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Isolated Power Systems and Wet Locations

The reason for using isolated power systems in surgery was the use of flammable anesthetics which had caused a number of fires... This was required by the National Electric Code (NEC) in the 1950s. After flammable anesthetics were discontinued in the 1980s, the only mandate from the NEC for isolated power was wet locations in 517.2. [Comments submitted to NFPA.] The current edition of NFPA 99 defines wet locations in 3.3.185 as; “The area in a patient care area where a procedure is performed that is normally subject to wet conditions while patients are present including standing fluids on the floor or drenching of the work area, either of which condition is intimate to the patent or staff.”

Currently, the labeling of a location as wet is determined by hospital personnel using risk assessment. If operating rooms are to be defined as wet locations, they will require isolation power systems.

There is a proposal before the NFPA to change the definition of wet locations to include all operating rooms. The rationale for making operating rooms wet locations is supposedly because: “there are frequent instances of standing pools of saline, water, blood and urine on the floor. Also intravenous fluids frequently drip on electronic equipment. The surgeons use irrigating fluids in many procedures. These fluids often end up on the floor. Major surgical procedures, trauma and transplant surgery often are associated with large amounts of blood loss. This blood can easily end up on the floor. The result is that modern operating rooms frequently have conductive fluids on the floor and this presents a hazard to OR personnel and patients.”

It is common hospital policy to take care of liquid spills as soon as possible and there are also procedures for handling hazardous (blood) waste.

The typical comment rebutting the proposal is:

“If an operating room is wet on a regular basis it is because of poor practice, poor housekeeping and poses many other issues other than electrical safety, those poor practices should be addressed and organizations who practice well should not be penalized.” [Comments submitted to NFPA.]

The second implication is that standing fluids or dripping intravenous fluids could somehow be a conduit for electrical shock. The FDA Manufacturing and User Facility Device Experience database (MAUDE) has 1,092,542 reported incidents from hospitals and there are none for anyone injured or dying from electrical shock involving medical devices.

Finally a number of studies reinforce the argument that isolated power is not necessary as a matter of course in surgical suites. The U.S. Department of Defense’s 2002 Military Handbook: Department of Defense Medical Military Facilities Design and Construction Criteria (MIL-HDBK-1191) specifies that “Operating rooms, delivery rooms, cystoscope rooms, oral surgery, cardiac catheterization rooms and other such rooms are not wet areas” (Section 10.1.2.3). The Association for the Advancement of Medical Instrumentation’s Electrical Safety Manual (2004) supports the position that ORs are not necessarily wet locations. [Comments submitted to NFPA.]

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