The
theatre
The siting of the theatre, by contrast to its design, is not of major
importance from a bacteriological point of view, although obviously it should
not be adjacent to an incinerator or refuse. Clean and dirty areas should be
separated and well demarcated with trafficking of personnel kept to a minimum
through the sterile area. The dirty corridor should have an independent exit for
contaminated materials.
The
scrub room
Design of the scrub room should incorporate:
• two doors leading to the corridor and into the theatre;
• sinks with taps that can be manipulated with the elbows and
soap holders that can be manipulated by foot pedals or the elbows. Good drainage
and suitable panels incorporated in the sink to prevent splashing of clothes;
• anti-slip floors;
• easily cleaned shelves for gownpacks and gloves;
• adequate facilities for separate disposal of linen and paper;
• brushes for cleaning finger nails.
The
operating room
The operating room should have a double-door entrance from the
anaesthetic room and a double-door exit into the clean corridor. There will also
be two small door entrances from the clean store room where sutures, dressings
and needles are kept (this is a subsidiary of the main store in the theatre
area) and an opening from the scrub room. There is also a single exit door to
the dirty corridor for removal of drapes, instruments and waste products at the
end of the
procedure. All the doors should be well sealed in order to comply with
the air ventilation system.
The
operating table should be adjustable with all working parts sealed. The cushions
should be easy to clean and in good repair. The lights should be adjustable,
sealed and easily cleaned with facilities for attachment of light handles so
that the surgeon and scrub team can adjust them. The plaster work and floor
should be well sealed and any defects must be repaired as a matter of urgency as
disturbance of plaster or the soaking through of leaking water will cause an
increase in the bacterial content in the theatre environment.
• Fixed surfaces in the operating theatre should be avoided and
reliance placed on steel trolleys. X-ray viewers should be inset into the wall
and kept in good repair, as should electric sockets.
Control
of air quality
Because the nonvisceral bacteriological contamination of wounds is
predominantly from the air in theatre, it is essential that modern theatres
are fitted with controlled ventilation and filters. For a general surgical
theatre the maximum benefits can be obtained from 20 air changes per hour using
a 5-mm pore size filter. In an unventilated operating theatre the bacteria
present in air can be as high as 3000 colony forming units (CFU) per in3.
With appropriate ventilation and air changes this can be reduced to 200 CFU/m3.
In
general surgery there is conflicting evidence as to whether improvement in
ventilation has reduced postoperative infection, but in orthopaedic surgery
there is no such ambiguity as air is a significant factor in the development of
postoperative infection and modern orthopaedic operating theatres utilise
ultra-clean air where the bacterial count is kept below 10 CFU/m3.
The principle includes the provision of a rapid high-volume flow of air over the
operating theatre with high-efficiency particulate filters. Essential measures,
in addition to efficient air ventilation and filtration, include:
• avoidance of excess movement of individuals in the theatre;
• ensuring that the air vents are not obstructed and that the
doors are closed.
Instruments
• Cleaning is a process which removes contamination but does not
necessarily destroy microorganisms. It is an essential prerequisite of
decontaminating equipment before sterilisation or disinfection is undertaken.
• Sterilisation results in the
complete destruction or removal of all viable microorganisms including spores
and viruses. In practice it may be difficult to establish. The term is usually
applied to solid objects, such as instruments and equipment, but not to skin.
• Disinfection reduces the number
of viable microorganisms but will not necessarily inactivate viruses and
bacterial spores. It may be classified into:
(a) high level — which is cidal to spores, bacteria and viruses;
(b) medium — which is cidal to bacteria and viruses;
(c) low — which is cidal to only bacteria and viruses of low
resistance.