Cold Sterilization of Cardiac Catheterization Equipment with Ethylene Oxide Gas

OCCASIONAL infections in sites of venous cutdowns and an episode of fever in a patient following cardiac catheterization caused us to review the procedures used in this laboratory for preparation of catheterization equipment. Materials not susceptible to damage by wet heat (surgical instruments, syringes and needles, drapes) are sterilized in a steam autoclave. Polyethylene catheters, cuvette oximeters,* Statham P23Db strain gages, and other fragile electronic or plastic apparatus, since they may be destroyed by autoclave sterilization, have been boiled in water or soaked with solutions containing variously alcohol, quaternary ammonium compounds, heavy metals, or acids. The standard Cournand cardiac catheter may be boiled or sterilized in an autoclave, but its useful life is shortened by such treatment. Furthermore, since procedures such as boiling and soaking in "antiseptic" solutions are ineffective against a variety of microorganisms, there is some basis for doubt that actual sterilization is thereby accomplished. In order to evaluate the effectiveness of current methods of sterilizing fragile equipment, we obtained a series of cultures from cardiac catheterization equipment prepared according to the usual regimen. Bacterial growth was demonstrated. Cold sterilization with ethylene oxide gas was then introduced; subsequent cultures have indicated that all equipment was then sterile. These results and a brief description of the simple, inexpensive, and convenient