Objectives: The objective of this study was to determine if the ultrasound probe can act as a vector for cross-infection and to compare two cleaning methods for ultrasound probes in order to limit or control the transmission risk.
Study design: Prospective study.
Patients and methods: The first part of the study (P1) was conducted to evaluate the possibility of the ultrasound probe to serve as a source of cross-contamination. Thirty blocks were placed under ultrasound guidance in elective outpatients. After each procedure (Proc), the ultrasound probe was decontaminated/cleaned using either an antiseptic solution spray (AS: n=15) or just wiped with two dry paper sheets (DP: n=15), in a randomly assigned order. Bacteriological samples were collected before and after each decontamination/cleaning methods and inoculated on a chocolate agar plates. The second part of the study (P2) was conducted to compare the effectiveness of two cleaning methods for ultrasound probes. The ultrasound probes were exposed to a large inoculum of three bacteria (Inoc). They were then cleaned/decontaminated using either DP (n=10) or AS (n=10), in a randomly assigned order. Bacteriological samples were collected before and after each cleaning/decontamination methods and inoculated on a chocolate agar plates.
Results: During P1, after Pro, all probes were found to be sterile before and after both AS and DP. During P2, after Inoc, all probes were found infected (CFU>150) but were considered sterile (CFU<10) after both DP and AS.
Conclusion: The results of this study suggest that the risk of cross-infection during ultrasound guidance in locoregional anaesthesia is really low. Our data suggest that wiping ultrasound probe with two dry paper sheets is an adequate cleaning method to prevent cross-contamination risk.