What's wrong with our operating rooms?

What’s Wrong with Our Operating Rooms? HAROLD

In the last analysis, it is the surgeon’s judgment and skill, how he coordinates his team and his environment, and how the patient’s physiologic responses are supported during all stages of surgical care which determine the outcome of a surgical operation. Nonetheless, as operations become more complicated and more prolonged, and as they require more and more equipment, both electronic and mechanical, the environment in which they are performed becomes an ever more important part of their success, The surgical environment in which operative tasks are carried out consists of a configuration of space and facilities in which equipment and soft goods are made available so that they can be used with efficiency and safety by a surgical team and by persons engaged in support activities. Support activities include those necessary for the preoperative preparation of the patient, anesthesia management, monitoring of physiologic variables, cardiopulmonary support, and laboratory and blood bank collaboration, as well as specific skills which are necessary at every level of a functional hierarchy ranging from those of laundry personnel to surgical nurse. How often have our best judgment and intentions been altered or actually stymied by faults in equipment, unconscionable delays, inaccessibility of necessary items, problems in communication, inefficient handling of materials, or human failure? We shall probably never have accurate statistics on these questions, but every experienced surgeon can recall more than one and perhaps many such instances of frustration. In terms of today’s needs, surgical suites built more than two decades ago and not recently UPdated possess a number of easily identifiable faults. These include the inappropriate use of space, a confused or poorly defined traffic pattern, an inefficient materials-handling system, and inadequate

From The Institute for Surgical Studies, a Division of The Department of Surgery, Montefiore Hospital and Medical Center, New York, New York.

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MD, PhD, New York, New York

electrical wiring system, or a poor ventilation system. It is possible for electrical and ventilating systems to comply with code specifications and still be responsible for catastrophic problems, Such problems can be identified in advance if they are looked for, and a program for their correction may be outlined. A more insidious set of faults is common in newly built surgical suites. These faults may be more difficult to identify because of the glitter and newness of the surroundings and the profusion of impressive instruments. It is important for surgeons, anesthesiologists, and nurses to sit in on early planning discussions. However, often these individuals are themselves responsible for some of the errors as well as some of the “overkill” in design, and therefore for some of the overexpenditure. Unfortunately, only a few surgeons have made the surgical environment their main research interest. Research interests of surgeons, at least until recently, have leaned toward surgical physiology and biochemistry, technics, and materials. Furthermore, not more than once in a surgeon’s professional lifetime does he get the opportunity to have a hand in designing his surgical environment. When he is consulted by professional planners, he finds it difficult to define the values by which he can be guided in judging the correctness of his old environment, let alone designing a new one. As a result, the task is taken over by nonsurgeons. Surgeons and nurses who have sat in on the planning of new operating rooms and then have actually had an opportunity to work in them after completion are often disheartened at the wide gap between their initial suggestions and the finished product. The planners, on the one hand, are often faced with an array of constraints which they cannot or do not communicate to the medical people, and the medical people, on the other hand, cannot understand some of the revisions they must accept, some of which are drastic enough to make the original plan unrecognizable.

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What’s Wrong with Our Operating

Efforts to improve the surgical environment are being made continually. Some of these efforts have gone off on expensive tangents which are not necessarjly concerned with the solution of relevant problems in surgical care. This is not to say that many important advances in surgical care have not come by way of developments made by industry or industry-related technology. But merely adding expensive new monitoring and computerized equipment to an otherwise outdated operating room will do little to modernize it and may only contribute to its hazards. Surgeons are becoming aware of instrumentation, devices, and equipment which were factory-designed more to create a profitable market than to answer specific needs in surgical care. A variant of this situation is represented by expensive solutions to minor problems. Examples are exotic tote systems and patient transport devices. Although a large number of such efforts are originated and promulgated by nonsurgeons, others of different types are often created by surgeons themselves whose inventive enthusiasm for their own special way of doing something convinces other surgeons that the new product is a necessity of life. Time itself is often the arbiter of the value of such products, but, unfortunately, only after the money has been spent. In any event, surgeons would do well to exercise the same high quality of judgment and skepticism in the acceptance of new devices and environmental inventions as they do in the acceptance of new surgical procedures. In a series of studies over the past five years aimed at evaluating the surgical environment [I] we found it necessary to consider the surgical environment as a series of related systems rather than as architectural layout, machines, and ventilation. The systems comprise sets of activities plus the necessary hardware required for the accomplishment of specific surgical goals. Reduced to its major components, the operating room system complex consists of four main systems [2] (Table I) : 1. Surgical support systems (the environment) 2. Traffic and commerce (the activities) 3. Communication and information (the record) 4. Administration (the management) By the appropriate meshing and balance of these systems, patients are scheduled for operations, brought to the proper operating room, anesthetized, operated upon by the surgical team which is supplied with all the equipment, instruments, and soft goods it requires for the operation and

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TABLE

I

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Surgical Suite Systems

Surgical Support Systems (Environment) Facilities Location in hospital; purposes to be served; projected loads; types of surgery; traffic considerations Design Number of rooms; relationship of rooms; corridors; materials storage space: patient holding area: recovery area; instrument processing; lounges; dictating areas; anesthesia equipment processing; anesthesia offices: elevators; chutes Surface materials and finishes; acoustics; color; texture; doors Electrical services Surgical lighting; room lighting; emergency service; electronic monitoring: x-ray; electrical maintenance; equip ment; radiofrequency shrelding Engineering services Heating: ventilation; air conditioning; gas supply; vacuum; compressed air; plumbing Equipment Built-in: plug-in; free-standing; anesthesia; view boxes; x-ray; cryogenic; cautery; surgical table: stands; holders; hooks; poles; tables Hazard control Infection; electrical; flame; explosion; power failure; housekeeping Traffic and Commerce (Activities) Patients Professional staff Surgeons; anesthesiologists and house staff: nurses; technicians: maintenance crew Materials handling and storage (packs and instruments) Instrument cleaning; sterilization; repack or store; disposa bles; recycled goods (hardware and laundry); on-site packaging; decontamination; delivery of blood Delivery, dispensing, disposal of all materials Information and data processing Hazard control Infection; electrical; flame; explosion; power failure; housekeeping Communication and Information (Records) Telephone Intercom: audio or audiovisual To blood bank; surgical pathology; laboratory; x-ray department; supervisor; recovery room: intensive care unit Electronic monitoring Data processing Record keeping Hazard control Infection; electrical; flame; explosion; power failure: housekeeping Administration (Management) Policy making Ordering supplies Scheduling operations Procedure systems Utilization records Statistics Inspection, maintenance, and repair of equipment Hazard control Infection: electrical; flame; explosion; power failure; housekeeping

for support of the patient’s life; the operating room itself is made safe by appropriate servicing, proper cleaning, and engineering services ; and materials, instruments and equipment are made available and kept in working order, ready for use as required. The hazards of infection, flame, explosion, and electrical shock are part of every functional sys-

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tern. Their control does not constitute an independent system in itself. If a defect in hazard control occurs in any of the aforementioned four main systems, the remaining three systems are affected to some degree. For example, if the architectural or engineering environment is not properly designed to control these hazards, the defect is reflected to some extent by necessary adjustments in traffic and commerce, communication, and administration which must be made to accommodate or compensate for the defect. Defects in hazard control may arise in any of the systems and reflect in all others. The degree of this interdependence is not necessarily equally distributed, but is transmitted by way of hazard control to all systems in varying degrees. Surgical Suite Design

Problems in the ,design of surgical suites are magnified as the facility increases in size. For example, a loo-bed community hospital would have a surgical suite with just two or three operating rooms (5 per cent of the surgical beds) and be relatively simple to design. Roughly half the beds in a community hospital in the United States are occupied by patients who have a surgical problem. Their rate of turnover is somewhat more rapid than that of medical patients, averaging ten to twelve days in larger hospitals. Thus, in a 100 bed hospital, 5 per cent of fifty surgical beds suggests that two operating rooms may be sufficient, but three would probably be built [3]. If we consider a surgical suite for an 800-bed hospital which would have a surgical suite of sixteen to twenty operating rooms, we are faced with a number of problems, the solutions to which are still controversial. In general terms, four basic faults were found with the design of relatively new surgical suites studied by the Institute for Surgical Studies: insufficient and poorly organized storage space ; a mixed and often confusing traffic pattern; inefficient materials-handling; and an unmistakable tendency to be overdesigned and overbuilt, often because of a lack of definition of the criteria for optimal design. Yet all the operating rooms were usable and were quite adaptable to handle a considerable surgical load. In other words, almost regardless of the design or errors in design or equipment of a surgical suite, it can be used, often fairly efficiently, for the performance of successful surgery by means of adjustments- in how things are done [4].

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Perhaps it is this wide margin of permissible error in operating room design which permits equally good surgery to be performed in so many different types of rooms. A number of basic plans for surgical suites have emerged over the years. Within the limits of space and proportion imposed by the shape, dimensions, and location of the assigned area, an effort is made to create ,a usable department which accommodates a meaningful traffic pattern, efficient surgical care of patients, and control of foreseeable hazards of infection, flame, explosion, and electricity. Generally speaking, four designs have emerged, each with variations and permutations [5] : 1. The central corridor, or hotel plan 2. The double central corridor, or clean core plan 3. The peripheral corridor, or race track plan 4. The grouping, or cluster plan Each of these designs has been found quite useful, perhaps because of the wide margin of variation to which operating room functions can be accommodated. However, efficiency does become affected if corridor distances are too long in proportion to other space, if illogical relationships between special functions exist, or if inadequate consideration is given to storage space, materialshandling, and personnel areas. Shape of the Operating Room

Virtually every imaginable shape has been applied to operating rooms. All seem usable, but none appears to hold any real advantage over the square or rectangle [5]. Aside from the usual square or rectangular room, we have seen the eggshaped room designed by Paul Nelson, the round room of Donald Douglas and Jean Blins, and the octagonal, so-called modular room built by Honeywell of Great Britain, as well as operating rooms encased in a huge hyperbaric cylindrical chamber. Although one must certainly pause to acknowledge these original contributions to operating room design, and although all of them are certainly usable, none has offered enough functional advantages to warrant its universal adoption over more conventional square or rectangular designs. Indeed, as surgical equipment becomes more complex, it is increasingly difficult to install into curved surfaces and multisided rooms. Similarly, in the planning of an entire suite, the efficient and economic use of space lends itself more readily to straight-line walls than to curved or broken lines.

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What’s Wrong with Our Operating

Size of Operating Rooms

The operating room in which most surgical operations can be performed is generally about 20 by 20 feet in size. This size room becomes a bit crowded when open heart surgery must be performed in it, because of the spatial requirements of an extracorporeal pump, the pump team, and the additional people required by the procedure [Cl. Therefore, somewhat larger rooms, such as those 24 by 26 feet, 26 by 28 feet, and 28 by 30 feet have been recommended as an ideal size for a cardiac operating room [?‘I. Many variants, depending upon available space, are also practicable, such as 19 by 25 feet, 20 by 22 feet, and the like. In the interest of economy and operational flexibility, it is often desirable to make all operating rooms about the same size, so that they can be used interchangeably for orthopedic surgery, neurosurgery, cardiac surgery, and general surgery. Specially equipped rooms, however, such as those in which cystoscopic surgery or other endoscopic surgery is to be performed, require special designing, but can be made to fit a standard operating room space. Setting aside a separate room designated for septic surgery is no longer considered feasible. Every operation is now considered “contaminated” in the sense that terminal sterilization of instruments is carried out after every procedure. Moreover, containerization of reusables and of trash is employed. Traffic Pattern in the Surgical Suite

The basic design of the surgical suite is usually a compromise between the spatial allowance in the architectural plan’and the requirements of the surgical specialties. In general, a clean central core from which all operating rooms can be reached is desirable. It need not be on the same floor level as the operating rooms. In recent years, much attention has been paid to a peripheral corridor scheme or “race track” plan in which a corridor surrounds the entire suite of operating rooms. Its advantage is purportedly to allow servicing the rooms from the periphery without the need of entering the sterile inner core. Another advantage is said to be an improved traffic pattern of “semi-clean” nature into which patients can be removed from an operating room after surgical operation before they are taken to a postoperative recovery facility. However, in practice, peripheral corridors occupy enormous square footage, and take the place of other, more realistic needs. The peripheral corri-

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dors in recently built facilities surveyed by the Institute for Surgical Studies revealed that they were being used as long storage areas [I]. In one hospital, eighty-nine floor-standing pieces of equipment worth more than 200,000 dollars were stored in the peripheral corridor, some pieces covered with plastic covers, others with linen sheets, and still others uncovered [5]. Furthermore, large peripheral corridors are difficult to keep clean and often require additional personnel for this purpose. None of the peripheral corridors examined at any of these newly built hospitals was fulfilling its intended purpose in the traffic pattern. For example, if a surgeon is to leave an operating room only by way of the peripheral corridor, he would be compelled to change all of his clothes, including shoe covers, if he is to return to the operating room to perform more than one operation. This in uneconomical, unnecessary, and especially difficult on the house staff. If the patient alone is to be carted out of the operating room by way of the peripheral corridor, again it is a more costly way of doing things. The question may well be asked whether a patient is truly more contaminated after his operation than before. If not, why should he need a separate corridor after surgery? Similarly, in the disposal of used surgical packs, as long as they are wrapped or bagged, why should a separate corridor be necessary for their removal after use [h]? In one plan I reviewed, several operating rooms were 16 by 16 feet in size, too small for surgical comfort and risky for contamination of sterile gowns and equipment. However, the suite was ringed by a peripheral corridor 12 feet wide and extending 400 linear feet, thereby using 36,000 square feet of valuable floor space at the expense of operating room size, storage space, and necessary ancillary working space. When the planner was asked why he planned it this way, he said that peripheral corridors are the “latest” advance in operation room planning. Before any plans are drawn, quantitative and qualitative design and performance criteria for the suite must be defined with consideration for possible future changes. Decisions must be made regarding location of the surgical suite in relation to other clinical, laboratory, and special-care facilities. Although it. is impossible to have everything next to everything else, it is possible to design efficient functional relationships by appropriate use of vertical and horizontal methods of transportation [8]. Adequate clean storage space must be provided,

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not only for disposable and reusable materials, instruments, and devices, but also for large mobile equipment. A sensible traffic pattern must be provided, less dictated by current trends in architectural artforms, but more attuned to flow charts depicting the realistic traffic and commerce of patients, personnel, and supplies, with careful attention to “clean” and “semiclean” work areas. Such debatable facilities as a preoperative room [9] with individual cubicles to supplant a holding area must be weighed against a series of constraints. Air Handling

Perhaps the most controversial utility of operating rooms, and certainly the most publicized, is the handling of air. The original concepts which led to the formulation of National Fire Protection Association (NFPA) codes [lo-231 and later USPHS recommendations were based upon the need to ventilate hazardous anesthesia locations. More recent applications of these concepts have attempted to convert air-handling into a means of providing a “clean room!’ environment to reduce the incidence of surgical infection. Mechanical ventilation of areas in which anesthesia is given was originally recommended, not as a means of removing bacteria from the ambient air, but “for the comfort of persons in the rooms and for removal of odors, and as a convenient means of introducing humidity into a room.” The NFPA Code 56, article A222 went on to state that, “Ventilation systems should be so designed as to provide a slight excess of air supplied over that exhausted, so balanced that the pressure in the operating room is positive but not sufficient to create possibilities of cross-infection.” Here, then, is recognition of the possibility that high pressure air may carry particulate infection from one area in the surgical suite to another, a point ignored by those who promote high-speed laminar air systems for operating rooms as well as by those who write the codes. By far the majority of cases of wound infection are traceable to direct implantation of bacteria from the patient [14-171. This endogenous source is usually the result of faulty technic or inadvertent breaks in technic in the surgical handling of bowel and its contents or other contaminated tissue. Other sources [4,10] include ischemic necrosis of tissue by tight sutures, pooling of blood or tissue fluids in tissue spaces, and other surgical

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errors. Breaks in technic also include torn or cut surgical gloves, inadequate scrubbing by the surgical team, and skin infections and long hair uncovered by cap, mask, or gown. Respiratory tract infections are commonly carried from patient to patient by anesthesiologists whose technic in the use of endotracheal tubes, laryngoscopes and anesthesia equipment disregards the tenets of the bacterial cause of disease. No amount of expensive air-blowing equipment will prevent a single infeetion due to these causes. However, under certain circumstances the role of the ambience in surgical infections takes on special significance [IS-211. Since the advent of open heart surgery, attention has been drawn to blood-stream infeotion with air contaminants such as Serratia marcescens and aspergillus fungi which do not ordinarily cause wound infections in other types of operations. It is believed that the strong suction used in open heart surgery tends to act as a slit sampler which concentrates airborne biocontaminants into the open heart and blood stream [19]. Aspergillus fungi and spores are the main contaminant in pigeon excreta, moss, and leaf compost. The location of outdoor air intakes and suboptimal filtering of operating room air contribute to these infections, as well as to other types of infection such as those due to the staphylococcus [ 191. Pathogens have been isolated from the hair of beards and sideburns of surgical personnel [22]. It has been estimated that circulating viable particles in the air of the operating room contribute 1 or 2 per cent, if that, to the incidence of surgical wound infection [17,21]. Efforts at improving air handling have taken several forms. A variety of attempts to transplant the clean room principle from the National Aeronautical and Space Agency (NASA) [18,23,24] directly to the operating room have been made. Increasing the volume of clean air and increasing its speed have both been attempted experimentally. Tremendous volumes are not feasible because of cost limitations. High speed flow for mass air-handling defeats its own purpose by disturbing and recirculating previously settled particles [5]. A modern air treatment plant for an operating room typically consists of a blower to move the necessary amount of air, a prefilter to remove particles over 50P in diameter, and an air conditioner which heats, cools, and dehumidifies or humidifies the air [20]. In older installations, a final filter is effective only for particles over 10~ in diameter.

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What’s

Some installations substitute an electrostatic precipitator for a final filter which removes most particles over 0.5~ in diameter. A high efficiency particulate air filter (HEPA) removes particles above 0.3~ in average diameter. Not many operating rooms more than a decade old have HEPAfiltered air systems. Whether or not the delivered air is HEPA-filtered, its cleanliness bears little or no resemblance in particulate count to the actual count in an operating room during active use. The people and activities in the operating room generate most of the particles and bacteria found in the operating room air during its use [17,.20,221].Such activities as opening and closing doors increase the particle counts exponentially, as does high speed air movement of any kind [Z]. Movement of Air

Until the recent changes in Hill-Burton specifications, an outside air source was required to supply the twelve room volumes to each operating room every hour [25]. The twelve volumes are still required, but only five of them need be from outside air, according to the revised regulations of the Hill-Burton program. Efforts to transpose the clean-room rapid-flow mass air movement to the operating rooms have failed because of the finding that as the rate of air changes approaches 30, the flow “sweeps the floor” and recirculates contaminated particles which had settled. The conditioned air can be sent into the room in a variety of ways. It may enter the operating room from the supply plenum either from a high wall grill or from the ceiling. A criticism of the wall grill is that it tends to carry particles from the periphery of the room toward the center where the surgical operation is taking place. The potential hazard of this system was demonstrated in a study by Walter, Kundsin, and Brubaker [dl] who found that bacteria in a wound infection coincided with those carried by a fully gowned, capped, masked, and shod operating room worker who only came into the room during the operation but did not assist in the procedure. The ceiling grill has been criticized on the basis that it blows air directly downward into the operative field against the upward convection air currents which arise from the warm wound, and furthermore would tend to direct downward toward the wound globules which escape from around the surgeons’ masks. Theoretically, a more suitable system would be to locate the grills near but not at the center

Volume 122, September 1971

Wrong with Our Operating Rooms?

of the room in a recessed portion of the ceiling so that the air is directed diagonally toward the surgical field. Although imperfect, such a system is a compromise between the vertical or piston effect and the peripherally placed grills. Regardless of the direction of the air, its circulation becomes turbulent within a few feet of its exit from the grill. This characteristic of air movement in a room containing moving, working people as well as a variety of stationary objects, negates the possibility of so-called laminar flow of air in an operating room. A somewhat higher pressure in the room than in the corridor of the operating room suite theoretically prevents the ingress of unfiltered air from the corridor when the door of the room is opened [ 10,261. In practice, this does not accomplish its intended purpose [5]. Despite the higher air pressure inside the room, particle counts within the room rise sharply whenever the door to the corridor is opened, indicating that despite its higher pressure, the room air is thrown into turbulence with the opening of the door, causing some settled particles to be reactivated and actually sucking in outside air against the higher pressure. Moreover, if foul odors, as in a case of gas gangrene, are generated within a pressured room, they tend to escape to the corridor and get disseminated throughout the surgical suite. Experimentation is now being carried out to determine whether adjustable air velocity for entering conditioned air, adjustable exhaust, adjustable percentages of recirculated air, and equally clean air under equal pressure in the operating rooms and in the corridors of the surgical suite are practicable solutions to these problems. Isolators, similar to the ones used for gnotobiotic animal studies, have been adapted for operating room use by isolating the surgical field inside an inflated plastic balloon and having the surgical team entirely excluded except for their gloves [27]. Glass or plastic gazebo enclosures [18, 241 have also been used to isolate the surgical field. Rigid plastic helmets have been devised for the surgical team. A hose carries expired air to a receptacle behind the wearer. Ultraviolet light is bacteriostatic [15,28] but its use poses “sunburn” risks to personnel if it is used constantly. In some institutions in which ultraviolet is used the lamps are only turned on when no personnel is in the room. None of these methods has become widely accepted, largely because their cost-effectiveness ratio is questionable.

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Physiologic Monitoring in the Operating Room

The planner must be cognizant of monitoring only insofar as he must provide pathways for electrical conduits, and a safe electrical environment with adequate power on the one hand, and appropriate shielding on the other. Monitoring of the physiologic status of a patient during surgery has been practiced in some form ever since the first operation was performed by primitive man. Observation of vital signs, palpation of pulses, and detection of abnormalities in heart action among other things are now accomplished expediently with the aid of the cathode ray oscilloscope and other electronic and mechanical aids. The adaptation of modern electronic monitoring to operating room use was initiated by cardiac surgeons who borrowed it from the cardiac catheterization laboratory. The effect of this close surveillance on patient care was so beneficial that it is now applied to virtually all patients undergoing major surgery, especially those in high risk categories. DeLand and Maloney [29] in a recent evaluation of current operating room monitoring technics have stated some simple truths : The electrocardiogram is the most commonly employed continuous monitoring technic used in the operating room, not because it is always the most valuable guide, but because it is readily available and can be used conveniently with a noninvasive sensor. The electroencephalogram is used in brain operations and occasionally in certain vascular operations in which it is necessary to determine electrical activity of the brain. Arterial blood pressure can be determined satisfactorily by sphygmomanometer in 98 per cent of the patients undergoing operation. In the remaining patients, for the most part those having open heart surgery or those with severe trauma, and SO on, intra-arterial pressure is obtained by a catheter inserted into a radial or brachial artery. This method provides, in addition to arterial pressure, the pulse contour which contributes information about myocardial contractility, valvular function, cardiac output, and peripheral vascular resistance. Blood gas analysis is a highly useful guide to circulatory failure by indicating impending changes in acidity and oxygen partial pressures in arterial blood. It is most useful in open heart surgery or other operations on severely injured or extremely ill patients. The analysis is conven-

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tionally performed by subjecting a withdrawn sample of blood to bench analysis by the Astrup apparatus. A recent development employs mass spectrometry for on-line in viva blood gas determination by insertion of a solid membrane-tipped catheter into a major vessel and obtaining direct readings. Central venous pressure is a popularly used measurement to obtain information on the hydrostatic pressure of the right atrium, and to provide some crude indication of blood volume and cardiac function. Because of the low pressures involved (0 to 12 cm of water) the use of electronic sensors has been found to be fraught with error. Therefore, most surgeons and anesthesiologists have reverted to the use of a fluid-filled catheter and direct manometric measurement. Temperature monitoring during operation is especially important in infants and children in whom changes in body temperature may occur during anesthesia and endanger life. In infants, hypothermia tends to occur and must be corrected by a heating blanket, In older children, sudden hyperthermia of up to 106”~ may occur without warning unless monitored. In many centers it has become routine to continuously monitor the rectal temperature of all infants and children undergoing surgery. Urine output during surgery may now be monitored by a variety of methods, the simplest of which is a calibrated collecting vessel. Other monitoring devices for the most part, correlate two or more findipgs, and are not ordinarily useful for standard surgical cases. An example is the automatic calculation of cardiac output by a calculator which computes the area of a dye-dilution curve. Multiple correlations provide continuous trend analysis. Trend predictions of several types appear to be an interesting development in monitoring. It is obvious that amount and type of operating room monitoring equipment should depend upon the type of surgery being performed, the characteristics of the patient being operated upon, and to some extent, on the capabilities of team personnel. Choice of appropriate operating room equipment should be a joint decision between surgeons and anesthesiologists. Overequipping is as imprudent as underequipping, and a good deal more expensive. To avoid problems of obsolescence, it is good policy to plug in rather than build in operating room monitoring equipment.

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What’s Wrong with Our Operating

Electrical Requirements of Operating Rooms

Not included in the NFPA codes nor in the National Electrical Code is information on the amount of current required by modern operating rooms. In our own studies, we have found that operating rooms in which open heart surgery is performed using the new type of pump with a built-in heating and cooling mechanism require a current flow of 100 amperes, or 12 kva [7]. The pump itself requires 40 amperes. Standard operating rooms in which such pumps are not used, require only 50 amperes, or 6 kva, of which 20 amperes is for illumination and 30 amperes for all other equipment. The National Electrical Code, NFPA 70, sets the standards for alternate sources of electrical power allowable for use in systems designed to assure continuity of electrical power. Code 76 delineates minimal factors governing the design, operation, and maintenance of hospital electrical systems. Code 565 defines precautions attending the installation, use, and maintenance of nonflammable medical gas systems. Although oxygen and nitrous oxide are nonflammable gases, they accelerate combustion, and therefore constitute a flame hazard. Considerable confusion has been generated by surgeons and anesthesiologists who declare that they see no need for conductive flooring because they do not use flammable anesthetic agents. As long as oxygen and nitrous oxide comprise part of the anesthetic armamentarium, precautions against flame and explosion must be maintained, including those designed to equalize static charges, such as the use of conductive floors and shoe covers. An ungrounded or “floating” electrical system, explosion-proof in hazardous locations as specified in NFPA Code 56, article 244 provides protection against, but does not entirely eliminate, spark and arc hazards in normal operation of electrical equipment, and from spark and electrical macroshock hazards due to most common types of insulation failure. Electrical shock hazards are said to be particularly aggravated in operating rooms because of the physiologic predisposition of injury of persons in such locations and because of the generally low electrical resistance resulting from the use of conductive floors and shoe covers necessary for the dissipation of static electricity. Because of the difficulty of achieving a sufficiently high level of insulation with ungrounded electrical distribution systems to permit operation

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of a ground indicator, certain exceptions have been allowed. For example, permanently installed x-ray equipment and adjustable lighting fixtures need not be supplied by the ungrounded system, provided the equipment and fixtures-except for the x-ray tube head and cable-are located above the 8 foot level, and provided the control switches are located outside the area used for induction of anesthesia. Such circuits may not be operated by switch within the room connected to the grounded circuit, unless the switch is a remote control device which is connected to an ungrounded circuit. Although isolation transformers are desirable in operating rooms because they pick up faults in instruments and connectors, it must be understood that they do not protect the patient against microshock. A separate isolation transformer and ground indicator are to be used for each room within the surgical suite, so that ground alarms in one room do not disturb work going on in another room [30]. In addition to precautions against macroshock, surgical personnel must be aware of a growing danger of microshock which may be equally lethal. Although the Code [IZ] permits a current from the detector to ground of as much as 2 milliamperes, this amount of current leak is considered unsafe if internal electrodes are used. General agreement has now been reached by a number of standard-setting bodies to the effect that the maximal current leak permitted in the frames or cases of instruments, or in detector to ground be established at 10 microamperes and 5 millivolts. This is a stringent criterion, but in the face of a profusion of electrical and electronic instrumentation and internally placed catheters and electrodes, it is believed to be essential in an effort to prevent iatrogenie electrocution from ventricular fibrillation or cardiac standstill [ 301. A spirited polemic remains unresolved at the time of this writing between those who advocate application of the isolated patient center with individual isolation transformers to every special care bed in a hospital, and equally authoritative antagonists who claim that the effectiveness of this method of hazard control is not proportionate to its cost. Radiofrequency Shielding for Operating Rooms 1311

Electric interference, referred to as electronic “noise,” disturbs or distorts the output signals while they are being displayed or recorded. Manufacturers of amplifiers and recording instruments

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are well aware of interference and have designed circuits which tend to minimize its effect. An example is the input filter fitted to many alternating current (AC) instruments to suppress noise from the power line. Effective filters, which cover a broad frequency range, are quite large and expensive, and those incorporated in instruments are often designed marginally to keep the cost and size down. Use of direct current to avoid this problem introduces new problems, such as battery life and the use of more complex amplifier circuitry. Companies which manufacture laminated walls, doors, floors, and ceilings advocate the use of steel screen radiofrequency shielding layers as a method of controlling interference by shielding the entire environment. These complete shielding systems can exclude electromagnetic interference effectively, provided it is generated from outside the shielded room. Such shields are highly effective when they are warranted. For instance, a 120 decibel shield will decrease electrostatic intensity by a factor of one million. An outside field of 150,000 microvolts per meter is decreased to 0.15 microvolts inside, a value’ which permits sensitive electronic measurement [ 301. Laminated walls, doors, ceilings, and floors are now available for the construction of radiofrequency-shielded rooms. Examples of such rooms are those in which electroencephalography or electromyography may be done. Electrocardiography, which operates in the millivolt range, ordinarily does not require radiofrequency shielding. Hence, expensive building materials with built-in radiofrequency shielding are desirable only in a few selected areas. Nonetheless, many interference problems are not solved by shielded rooms. If one of these problems is not foreseen, if may be investigated as it occurs ; the specific cause can then be tracked down and eliminated or circumvented. There is no one solution to all interference problems, and it would be a mistake to suppose that shielding an operating room will be a cure-all for electronic interference in that room. In the opinion of some authorities, built-in wall shielding is, in fact, seldom justified since most interference is a result of faulty electronic technic, or occurs as a result of one piece of equipment affecting another within the same room. Moreover, shielding is expensive and restricting, Even after wall radio frequency shielding is installed, at a cost of upwards of 6,000 dollars per operating room, one must still shield the fluorescent light fixtures or else be limited to incandescent filament

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lighting. The ducts, pipes, and wires of any services which penetrate the walls serve as channels through which electronic noise may enter, largely defeating the whole purpose of the built-in wall shielding. Shielding of rooms in projected operating or monitoring areas is not to be considered routine, but should be done only after careful investigation of the physiologic measurements required and the technics to be used. Most of the time, electronic noise, when it occurs, is spasmodic and short-lived. Operating

Room Illumination

Surgical lighting has been criticized through the years by surgeons chiefly because of difficulties in focussing on the appropriate spot and delays in achieving good lighting especially in the depths of an operative wound [31]. Conventional operating room light fixtures are usually adjusted by the circulating nurse or by the anesthetist. Ideally, the central ray of the main light is directed past the right-handed surgeon’s right ear toward his right index finger. Because she can rarely see both the light and the operation, the nurse must often follow instructions blindly. To overcome this difficulty, some fixtures have a handle which can be sterilized, so that the surgeon can direct his own light. This arrangement carries the risk of contamination of the surgeon’s glove. The inverted-dish type of surgical light is a notorious dust collector. As the lamp heats up, the convection currents tend to disturb some settled particles and cause them to be air-borne. Also, every time the lamp is moved more particles are activated. Some lights are mounted on tracks. Particle counts made during the sliding of these fixtures in the tracks reveal a heavy fallout of particles. One manufacturer has overcome some of these problems by making a light with five individual lamps, each with a heat-dissipating dome and a satellite with three such lamps. This light has five intensities of illumination. Portable floor units are commonly used to SUPplement ceiling-mounted lights, but these lights are undesirable because of the vertical post which clutters the clean area. Fiberoptic units are useful for small areas and for endoscopic work. Headlights and lighted retractors are other useful methods of lighting, but they can only be used in the absence of flammable anesthesia gases. Remote control of surgical lighting is not yet available, but promises to offer a practical solution The American Journal of Sut'tWrY

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for many current problems. Another possible solution which has been tried in a number of variations is the fixed installation of ceiling dome lights of such intensity and so directed and focussed as to require little or no adjustment for any operation. Lighting of the perimeter of the room recently has been the subject of renewed interest. The previously held opinion was that the center surgical light should be extremely bright and the periphery dim, a step down from 2,500 foot candles at the operation to 150 foot candles in the remainder of the room. Now, it is considered less fatiguing for the entire surgical team and easier to adjust when looking away from the back to the surgical field to have higher-intensity peripheral lighting, such as 340 foot candles for a 10 foot radius and 260 foot candles peripherally. Surface

Materials

Basically, prime prerequisites are that surface materials be hard, nonporous, resistant, waterproof, stain-proof, seamless, and easy to clean. In addition, certain special requirements are applicable to walls, ceilings, floors, and doors. Walls. The traditional use of ceramic tile in operating rooms is the result of the various characteristics of tile. It is economical, neat, has a hard surface, is easy to clean, and in the event of broken tiles can be repaired by replacement of individual tiles [32]. However, several shortcomings of ceramic tile walls have been described. The mortar between tiles is not smooth, and indeed most grout lines are porous enough to collect and harbor bacteria, even after washing. Because tiles change color subtly, replaced tiles rarely match the original color, Moreover, objections to the use of tile have been raised on the esthetic grounds that the tiled operating room tends to look like a large bathroom. Epoxy paint has been used on the walls of operating rooms in an effort to provide a hard, seamless surface. One of the problems encountered with the use of epoxy is its tendency to flake and chip away from the plaster or wall brick. Wall paneling of hard vinyl materials such as Formica and comparable materials are meeting with some acceptance by hospital builders for use in operating rooms and other special care areas. Modular panels are available in almost any size. These materials provide an easy to clean, hard surface which is impervious to moisture. The seams can now be sealed by a plastic filler. Most brands are now supplied with a foam core which permits mounting on irregular surfaces. Hard

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panels with a glass paste filler between panels have also been suggested. A seamless wall able to withstand considerable impact without affecting the surface is the laminated polyester wall. Of all the methods mentioned, ceramic tile is the cheapest and therefore is still preferred by most hospital builders despite its drawbacks. FZoors. Conductive floors are available in almost any material including asphalt tile, linoleum, stone terrazzo, and most recently, vinyl terrazzo. The choice will depend upon whether a renovation is being carried out or a new floor is being laid. Budget restrictions are an ever-present constraint. Recommendations are based more upon suitability for cleaning properties by the flooding-wet vacuuming technic than by type of material chosen. It should be understood that regardless of the type of flooring in an operating room it must fulfill the conductivity requirements laid down in NFPA Code 56, article 252. Ceilings. The ceilings of operating rooms are being used more and more to mount devices, utilities, and equipment in an effort to reduce the clutter on the floor of power cords, hoses and tubes. In addition to the surgical lights, the operating room ceiling may be used for mounting an anesthesia service core, surgical microscope, cryosurgery device, x-ray tube and image intensifier, electronic monitor, and a variety of hooks, poles, and tubes. Because the demands for ceiling-mounted equipment are so diversified, a careful programming of needs is required from the start of planning. It is prudent to install metal stints capable of bearing heavy mounted equipment in anticipation of future ceiling-mounted equipment. Track mounts are not recommended because of the heavy particle fallout they engender. If movable or track ceiling devices are installed, they should not be mounted directly over the operating table, but preferably away from the center of the room. Sound conditioning of the ceiling will depend upon a variety of conditions. In this regard, whether or not sound tiles or other surfaces are used, they should be easily cleanable, as nonporous as possible, and mounted to minimize the possibility of dust accumulation and particle fallout. Doors. Traditionally, the doors of operating rooms have been of the swinging type. Particlecount studies, however, indicate that with each swing of the door, especially inward, the disturbance in previously-settled particles in the room is marked. It has been shown repeatedly that the particle count in most operating rooms is usually

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at its peak at the time of the first skin incision. This moment follows disturbance of the air by draping, gowning, movements of personnel, and swinging doors. During an operation, the particle count mounts sharply every time the doors swing open from either direction. Concern over this finding has led planners to specify sliding doors and pass-through wall cabinets for operating rooms. The sliding doors should not recede into the wall but should be of the surface sliding type. Fire regulations require that sliding doors for operating rooms be of the type which can be swung open if necessary.

systems, air walls which can create sterile hurricanes in operating rooms, sixteen-way closed circuit hookups with instant replay, color video tape recording and computerized retrieval of up to ten physiologic variables, all of which are currently available capabilities. Such reports do not mean, however, that every hospital must have such hookups today or even that they are appropriate. Rather, they should be looked upon as noble experiments which someone must carry out in order to reach horizons and to innovate. The pragmatic application of such investigations must await sober evaluation and optimization.

Operating

Summary

Room Equipment

Operating room equipment is ordinarily designated as class 1 (fixed), class 2 (floor standing ; movable), and class 3 (instrumentation ; portable). The separation of these three designations is not always sharp, but it does serve a useful purpose for planners. In ordering equipment for a new or renovated surgical suite, surgeons sooner or later will meet with a person known as an equipment consultant. He is usually hired by the architect, and is responsible for ordering and arranging the delivery of equipment at the appropriate time to fit in with the critical path program. He is a virtuoso on the five-foot catalogue and knows a good deal about specifications and performance criteria of equipment, and where to put things. When the equipment consultant asks the surgeon what kind of equipment he wants, it is wise, for the surgeon to be precise and realistic with respect to model number, brand name, and cost. Therefore, the surgeon must know something about equipment as well as the equipment budget. Unless the surgeon makes it a point to participate meaningfully in planning the equipment for his surgical environment when he has the chance, he automatically surrenders this responsibility to nonsurgeons. Under these circumstances the equipment consultant may simply turn over the entire project to a manufacturer or he may get advice from nurses, anesthesiologists, administrators, or well-meaning neighbors. These are some of the circumstances which may lead to errors of overdesign, overequipment, and overkill in hazard control, let alone misdirected ex post facto criticism from the surgeon. A difference must be recognized between extensive experimental installations [33] and up to date equipment necessary for sound day to day care of patients. Glowing reports are seen with growing frequency of grant-supported surgical information

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Faults in surgical suites built more than two decades ago are easily identified and usually consist of inappropriate use of space, a confused or poorly defined traffic pattern, inefficient materialshandling system, inadequate electrical wiring system, or a poor ventilation system. Faults in newly built surgical suites are more difficult to identify, but may repeat one or more faults of old suites, or may consist of expensive overdesign and overequipment far in excess of requirements of efficiency or safety. Surgeons are encouraged to take a greater hand in the design and function of the environment in which surgical care is administered. References 1. Laufman H: Critical survey of surgical suites. TO be published. 2. Laufman H: Operating room systems as seen by a SW geon. JAHA 44: 56,197O. 3. Gainsborough H, Gainsborough J: Principles of hospital design. Architectural Press, London, 1964. 4. Laufman H: The surgeon views environmental controls in the operating room. Bull Amer Coil Surg 54: 1, 1969. 5. Laufman H: Developments in operating room design and instrumentation. Medical Engineering (Ray CD, ed). Chicago, Yearbook Medical Publishers, in press. 6. Beall AC Jr: The ideal operating room enVirOnment for open heart surgery. Bull Amer Coll Surg 55: 39,197O. 7. Laufm.an H: Report of inter-society commission for heart disease resources: surgery study group. V. Plant and equipment. To be published. 8. Souder~JJ, et al: Planning for Hospitals: 9 Systems Aporoach Using Computer-Aided Techniques. Monograph, American Hospital Association, Chicago, 1967. 9. Jacobs RH Jr: The surgical center: a proposal for the reorganization of the surgical service. Amer lnst Arch J. November, 1962. 10. NFPA Code No. 56 (National Fire Protection Association): Code for Flammable Anesthetics, Boston, 1968. 11. NFPA Code No. 70 (National Fire Protection-Association): Recommended Safe Practice for Hospital Operating Rooms, Boston, 1968. 12. NFPA Code No. 76 (National Fire Protection Association): Essential Electrical Systems for Hospitals, Boston, 1967.

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13. NFPA Code No. 565 (National Fire Protection Association): Nonflammable Medical Gas Systems, Boston, 1967. 14. Altemeier WA, Culbertson WR, Hemmel RP: Surgical considerations of endogenous infections: sources, types and methods of control. Surg Clin N Amer 48: 227, 1968. 15. Bernard HR, Speers RJ, O’Grady F, Shooter RA: Reduction of dissemination of skin bacteria by modification of operating-room clothing and by ultra violet irradiation. Lancet 458, September 4, 1965. 16. Howe CW: Experimental studies on determinants of wound infection. Surg Gynec Obstet 123: 507, 1966. 17. Williams REV, Blowers R, Garrod LP, Shooter RA: Hospital infections: causes and prevention, 2nd ed. Chicago, Year Book Medical Publishers, 1966. 18. Charnley JA: A clean-air operating enclosure. 8rit J Sorg 51: 201, 1964. 19. Gage AA, Dean DC, Schimert G, Minsley N: Aspergillus infection after cardiac surgery. Arch Surg 101: 384, 1970. 20. Goodrich EO Jr, Whitfield WW: Air environment in the operating room. Bull Amer Co/l Surg 55: 7, 1970. 21. Walter CW, Kundsin RB, Brubaker MM: The incidence of airborne wound infection during surgery. JAMA 196: 908, 1963. 22. Dineen P: Staphylococcus wound infection traced to hair of surgical team. Symposium on Medical and Surgical Antiseosis. Universitv of Miami. Medical School. March, 19h. 23. Allander C, Abel E: Investigation of a new ventilating system for clean rooms. Med Res Engin 7: 28, 1968.

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24. Coriell LC, Blakemore WS, McGarrity GJ: Medical applications of dust-free room. II. Elimination of airborne bacteria from an operating theater. JAMA 203: 1038, 1968. 25. Beck WC: Air systems requirements are revised by HillBurton program. Bull Amer Co/l Sorg 54: 134, 1969. 26. Public Health Service Publication No. 930.A07: General Standards of Construction and Equipment for Hospital and Medical Facilities (revised). Washington, DC, US Government Printing Office, 1969. 27. Levenson SM, Trexler PC, Malin OJ, Horowitz RE, Moncrief WH Jr: A disposable plastic isolator for operating in a sterile environment. Surg Forum 11: 306, 1960. 28. Walter CW: Ventilation and air conditioning as bacteriological engineering. Anesthesiology 31: 186, 1969. 29. DeLand EC, Maloney JV: Physiologic monitoring in the operating room. Bull Amer Co/l Surg 55: 7, 1970. 30. Walter CW: Safe electric environment in the hospital. Bull Amer Co/l Surg 54: 4, 1969. 31. Laufman H: Radio-frequency shielding for operating rooms. Bull Amer Coil Surg 54: 367, 1969. 32. Feige K: How electronic “noise” affects instrumentation. Mod Hosp 110: 122,1968. 33. Beck WC: Operating room illumination. Bull Amer Co/l Surg 54: 277, 1969. 34. Putsep EP: Planning of surgical centers. London, LloydDuke Ltd, 1969. 35. Sheppard LC, Kouchoukos NT, Kurtis MA, Kirklin JW: Automated treatment of critically ill patients following operation. Ann Surg 168: 596, 1968.

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