Automatic multi-slice CT injectors: hygiene and efficiency of disposable, prefilled and multi-dosing roller pump systems in clinical routine

Transcription

1 Automatic multi-slice CT injectors: hygiene and efficiency of disposable, prefilled and multi-dosing roller pump systems in clinical routine Poster No.: C-0305 Congress: ECR 2011 Type: Authors: Keywords: DOI: Scientific Paper B. Buerke, M. Puesken, A. Mellmann, W. Heindel, J. Wessling; Münster/DE Contrast agents, CT, CT-Angiography, Contrast agent-other /ecr2011/C-0305 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 12

2 Purpose Automatic injectors for intravenous application of contrast agent and saline allowhave become a standard in multi-slice computed tomography (MSCT). According to national restrictions by regulatory authorities, disposable syringes, tubes and connectors used with automatic injectors are approved for single use only. Recent clinical studies documented microbiological contamination of syringes for contrast agent and saline in the case of multiple use in more than one patient or application. Only the single use of conventional injection syringes in one patient ensured hygienic conditions and sterility of the CT injection system. Three different syringe systems for automatic injectors/injections systems are currently available: 1. Standard disposable syringes 2. Prefilled disposable contrast agent syringes. 3. Roller pump injection systems delivering the injection directly from a contrast agent and saline container through a special injection tube. However, analyzing hygienic aspects of these systems are lacking. This study aims to evaluate potential microbiological contamination, time efficiency and user handling of disposable, prefilled contrast agent syringes and a roller pump injector in clinical routine. Methods and Materials Patients A total of 800 patients (one application per patient i.e. 800 application procedures) with a clinical indication for MSCT were included. Page 2 of 12

3 Written informed consent was obtained from all patients. The study was approved by the local ethics committee. Multi-slice CT (Somatom Definition, Siemens, Forchheim, Germany) examination protocols used in this study consisted of one or more contrast agent bolus injection(s). Double-syringe CT injector The double-syringe CT injector (Stellant CT Injection System, Medrad Inc., Indianola, PA, USA) comprises two injection syringes, one for contrast agent and another for saline, which are connected by a T-shaped connector. (Fig. 1 and 2). The double-syringe system was analyzed using disposable syringes (system A) and prefilled syringes (system B): System A. Disposable syringes (volume 150 ml; Medrad Stellant Syringe Kit, Medrad Inc., Indianola, PA, USA) manually filled with contrast agent (Ultravist-370, Bayer Schering Pharma, Germany) and saline (Fig. 1). System B. Prefilled disposable syringes containing iodine contrast agent (Ultravist-370; 150 ml, prefilled syringe, Bayer Schering Pharma, Germany) and conventional disposable syringes for saline (Fig. 2). System C - Roller pump injector. The roller pump injector (Mississippi ; Ullrich Medical, Germany) delivers the injection directly from the contrast agent and saline supplies. The patient tube is changed for each new patient, while the injection tube is certified for use up to 24 hours (Fig. 3). Hygienic background: Bacterial contamination of palms and surfaces Adequate hygienic conditions in terms of the palms of the hands and work surfaces (i.e. hygienic background) are essential when operating automatic injectors. by taking palm imprints from technical and medical staff and surfaces without prior warning. Bacterial contamination of injection systems The bacterial contamination of syringes and injection tubes of the double-syringe injector were analyzed after each application procedure (System A and B: 150 disposable syringes for contrast agent and saline. The roller pump injector were microbiologically Page 3 of 12

4 analyzed after a mean daily use of 12±1.2 h (System C: n=13 days, i.e. 13 pump and injection tubes). After the examinations, syringes and/or injection tubes were removed from the automatic injectors and prepared for microbiological examination. Time efficiency of use of injection system A (disposable syringes) versus B (prefilled syringes) and C (roller pump) To evaluate time efficiency, assembly of the automatic injection systems, including installation of disposable syringes and prefilled syringes and filling of saline syringes (system A and B), or connection of injection tubes and contrast agent and saline supplies (system C), was timed. Subjective ranking of injector handling After finalization of the clinical investigation the technical staff (eight technicians) were asked to rank injection system A, B and C. Data analysis Microbiological analysis of bacterial contamination of palms, surfaces, syringes and injection tubes Analysis of bacterial contamination was performed using standard microbiological methods for species differentiation. Data interpretation and statistics Contamination of surfaces and palms: The bacterial contamination of surfaces and palms was counted in colony forming units (CFU). Each surface and palm was considered separately. Contamination of syringes: Contrast agent and syringes are designated for parenteral application. Every incident of microbiological contamination has to be evaluated as "contaminated". The time for injector assembly and filling/refilling of syringes was statistically analyzed using the t-test (p<0.01). Images for this section: Page 4 of 12

5 Fig. 1: Injection system A Page 5 of 12

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7 Fig. 2: Injection system B Page 7 of 12

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9 Fig. 3: Injection system C Page 9 of 12

10 Results Hygienic background: Bacterial contamination of palms and surfaces Microbiological analysis of the imprints of the palms of the hands of medical and technical staff and of the surfaces in the CT unit during clinical routine revealed bacterial contamination within acceptable ranges. Bacterial contamination of injection syringes Microbiological analysis revealed no bacterial contamination in 0/150 disposable syringes for contrast agent and 0/150 syringes for saline (system A), and in 0/150 prefilled syringes for contrast agent and 0/150 disposable syringes for saline (system B). Analysis of the roller pump system (system C) showed no contamination of tubes or supply containers. Time efficiency of use of injection system A (disposable syringes), B (prefilled syringes) and C (roller pump) The mean time required to assemble system A was 2.5±1.1 minutes, for system B 2.0±1.4 minutes (not statistically significant, p=0.12). Mean time for tube connection was significantly shorter with system C (0.9±0.6 minutes, A: p<0.05, B: p<0.05). Initial assembly of the roller pump injector performed once prior to the first application procedure took 4.5±09 minutes on average. System C outperformed system A and B after six examinations. Subjective ranking of injector handling In subjective ranking of injector handling, system B and C were preferred. Conclusion As revealed by the results of this study the single use of disposable syringes for contrast agent and saline (system A) and the use of prefilled syringes for contrast agent in combination with disposable syringes for saline (system B) prevents microbiological contamination. Also, the roller pump system (system C) ensured sterility. Page 10 of 12

11 Reduced personal contact with the injection system is probably a causal factor in the optimized hygienic conditions in system A and B. In addition, the particle filter and oneway valves incorporated in the injection tube of the roller pump system (system C) prevent microbiological infiltration. This study revealed, that syringe exchange, filling and connection took more time for a single syringe (system A), but less time for prefilled syringes (system B). Using system C, significantly less time is needed than with system A and B, because the injection is taken directly from the contrast agent and saline containers and there is no handling time for syringe exchange etc. This study does have limitations. Future advancements in the construction of automatic injectors should also focus on hygienic aspects (e.g. special one-way valves). We conclude that double-syringe injectors used with disposable or prefilled contrast agent syringes, as well as roller pump injectors, asssure hygienic conditions in clinical routine. However, time efficiency and handling are aspects in favor of prefilled and roller pump systems. References Buerke B, Sonntag AK, Fischbach R, Heindel W, Tombach B. [Automatic injectors in magnetic resonance imaging and computed tomography: pilot study on hygienic aspects]. Rofo 2004; 176: Jeske HC, Tiefenthaler W, Hohlrieder M, Hinterberger G, Benzer A. Bacterial contamination of anaesthetists' hands by personal mobile phone and fixed phone use in the operating theatre. Anaesthesia 2007; 62: Buerke B, Mellmann A, Stehling C, Wessling J, Heindel W, Juergens KU. Microbiologic contamination of automatic injectors at MDCT: experimental and clinical investigations. AJR Am J Roentgenol 2008; 191:W Buerke B, Puesken M, Mellmann A, Seifarth H, Heindel W, Wessling J. Microbiologic contamination and time efficiency of use of automatic MDCT injectors with prefilled syringes: Results of a clinical investigation. AJR Am J Roentgenol; 194: Page 11 of 12

12 Dominik RH, Segebade IE, Taenzer V. Risk of microbial contamination of iodinated contrast media on multiple use of large-volume bottles. Eur J Radiol 1995; 19: Lisle D, Ratcliffe JF, Faoagali J, Cherian S. Bacterial contamination of contrast media stored after opening. Br J Radiol 1990; 63: Personal Information Page 12 of 12