer’s instructions must be followed.

The sterilizer, a plastic container fitted with a ventilation system, should be located in a well-ventilated area, such as a fume cupboard away from working areas. Room temperature must be kept at a minimum of 20 °C during the cycle.

Procedure: Use of the ethylene oxide sterilizer

1. Action: Place individually packed items into a polythene liner bag.

    Rationale: Liner bags are supplied with the sterilizer.

2. Action: Place a scored ampoule containing ethylene oxide liquid inside the liner bag and seal the bag with a metal twist tie.

    Rationale: The bag must be sealed in order to keep the gas circulating around the contents.

3. Action: Put the liner bag into the sterilizer unit.

4. Action: Snap the ampoule from outside the bag to release the gas.

    Rationale: To minimize exposure to gas.

5. Action: Close and lock the door to the sterilizer unit and turn the ventilator on.

    Rationale: Accidental opening of the unit can be prevented if the unit is locked.

6. Action: After 12 hours turn on the pump.

    Rationale: This aerates the unit before it is safe for the operator to open.

7. Action: Two hours after aerating, remove sterilized items.

    Rationale: This will ensure that any toxic gas has been removed.

8. Action: Store items for a further 24 hours in a well-ventilated room.

    Rationale: This makes sure that all the ethylene oxide has dissipated.

Sterilization by ethylene oxide is suitable for anaesthetic tubing, endotracheal tubes, fibreoptic equipment, optical instruments, plastic items such as catheters and syringes, high-speed drills and battery-operated drills.

Everyday items such as instruments, gowns and drapes may also be sterilized in this manner but the length of the cycle restricts its use.


It is essential that the effectiveness of any sterilization method be constantly monitored to ensure that all microorganisms, including bacterial spores, are destroyed. Different sterilization methods require different working conditions in terms of time and temperature. It is also important to choose the correct method of monitoring the efficacy of sterilization (Table 7.3).

Table 7.3

Methods of monitoring the efficacy of sterilization

Method Description Use
Chemical indicator strips Paper strips which change colour when the correct temperature and time have been reached. They are placed in the centre of the pack prior to sterilization Autoclave – select the correct strip for the cycle
Ethylene oxide
Browne’s tubes Small glass tubes filled with an orange liquid which turns green when the correct temperature is reached and maintained for the correct time Autoclave
Hot-air oven
Bowie-Dick indicator tape A beige tape impregnated with chemical stripes that change to black when the correct temperature has been reached (121 °C). It does not indicate that the pack has been exposed for the correct time; therefore it is not a reliable method Autoclave
Ethylene oxide tape As above, only the tape is green with lines that change to red on exposure to ethylene oxide Ethylene oxide
Spore strips Strips of paper impregnated with spores (usually Bacillus stearothermophilius) are placed in the load. After sterilization, they are cultured for 72 hours. Provided that sterilization has been achieved, no growth will be visible. This is an accurate method, although the delay in obtaining the results is a major disadvantage Autoclave
Ethylene oxide
Hot-air oven
Thermocouples Electrical leads with temperature-sensitive tips which are placed in the autoclave with the leads passed out and attached to a recording device. The temperature is checked throughout the cycle and the results are recorded Autoclave


There are a number of different packing materials available for the preparation of items to be sterilized. Selection will depend largely on the method of sterilization but factors such as cost and personal preference may also be taken into account (Table 7.4).

Procedure: Packing an item for sterilization

1. Action: Select the appropriate packaging material for the method of sterilization to be used.

    Rationale: A packing material that is non-permeable to steam would not be suitable for an autoclave.

2. Action: Select the correct size for the item to be sterilized.

    Rationale: Some methods of packing, such as self-seal pouches, can be costly to use so do not choose too large a pouch.

3. Action: Label the pack with the contents.

    Rationale: This will save opening incorrect packs, which would then require re-sterilization.

4. Action: Write the date on the pack.

    Rationale: Sterilized items should be repackaged and sterilized again if not used within 3 months.

5. Action: Write the name of the person preparing the pack on the pack label.

    Rationale: This allows any problems with the packing to be traced.


It is vital to have a strict cleaning regime in the operating theatre and preparation room to maintain a high standard of asepsis. Both daily and weekly cleaning procedures are essential. In addition to this, there are some general rules for maintaining asepsis in the theatre (Table 7.5).

Procedure: Daily cleaning routine

1. Action: Damp dust all surfaces and equipment using dilute disinfectant.

    Rationale: Using a dry cloth would merely move dust around the room.

2. Action: Wipe the table and surfaces in between patients, with dilute disinfectant. Clean the floor if it is soiled.

    Rationale: This prevents cross-contamination from one patient to the next.

3. Action: Remove used instruments and drapes after each procedure.

    Rationale: To avoid contaminating the next surgical site.

4. Action: At the end of the day, vacuum to remove debris and hair.

    Rationale: Fine particles will be collected more efficiently using a vacuum.

5. Action: All waste material and soiled equipment must be removed.

    Rationale: The warm operating theatre is an ideal breeding ground for microorganisms.

6. Action: All surfaces, including lights and sinks, must be thoroughly cleaned using dilute disinfectant.

    Rationale: Contaminated dust particles will settle on all surfaces and must be removed.

Procedure: Weekly cleaning routine

1. Action: Remove all portable equipment from the operating theatre.

    Rationale: Dirt and debris quickly build up in less accessible areas such as those behind equipment.

2. Action: Clean the equipment including the castors.

    Rationale: Castors soon fail to run smoothly if they are not cleaned regularly.

3. Action: Scrub the ceiling, walls, floor and all fixtures thoroughly using a disinfectant with detergent properties.

    Rationale: Detergent will remove any organic matter which could otherwise inactivate the disinfectant.

4. Action: Use cleaning utensils that are specifically designed for the operating theatre. They should be sterilized or washed in a washing machine after use.

    Rationale: This will minimize cross-contamination from other areas of the veterinary practice.


A general hand-washing procedure is carried out at the beginning of the day and, with the rise in resistant organisms such as meticillin-resistant Staphylococcus aureus (MRSA), it is good practice to follow this up with hand cleaning using an alcohol-based rub at regular intervals throughout the day. Prior to the first surgical procedure of the day, a full surgical scrub lasting up to 10 minutes is carried out, then a shorter scrub may be carried out in between subsequent procedures provided there has been no major contamination of the hands.

Before beginning any hand-washing procedure, all jewellery and watches must be removed. Nails should be short and free from varnish. If you wear a wedding ring it is acceptable to wash thoroughly around and under it – the ring must be easily movable to do this. If the ring is too tight to move, you should remove it entirely and put it in a safe place such as your pocket. All other rings must be removed.

Procedure: General hand-washing routine

1. Action: Turn on the water and adjust to a warm temperature.

2. Action: Allow the water to wash over the hands and drain from the wrists to the fingertips.

    Rationale: This will remove any gross contamination.

3. Action: Clean the fingernails with an orange stick or nail file.

    Rationale: Once this has been carried out each day, it may be omitted from further washing procedures.

4. Action: Apply plain soap and massage into the hands, from the wrists to the fingertips, in a circular motion, including the backs of the hands.

    Rationale: It is important to remove all traces of dirt because these may inactivate the antiseptic solution used in the surgical scrub.

5. Action: Rinse, allowing the water to drain from the fingertips. Repeat step 4.

    Rationale: Repeating the washing procedure will ensure the removal of any residual organic matter.

6. Action: Turn off the water.

    Rationale: The hands must not touch the tap so if the elbow, foot or knee cannot operate it, an assistant may be required. If this is not possible, a paper towel may be used and then discarded.

7. Action: Dry hands thoroughly with paper towels.

    Rationale: Air hand-dryers are unsuitable because they spread microorganisms around the environment. Reusable towels are unsuitable because they harbour microorganisms.

Procedure: Routine hand hygiene using an alcohol-based rub (based on the World Health Organization (WHO) guidelines)

This should be done as often as possible during the working day as it helps to reduce the spread of pathogens between patients and around the hospital environment. Research shows that regular hand washing significantly reduces the risk of nosocomial infections (WHO 2009).

1. Action: Remove all rings and watches and roll up your sleeves.

    Rationale: Dirt and microorganisms may accumulate under rings or watch straps.

2. Action: Apply 3–5 ml of alcohol rub to your right or left palm (Fig. 7.1).

    Rationale: Sterilizing alcohol is widely available in many forms.

3. Action: Rub the palms of your hands together using a minimum of 3 strokes.

    Rationale: To ensure that the rub is well spread.

4. Action: Rub your right palm over the back of your left hand using a minimum of 3 strokes.

    Rationale: To clean the back of your left hand.

5. Action: Rub your left palm over the back of your right hand using a minimum of 3 strokes.

    Rationale: To clean the back of your right hand.

6. Action: Interlace your fingers and rub the palms together using a minimum of 3 strokes.

    Rationale: To clean the interdigital spaces and the palms.

7. Action: Clasp your fingers to rub the backs of your fingers using a minimum of 3 strokes.

    Rationale: To clean the backs of your fingers.

8. Action: Rotationally rub the left thumb with the right palm using a minimum of 3 strokes.

    Rationale: To clean the left thumb.

9. Action: Rotationally rub the right thumb with the left palm using a minimum of 3 strokes.

    Rationale: To clean the right thumb.

10. Action: With the left finger tips rub the palm of your right hand using a minimum of 3 strokes.

    Rationale: To clean the tips of the left fingers.

11. Action: With your right finger tips rub the palm of your left hand using a minimum of 3 strokes.

    Rationale: To clean the tips of the right fingers.

12. Action: Air dry your hands or ensure that your hands are dried before continuing to do anything else.

    Rationale: Your hands should be completely covered in alcohol rub and you should allow it to dry to ensure that moist rub does not contaminate sensitive parts of the patient and that your hands are not sticky.

Stay updated, free articles. Join our Telegram channel

Jan 8, 2017 | Posted by in NURSING & ANIMAL CARE | Comments Off on Theatre practice

Full access? Get Clinical Tree

Get Clinical Tree app for offline access