Description

When surgery reentered the medical world in the mid-19th century, it called for specific spaces that in later years developed into the operating theater: a suite of rooms, each with an operating table at its center. There was a preference for spaces with daylight — bright, but without direct sunlight or hard shadows. Spacious rooms with high ceilings and large glass walls facing north could provide it, and for years these were the most distinguishing features of the operating theater. Daylight was deemed superfluous when the quality of artificial illumination improved. With the introduction of special (eventually shadow-free) lamps positioned above the patient, the shift from natural to artificial light marked the beginning of the transformation of the surgery suite — also called the operating department or the operating room (OR) — from a relatively simple set of rooms into one of the most technologically advanced components of the hospital. Recent years have seen an increase in the percentage of surgeries performed in outpatient settings (up to 80 % of all surgical procedures in some hospitals).

Surgery is becoming less invasive while imaging is becoming more interventional. The hybrid operating room allows doctors ‘(…) to see inside the body and make repairs in real time, with technology like fluoroscopy (moving X-ray machines that capture motion) and sonography’.[121] Since the imaging machines tend to be quite big and need special radiation-shielding construction, the dimensions of hybrid ORs are much larger than those of conventional ones; moreover, they have to accommodate a team of technicians in addition to the surgical and anesthesiology teams. Control rooms, supply spaces, scrub areas, a locker sequence and the generator rack room may result in complex configurations for hybrid ORs.[122] Remarkably, daylight has made its comeback in operating theaters, because it is still superior to artificial light in at least some ways and because it provides the staff with views to the outside world and the weather, as well as with the circadian (day and night) rhythm.

The characteristics of the operating theater are to some extent generic, yielding a rather limited range of spatial options. Surgery occurs in a space filled with machinery on wheels or ceiling/wall-mounted (some taking over vital body functions during surgery), computer screens, depositories for instruments, sometimes robots, always surgical lamps and special ceilings with plenums that regulate sterile air flows, preventing contamination of the wound.

Trends

The design of the surgical suite is undergoing frequent adaptations in response to changing medical requirements. As the operating department is an area of high investment for any hospital, its design should contribute significantly toward an optimal workflow in order to allow the maximum return on investment; this is accomplished by maximizing the patient-throughput in these facilities. Because of the ever-present danger of infection, patients’ risks of exposure to pathogens in the OR have to be minimized. Sophisticated hygiene regimes, including clean-air-flow systems and stringent hygiene protocols, have been developed over the past decades to reduce the post-operative infection rate, as described in the well-known Lidwell study from 1982.[123] It should be noted, however, that the differences in infection rates between surgeries done under high-end clean-air-flow conditions and those administering pre-operative antibiotic prophylaxis in a timely manner are statistically insignificant.

Spaces

Operating theaters consist of three distinct zones distinguished by the required level of sterility: a restricted area that must meet the highest hygienic norms and contains the OR; a semi-restricted area used for storage, sterilization of instruments (a ubiquitous feature in earlier designs; contemporary sterilization departments are now located in a separate area or even off-site) and the preparation of instruments; and the non-restricted spaces where, in some cases, even visitors are allowed. The position of the area where patients are prepared for surgery is one of the defining characteristics of operating theaters; the number of ORs is another. Patients can be prepared either in their own room or in designated zones in the OR (even on the operating table itself). The configuration of the ORs depends on their number: single corridor (for small hospitals with a limited number of ORs), double corridor (with five to 15 ORs arranged in an I- or U-shape), the peripheral corridor with a central restricted area or the cluster type, consisting of pods, each with three to five ORs, sharing a central core. Easy-to-clean materials are needed here, which in practice results in a preference for hard, glass-like surfaces. Green was the preferred color for operating theaters until recently. The San Francisco surgeon Harry Sherman is reported to have introduced it in 1914, annoyed by the white hues that prevailed back then. Now some commentators note a trend to move away from green, which is sometimes seen as depressing.[124]

Perspective of the Patient

Transfer and waiting zones, as well as patient preparation and anesthesia zones, must be designed to promote the reduction of patient anxiety. An important issue in this context is the reduction of exposure to noise and ‘technical’ sounds. With the increasing use of local or regional anesthesia leading to a larger proportion of patients being conscious during surgical interventions, the ambience and the design of the OR is becoming an important factor in putting patients at (relative) ease. In recent years, the trend has been to administer anesthesia and bring the patient back to consciousness in the OR, on the operating table, replacing the older practice of using a separate space outside the OR for this purpose. The focus on efficient turnaround times for the OR and haste in termination of anesthesia can be discomforting for the patient. The trade-off between the type of anesthetics and the associated specific recovery time, on the one hand, and administering (and recovery from) anesthesia, in the OR or in a separate room, on the other, needs to be made on a case-by-case basis.

Functional Perspective

In addition to air treatment devices a stringent hygiene concept is needed. Hygiene design efforts in the OR should focus on risk reduction around so-called pathogen communication surfaces. Such zones, which are continuously touched by many hands, include door handles, keyboards, touch screens, handles of transport and logistical items, dispenser grips for disinfectants or soaps, etc. In a successful hygiene regime potential infection chains have to be interrupted by minimizing contact surfaces and by enabling ‘contact-free’ work sequences.

In recent years, the pros and cons of separating OR facilities for elective and ambulatory surgical interventions from the OR facilities for complex and acute interventions have been discussed in regard to an increased functional efficiency. The provision of a backbone OR structure with an adequate number of transfer zones and with sufficient scale for efficient utilization of the support infrastructure can enable the department to carry out both elective/ambulant and complex/acute surgical activities in an efficient manner. The advantage of a combined backbone structure is that it provides total flexibility in shifting capacity utilization dynamically from ambulant/elective to complex/acute and back, as the demand and duration of complex/acute interventions change.

The complex technical environment in the OR requires that attention be paid to ‘human factors’ engineering. Architectural design should contribute to enhancing staff understanding of the technical equipment by addressing issues such as the readability of devices, spatial clarity and intuitiveness. In recent years, a range of OR layout alternatives has been explored aimed at synergies, especially for anesthesia — including the concept of an open-space OR with several operating tables in one large, open room. This concept, however, shows significant deficiencies with regard to noise and X-ray protection. Still, there are possible ways to transform existing OR structures into internally connected ORs combining the advantages of both the individual and the open-space OR.[125]

Efforts to improve the overall efficiency of the OR by allowing an overlapping instead of a merely sequential workflow led to the development of the so-called ‘Berner-Cluster-OR’ in 1999.[126] This concept has now been realized in various hospitals in Germany, e.g. University Hospital Hamburg-Eppendorf. With the ‘Berner-Cluster’ model, net operating time can be increased by around 20 %, due to the execution of preparatory activities outside the OR. ORs can be positioned in one centrally located cluster close to the intensive care unit, but there is a strong trend toward decentralization in smaller clusters across the hospital, with each cluster being situated close to the wards.

Components of the Operating Theater

Comprising several zones, from the most sterile (the OR and the sterile instruments preparation room) to the least sterile (preparation areas for patients, medical staff and medical samples), the operating block also has to accommodate additional functions such as transition areas, holding and recovery areas and back-office spaces. The design of all components in the operating block (OB) must be calibrated to ensure safe interventions. The main determining factors are the operating table (OT), the OR, the operating block (OB) and their position in the overall layout. There are several available choices.

Operating Table (OT)

Position of anesthesiologist and equipment relative to the OT/patient:

The anesthesiologist is positioned close to the patient’s head, with the equipment on the main-hand side (usually right).

Position of surgical team and equipment relative to the OT/patient:

The position of the surgical team depends on the intervention location, which is usually toward the center of the operating table. The procedure-based trolleys (PBT) for surgical interventions need to travel the shortest distance possible through the OR and are usually positioned next to the surgical team, on the side of the OR with the instrument entrance.

Position of OT relative to the patient entrance:

The patient’s head is close to the patient entrance to ensure the least possible distance (and, therefore, disturbance) when the anesthesiologist goes in and out of the OR. The OT is positioned with the head close to the patient entrance, parallel to the direction of the patient bed coming into the OR.

Operating Room (OR)

Recommended generic dimensions are 7 × 7.5 m for most ORs, with larger or smaller configurations for specialized operating environments (for instance, 70 m² for hybrid ORs or 36 m² for ophthalmology).

Plenum

Plenum dimensions vary widely, but there is a clear trend to increase their coverage area. Their shape is usually rectangular or square, with an area of 9 m². The OT center coincides with the center of the plenum.

Entrance

The entrance for the patient bed should have a width of at least 1.5 m and its position should allow for easy maneuvering of the patient bed in and out of the OR. A widely used closing system is one with a single sliding door, placed on the outer wall of the OR.

Traffic and Logistics

Traffic in the OR is a matter of great importance. Well-organized traffic promotes efficiency as well as the maintenance of a sterile environment. This book addresses four models of OR traffic from the point of view of process organization, hygiene and functional configuration and describes its main effects. The simplest and also oldest model allows for patient, medical staff, medical instruments and waste to share the same entrance to the OR. There are clear disadvantages to allowing contaminated and sterile traffic to use the same route. Nevertheless, this model can still be employed safely by using special containers for sterile instruments and transporting them in a sterilized, sealed trolley, while using other containers for waste and used medical equipment.

All traffic sharing one door (A)

• OR processes are linear and have a longer turnaround time.

• Sterile instruments are unpacked and prepared in the OR next to the OT.

• Sterile, non-sterile and contaminated traffic flows intersect each other and increase the risk of infection.

• Separate, sealable containers are recommended in order to separate sterile instruments, non-sterile materials, waste, used instruments and linen.

• Access to natural light from a side wall allows for better lighting schemes, better visibility, and regulation of the circadian rhythm of the medical staff.

The waste traffic route can be separated from the sterile traffic route by using either a dedicated ‘sterile corridor’ to bring sterile equipment into the OR or a dedicated ‘waste disposal corridor’ to transport the waste and the used materials out of the OR. This choice entails a number of significant consequences:

Dedicated waste disposal route (B)

• OR processes can be executed (partially) in parallel and used instruments can be packed in the waste disposal corridor while the patient is regaining consciousness after the procedure.

• Sterile instruments are unpacked and prepared in the OR next to the OT.

• Sterile traffic and the waste route do not intersect.

• Sterile instruments, the medical staff and the patient use the same corridor and entrance.

• Sealed containers can be used to separate instruments from patient traffic during their transportation to the OR.

• Direct access to natural light through a lateral wall is not possible.

Separated sterile instruments route (sterile corridor; C)

• OR processes can be executed (partially) in parallel and instruments can be prepared while the OR is cleaned, reducing the turnaround time.

• Instruments are prepared in a separate sterile environment under a downflow (or in front of a crossflow) plenum.

• Sterile traffic and the waste route do not intersect.

• The medical staff, the patient and waste use the same corridor and entrance, increasing the risk of contamination.

• Sealed containers are recommended to separate waste, used instruments and linen traffic from patient traffic.

• Direct access to natural light through a lateral wall is not possible.

In the most elaborate model, patient and medical staff traffic use a main entrance point, sterile instruments arrive by a secondary entrance point, and waste and used instruments and linen are removed via a separate waste disposal route.

Separated sterile instruments and waste disposal routes (D)

• OR processes can be executed (partially) in parallel, instruments can be prepared while the OR is cleaned and used instruments can be packed in the waste disposal corridor while the patient is regaining consciousness, reducing turnaround time.

• Instruments are prepared in a separate sterile environment, under (or in front of) a plenum.

• Sterile equipment, waste disposal and patient and staff routes do not intersect.

• Access to natural light through a lateral wall is not possible.

Decentralized Instruments Preparation Area

Decentralized, shared by two ORs and positioned between the ORs (A)

• Preparation of the instruments takes place in a sterile environment under a downflow (or in front of a crossflow) plenum.

• Sharing the facility could result in errors due to distraction, but given the limited number of people in the preparation room (a maximum of two), chances of distraction are lower than in centralized models.

• Mirrored OR configuration could lead to errors.

• The niche at the entrance of the preparation room can be used for a different function, e.g. for stationing the patient’s bed instead of bringing the bed to a station further away in the operating block (logistical efficiency).

Decentralized, shared by two ORs and positioned in the corridor (B)

• Preparation of the instruments takes place in a sterile environment under a downflow (or in front of a crossflow) plenum.

• Sharing the facility could result in errors due to distraction, but given the limited number of people in the preparation room (a maximum of two), chances of distraction are lower than in centralized models.

• Mirrored OR configuration could lead to errors.

• The niche at the entrance of the preparation room can be used for a different function, e.g. for stationing the patient’s bed instead of bringing the bed to a station further away in the operating block (logistical efficiency).

• The lines of sight in the corridor are obstructed by the preparation rooms.

• The total length of the block is shorter than in the configuration with the preparation rooms between the ORs.

Decentralized, dedicated per OR (C)

• Preparation of the instruments takes place in a sterile environment under a downflow (or in front of a crossflow) plenum.

• Facilities are not shared, minimizing errors due to distraction.

• The niche at the entrance of the preparation room can be used for a different function, e.g. for stationing the patient’s bed instead of bringing the bed to a station further away in the operating block (logistical efficiency).

Centralized Instruments Preparation Area

Centralized, ORs on the side (D)

• Shared facilities increase the risk of errors due to distraction.

• Storage area for the patient bed is placed in the corridor, in a special niche along the corridor or in a special room at the entrance to the operating block. Using a special room at the entrance to the operating block is recommended, as it reduces the risk of contamination, but this means less efficient patient and bed logistics.

• One sterile corridor and two patient and waste corridors

Centralized ORs in the middle (E)

• Shared facilities increase the risk of errors due to distraction.

• Storage area of the patient bed is placed in the corridor, in a special niche along the corridor or in a special room at the entrance to the operating block.

• Two sterile corridors and one patient and waste corridor

Another concern is the anesthesiologist traffic which can use a separate door or a sluice inside/outside the OR. The anesthesiologist comes in and out of the operating room at least twice per operation. Opening the door between spaces with different air pressures creates turbulence; that can result in movement of airborne particles (such as germs) into the sterile area and therefore lead to contamination. Using a smaller separate door in the corner helps minimize this risk. A sluice adjoining the OR entrance (or adjoining the smaller door) could eliminate this risk, but it requires additional investment and space.

Smaller entrance included in the OR door for the access of the anesthesiologist

• Reduces but does not eliminate air turbulence and the associated risk of infection.

• Could also serve as a decentral sanitizing point (alcohol dispenser) placed at the entrance to the OR (the centralized washing station is preferably situated next to the changing room for medical staff).

Sluice inside the OR

• Reduces air turbulence to a negligible level, practically eliminating the risk of infection

• Could also serve as a decentralized sanitizing point (alcohol dispenser) placed at the entrance to the OR.

Sluice outside the OR

• Reduces air turbulence to a negligible level, practically eliminating the risk of infection.

• Could be used as an additional cleaning space with washbasins for the medical staff.

Operating Block (OB)

The operating block can be configured in multiple ways. The main layout options are described here schematically, in groups of 12 ORs, to illustrate the configuration, traffic and walking distances for the various actors.

Single corridor model (A)

The single corridor model arranges all the ORs along one corridor which leads to the patient preparation and recovery areas, to the medical staff preparation area and to other functional areas.

• Distances covered are longer in general for patients and medical staff going in and out of the OR than in the other models.

• The waste traffic has a direct, separate route.

• Indirect access to daylight through a lateral wall is possible for all ORs.

Cluster model (B)

The cluster model groups ORs around a central instruments preparation room. Clusters can vary in size and number, but a group of four is most often used.

• Access directions for medical staff and patients on their way to ORs are similar.

• Waste traffic does not have a separate route.

• Access to direct or indirect daylight is possible only for a limited number of ORs.

• More compact layout than the single corridor model

• Storage areas can be situated adjacent to the instruments preparation room, which functions as a sluice for various medical supplies.

Double-loaded corridor model (C)

The double-loaded corridor layout has a simple version, with storage facilities positioned separately from the ORs, and a more compact and traffic-effective one, with the storage area positioned along the corridor.

• Medical staff and patients travel similar distances, though in some cases the patients must cover long distances along the corridor.

• Waste traffic has a direct, separate route.

• Access to indirect daylight from a lateral wall is possible.

• More compact layout than the single corridor model

Clean corridor in the middle (D)

The clean corridor model is very effective in terms of traffic, since it arranges the ORs around the centralized instruments preparation area.

• Medical staff and patients travel similar distances, though in some cases the patients must cover long distances to the ORs.

• Waste traffic has a direct, separate route.

• Access to indirect daylight from a lateral wall is not possible.

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Originally published in: Cor Wagenaar, Noor Mens, Guru Manja, Colette Niemeijer, Tom Guthknecht, Hospitals: A Design Manual, Birkhäuser, 2018.