A technique for disinfection of the MDO oxygen electrode

A method for disinfection and aseptic assembly of the MDO (Mehrdraht Dortmund Oberfläche) oxygen electrode has been evaluated. The method is based on treating each electrode component separately and then assembling the different parts under aseptic surgical conditions. The performance of the disinfected electrode was studied and found to be unchanged as compared with a non-disinfected electrode. Bacteriological studies on the effectiveness of the disinfection technique described and on the permeability of the electrode membranes to bacteria and bacterial spores were performed. The electrode membranes were penetrated by bacteria in experiments simulating in-use conditions in about 11% of membranes tested, after contamination of the inner electrode surface with heavy inocula. When studies were performed with the disinfected MDO oxygen electrode on humans, routine cultures from the wound were positive in about 10% of the cases. No clinical wound infection was seen. The majority of the positive cultures were probably caused by the surgical technique rather than the handling of the electrode. The disinfection method for the MDO oxygen electrode described in this paper makes it possible to use the electrode clinically, except in cases of hepatitis.