SCHEDULING

Proper scheduling in the OR is perhaps the most important part of running an efficient surgical service.^[11] Organizing plus assembling all the necessary personnel and equipment to perform a procedure is where the whole process begins. If scheduling is done poorly, it is unlikely that on the day of surgery the operations will go smoothly and patients and surgeons will be satisfied.

Scheduling accuracy is paramount. Seemingly minor things such as accurate name spelling, age, patient disposition (inpatient versus outpatient), complete procedure description, and surgical case duration can have a major impact on how well an OR functions. Most ORs have evolved from a handwritten schedule to a computerized scheduling system. Personnel who input the data should be sufficiently skilled to reduce errors. Many computerized systems will track posted cases to verify the availability of equipment or other resource needs to identify overbooking of items such as C-arm x-ray machines or microscopes. Surgical case duration is also important because it may have an impact on the predicted start for all subsequent cases in the same room. Accurate prediction of surgical case times is essential. Several authors have described how computer and statistical modeling can improve case duration estimates.^{[12] [13] [14] [15]}

Historically, most ORs scheduled under an "open block" system. Surgeons scheduled cases on a first-come-first-served basis in any room that was available. This system worked if there was little competition for OR time and all procedures could be done in any room. However, this open scheduling system led to many undesirable consequences. Surgeons with a short lead time in deciding to operate on a patient had poor predictability for when they could get their cases started. If complex equipment was needed for a procedure, OR personnel were forced to move it from room to room. There was marked variability between busy and light days, and overall OR efficiency was poor.

Because of these limitations, a system of guaranteed rooms, or "block" scheduling, was developed. Under this system, a surgeon or surgical group was given a specific room on a specific day in which to schedule cases. This arrangement permitted the development of specialized rooms with heart-lung machines for cardiothoracic surgery, rooms with ophthalmologic fixed ceiling-mounted microscopes, and dedicated laparoscopic rooms. The reduced movement of personnel and equipment led to improvements in room setup and turnover times. Rules were developed on how these blocks were used. Usually, some measure of surgical demand, such as historical hours of surgery performed per week, was equated with the number of blocks granted. Block time works most effectively when it is granted to a surgical service (such as orthopedics or gynecology) rather than to one individual surgeon. Full-day blocks (8 hours of OR availability) work better than half-day blocks because there is better predictability of patient flow and case start times. Examples of the block system at the University of Kansas Hospital are shown in Table 86-3 and Table 86-4 . Rules must be developed for how scheduling into these blocks is to be handled. Advance scheduling and hold time or release time are key factors in making block scheduling work.^[16] The release time, which may vary among surgical specialties, is the time when the block is no longer reserved for a particular service. Release times vary in accordance with the nature of the institution and surgical practice.^[17] Services performing procedures that have some urgency or a short lead time, such as heart surgery or vascular insufficiency procedures, will have shorter times from release to the surgery date than services with a more elective practice (cosmetic plastic surgery, orthopedic joint replacement). Services with a high referral practice, cancer procedures or trauma, will also need shorter release periods for their blocks ( Table 86-5 ). Once a release time is reached, if available hours remain in a room (unused block time), they would be available to any surgeon on a first-come-first-served basis. Block time should be adjusted as surgical practice changes within a hospital. Generally, a measure of surgical activity, such as utilization of a block, is used to determine thresholds for gaining or losing block time. This block time may or may not include turnover time and is usually re-evaluated at predetermined time intervals.^{[18] [19]} A more comprehensive discussion of OR utilization will follow in this chapter, but some general statements will be made concerning adjustments in block time and utilization.

If a surgical service is using nearly all its block time, say 95%, a situation will be created in which it is difficult to

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Another aspect of scheduling that is important to note is how non-OR anesthesia cases such as endoscopy, radiology, computed tomography, and magnetic resonance imaging are managed. Even though these patients are not brought into the OR, they often use perioperative resources. They may be processed through the same-day surgery facility, use the PACU, and require dedicated anesthesia teams. Because of these factors, these patients and procedures should be included in the OR scheduling system. Such inclusion will help the managers of same-day surgery and the PACU and the anesthesia schedule director to be able to assign appropriate resources for these cases and track their progress. Strategies to maximize surgical blocks and reduce variability to further improve utilization have been described by several authors. ^{[23] [24]}