Residual bacterial contamination on reusable pulse oximetry sensors

An early study demonstrated that standard cleaning techniques did not adequately disinfect reusable pulse oximetry sensors that had been intentionally contaminated with high titers of pathogenic microorganisms. This current study evaluated patient-ready sensors being used in hospitals, by testing them for bacterial contamination.

Reusable pulse oximetry sensors from 15 hospitals throughout the United States were tested. Each sensor was deemed by the hospital to be ready for patient use, and it had been prepared for use according to hospital procedures. Patient-contact areas of each sensor were swabbed, and the swabs were analyzed for bacterial contamination using standard testing procedures. This study had two stages, and different sensors were tested in each stage. In the "bacterial-growth stage," swabs were evaluated for bacterial contamination but organisms were not identified; in the "identification stage," bacterial species were identified.

Forty-four sensors were evaluated, 16 in the bacterial-growth stage and 28 in the identification stage. Bacteria were cultured from 29 of the 44 sensors (66%), including 20 that had been cleaned with alcohol or an antibacterial/antiviral agent. Among the isolated organisms were Staphylococcus aureus, Staphylococcus haemolyticus, Enterococcus faecalis, and Klebsiella oxytoca. Bacterial contamination was found on sensors from 12 of the 15 participating hospitals.

These data demonstrate the need to define effective cleaning methods for reusable sensors, and we are currently conducting such studies. The data also suggest that disposable patient-dedicated sensors may be the most appropriate choice when infection control is of particular concern.