Clean operating room purification requirements and principles

The air pressure in the operating room varies according to the different cleanliness requirements of different areas (such as the operating room, aseptic preparation room, brush room, anesthesia room and surrounding clean area). Different levels of laminar flow operating rooms have different air cleanliness standards .

For example, US federal standards :

Per 1000 cubic feet of air in the number of dust particles ≥ 0.5 μ m of, ≤ 1000 Ke ≤ 35 per liter of air or stars.

Standard Laminar Flow Operating Room 10,000 cubic feet of air per ≥ 0.5 μ m of the number of dust particles, ≤ 10000 Ke ≤ 350 per liter of air or stars, and so on.

The main purpose of ventilation in the operating room is to eliminate the exhaust gases in each working room , to ensure the necessary amount of fresh air in each working room; to remove dust particles and microorganisms , and to maintain the necessary positive pressure in the room. There are two types of mechanical ventilation that can meet the ventilation requirements of the operating room :

Mechanical air supply and mechanical exhaust air use type: This ventilation mode can control the number of air exchanges, air exchange volume and indoor pressure, and the ventilation effect is better.

The mechanical air supply is combined with the natural exhaust air. The ventilation and ventilation times of this ventilation mode are limited, and the ventilation effect is not as good as the former.

The cleanliness level of the operating room is mainly distinguished by the number of dust particles in the air and the number of biological particles. Currently, * commonly used is the NASA taxonomy. The purification technology achieves the purpose of sterility by controlling the cleanliness of the supply air flow by positive pressure.

Hospital operating room cleanliness level

According to different air supply methods, purification technology can be divided into two types: turbulence system and laminar flow system.

( 1 ) Multi - directionalal Manner : The air supply port and high-efficiency filter of the turbulent flow system are located in the ceiling, and the return air outlet is located on the two sides or the lower part of the wall surface. The filter and air treatment are relatively simple and convenient to expand. The cost is low, but the number of air changes is small, generally 10 to 50 times / h , which is prone to eddy currents. The contaminated particles may float and circulate in the indoor vortex area to form a polluted airflow and reduce indoor purification. It is only applicable to the clean room of 10000 to 1000000 in the NASA standard .

( 2 ) Laminal Flow System ; Laminar Flow System uses a gas flow with uniform distribution and appropriate flow rate to carry particles and dust out of the operating room through the return air vent, without eddy currents, so there is no floating dust, and the degree of purification varies with the number of air changes. The increase is increased for the Class 100 operating room in NASA standards . However, the filter seal breakage rate is relatively large and the cost is high.