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Operating Room Scheduling
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Operating Room Scheduling A LITERATURE REVIEW
Zbigniew H. Przasnyski
E
fficient scheduling of operating rooms involves complex technical and interpersonal interactions. This article provides a summary of what has been published on OR scheduling in the hope that it will stimulate further investigation. The literature on O R scheduling illustrates five general areas of concern: OR utilization, cost containment, planning and organization, scheduling specific resources (eg. nursing staff, anesthesia, blood bank), and the scheduling of surgical operations into operating rooms.
Determining OR Utilization
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tudies designed to evaluate O R utilization are usually characterized by (1) a definition of utilization (ie, the time ORs are occupied divided by the time they are available), and (2) the use of an OR logbook or data sheet. The data sheet is designed for collection of pertinent
information about each surgical procedure (eg, starting and ending times, reasons for delay, instrument requirements, names of surgeon and anesthesiologist). Two studies in the early 1960s used the standard approach of analyzing the information gathered in the O R data record.] One of the studies attempted to find reasons for unused time, but without much success. After looking at the delays produced by the late amval of personnel, one author stressed the need for cooperation and coordination of all staff concerned to achieve real improvements in utilization.* A graphic approach to track OR utilization has also been attempted.3 With that approach, a grid is constructed with time as the ordinate (x) and operating rooms as the abscissa (y), and the times the operating rooms are in use are blacked out. Whenever an OR is not being used, the reasons are obtained and thus trends can be visualized.
profersor of business adminutration,Loyoh Marymount University, Los Angeles. His doctoral degree in operational reAearch IS from the University of Sussex, Englad hrs master of science degree in mathematical computation I S from the University of Essex, England and he has a bachelor of scmce degree in engineenng and operational research from the University of Sussex.
Zbigniew H. Przasnyski, PhD, is an associate
The author acknowledges the department of epidemiology and preventive medicine, University of Maryland, Baltimore, for providing facilities and encouragement for the conduct and reporting of thrr study. 61
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Use of one type of scheduling system resulted in approximately a 30%decrease in the time taken to produce monthly reports. Although this approach is easy to use, the information produced is limited. A study noting that “automated surgical record keeping reduces errors, saves times, and facilitates greater infcirmation recall than does traditional human logging,” did not result in any cost savings.4 Costs were merely displaced from hand transcription and manual data collection to computer costs; however, there were considerable gains in flexibility, and it was possible to obtain information that was previously unavailable. Priest and colleagues described the considerable effort spent on minimizing transcription errors, both in handling of forms and in computer coding.5 The reports generated are circulated to various department!!. Among the benefits of computerizing the OR log, according to the study, are: (1) reduction in the time needed by the surgical staff to produce reports; (2) more accurate statistics and data, which the authors indicate can be used to aid in scheduling through more realistic operation predictions; and (3) the ability to generate special reports from the information held in the data base. One author described a standard approach to analyzing information from the OR data sheet, but instead of generating the reports on a mainframe computer, a word processor with mathematical capabilities was used? The system was functional in two months because it only involved combining data input with existing manual reporting. Approximately a 30%decrease in the time taken to produce the monthly reports was noted. The flexibility of the system, as well as the simplicity and extensiveness of the data base, were praised by the author. Although utilization studies involve large amounts of data that require careful classification and coding, they are, in effect, management information systems. Some provide high levels of sophistication in the reports they generate, and in the information they make available.’ 68
Reviewing those utilization studies in more detail, it becomes apparent that there are essentially two operating room scheduling methods: firstcome, first-served, and block booking. The main disadvantages of a firstame, first-served system are: high cancellation rates as a result of overbooking, and vastly different OR utilization rates among surgical services. The block booking system was developed to overcome these disadvantages. Its advantages include: reduction in competition between physicians because guaranteed blocks of surgical time are available, booking does not have to be done so far in advance to ensure that an operation is performed on a certain day, and better overall utilization of operating rooms. The biggest disadvantage of block booking is that even when it is known in advance that time booked will not be used, it is not readily given up for another surgical service to use. One review of the literature: on this subject points out the lack of systematic and exhaustive comparisons of the two strategies.* Simulation would provide a valid vehicle for such a comparison, but problems arise in the availability and accuracy of data necessary to simulate the other system. Simulation could only be considered if a hospital changed from one system to the other, but even then the hospital would have little motivation to compare the two approaches after the decision has been made to lchange from one to the other.
Containing Costs
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perating rooms are an expensive resource, and various suggestions have been made for containing costs. One article describes
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Methods for cost reduction such as more efficient traffic patterns within the OR have been suggested. a system for recording operating room supplies in which the circulating nurse is provided with a preprinted form listing the most-used supplies in the OR.9The rationale is that if an item used during surgery is not properly recorded, it is a lost charge, and becomes part of the hospital overhead costs. A more global perspective of cost containment in the operating room with general recommendations such as investigating ordering supplies in bulk, balancing out holdmg costs,and considering outpatient surgery is offered in another article.I0 This article stresses the importance of physician awareness of the costs of laboratory tests, x-rays, and other proceduresso that they can better control superfluoustests. Another suggestion for reducing operating room costs is for the purchasing director to shop around for surgical supplies,cutting down on unneceSSary waste (eg, items are often removed from their plastic wrappers, but not used), standardization of supplies for surgeons without compromising quality, and critical reviews of inventories to determine which items are not being used.I1 The Ontario Hospital Association lists a number of cost containment ideas for operating rooms to cope with common problemssuch as uneven work load and overtime.12Those suggestions include closing an operating room, starting precisely on time, and including the changeover time on the schedule. A slightly Werent approach has been proposed, which states that savings can be obtained through the appropriate use of the charging system.I3 This work was originally motivated as a result of the competition posed by freestanding outpatient surgery centers. The authorscontend that operating room charges are usually based on a scale that increases with the duration of surgery. Costs, therefore, are not always allocated according to the type or difficulty of surgery performed. Thus, they developed a fourcategory hierarchy of 70
operations from minor general surgery to major orthopedic surgery and compared their model on charging data at a hospital in Utah. Use of the model resulted in more equitable charges for surgery. In addition to providing an interesting account of the growth and advances of technology in the operating room over the past 30 years, one article describes some general directions in cost containment from a broad planning point of ~ i e w . These 1~ include standardizingoperating rooms to promote multipurpose use, and adequate planning for bed allocation. The author points out that averages from each surgical seMce are not sufficiently accurate (eg,that a typical neurology patient will be in the hospital for 11 days, versus an otolaryngologypatient stay of two days). Methods for cost reduction in the OR such as more efficient traffic patterns within the OR have also been suggested.l5 An excellent summary of cost containment in the operating room, including some of the suggestions discussed above, was done by Comper.16 In addition to specifc improvements, the author cites advances in preventive medicine that lead to a reduction in surgical intervention. He contrasts this with the rise in the percentage of patients over 65 years of age, which results in increases in certain types of surgeq, and the implications for operating room managers.
Planning and Organization
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t has been calculatedthat the constructioncosts per square foot for operating rooms are higher than for any other hospital department.17 According to one author, goals in planning a new surgical suite include: (1) optimal patient care, (2) high operating room utilization, (3) high personnel productivity level, (4) safe patient environment, (5) efficient running of the suite, (6) accommodation of staff scheduling needs, and (7)
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One study considered the diagnostic category of the patient on admission in relation to the expected length of surgery. coordmation with other departmentsi8The author suggests identifying population markets with analysis and projection of demographics, a similar analysis of the pool of physicians, and a careful analysis and forecasting of resource requirements as part of the planning process. A more technical approach through a simulation study has been In this study, historical data was analyzed to provide input for the model, and an OR data sheet was used to evaluate utilization in the design of a surgical suite. To determine the optimum number of operating rooms, Goldman and Knappenberger totaled the costs of the building, staffing, and equipping an operating room, overtime, and patient waiting time and presented a breakeven analysis.20Their model was intended to indicate at what levels a new operating room would be viable. That approach is reasonably useful, but suffers from the usual drawbacks of breakeven analysis in making the original cost estimates. An interesting account on how to modernize the operating room suite is given by Tornello, and includes useful references on requirements and planning guidelines?' The article describes the seven years of planning design and redesign that took place before the suite was opened. Another study presents a method for planning a surgical suite by quantifying the relevant costs of all departments concerned.22 Using sophisticated formulas, the researchers translated work-load requirements into space needs. Both manual simulation and computer simulation approaches have been used to study the organization and workings of the operating room suite.23Two such studies concerned the number of beds required in a recovery room to prevent a backlog of patients." Another study used simulation to evaluate various operating room scheduling policies (eg, firstcome, first-served, longest case first, shortest case first) and concluded that the highest utilization (as measured by idle
time and overtime, for example) was obtained by schedulingthe longest case Such a policy, however, could lead to bunching and possible overloading late in the day in the recovery room. A mathematical model based on data from Stanford University Hospital is described in a study that combines surgical demand with a tinancial anaIysis.26 The model allows for a financially optimal solution to be obtained to determine how many operating rooms should be included in a surgical suite. Satisfactory operating room turnover is to a large extent dependent on appropriate admission policies. There have been many studies on admission scheduling, but few adequately consider the implications of surgical resources. A more precise admissions-surgery model addresses the great variation in the length of stay between patients admitted to the various surgical specialties.27The author of the study advises caution in applying data from one hospital to another because of the many factors involved and local differences, and suggests periodic review of all recommendations to ensure that they are still accurate. One realistic and detailed admissionsurgery model provides the link between admissions and surgery by considering the diagnostic category of the patient in relation to the expected length of surgery.28 The effects of operating room design and policy on recovery room and intensive care unit design and policies have also been studied.29
tudies on scheduling nursing staff for various shifts so that they can provide good health care, cope with problems due to holidays, and devise various alternatives to five-day, eighthour shifts have been investigated (eg, four-day, 10-hour shifts, or flexible work weeks of seven to 10 four-hour shifts).w For each alternative,
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When the nurses were involved in producing their ‘ideal‘ schedule, they found the system to be very fair. benefits were perceived primarily because of the interest taken on the part of management in personnel scheduling and, second, in tangible improvements (eg,time off during the week) to the staff. Different studies reported various alternatives to the standard eight-hour day, but no one alternative emerged as the best; specific local conditions usually determined the best alternative schedule for a particular hospital. In general, the literature reports that any systematic approach, whether it is manual or computerized, results in greater staff satisfaction if it is not arbitrary and especdly if staff members have a say in the scheduling process?’ For example, one paper describes a study where initially there was much dissatisfaction with the scheduling process on the part of the nursing staff.32 Then the nurses were involved in the scheduling process by producing their own “ideal” schedule for a month, including contractual obligationsand constraints, but ensuring that a certain number of shifts were included. These individual schedules were combined into a master schedule and loose ends were ironed out through discussions. The master schedule was then modified slightly to be workable and implemented for a trial period. The scheduling process was previewed by the staff and found to be very fair. Another paper provides a fascinating account of the conflicts involved in scheduling holidays when the staff is split into two camps (ie, those who work and those who do not)?3 The difficulties in ensuring fairness to everyone may lead to bad feelings among staff who work together outside the holiday period; patient care may suffer as a result. The suggested solution to this problem was to plan well ahead of holidaysand to keep accurate records of who works which holidays so that fairness can be clearly demonstrated. One paper described a computer scheduling system for nurSeS in which three schedules were produced: four weeks ahead, 16 days ahead, and 12
three days ahead, for a tweweek period.” A number of reasonsfor both employee and hospital satisfaction were cited, including: (1) employee satisfaction with well-planned, accurate schedules produced on time; (2) appropriate staffing levels achieved by the hospital within budget restrictions (ie, lower overtime mts);and (3) effective budget control and planning through efficient management reports. Another computer staff scheduhg system took into account staff preferences, thereby increasing staff satisfaction, while at the same time greatly reducing the time taken to produce monthly ~chedules.3~ A common theme throughout these studies was the importance of systematic and careful scheduling in order to create the greatest satisfaction and where unpopular shifts could clearly be seen to be fairly and uniformly distributed among all staff. One study reported the benefits of a 10-week cycle rotation schedule for operating room personnel that allowed surgical technicians and circulating nurses to know well in advance when they would have time off and when they were scheduled to work. The hospital benefitted by having more even staang in the OR at all times, including second shift and weekends.” Alternative shift patterns were investigated in a number of studies. One such study suggested working combinations of eight-, lo-, and 12-hour ~hiffS.3~ The objectivewas to minimize the number of staff hours worked each day, subject to the constraints imposed by the levels of staffing required during each hour of the day. It was found that productivity could be increased by 8.1% and personnel requirements reduced by one full-time equivalent. Use of this method, however, would require willingness of the staff to work 10- and 12-hour shifts, and an effective format for communicating information about patients between staff on different shifts.
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Literature dealing with management of detailed operating room scheduling is scarce. Two studies describe the implementation of a computer scheduling system for anesthesiologists, which increased satisfaction for them.38 Other studies have looked at the scheduling of other resources that impinge on operating room services, such as the availability of blood and laboratory tests.39
Scheduling Surgery
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iterature dealing with the management of detailed operating room scheduling is scarce. A review of 45 operating room scheduling studies was done in a study by categorizing them according to the contraints involved (ie, just time, time and resources, only bookings considered).40The majority of proposed schemes, however, were never implemented. Stevens points out that although patient care is the highest priority in any nursing setting, good patient care is likely to occur only in a systematic and efficient operating room setting!’ The author therefore emphasizes the necessity for a “system approach” to accomplish smooth and efficient coordination of personnel, time, space, and equipment involved in OR management. The author concludes that for the system to be effective, managers should determine clear entry criteria and use feedback to monitor results and identify necessary changes. A study to investigate a number of scheduling disciplines, although theoretically sound, used underlying assumptions about such things as amval and procedure time distributions that were unduly restrictive and may not adequately represent the intricacies of an actual Another problem with the study is that it fails to address the many resource restrictions found in hospitals. A number of studies, which purport to describe operating room scheduling systems but actually describe operating room management systems, 14
have been done. One such study describes a computer system that is capable of producing many types of reports, but most notably can compare actual and predicted operation durations.“ All scheduling in this study, however, is in effect a booking approach in which the surgeons’ requests for a particular time and date are accepted or rejected on the basis of the information in the data base, and no rescheduling or updating is performed. A similar model based on an operating room information data base produces all expected reports, as well as charging informatioaMIts main improvement over the study that compares actual and predicted operation duration is that available time slots can be Seen easily in answer to a request for the earliest possibledate for a procedure. Again, the model does not provide for updating of the schedule. Only two descriptions of implemented systems that actually perform the scheduling of operations could be found. The first approach is one of sorting the requests for a particular day on the basis of four parameters (service priority, time, surgeon priority, and room preferred by service) before assigning the procedures to The relative priority of the parameters can be modified. Although the resulting schedule can be amended using a terminal, any updates to the schedule on the day must be done by hand; no automatic rescheduling is performed. Admissions information can be consulted on-line by the scheduling clerk using the appropriate data base.The authors of the paper note considerable satisfaction with the system, saying that the “high quality schedules [produced]have reduced discord among operating room personnel.” As a result of an admissions department and operating room study that sought to assess admitting practices, operating room booking procedures, and bed allocation among the surgical services in a relatively small hospital, a patient
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One of the most important pieces of information on which all scheduling systems depend is the predicted length of surgery. reservation system was developed for nonemergency surgical patients, which simultaneously assigns a date of admission and date and time of ~urgery.~6Benefits of the system include reduction in average length of stay and an increase in operating room utilization. One of the most important pieces of information on which all such systems depend is the predicted estimate of length of surgery. In 1963, an author pointed out the necessity for accurate estimates of surgery duration and feedback to compare the actual duration with e~timates.4~ Another study found that surgeons request an average of 4% more time than they take!* The study is noteworthy because it is one of the few that kept a file to confirm surgeons’ requests. Usually, the clerk taking the bookings and the surgeon agree on an estimate of length of the procedure. Although guidelines for durations of procedures exist, surgeons work at different speeds and indeed few cases are of a standard length. Most require adjustments, which are made by the booking clerk using his/her experience and memory. When the experienced clerk is absent, the schedules are inferior in quality. Producing realistic surgery estimates is therefore in great need of systematic investigation and coordination. A method to reduce the time a surgeon is idle between operations has been st~died.4~ If a surgeon is scheduled to operate on two successive patients in the same operating room, he is idle from the time the first patient’s closure is started until the patient is removed, the room is prepared, the next patient is brought in, and anesthesia is started. The study proposes using a two-room (or more) system whereby the surgeon transfers to another operating room as soon as closure on one patient is begun to start surgery on another patient. Although such a system may be tiring for the surgeon, the author of the study claims that implementation in his hospital resulted in elimination of overtime.
A general application of such an approach may not be practicable because such alternation between operating rooms presupposes that all rooms are identical in size, fixtures, personnel requirements, and the procedures that can be carried out in them. Furthermore, for such a strategy to be most effective, the duration of procedures performed by the alternating surgeons would have to be carefully matched, perhaps with staggered starting times at the beginning of the day to prevent a situation where two surgeons are competing for the same room. On a more specific technical level, one author addresses the mechanics of the sequencing of the operations within the operating rooms by comparing the problem to the classic “job scheduling problem,” and states the permutational complexities.50 The paper is an introduction for the medical community to combinatorial mathematics and scheduling applications. The author makes recommendations for improving the efficiency of the operating rooms, the most important of which is that operating rooms should be made large enough to accommodate all surgical procedures. Other suggestions include instituting shifts other than the standard eight-hour shift. An average thoracic case may take four to four and one-half hours, and could thus prevent two thoracic cases from being done in that room on the same day. Although comparison of operating room scheduling to well-known scheduling problems in other areas is valid and interesting, the conclusions drawn from them cannot be rigidly applied because operating room scheduling presents some unique problems not present elsewhere. In particular, an unlimited supply of cases waiting for surgery (compared to jobs on computers, for example), cannot necessarily be assumed. Patients must be prepared both physically and psychologically, with sensitivity and consideration. In addition, the information regarding surgical 15
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One study indicated little difference in recovery quality of patients taken at early definite or late indefinite times. procedures is in a constant state of flux. Finally, a study of 60 patients who underwent total hip replacement arthroplasty examined the effects on recovery of patients scheduled for surgery at definite times with patients scheduled with indefinite (to-follow) start times?’ A series of physiological measures was taken from two days before surgery to 14 days after surgery. The results indicated little difference in the quality of recovery of patients taken at early definite or late indefinite times when other variables were held constant, and when patients were convinced that surgery would relieve pain and restore function. This study is most notable in that it gives a different perspective-the point of view of the patient-to operating room scheduling.
Conclusions
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he complexity of OR scheduling is a result of the large amount of different types of information involved that are everchanging. The active cooperation of all concerned staff and a decision maker with enough authority to enforce the system are basic requirements for any attempt at a successfbl solution. An authority figure can help avoid the perception by staff members that there is a lack of direction and control. The literature on OR scheduling is split into two types: very technical, with presentation of solutions to problems, but with many assumptions and restrictions; or completely nontechnical statements of associated problems, often with common sense proposals for local improvements in a few areas. Clearly, to make any real progress, solutions using technical methodology have to be combined or sacrificed to provide an indepthh understandingand consideration of all day-today details so that the complete problem, and not a theoretical subset, is attacked. 76
Although many suggestions and proposals to solve the operatingroom schedulingproblem have been made, the successful implementation rate is very low. One reason was summed up best by an author who said, “as every health service administratorknows, there is rarely a large degree of finality when trying to arrive at an answer to a question concerning the organization of hospitals.”52 This seems to be due to a vast and complicated web of politics, fear, lethargy, maintenance of the status quo, illdefined goals, and lack of overall direction inherent in large systems such as these. The many nontechnical problems (ie, political and behavioral) assoCiated with operating room scheduling Seem to be particularly characteristic of many of those negativefactors. With appropriate education, time, and demonstration of effective solutions to real problems, however, the tide will slowly change toward realisticexpectationsand positive attitudes toward systematicdecision making. The inertia in this area of operating room scheduling is somewhat of a chicken and egg situation: no progress will be made toward an effective solution until practical (ie, nontheoretical) success can be demonstrated, but this involves overcoming the inertia that opposes significant changes and involves a substantial initial commitment and overhead costs.The way forward from such a downward spiral is a kind of bootstrapping procedure. Modest improvements already cited in the literature should stimulate serious interest on the part of the decision makers within the hospital to be prepared to undertake and enforce progress and the changes neceSSafy to achieve an effective solution. The responsibility of the technical analyst would then be to produce a meaningful solution methodology sensitive to all perceived needs that is also flexible. The advent of increasingly powerful microcomputers might provide the catalyst for such boots(rapping. With a dedicated microcomputer,
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total control can be easily within the operating room domain.
Research Needs
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ain avenues for future research include
(1) systematicstudy to fully evaluateand
compare, under controlled circumstances, block versus nonblock booking systems, (2) analysis and determination of procedures and practices to ensure accurate forecasts of length of surgeries, (3) planning and forecasting of populations that would require various hospital surgical services, (4) investigation of medical systems in other countries to determine possible improvements in strategy, ( 5 ) economic analysis to determine the most effective charging strategies, (6) determination of realistic standby levels, if any, and detailed study of assoCiated problems, and (7) analysis of expectations and misgivings of personnel regarding introduction of a computerized scheduling system in the operating room. 0 Notes 1. 0 C Zimmerman, “Utilizing operatmg room time,” Hospital Topics 41 (February 1%3) 99-102; M London, “Know your OR vacancy rate to improve surgical scheduling,” Modern Hospitals 103 (October 1964) 110-114. 2. W L Williams, “Improved utilization of the surgical suite,” Hospitak 45 (March 1, 1971) 93-96. 3. M Hoffman, “A graphic look at operating room utilization,” AORN Journal 22 (September 1975) 473478. 4. J Cresto, S Devor, “Computerize the log,” Hospitah 47 (July 1, 1973) 58-60. 5. S L Priest, B D A Pelati, D E Marcello, Jr,
“Computerized OR log system has many uses,” Hospitak 54 (June 1, 1980) 79-82. 6. G Morrison, “Word processing in OR management,” Dimensions in Health Service 57 (March 1980) 18-20. 7. D K Rohe, “Operating room statistical infor-
mation system (ORSIS): What an information system should be”, Center for Hospital Management Engineering (Chicago: American Hospital Association, 1979). 8. J M Magerlein, J B Martin, “Surgical demand scheduling: A review,” Health Services Research 13 (Winter 1978) 418433. 9. J Botsford, “New operating room record system,”
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Hospital Topics 59 (September-October 1981) 22-23. 10. J A Koncel, “Practical tips on cost containment: Surgical suite,” Hospiirclrs 54 (Aug 16, 1980) 151-155. 11. W Warren, “Cost containment in the operating room,” T e r n HospitarS 37 (October 1981) 10. 12. “Cost containment in the OR,” Dimenrions in Health Sewice 57 (March 1980) 16. 13. C R Skousen, G L Hooper, “An alternative approach: Determining hospital surgical suite charges,” Hospital Fb~anckzlManagement 35 (December 1981) 50-61. 14. L Block, “OR costs: Control or cutting,” AORN Journal 15 (June 1972) 59-65.
15. “Recommended practices for traffic patterns in the surgical suite,” AORN Journal 35 (March 1982) 750-758. 16. A Comper, “The OR utilization fixtor,”Surgical Business 43 (March 1980) 30-31. 17. J T Martin, “An anesthesiologist looks at OR design,” AORN Journal 21 (February 1975) 259-278. 18. H B S c h n e i d e m , ‘‘Building a new surgical suite,’’ AORN Journal 30 (July 1979) 3543. 19. F Zilm, L Calderaro, M Del Grande, “Computer
simulation model provides design framework,” Hospitals 50 (Aug 16,1976) 79-85. 20. J Goldman, H A Knappenberger, “HOW to determine the optimum number of operating rooms,” Modern Hospitak 111 (September 1%8) 114-1 16. 21. J D Tornello, “When I build my OR: Dream and reality,” AORN Journal 30 (July 1979) 44-50. 22. J S Moore, W J Spencer, ‘‘F‘lannq space around systems,” Hospitals 49 (Feb 1, 1975) 115-118. 23. H Schmitz, N K Kwak, “Monte Carlo simulation of operating and recovery usage,’’ OperationsResearch 20 (November-December 1972) 1171-1 180; S Barnoon, H Wolfe, ‘‘Scheduhg a multiple operating room system: A simulation approach,” Health Services Research 3 (Winter 1%8) 272-285; G M Luck et al, Path&, Hospiirclrs, and OperationalResearch (London: Tavistock Publishers, 1971). 24. P Kuzdrall, N K Kwak, H H Schmitz, “The Monte Carlo simulationof operating room and recovery usage,” Operations Research 22 (March-April 1974) d , H Schmitz, 4344@ N K Kwak, P J K ~ ~ d r H “Simulating the use of space in a hospital surgical suite,” Simulation 25 (November 1975) 147-152. 25. J Goldman, H A Knappenberger, E Moore, “Evaluation of operating room scheduling policies,” Hospital Management 107 (April 1%9) 40-51. 26. D S Hopkins et al, “A model for optimizing the number of operating rooms in a hospital surgical suite,” Health Care Management Review 7 (Spring
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1982) 49-64. 27. J T Stewart, “Surgical specialties affect scheduling: Formula for admissions,”Hospitals 45 (Sept 1, 1971) 132-136. 28. J A George, D R Fox, R W Canvin, “A hospital throughput model in the context of long waiting lists,” Journal of the Operational Research Society 34 (January 1983) 27-35. 29. S Schwartz,C Cullen, “How many intensivecare beds does your hospital need?’’ Crirical Care Medicine 9 (September 1981) 625-629. 30. M McCarville, “The 10-hour day,” Dimensions in Health Service 53 (February 1979) 34-37;R T Ward, P A Fuhs, “Change in nursing shift patterns improves emergency department,” Hospitals 55 (Oct 16, 1981) 64-68; “Would flexible schedules work in the OR?” AORNJournal30(December 1979) 1166,1174-1175. 31. J M Ganong, W L Ganong, “Staffing and scheduling: ‘Numbers game’ or nursing management?” Healfh Services Manager 1 1 (December 1978) 6-7; C W Axelrod, “Computerized call scheduling for hospital departments,” Journal of Medical Systems 2 (1978) 85-97; M S Alvizatos, “A new concept in scheduling for nurses,” Supervisor Nurse 12 (February 1981) 20-22; M Van Meter, “A ‘magic’ solution for all our staffing ills,” RN 45 (January 1982) 49-53; L D Smith, D A Bird, A C Wiggins, “A computerized system to schedule nurses that recognizes staff preferences,”Hospital and Health Services Administration 24 (Fall 1979) 19-35. 32. F Coopemder, “Staff input in scheduling boosts morale,” Hospitals 54 (Aug 1, 1980) 59-61. 33. C T Roe, “How to call a truce in the holiday scheduling wars,” RN 42 (November 1979) 83-88. 34. D J Ballantine, “A computerized scheduling system with centralized staffing,” Journal of Nursing Administration 9 (March 1979) 38-45. 35. L D Smith, D A Bird, “Designing computer support for daily hospital staffing decisions,” Medecine et Informatique/Medical Infomtics 4 (April-June 1979) 68-78. 36. D P Mazzolla, R Oppenheimer, “Matrix schedules for operating room nurses,” Industrial Engineering 5 (March 1973) 36-37. 37. R B Cooper, “A linear programming model for determining efficient combinations of eight-, 10-, and 12-hour shifts,’’ Respiratory Care 26 (November 1981) 1105-1 108. 38. E A Ernst et al, “Anesthesiologist scheduling using a set partitioning algorithm,” Computers and Biomedical Research 6 (December 1973) 561-569. 39. M Rabinowitz, “Blood bank inventory policies:
A computer simulation,” Health Servim Research 8 (Winter 1973) 271-282; R T Golembiewski, “A survey of the empirical literature on flexible work hours: Character and consequences of a major innovation,” Academy of Management Review 3 (October 1978) 837853; L I Boral et al, “A guideline for anticipated blood usage during elective surgical procedures,” American Journal of Clinical Pathologv 71 (June 1979) 680-684; R S Seshadri et al, “Effective use of blood in elective s u r g d procedures,” Medical Journal of Australia 2 (Dec 1, 1979) 575-578; W N Shannon, “Advantages of the ‘on-line’ multipurpose lab computer,” Hospital Progress 53 (February 1972) 62-66. 40. Magerlein, Martin, “Surgical demand scheduling: A review.” 41. B J Stevens, “Systems approach to managing an OR,” AORN Journal 27 (June 1979) 1322-1338. 42. A M 0 Esogbue, “Mathematical and computational approaches to some queueing processes arising in surgery,” Mathemafical Biosciences 4 ( 1969) 53 1 542.
43. R Bendix et al, “Computer scheduling for the operating room,” Modern Healthcare 5 (June 1976) 16m- 160. 44. T Mathis, “Automated system solves major problems of scheduling, charging, and data collecting,” HospitarS 56 (May 16, 1972) 59-60. 45. E A Ernst et al, “Operating room scheduling by computer,” Anesthesia and Analgesia 56 (November-December 1977) 83 1-835. 46. W Drozda, “A scheduling and preadmission system for nonemergent surgical patients,” Center for Hospital Management Engineering(Chicago: American Hospital Association, 1980). 47. E T Sheen, “Realistic surgery schedule based on surgeons’ own estimates,” Hospitals 37 (1963) 49-50. 48. K T Phillips, “Operating room utilization,’’ Hospital Topics 53 (March-April 1975) 42-45. 49. J Kildea, “Operating room scheduling methods: The two-room system,” Hospitals 44 (Nov 16, 1970) 99-101. 50. D G McQuarrie, “Limits to efficient operating room scheduling: Lessons from computer-use models,” Archives of Surgery 116 (August 1981) 1065-1071. 51. Barbara Blake Minckley, Physiological and Psychological Responses of Elective Surgical Patients in Ear4 Definite or Lute Indefinite Scheduling of Their Surgical Procedure, Thesis Docu. No. 72-74, 929 (San Francisco: University of California, 1972). 52. L D Cox, “Theatre organization under Salmon,” Hospital Health Services Review 68 (March 1972) 9293.
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NOVAFlL" (MonofilamentPolybutesterSuture) (NonabsorbableSurgtcal Sutwe US P) (Clear M Blue)
A Brief Summary INDICATIONS NGVAFIPis indicated for use in all types of soft tissue approximaton. including use in cardiovascular and ophthalmic surgery.but not in microsurgeryand neural tissue It is recommendedfor use where the possibility of reduced suture reaction is desired CONTRAINDICATIONS There are no known contraindications PRECAUTIONS Since any foreign material in the presence of bacterial contaminationmay enhance bacterial infectivity standard surgical practice should be followed with respect to drainage and closure of infected wounds NOVAFIC did not enhance infection in animal or in in-vitro studies ADVERSE REACTIONS As with any foreian body, transitory local inflammatory reactionscoild occur WARNINGS Do not resterilize Discard open, unused sutures CAUTION Federal Law restrictsthis device to sale, distribution and use by or on the order of a phystcian or veterinarian
American Cyanamd Company Wayne, New Jersey 07470 8 Registered trademark American CyanamidCompany
Metoprolol Safe, Effective Treatment for Hypertension Elderly patients whose hypertension was treated with metoprolol, a beta blocker, had similar results with fewer side effects than patients treated with the antihypertensive diuretic drug hydrochlorothiazide, according to an international study reported in the March 14 Journal of the American Medical Association. Researchers in Sweden coordinated the study that included 40 clinical centers in 12 countries. In all, 562 patients with diastolic blood pressure over I00 mm Hg and between 65 and 75 years of age participated. Patients were divided into two groups; one received 100 mg of metoprolol, the other received 25 mg to 50 mg of hydrochlorothiazide. Each dosage was given on a daily basis for four to eight weeks. Results showed that the patients' blood pressures were significantly reduced in both groups. After four weeks, 50%of the metoprolol patients and 47% of the hydrochlorothiazide patients had 82
diastolic blood pressures of 95 mm Hg or less. After eight weeks, the percentages increased to 65%and 61%, respectively. Although both regimens reduced the patients' blood pressures, patients taking hydrochlorothiazide experienced significantly more hyperuricemia and hypokalemia than the metoprolol group. Based on the results, researchers concluded that W n n i n g antihypertensive treatment with 100 mg of metoprolol daily and adding 12.5 mg of hydrochlorothiazide in patients with unsatisfactory results appears to be an effective and safe treatment for elderly hypertensive patients. Traditionally, elderly patients with hypertension were given 25 mg of hydrochlorothiazide, or other diuretic drug, which was doubled if ineffective.
Binging and Purging Common Teen Behavior Using the binge-and-purge eating behavior as a means of staying thin is being practiced by as many as 13%of American teenagers, according to research published in the March 20 Journal of the American Medical Association. Researchers at Stanford University, Palo Alto, Calif, surveyed 1,728 10th graders and found that 13%reported using some type of purging behavior to control their weight, and that female purgers outnumbered male purgers two to one. Binging and purging is one of the bulimia eating disorders. Bulimia involves a self-perpetuating pattern of binge eating followed by fasting and/ or purging such as self-induced vomiting, or abuse of laxatives. According to the researchers, the purgers felt more guilty after eating large meals, counted calories more often, dieted more frequently, and exercised less when compared to nonpurgers. Male student purgers were significantly heavier than nonpurgers. Although most students purged less than once a week, researchers warned that it could lead to longterm bulirma; most adult purgers began purging during late adolescence or early adulthood.
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Operating Room Scheduling A LITERATURE REVIEW
Zbigniew H. Przasnyski
E
fficient scheduling of operating rooms involves complex technical and interpersonal interactions. This article provides a summary of what has been published on OR scheduling in the hope that it will stimulate further investigation. The literature on O R scheduling illustrates five general areas of concern: OR utilization, cost containment, planning and organization, scheduling specific resources (eg. nursing staff, anesthesia, blood bank), and the scheduling of surgical operations into operating rooms.
Determining OR Utilization
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tudies designed to evaluate O R utilization are usually characterized by (1) a definition of utilization (ie, the time ORs are occupied divided by the time they are available), and (2) the use of an OR logbook or data sheet. The data sheet is designed for collection of pertinent
information about each surgical procedure (eg, starting and ending times, reasons for delay, instrument requirements, names of surgeon and anesthesiologist). Two studies in the early 1960s used the standard approach of analyzing the information gathered in the O R data record.] One of the studies attempted to find reasons for unused time, but without much success. After looking at the delays produced by the late amval of personnel, one author stressed the need for cooperation and coordination of all staff concerned to achieve real improvements in utilization.* A graphic approach to track OR utilization has also been attempted.3 With that approach, a grid is constructed with time as the ordinate (x) and operating rooms as the abscissa (y), and the times the operating rooms are in use are blacked out. Whenever an OR is not being used, the reasons are obtained and thus trends can be visualized.
profersor of business adminutration,Loyoh Marymount University, Los Angeles. His doctoral degree in operational reAearch IS from the University of Sussex, Englad hrs master of science degree in mathematical computation I S from the University of Essex, England and he has a bachelor of scmce degree in engineenng and operational research from the University of Sussex.
Zbigniew H. Przasnyski, PhD, is an associate
The author acknowledges the department of epidemiology and preventive medicine, University of Maryland, Baltimore, for providing facilities and encouragement for the conduct and reporting of thrr study. 61
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Use of one type of scheduling system resulted in approximately a 30%decrease in the time taken to produce monthly reports. Although this approach is easy to use, the information produced is limited. A study noting that “automated surgical record keeping reduces errors, saves times, and facilitates greater infcirmation recall than does traditional human logging,” did not result in any cost savings.4 Costs were merely displaced from hand transcription and manual data collection to computer costs; however, there were considerable gains in flexibility, and it was possible to obtain information that was previously unavailable. Priest and colleagues described the considerable effort spent on minimizing transcription errors, both in handling of forms and in computer coding.5 The reports generated are circulated to various department!!. Among the benefits of computerizing the OR log, according to the study, are: (1) reduction in the time needed by the surgical staff to produce reports; (2) more accurate statistics and data, which the authors indicate can be used to aid in scheduling through more realistic operation predictions; and (3) the ability to generate special reports from the information held in the data base. One author described a standard approach to analyzing information from the OR data sheet, but instead of generating the reports on a mainframe computer, a word processor with mathematical capabilities was used? The system was functional in two months because it only involved combining data input with existing manual reporting. Approximately a 30%decrease in the time taken to produce the monthly reports was noted. The flexibility of the system, as well as the simplicity and extensiveness of the data base, were praised by the author. Although utilization studies involve large amounts of data that require careful classification and coding, they are, in effect, management information systems. Some provide high levels of sophistication in the reports they generate, and in the information they make available.’ 68
Reviewing those utilization studies in more detail, it becomes apparent that there are essentially two operating room scheduling methods: firstcome, first-served, and block booking. The main disadvantages of a firstame, first-served system are: high cancellation rates as a result of overbooking, and vastly different OR utilization rates among surgical services. The block booking system was developed to overcome these disadvantages. Its advantages include: reduction in competition between physicians because guaranteed blocks of surgical time are available, booking does not have to be done so far in advance to ensure that an operation is performed on a certain day, and better overall utilization of operating rooms. The biggest disadvantage of block booking is that even when it is known in advance that time booked will not be used, it is not readily given up for another surgical service to use. One review of the literature: on this subject points out the lack of systematic and exhaustive comparisons of the two strategies.* Simulation would provide a valid vehicle for such a comparison, but problems arise in the availability and accuracy of data necessary to simulate the other system. Simulation could only be considered if a hospital changed from one system to the other, but even then the hospital would have little motivation to compare the two approaches after the decision has been made to lchange from one to the other.
Containing Costs
0
perating rooms are an expensive resource, and various suggestions have been made for containing costs. One article describes
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Methods for cost reduction such as more efficient traffic patterns within the OR have been suggested. a system for recording operating room supplies in which the circulating nurse is provided with a preprinted form listing the most-used supplies in the OR.9The rationale is that if an item used during surgery is not properly recorded, it is a lost charge, and becomes part of the hospital overhead costs. A more global perspective of cost containment in the operating room with general recommendations such as investigating ordering supplies in bulk, balancing out holdmg costs,and considering outpatient surgery is offered in another article.I0 This article stresses the importance of physician awareness of the costs of laboratory tests, x-rays, and other proceduresso that they can better control superfluoustests. Another suggestion for reducing operating room costs is for the purchasing director to shop around for surgical supplies,cutting down on unneceSSary waste (eg, items are often removed from their plastic wrappers, but not used), standardization of supplies for surgeons without compromising quality, and critical reviews of inventories to determine which items are not being used.I1 The Ontario Hospital Association lists a number of cost containment ideas for operating rooms to cope with common problemssuch as uneven work load and overtime.12Those suggestions include closing an operating room, starting precisely on time, and including the changeover time on the schedule. A slightly Werent approach has been proposed, which states that savings can be obtained through the appropriate use of the charging system.I3 This work was originally motivated as a result of the competition posed by freestanding outpatient surgery centers. The authorscontend that operating room charges are usually based on a scale that increases with the duration of surgery. Costs, therefore, are not always allocated according to the type or difficulty of surgery performed. Thus, they developed a fourcategory hierarchy of 70
operations from minor general surgery to major orthopedic surgery and compared their model on charging data at a hospital in Utah. Use of the model resulted in more equitable charges for surgery. In addition to providing an interesting account of the growth and advances of technology in the operating room over the past 30 years, one article describes some general directions in cost containment from a broad planning point of ~ i e w . These 1~ include standardizingoperating rooms to promote multipurpose use, and adequate planning for bed allocation. The author points out that averages from each surgical seMce are not sufficiently accurate (eg,that a typical neurology patient will be in the hospital for 11 days, versus an otolaryngologypatient stay of two days). Methods for cost reduction in the OR such as more efficient traffic patterns within the OR have also been suggested.l5 An excellent summary of cost containment in the operating room, including some of the suggestions discussed above, was done by Comper.16 In addition to specifc improvements, the author cites advances in preventive medicine that lead to a reduction in surgical intervention. He contrasts this with the rise in the percentage of patients over 65 years of age, which results in increases in certain types of surgeq, and the implications for operating room managers.
Planning and Organization
I
t has been calculatedthat the constructioncosts per square foot for operating rooms are higher than for any other hospital department.17 According to one author, goals in planning a new surgical suite include: (1) optimal patient care, (2) high operating room utilization, (3) high personnel productivity level, (4) safe patient environment, (5) efficient running of the suite, (6) accommodation of staff scheduling needs, and (7)
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One study considered the diagnostic category of the patient on admission in relation to the expected length of surgery. coordmation with other departmentsi8The author suggests identifying population markets with analysis and projection of demographics, a similar analysis of the pool of physicians, and a careful analysis and forecasting of resource requirements as part of the planning process. A more technical approach through a simulation study has been In this study, historical data was analyzed to provide input for the model, and an OR data sheet was used to evaluate utilization in the design of a surgical suite. To determine the optimum number of operating rooms, Goldman and Knappenberger totaled the costs of the building, staffing, and equipping an operating room, overtime, and patient waiting time and presented a breakeven analysis.20Their model was intended to indicate at what levels a new operating room would be viable. That approach is reasonably useful, but suffers from the usual drawbacks of breakeven analysis in making the original cost estimates. An interesting account on how to modernize the operating room suite is given by Tornello, and includes useful references on requirements and planning guidelines?' The article describes the seven years of planning design and redesign that took place before the suite was opened. Another study presents a method for planning a surgical suite by quantifying the relevant costs of all departments concerned.22 Using sophisticated formulas, the researchers translated work-load requirements into space needs. Both manual simulation and computer simulation approaches have been used to study the organization and workings of the operating room suite.23Two such studies concerned the number of beds required in a recovery room to prevent a backlog of patients." Another study used simulation to evaluate various operating room scheduling policies (eg, firstcome, first-served, longest case first, shortest case first) and concluded that the highest utilization (as measured by idle
time and overtime, for example) was obtained by schedulingthe longest case Such a policy, however, could lead to bunching and possible overloading late in the day in the recovery room. A mathematical model based on data from Stanford University Hospital is described in a study that combines surgical demand with a tinancial anaIysis.26 The model allows for a financially optimal solution to be obtained to determine how many operating rooms should be included in a surgical suite. Satisfactory operating room turnover is to a large extent dependent on appropriate admission policies. There have been many studies on admission scheduling, but few adequately consider the implications of surgical resources. A more precise admissions-surgery model addresses the great variation in the length of stay between patients admitted to the various surgical specialties.27The author of the study advises caution in applying data from one hospital to another because of the many factors involved and local differences, and suggests periodic review of all recommendations to ensure that they are still accurate. One realistic and detailed admissionsurgery model provides the link between admissions and surgery by considering the diagnostic category of the patient in relation to the expected length of surgery.28 The effects of operating room design and policy on recovery room and intensive care unit design and policies have also been studied.29
tudies on scheduling nursing staff for various shifts so that they can provide good health care, cope with problems due to holidays, and devise various alternatives to five-day, eighthour shifts have been investigated (eg, four-day, 10-hour shifts, or flexible work weeks of seven to 10 four-hour shifts).w For each alternative,
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When the nurses were involved in producing their ‘ideal‘ schedule, they found the system to be very fair. benefits were perceived primarily because of the interest taken on the part of management in personnel scheduling and, second, in tangible improvements (eg,time off during the week) to the staff. Different studies reported various alternatives to the standard eight-hour day, but no one alternative emerged as the best; specific local conditions usually determined the best alternative schedule for a particular hospital. In general, the literature reports that any systematic approach, whether it is manual or computerized, results in greater staff satisfaction if it is not arbitrary and especdly if staff members have a say in the scheduling process?’ For example, one paper describes a study where initially there was much dissatisfaction with the scheduling process on the part of the nursing staff.32 Then the nurses were involved in the scheduling process by producing their own “ideal” schedule for a month, including contractual obligationsand constraints, but ensuring that a certain number of shifts were included. These individual schedules were combined into a master schedule and loose ends were ironed out through discussions. The master schedule was then modified slightly to be workable and implemented for a trial period. The scheduling process was previewed by the staff and found to be very fair. Another paper provides a fascinating account of the conflicts involved in scheduling holidays when the staff is split into two camps (ie, those who work and those who do not)?3 The difficulties in ensuring fairness to everyone may lead to bad feelings among staff who work together outside the holiday period; patient care may suffer as a result. The suggested solution to this problem was to plan well ahead of holidaysand to keep accurate records of who works which holidays so that fairness can be clearly demonstrated. One paper described a computer scheduling system for nurSeS in which three schedules were produced: four weeks ahead, 16 days ahead, and 12
three days ahead, for a tweweek period.” A number of reasonsfor both employee and hospital satisfaction were cited, including: (1) employee satisfaction with well-planned, accurate schedules produced on time; (2) appropriate staffing levels achieved by the hospital within budget restrictions (ie, lower overtime mts);and (3) effective budget control and planning through efficient management reports. Another computer staff scheduhg system took into account staff preferences, thereby increasing staff satisfaction, while at the same time greatly reducing the time taken to produce monthly ~chedules.3~ A common theme throughout these studies was the importance of systematic and careful scheduling in order to create the greatest satisfaction and where unpopular shifts could clearly be seen to be fairly and uniformly distributed among all staff. One study reported the benefits of a 10-week cycle rotation schedule for operating room personnel that allowed surgical technicians and circulating nurses to know well in advance when they would have time off and when they were scheduled to work. The hospital benefitted by having more even staang in the OR at all times, including second shift and weekends.” Alternative shift patterns were investigated in a number of studies. One such study suggested working combinations of eight-, lo-, and 12-hour ~hiffS.3~ The objectivewas to minimize the number of staff hours worked each day, subject to the constraints imposed by the levels of staffing required during each hour of the day. It was found that productivity could be increased by 8.1% and personnel requirements reduced by one full-time equivalent. Use of this method, however, would require willingness of the staff to work 10- and 12-hour shifts, and an effective format for communicating information about patients between staff on different shifts.
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Literature dealing with management of detailed operating room scheduling is scarce. Two studies describe the implementation of a computer scheduling system for anesthesiologists, which increased satisfaction for them.38 Other studies have looked at the scheduling of other resources that impinge on operating room services, such as the availability of blood and laboratory tests.39
Scheduling Surgery
L
iterature dealing with the management of detailed operating room scheduling is scarce. A review of 45 operating room scheduling studies was done in a study by categorizing them according to the contraints involved (ie, just time, time and resources, only bookings considered).40The majority of proposed schemes, however, were never implemented. Stevens points out that although patient care is the highest priority in any nursing setting, good patient care is likely to occur only in a systematic and efficient operating room setting!’ The author therefore emphasizes the necessity for a “system approach” to accomplish smooth and efficient coordination of personnel, time, space, and equipment involved in OR management. The author concludes that for the system to be effective, managers should determine clear entry criteria and use feedback to monitor results and identify necessary changes. A study to investigate a number of scheduling disciplines, although theoretically sound, used underlying assumptions about such things as amval and procedure time distributions that were unduly restrictive and may not adequately represent the intricacies of an actual Another problem with the study is that it fails to address the many resource restrictions found in hospitals. A number of studies, which purport to describe operating room scheduling systems but actually describe operating room management systems, 14
have been done. One such study describes a computer system that is capable of producing many types of reports, but most notably can compare actual and predicted operation durations.“ All scheduling in this study, however, is in effect a booking approach in which the surgeons’ requests for a particular time and date are accepted or rejected on the basis of the information in the data base, and no rescheduling or updating is performed. A similar model based on an operating room information data base produces all expected reports, as well as charging informatioaMIts main improvement over the study that compares actual and predicted operation duration is that available time slots can be Seen easily in answer to a request for the earliest possibledate for a procedure. Again, the model does not provide for updating of the schedule. Only two descriptions of implemented systems that actually perform the scheduling of operations could be found. The first approach is one of sorting the requests for a particular day on the basis of four parameters (service priority, time, surgeon priority, and room preferred by service) before assigning the procedures to The relative priority of the parameters can be modified. Although the resulting schedule can be amended using a terminal, any updates to the schedule on the day must be done by hand; no automatic rescheduling is performed. Admissions information can be consulted on-line by the scheduling clerk using the appropriate data base.The authors of the paper note considerable satisfaction with the system, saying that the “high quality schedules [produced]have reduced discord among operating room personnel.” As a result of an admissions department and operating room study that sought to assess admitting practices, operating room booking procedures, and bed allocation among the surgical services in a relatively small hospital, a patient
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One of the most important pieces of information on which all scheduling systems depend is the predicted length of surgery. reservation system was developed for nonemergency surgical patients, which simultaneously assigns a date of admission and date and time of ~urgery.~6Benefits of the system include reduction in average length of stay and an increase in operating room utilization. One of the most important pieces of information on which all such systems depend is the predicted estimate of length of surgery. In 1963, an author pointed out the necessity for accurate estimates of surgery duration and feedback to compare the actual duration with e~timates.4~ Another study found that surgeons request an average of 4% more time than they take!* The study is noteworthy because it is one of the few that kept a file to confirm surgeons’ requests. Usually, the clerk taking the bookings and the surgeon agree on an estimate of length of the procedure. Although guidelines for durations of procedures exist, surgeons work at different speeds and indeed few cases are of a standard length. Most require adjustments, which are made by the booking clerk using his/her experience and memory. When the experienced clerk is absent, the schedules are inferior in quality. Producing realistic surgery estimates is therefore in great need of systematic investigation and coordination. A method to reduce the time a surgeon is idle between operations has been st~died.4~ If a surgeon is scheduled to operate on two successive patients in the same operating room, he is idle from the time the first patient’s closure is started until the patient is removed, the room is prepared, the next patient is brought in, and anesthesia is started. The study proposes using a two-room (or more) system whereby the surgeon transfers to another operating room as soon as closure on one patient is begun to start surgery on another patient. Although such a system may be tiring for the surgeon, the author of the study claims that implementation in his hospital resulted in elimination of overtime.
A general application of such an approach may not be practicable because such alternation between operating rooms presupposes that all rooms are identical in size, fixtures, personnel requirements, and the procedures that can be carried out in them. Furthermore, for such a strategy to be most effective, the duration of procedures performed by the alternating surgeons would have to be carefully matched, perhaps with staggered starting times at the beginning of the day to prevent a situation where two surgeons are competing for the same room. On a more specific technical level, one author addresses the mechanics of the sequencing of the operations within the operating rooms by comparing the problem to the classic “job scheduling problem,” and states the permutational complexities.50 The paper is an introduction for the medical community to combinatorial mathematics and scheduling applications. The author makes recommendations for improving the efficiency of the operating rooms, the most important of which is that operating rooms should be made large enough to accommodate all surgical procedures. Other suggestions include instituting shifts other than the standard eight-hour shift. An average thoracic case may take four to four and one-half hours, and could thus prevent two thoracic cases from being done in that room on the same day. Although comparison of operating room scheduling to well-known scheduling problems in other areas is valid and interesting, the conclusions drawn from them cannot be rigidly applied because operating room scheduling presents some unique problems not present elsewhere. In particular, an unlimited supply of cases waiting for surgery (compared to jobs on computers, for example), cannot necessarily be assumed. Patients must be prepared both physically and psychologically, with sensitivity and consideration. In addition, the information regarding surgical 15
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One study indicated little difference in recovery quality of patients taken at early definite or late indefinite times. procedures is in a constant state of flux. Finally, a study of 60 patients who underwent total hip replacement arthroplasty examined the effects on recovery of patients scheduled for surgery at definite times with patients scheduled with indefinite (to-follow) start times?’ A series of physiological measures was taken from two days before surgery to 14 days after surgery. The results indicated little difference in the quality of recovery of patients taken at early definite or late indefinite times when other variables were held constant, and when patients were convinced that surgery would relieve pain and restore function. This study is most notable in that it gives a different perspective-the point of view of the patient-to operating room scheduling.
Conclusions
T
he complexity of OR scheduling is a result of the large amount of different types of information involved that are everchanging. The active cooperation of all concerned staff and a decision maker with enough authority to enforce the system are basic requirements for any attempt at a successfbl solution. An authority figure can help avoid the perception by staff members that there is a lack of direction and control. The literature on OR scheduling is split into two types: very technical, with presentation of solutions to problems, but with many assumptions and restrictions; or completely nontechnical statements of associated problems, often with common sense proposals for local improvements in a few areas. Clearly, to make any real progress, solutions using technical methodology have to be combined or sacrificed to provide an indepthh understandingand consideration of all day-today details so that the complete problem, and not a theoretical subset, is attacked. 76
Although many suggestions and proposals to solve the operatingroom schedulingproblem have been made, the successful implementation rate is very low. One reason was summed up best by an author who said, “as every health service administratorknows, there is rarely a large degree of finality when trying to arrive at an answer to a question concerning the organization of hospitals.”52 This seems to be due to a vast and complicated web of politics, fear, lethargy, maintenance of the status quo, illdefined goals, and lack of overall direction inherent in large systems such as these. The many nontechnical problems (ie, political and behavioral) assoCiated with operating room scheduling Seem to be particularly characteristic of many of those negativefactors. With appropriate education, time, and demonstration of effective solutions to real problems, however, the tide will slowly change toward realisticexpectationsand positive attitudes toward systematicdecision making. The inertia in this area of operating room scheduling is somewhat of a chicken and egg situation: no progress will be made toward an effective solution until practical (ie, nontheoretical) success can be demonstrated, but this involves overcoming the inertia that opposes significant changes and involves a substantial initial commitment and overhead costs.The way forward from such a downward spiral is a kind of bootstrapping procedure. Modest improvements already cited in the literature should stimulate serious interest on the part of the decision makers within the hospital to be prepared to undertake and enforce progress and the changes neceSSafy to achieve an effective solution. The responsibility of the technical analyst would then be to produce a meaningful solution methodology sensitive to all perceived needs that is also flexible. The advent of increasingly powerful microcomputers might provide the catalyst for such boots(rapping. With a dedicated microcomputer,
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total control can be easily within the operating room domain.
Research Needs
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ain avenues for future research include
(1) systematicstudy to fully evaluateand
compare, under controlled circumstances, block versus nonblock booking systems, (2) analysis and determination of procedures and practices to ensure accurate forecasts of length of surgeries, (3) planning and forecasting of populations that would require various hospital surgical services, (4) investigation of medical systems in other countries to determine possible improvements in strategy, ( 5 ) economic analysis to determine the most effective charging strategies, (6) determination of realistic standby levels, if any, and detailed study of assoCiated problems, and (7) analysis of expectations and misgivings of personnel regarding introduction of a computerized scheduling system in the operating room. 0 Notes 1. 0 C Zimmerman, “Utilizing operatmg room time,” Hospital Topics 41 (February 1%3) 99-102; M London, “Know your OR vacancy rate to improve surgical scheduling,” Modern Hospitals 103 (October 1964) 110-114. 2. W L Williams, “Improved utilization of the surgical suite,” Hospitak 45 (March 1, 1971) 93-96. 3. M Hoffman, “A graphic look at operating room utilization,” AORN Journal 22 (September 1975) 473478. 4. J Cresto, S Devor, “Computerize the log,” Hospitah 47 (July 1, 1973) 58-60. 5. S L Priest, B D A Pelati, D E Marcello, Jr,
“Computerized OR log system has many uses,” Hospitak 54 (June 1, 1980) 79-82. 6. G Morrison, “Word processing in OR management,” Dimensions in Health Service 57 (March 1980) 18-20. 7. D K Rohe, “Operating room statistical infor-
mation system (ORSIS): What an information system should be”, Center for Hospital Management Engineering (Chicago: American Hospital Association, 1979). 8. J M Magerlein, J B Martin, “Surgical demand scheduling: A review,” Health Services Research 13 (Winter 1978) 418433. 9. J Botsford, “New operating room record system,”
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Hospital Topics 59 (September-October 1981) 22-23. 10. J A Koncel, “Practical tips on cost containment: Surgical suite,” Hospiirclrs 54 (Aug 16, 1980) 151-155. 11. W Warren, “Cost containment in the operating room,” T e r n HospitarS 37 (October 1981) 10. 12. “Cost containment in the OR,” Dimenrions in Health Sewice 57 (March 1980) 16. 13. C R Skousen, G L Hooper, “An alternative approach: Determining hospital surgical suite charges,” Hospital Fb~anckzlManagement 35 (December 1981) 50-61. 14. L Block, “OR costs: Control or cutting,” AORN Journal 15 (June 1972) 59-65.
15. “Recommended practices for traffic patterns in the surgical suite,” AORN Journal 35 (March 1982) 750-758. 16. A Comper, “The OR utilization fixtor,”Surgical Business 43 (March 1980) 30-31. 17. J T Martin, “An anesthesiologist looks at OR design,” AORN Journal 21 (February 1975) 259-278. 18. H B S c h n e i d e m , ‘‘Building a new surgical suite,’’ AORN Journal 30 (July 1979) 3543. 19. F Zilm, L Calderaro, M Del Grande, “Computer
simulation model provides design framework,” Hospitals 50 (Aug 16,1976) 79-85. 20. J Goldman, H A Knappenberger, “HOW to determine the optimum number of operating rooms,” Modern Hospitak 111 (September 1%8) 114-1 16. 21. J D Tornello, “When I build my OR: Dream and reality,” AORN Journal 30 (July 1979) 44-50. 22. J S Moore, W J Spencer, ‘‘F‘lannq space around systems,” Hospitals 49 (Feb 1, 1975) 115-118. 23. H Schmitz, N K Kwak, “Monte Carlo simulation of operating and recovery usage,’’ OperationsResearch 20 (November-December 1972) 1171-1 180; S Barnoon, H Wolfe, ‘‘Scheduhg a multiple operating room system: A simulation approach,” Health Services Research 3 (Winter 1%8) 272-285; G M Luck et al, Path&, Hospiirclrs, and OperationalResearch (London: Tavistock Publishers, 1971). 24. P Kuzdrall, N K Kwak, H H Schmitz, “The Monte Carlo simulationof operating room and recovery usage,” Operations Research 22 (March-April 1974) d , H Schmitz, 4344@ N K Kwak, P J K ~ ~ d r H “Simulating the use of space in a hospital surgical suite,” Simulation 25 (November 1975) 147-152. 25. J Goldman, H A Knappenberger, E Moore, “Evaluation of operating room scheduling policies,” Hospital Management 107 (April 1%9) 40-51. 26. D S Hopkins et al, “A model for optimizing the number of operating rooms in a hospital surgical suite,” Health Care Management Review 7 (Spring
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NOVAFlL" (MonofilamentPolybutesterSuture) (NonabsorbableSurgtcal Sutwe US P) (Clear M Blue)
A Brief Summary INDICATIONS NGVAFIPis indicated for use in all types of soft tissue approximaton. including use in cardiovascular and ophthalmic surgery.but not in microsurgeryand neural tissue It is recommendedfor use where the possibility of reduced suture reaction is desired CONTRAINDICATIONS There are no known contraindications PRECAUTIONS Since any foreign material in the presence of bacterial contaminationmay enhance bacterial infectivity standard surgical practice should be followed with respect to drainage and closure of infected wounds NOVAFIC did not enhance infection in animal or in in-vitro studies ADVERSE REACTIONS As with any foreian body, transitory local inflammatory reactionscoild occur WARNINGS Do not resterilize Discard open, unused sutures CAUTION Federal Law restrictsthis device to sale, distribution and use by or on the order of a phystcian or veterinarian
American Cyanamd Company Wayne, New Jersey 07470 8 Registered trademark American CyanamidCompany
Metoprolol Safe, Effective Treatment for Hypertension Elderly patients whose hypertension was treated with metoprolol, a beta blocker, had similar results with fewer side effects than patients treated with the antihypertensive diuretic drug hydrochlorothiazide, according to an international study reported in the March 14 Journal of the American Medical Association. Researchers in Sweden coordinated the study that included 40 clinical centers in 12 countries. In all, 562 patients with diastolic blood pressure over I00 mm Hg and between 65 and 75 years of age participated. Patients were divided into two groups; one received 100 mg of metoprolol, the other received 25 mg to 50 mg of hydrochlorothiazide. Each dosage was given on a daily basis for four to eight weeks. Results showed that the patients' blood pressures were significantly reduced in both groups. After four weeks, 50%of the metoprolol patients and 47% of the hydrochlorothiazide patients had 82
diastolic blood pressures of 95 mm Hg or less. After eight weeks, the percentages increased to 65%and 61%, respectively. Although both regimens reduced the patients' blood pressures, patients taking hydrochlorothiazide experienced significantly more hyperuricemia and hypokalemia than the metoprolol group. Based on the results, researchers concluded that W n n i n g antihypertensive treatment with 100 mg of metoprolol daily and adding 12.5 mg of hydrochlorothiazide in patients with unsatisfactory results appears to be an effective and safe treatment for elderly hypertensive patients. Traditionally, elderly patients with hypertension were given 25 mg of hydrochlorothiazide, or other diuretic drug, which was doubled if ineffective.
Binging and Purging Common Teen Behavior Using the binge-and-purge eating behavior as a means of staying thin is being practiced by as many as 13%of American teenagers, according to research published in the March 20 Journal of the American Medical Association. Researchers at Stanford University, Palo Alto, Calif, surveyed 1,728 10th graders and found that 13%reported using some type of purging behavior to control their weight, and that female purgers outnumbered male purgers two to one. Binging and purging is one of the bulimia eating disorders. Bulimia involves a self-perpetuating pattern of binge eating followed by fasting and/ or purging such as self-induced vomiting, or abuse of laxatives. According to the researchers, the purgers felt more guilty after eating large meals, counted calories more often, dieted more frequently, and exercised less when compared to nonpurgers. Male student purgers were significantly heavier than nonpurgers. Although most students purged less than once a week, researchers warned that it could lead to longterm bulirma; most adult purgers began purging during late adolescence or early adulthood.