Does the Use of Ultrasound Affect Contamination of Musculoskeletal Injections Sites?

Abstract

Background Therapeutic musculoskeletal injections require a clean or sterile skin preparation to minimize the risk of infections. Ultrasound guidance for this procedure requires the use of transmission gel in proximity to the injection site, and its effect on maintaining sterility is unknown. Questions/purposes We asked: (1) Does sterile ultrasound transmission gel increase skin contamination during therapeutic orthopaedic injections? (2) Does nonsterile gel application result in increased contamination? (3) Does a manufacturer-approved ultrasound probe disinfecting agent in the form of 17.2% isopropanol and 0.28% diisobutylphenoxyethoxyethyl dimethyl benzyl ammonium chloride wipes adequately decontaminate the ultrasound transducer? (4) Does 70% isopropyl alcohol effectively decontaminate skin for administration of musculoskeletal injections? Methods Twenty-six healthy volunteers in an outpatient orthopaedic clinical setting were recruited. The subjects' skin was prepared to simulate a therapeutic intraarticular shoulder injection under ultrasound guidance. Four skin swabs for culture from each subject were taken: one sample before preparation with isopropyl alcohol, one sample after skin preparation, one after simulated injection procedure with sterile ultrasound transmission gel using the transducer, and one after mock procedure with nonsterile ultrasound transmission gel. In addition, samples were taken from the nonsterile ultrasound transmission gel and the transducer for culture analysis. Aerobic and anaerobic cultures were incubated during a 5-day period for bacterial species identification. Results Sterile ultrasound gel use results in an increase in skin contamination (odds ratio [OR], 9; 95% CI, 1.4-57.1; p = 0.005). Compared with sterile gel use, application of nonsterile gel did not increase contamination proportion (OR, 1.1; 95% CI, 0.8-1.7; p = 0.56). All cultures from nonsterile gel were negative. None of the samples cultured directly from the ultrasound probe were positive for bacteria (0%). Skin preparation with 70% alcohol decreased the proportion of contamination when compared with unprepared skin (OR, 21.0; 95% CI, 3.1-142.2; p = 0.001). Conclusions Use of ultrasound probes and transmission gel results in greater contamination in simulated intraarticular injections of the shoulder. As such, sterile preparation of the entire injection field, including the

Ultrasound Diagnostic and Therapeutic Injections of the Hip and Groin

“…Injections should be performed with adherence to aseptic technique although this varies between institutions and radiologists attributable to resources, training, perceived risk and experience [6]. In a survey of 250 health professionals in the United Kingdom, 43.5% believed infection rates were < 1/1000 following intra-articular injections, 33.0% perceived rates were < 1/100, and 2.6% perceived the risk as negligible [7].…”

“…In a survey of 250 health professionals in the United Kingdom, 43.5% believed infection rates were < 1/1000 following intra-articular injections, 33.0% perceived rates were < 1/100, and 2.6% perceived the risk as negligible [7]. Sterile preparation of the entire injection field, including adjacent skin where the gel and probe are applied, is recommended [6]. Areas of superficial infection such as cellulitis or abscess should be avoided to prevent deeper spread.…”

Sepsis, parenteral vaccination and skin disinfection

“…Sherman et al 24 reported it decreased the proportion of contaminants (odds ratio 21, 95% CI 3.1–142.2), with 20 of 26 patients who were initially culture positive being culture negative after disinfection. One patient remained culture positive despite disinfection.…”

Reply to the Letter to the Editor: Does the Use of Ultrasound Affect Contamination of Musculoskeletal Injections Sites?

“…W e would like to thank Dr. Ata and colleagues for their interest in our recent article [5] that investigates the effect of ultrasound guidance on skin contamination at injection sites. Their response highlights the variety of techniques with which musculoskeletal injections are performed, particularly in the presence of ultrasound guidance.…”