4.2. Indoor environmental standardization
Operating room working areas require efficient ventilation systems. They
provide adequate working conditions for patients and medical staff
involved into surgical activities. An overview of the main European
standards for the operation of the ventilation system for operating
rooms allows identification of the most common problems at actual
locations. The problems are, among others, insufficient air intake
within the OR, poor control in closed thermal conditions, and
inefficient functioning of ventilation systems. International standards
ISO 14644-1 and ISO 14698-1 define requirements for clean rooms and
controlled environments concerning biocontamination
control.43,44 According to contamination level, risk
zones are identified, as well as monitoring methods to avoid
contamination in OR areas.
Clean air and ventilation systems are important to decrease the
probability of contamination in OR areas. Healthcare buildings need
adequate ventilation and air conditioning systems, where especially
important is laminar airflow.45 Robert Koch Institute
proposed hygiene guidelines for OR ventilation,46
while German Society for Hygiene of Hospitals sets out several
recommendations supporting DIN 1946 standard concerning OR ventilation
and use of laminar airflow even in small ORs emphasizing that this
solution is superior to conventional turbulent
ventilation.47
An important recommendation is to take care of the contamination in the
air of the immediate surrounding area of the operating table and
instrument table, which may result in direct or indirect contamination
of the site.25 There is a difference in the context of
ventilation systems for hospital purposes in different countries.
Germany and Austria also introduced standards for ventilation systems in
ORs enabling adequate air flow that is enough
clean.48,49 French Standard NF S90-351 recommends the
medical requirements for each area, where the ORs are classified as
Level 4 risk areas. ASHRAE proposes ventilation of health care
facilities requiring an outdoor air change rate, as well as how to
consider contaminants affecting the delivery of medical care services to
patients and the occupational safety and health of workers and
visitors.50