I. Project Overview

Yunnan Kidney Disease Hospital is a specialized kidney disease hospital integrating medical treatment, scientific research, and prevention, established with the approval of the Yunnan Provincial Health Department. In recent years, with the improvement of people's living standards, the requirements for specialized departments have become higher and higher, and the hospital operating room has become the core of the hospital. Under such circumstances, the hospital decided to build a high-standard clean operating department. The operating rooms are located on the 7th floor of the general ward building; the machine room of this clean operating department is arranged on the roof above the 7th floor, and a lightweight machine room of color steel panels is built on the roof. The building area of the entire operating department floor is about 600m². According to the hospital's requirements, a comprehensive clean operating department comprising 5 operating rooms and their auxiliary rooms was to be renovated on this floor. The 5 operating rooms include 1 Class I operating room, 1 Class II operating room, and 3 Class III operating rooms.

In the design scheme, in addition to satisfying the owner's requirements for the functional use of the clean operating department, the parameters and requirements of the Construction Standard for Hospital Clean Operating Rooms and the Technical Code for Hospital Clean Operating Room Construction must be implemented without any compromise. The operating rooms should have complete functions, the systems should be advanced, and energy saving in operation should be taken into account. The new concepts and new measures proposed by the standard code for hospital clean operating room construction should be realized as much as possible, so as to maintain a domestically advanced level for a considerable period of time. Since this project is for a kidney disease hospital, the particularity of operations and factors such as the discharge of odor gases must also be considered in the design.

II. Floor Plan Layout

In the floor plan design, we should strive for a rational layout with clean items and soiled items separated, while also meeting the standard requirements, so that this operating department keeps up with the trends of the times.

Features of the operating department layout:

(1) Based on the characteristics of the existing building, the clean operating department is arranged in a three-corridor form: the central corridor serves as the clean corridor, used for pre-operative patients and clean items; the corridors on both sides serve as cleaning corridors, used for post-operative patients and soiled items.

(2) The particularly clean Class I and Class II operating rooms are grouped at the end of the clean corridor, where the flow of people is relatively small. This not only keeps these operating rooms free from interference by other non-surgical personnel, but also helps to guarantee their cleanliness class and bacterial concentration, making them safer and more reliable, with the advantages of less interference and convenient operation and management. The Class III operating rooms that share an air system are grouped together as well, which facilitates both operation and management and the piping design of each system.

(3) One sterile storage room is provided for the Class I and Class II operating rooms, and another sterile storage room is provided for the Class III operating rooms, for the convenience of operation.

(4) So that disinfected items can enter the clean zone directly and the possibility of contamination during transport can be reduced, a double-door autoclave is adopted for item disinfection: instruments and dressings are washed and packed in the non-clean zone, then disinfected through the double-door autoclave, and the disinfected items can be taken out directly in the clean zone.

III. Air-Conditioning and Purification System

(1) System division. In accordance with the provisions of the new standard, and taking into account both energy saving and convenience of operation and management, the entire clean operating department and the ICU ward are divided into six independent purification air-conditioning systems (J-1～J-4):

  • One purification air-conditioning system (J-1) for the Class I operating room;
  • One purification air-conditioning system (J-2) for the Class II operating room;
  • One purification air-conditioning system (J-3) shared by the 3 Class III operating rooms;
  • One purification air-conditioning system (J-4) shared by the other auxiliary rooms of the operating department.

In this way, whichever operating room is in use, its corresponding system is turned on, while the purification systems of the operating rooms not in use are kept off, so as to achieve the goal of energy saving. The auxiliary room systems serving the operating rooms, however, must be turned on no matter which operating room is in use. (2) System composition. Both the operating room systems and the auxiliary rooms of the surgical department are composed of a fresh air system and a purification air-conditioning system. Each system adopts an independent fresh air system, and the fresh air units all adopt a new fresh air treatment measure with three-stage filtration—coarse, medium, and sub-high efficiency—but the fresh air units do not undertake the heat and moisture treatment of the air; the heat and moisture treatment is undertaken by the air-conditioning units. The exhaust air units of each operating room system adopt an exhaust air treatment measure with two-stage filtration—sub-high efficiency and medium efficiency. The air purification treatment process is shown in Figure 1,

Figure 1 Air purification treatment process

(3) System cooling source, heat source, and humidification source. The summer cooling source of the air-conditioning system is provided by an air-cooled water chiller unit, and the winter heat source uses steam provided by the hospital's original boiler room. Since the hospital's clean surgical department belongs to biological cleanrooms and the growth of bacteria should be avoided as much as possible, the humidification of each system should not adopt the form of water humidification but should adopt the form of steam humidification; the steam is also provided by the hospital's original boiler room.

(4) Selection of the system form. Since the air change rates of clean operating rooms are all relatively large, even the Class III operating room, which has the lowest air change rate requirement, must reach 24 air changes per hour according to the national standard requirements. In addition, since personnel are concentrated in the operating room during surgery, the required fresh air volume is large, and the heat loads from personnel, lighting, and equipment are all relatively large. Therefore, in order to achieve the goal of energy saving, all the purification air-conditioning systems adopt the secondary return air system; considering the practical operability of operation, the primary and secondary return air ratios and the fresh air volume are fixed throughout the year. The heat and moisture treatment process of the system is shown in Figure 2. The Class I operating room adopts secondary return air, with the fresh air ratio kept unchanged throughout the year.

Figure 2 Schematic diagram of the system heat and moisture treatment process

IV. Indoor Air Distribution

(1) Air distribution form. In clean operating rooms, the supply air, in accordance with the provisions of the national standard, adopts the form of centralized arrangement above the operating table, while the return air adopts the form of continuously arranged return air outlets at the lower part on both sides of the operating table. The size of the centralized air supply device meets the dimensional requirements of the national standard; the return air velocity is ≤2m/s; the return air outlets adopt a vertical louver form that is not prone to dust accumulation, and coarse-efficiency filtered adjustable outlets are used.

Other clean auxiliary rooms adopt the air distribution form of uniformly arranged supply air at the upper part and return air from both lower sides (or a single lower side), while the clean corridor and the semi-clean corridor adopt the air distribution form of top supply and top return.

(2) Air supply device of the clean operating room. We adopted a new type of nationally patented terminal air supply device—the leakage-preventing layer. The leakage-preventing layer air supply device consists of a high-efficiency filter box, a supply air plenum, a leakage-preventing layer air supply outlet, and air ducts connecting the high-efficiency filter box and the supply air plenum. The conventional local Class 100 approach, which uses high-efficiency filters as the terminal air distribution devices, arranges the high-efficiency filters inside a plenum; the principle is shown in Figures 3 and 4. Figure 3　Schematic diagram of the leak-proof layer air supply device

Figure 4　Schematic diagram of the air supply device for a conventional clean operating room

V. Drawings of the Operating Department

The floor plan of the clean operating room is shown in Figure 5, and the zoning diagram and flow chart of the clean operating department are shown in Figures 6 and 7.

Figure 5　Floor plan of the clean operating room of Kunming Kidney Hospital, Yunnan Province Figure 6 Zoning map of the clean operating department of Kunming Kidney Hospital, Yunnan Province Figure 7　Flow Chart of the Clean Operating Department of Kunming Kidney Hospital, Yunnan Province

Clean item flow　　Waste flow　　Medical staff flow　　Patient flow