VENTILATION

Operating theatres require appropriate ventilation systems to aid in controlling microbial contamination. To discourage bacterial growth the temperature is often kept between 20-23 degrees. The temperature should be set according to the type of procedure, and the patient's age. Increased warmth is required for pediatric patients and elderly patients to prevent hypothermia during the case.

The air exchange in the operating theatre should be 15-20 changes per hour. This air should be filtered through High efficiency air filters (HEPA). Airflow is usually directed from clean areas to less clean areas and then exhausted.

The main functions of effective ventilation within the operating theatre department are:

1.To reduce the number of air-borne microorganisms.

2.To remove anesthetic gases.

3. To allow regulation of the temperature and humidity for patient comfort and safety and a good working environment for operating theatre personnel.

The most common ventilation is known as 'downward displacement'. The air is forced in a downward direction, which is then expelled via flaps at a floor level.

To maintain the adequate function of this ventilation system some basic guidelines should be adhered to:

1.All vents on the floor level should remain uncovered at all times.

1.All doors to theatre should remain closed except for patient movement and necessary equipment movement.

2.The temperature should be maintained within a range suitable to staff and operating theatre personnel.

3.Filters should be checked and changed according to recommended guidelines.

LIGHTING

The lighting in operating theatres often has to rely completely on artificial light. Fluorescent lighting is housed in the ceiling.

Lighting has to be 'true' lighting to provide a measure to judge a patient's skin colour. This is particularly important in the anesthetic bay; OR and PACU.

All operating theatres require overhead mobile ceiling mounted lights, one of which is a main light and one is known as a satellite. These lights have specialised features, including that they are powered by between four and eight lamps and they have heat filters, which act as a heat reflector to prevent over heating of the patient and the surgical team. These lights require maneuverability and stability ensuring ease of positioning. Emergency lighting will automatically provide a backup system should there be any disruption in power. These should be tested regularly.