The Electrical and Mechanical Challenges of Hybrid Cath Labs

The hybrid cath lab is a new concept for delivering advanced patient care. In a hybrid application, the cath lab doubles as an operating room so that a patient undergoing a cardiac cath procedure can immediately have surgery if required. This cutting-edge setting allows physicians to address patient needs quickly, eliminating the need to schedule additional surgical procedures, and may become increasingly commonplace in contemporary healthcare facilities. However, combining the requirements of surgery rooms and cardiac cath rooms in an existing cath room does pose design and construction challenges. The project described below took place at Children's Hospital in Omaha, Nebraska, over approximately 10 months. Children's Hospital originally had a cath lab directly adjacent to 6 existing operating rooms (OR). Based on the amount of procedures resulting in the need for surgery, it was decided that a hybrid cath lab was necessary. HDR Architecture, Inc. (Omaha, NE) started design in January of 2006. Today, Children's hybrid cath lab also functions as an additional, fully functional OR. Cath Lab Ceiling Support Structure For the Children's Hospital project, new cath lab equipment (Toshiba Medical Systems, Tustin, CA) was designed for an existing cath lab room. Initially, the new equipment had a C-arm configuration, which required greater clearances than were available in the room. As is typical of cath labs, the structure to support the ceiling-hung equipment is quite significant. Consequently, changing the structure height to accommodate the new equipment was evaluated. In the end, the equipment vendor was able to fit the new equipment into the existing space by increasing the ceiling height by only one increment. A second increment of height increase, which would come at a much higher cost, was not needed. Illuminating an Operating Room Versus a Cath Lab Lighting a cath lab typically involves flexible general illumination, which is required for setting up the room, preparing for the procedure, and cleaning. A flexible level of lighting is also critical for the staff performing the procedure and for enhanced patient comfort. Usually can lighting or 1 x 4s are used in cath labs, which can be accommodated by the significant structure in the ceiling above the procedure table. An operating room, however, requires a much higher level of lighting. Asymmetrical/symmetrical 6-lamp 2 x 4 troffers (the inverted, usually metal trough suspended from a ceiling as a fixture for fluorescent lighting tubes) circulating the HVAC laminar flow diffusers (providing a smooth, undisturbed flow of air) are usually placed directly over the procedure table. A problem arose in Children's Hospital where the lowest level of unistrut (used to support cath lab equipment) had a spacing of 24 to 26 inches, thus preventing the use of high-output 6-lamp 2 x 4 troffers. The only option was 2 x 2 troffers running parallel to the table. However, a typical surgery-grade troffer is 6.5 inches, which posed the next challenge, because in this instance, the lowest level of structure was 6 inches from the perpendicular structure above. The equipment vendor had already decreased its room height requirements, and a decision had been made against increasing the structural ceiling height by the second increment. We were able to locate a lighting manufacturer offering options that could meet the specified requirements within these physical constraints. We found that Kenall Lighting (Gurnee, IL) was the only manufacturer producing a 4.5 inch-deep operating room troffer. Lamping included 3-T5HO in the 1 x 4s, and 3-50WBiax in the 2 x 2s.* Switches were subsequently placed in two locations to control room lighting as follows: The 1x4 fixtures over procedure table The main 2x2 room illumination The perimeter dimmable down-lighting Lighting over a work table To meet the lighting flexibility desired, combined with two-level fixtures with three-way lighting, required both sets of switches to be labeled. Additionally, the control room included dimmable, lensed troffer lighting in an effort to provide the option for a darker environment versus that of the procedure room. Power and Communications Communication between the cath lab equipment vendor and the electrical engineer is critical. The vendor may think existing raceways for the new cath equipment cabling can be used, and in some cases, they may be correct. It is crucial that a review of existing plans be conducted and modifications made for all new raceway requirements, from circuits to conduits. Modifications may be as simple as adding some wall duct or an additional conduit or two, or as major as relocating the main connection point in the floor. In the first instance, adding a conduit or wall duct prior to the cath equipment being delivered aids the construction schedule, but can still be done after the fact. However, moving the central point where all conduits run home to the main cath equipment is a major issue involving floor penetration or trenching. In this case, the structural engineer will have direct concerns regarding structure integrity and so needs to be involved early if floor penetrations or floor trenching is considered. An experienced cath lab equipment installer also should be an integral part of the team to offer invaluable field knowledge. He will be able to determine if existing raceway plans are accurate, and if the existing equipment was installed as originally designed. Finally, it is important that the number of 120v power receptacles meet surgical equipment requirements. At Children's Hospital, we added 4-plex wall receptacles as well as two more circuits to the existing power columns. The existing cath lab equipment ran on generator power, and the new equipment power requirements were only slightly higher. Consequently, the equipment continued to be fed from the essential power source. Additional Concerns As the Children's Hospital project progressed, additional issues were encountered, and solutions investigated and identified: HVAC: Laminar flow diffusers were custom-built to meet the air requirements for surgery rooms while coordinating with the over-bed lighting fixtures. In addition to working with structural requirements for a cath lab, this was a large, multi-disciplined coordination effort with a goal to meet the patient needs while keeping the cost down. Low Voltage Systems: As with any new medical equipment, added data connections are typical within the room as well as to the main control council equipment. We added data drops to support medical equipment typical to surgery space, as well as the additional telephone requirements. Conduits were installed in room corners for future cameras. The empty boxes are routed to the equipment room and to each boom. Construction: The hybrid cath lab concept is new, and so the Children's Hospital project wasn't able to benefit from lessons learned in previous installations. In fact, vendor drawings were continually changing as existing conditions were discovered. Multiple site visits with a core team of problem solvers proved essential to having the room ready for the medical equipment to be installed on schedule. The first procedure took place in mid-October 2006. Today the hybrid cath lab at Children's Hospital continues to deliver cutting-edge care. *Note: T5HO is a type of lamp. T5 is the latest lamp, introduced to replace the T8, which replaced the T12. With each introduction, the lamps have become more efficient and smaller in diameter. The HO stands for High-Output, meaning the lamp produces a higher lumen output than the standard lamp. (3) is the number of lamps in each fixture. 50WBiax is another fluorescent lamp type. 50W represents the lamp wattage. Biax is a compact fluorescent lamp type commonly used in 2 foot-long fixtures. It produces a higher lumen output over a T8 or U-tube-type lamp. Joe Wehling and Timothy Koch PE were the electrical designers for the new hybrid cath lab at Children's Hospital in Omaha, NE. They are project electrical designers for HDR Architecture, Inc., based in Omaha and online at www.hdrinc.com.

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