Hospital operating room purification air conditioning management

The laminar flow purification air conditioner is needed in the hospital operating room to remove harmful gases, introduce fresh and Clean air, control the indoor temperature and humidity, and meet the temperature, humidity and cleanliness requirements of the operation. It is quite different from ordinary comfort air conditioners. Every link of the whole system needs to be extremely meticulous and requires regular maintenance by professionals.

1. Introduction

The important guarantee for the success of the operation is to establish a strict aseptic concept, attach importance to aseptic technical operations during the operation, and prevent surgical infection. Once an infection occurs after the operation, the consequences will be caused. In order to avoid similar situations, many hospitals have to increase the dosage of antibiotics for patients. This method is very harmful to patients. At present, the country is also legislating to control the dosage of antibiotics through administrative means. Therefore, the aseptic control of each link in the operation is increasingly valued by various hospitals.

(Figure 1: Operating room in hospital)

2. Sources of pollution in the operating room: outside and inside the operating room

2.1 The pollution source from the outside is mainly the fresh air sent to the operating room.

According to statistics, the number of bacteria and microorganisms in the outdoor air is about 1-1000/foot, and most of these bacteria and microorganisms are attached to dust particles, and the degree of pollution in different regions is also different.

(Figure 2: Wearing surgical gown)

2.2 The pollution sources from inside the clean operating room are mainly the doctors and nurses performing the operation, the patients performing the operation, and the bacteria and dust produced during the operation. The biggest internal pollution sources are the surgeons, anesthesiologists, nurses, etc. Their clothes, skin, and breathing will produce a lot of dust and bacteria. The amount of dust and bacteria produced is related to their clothing, the intensity and frequency of their movements, the doctor's skills, the degree of disinfection, and the level of overall management. 

Therefore, in addition to wearing underwear, all medical staff entering the operating room must change into special clothing, hats, masks, and shoes for the operating room. The hat should cover all the hair and minimize the exposed skin. The operation should be gentle, and the delivery of surgical instruments should be steady and accurate.

3. Introduction to the purification air conditioning system of the operating room

To manage the purification Air conditioning system of the operating room well, you must first understand the system composition of the purification air conditioning:

• Cold and heat sources

• Combined medical purification air handling unit and fresh air handling unit

• Purification air duct and various valves

• Water pipes and valves

• End return air device

• Humidification system

Schematic diagram of purification operating room air conditioning

(Figure 3: Operating room purification air conditioning system)

4. Division of purification operating room

The division of purification air conditioning system should be based on the principles of compliance with regulations, prevention of cross contamination, clear functional distinction, convenient management, moderate size, and economical and practical. The operating room can be normally divided into Class I, Class II and Class I according to the purification level. The normal design parameters are as follows [1]:

5. Selection of materials for purification operating room air conditioning components

5.1 The selection of purification air conditioning units should be based on the principle of preventing secondary contamination of microorganisms. The surface of the unit and the built-in components should be made of materials that are resistant to corrosion by disinfectants, and the surface of the material should be smooth and not easy to collect dust.

5.2 The outlet of the condensate of the surface cooler should be located in the positive pressure section, otherwise an anti-backflow device should be installed, and the condensate should not be directly connected to the sewer.

(Figure 4: Purified exhaust in operating room)

5.3 Sprinkler air handlers should not be used. When surface cooling is used, the air velocity through the cross section of the coil of the air-conditioning unit without fresh air centralized dehumidification should not be greater than 3m/. The humidifier of the unit should not be in the form of direct water intervention, and a dry steam humidifier should be used. The humidification water quality should meet the standards for domestic water applications. The humidifier material should be resistant to corrosion and easy to clean and inspect.

5.4 The unstage filter of the purification air conditioner shall not use wooden frame products, the finished product shall not have a pungent smell, shall not fall dust, the air volume used shall not be greater than 70% of its rated air volume, and when the positive force reaches 2 times the initial resistance of operation, it needs to be replaced.

5.5 Non-positive isolation air purification devices shall not be used as unstage purification facilities, unstage purification facilities shall not produce harmful gases and substances, shall not produce electric collision interference, and shall not have the effect of promoting biological mutation.

(Figure 5: Contamination control in operating rooms)

5.6 The shaft and parts of the air valve should be treated with anti-corrosion treatment. The shaft end extending out of the valve body should be sealed. The blades should be flat and smooth. The blade opening angle should be marked. The adjustment handle should be fixed reliably.

5.7 The metal parts in the purification air conditioning system and Clean Room that are in contact with the circulating air should be rust-proof and corrosion-resistant. The exposed parts of the metal parts that have been surface treated should be treated with surface protection again.

5.8 The air conditioning equipment should be placed in a relatively spacious place and should not be exposed to the open air.

6. Daily management of operation and maintenance

6.1. Maintenance purpose

Ensure that the purification system and strong and weak current system equipment of the hospital inpatient operating room are always in good operating condition. The seven cleanliness indicators of the clean operating room (temperature, humidity, Wind speed, noise, pressure difference, illumination, dust particles) meet the "Technical Specifications for Hospital Clean Operating Room Building" GB50333-2013 standard, "Hospital Air Purification Management Specifications" WS/T368-2012 and "Technical Specifications for Hospital Infection Prevention and Control in Operating Departments" standard [2]. 

(Figure 6: Daily maintenance of the operating room)

6.2. Safety Assurance

During the maintenance period, the equipment and facilities to be maintained shall be operated safely, and the operators shall be trained and supervised to implement the operating regulations.

6.3. Quality Assurance

To ensure that the equipment and facilities are in a safe and normal state, the maintenance schedule shall be submitted to the hospital in advance every quarter so that the work can be arranged in advance. The daily maintenance time shall be determined by the hospital according to the actual situation to avoid the peak of use. Monthly, quarterly and annual inspections shall be implemented and relevant records shall be kept. 

A maintenance file shall be established for each operating room and auxiliary room, and the original technical data, maintenance records, repair records and component replacement records shall be registered and managed. Maintenance work shall be organized and planned from the perspective of long-term sustainable and safe operation of equipment and facilities. Ensure that the technical indicators of the clean operating room meet the corresponding requirements. 

(Figure 7: Operating room monitoring)

6.4. Technical Strength Assurance

Due to the complexity and professionalism of the hospital's purification and air conditioning system, it is necessary to ensure that there are enough personnel involved in operation and maintenance every day. The maintenance personnel must be proficient in handling various faults. The project leader must have an intermediate or higher professional title in HVAC or electromechanical installation and lead the class for 8 hours a day. 

Since some departments of the hospital operate 24 hours a day, the air conditioning room must arrange personnel to be on duty 24 hours a day. The job description and regular business learning and training system, patrol inspection system, maintenance and maintenance system, detection and repair system and operation and overhaul system for on-site maintenance and management personnel must be clarified. Professional tools and testing instruments (dust particle counter, thermometer and hygrometer, anemometer, differential pressure meter), etc. must be equipped.

6.5. Guarantee of maintenance system

(1) The job description and regular business learning and training system for on-site maintenance and management personnel must be clarified.

(2) Patrol inspection system

(3) Maintenance and maintenance system

(4) Detection and repair system and operation and overhaul system

(Figure 8: Cleaning and replacement of operating room)

6.6 Maintenance content

(1) Replace the coarse filter once every 1-2 months (clean once every 2 days), the medium filter once every 3 months (clean once a week), the sub-high efficiency filter once a year, and the high efficiency filter at the end of the operating room once a year (replace every 2 years)

(2) The mode should be switched in time during the transition season and the heating and cooling period of the building.

(3) Cleaning of new return air ducts (robot method). Clean once every quarter to ensure the cleanliness requirements of the operating room.

(4) Maintenance of the purified operating room should also include cold and hot source equipment (heat pump module unit), air conditioning water system, clean air conditioning system, exhaust system, strong and weak electric lighting system, door control system, water supply and drainage system, purified air conditioning unit, PLC programmable intelligent control system [3]

The hospital operating room needs to use laminar flow purified air conditioning to remove harmful gases, introduce fresh and clean air, control indoor temperature and humidity, and meet the temperature, humidity and cleanliness requirements of the operation. It is quite different from ordinary comfort air conditioning. Every link of the entire system needs to be extremely meticulous and requires regular maintenance by professionals.