Journal of Hospital Infection (2001) 49: 293±295 doi:10.1053/jhin.2001.1096, available online at http://www.idealibrary.com on
A new concept of plaster for preventing hand-borne infections M. Perraud and F. Tissot Guerraz Unite d'HygieÁne, Edouard Herriot Hospital, Lyon, France Summary: A new plaster has been developed to improve asepsis in current medical and nursing care. Technical improvements were achieved via a `no touch' technique. The experimental protocol used to evaluate this new plaster allows us to claim its evident superiority because of the `no touch' principle and rapid application. Such a plaster appears to be very helpful in diminishing the incidence of hand-borne infections during medical and nursing care. & 2001 The Hospital Infection Society
Keywords: Hand-borne infections; plaster; experimental technique.
Introduction Plasters should be placed on accidental and surgical wounds using sterile materials and an aseptic technique.1,2 The quality of asepsis depends not only on operator training and conscientiousness, but also on how easily the materials can be deployed. A new plaster (Innovating Bandage Systems, Yverdon, Switzerland) has been developed to optimize safety. We compared it with a similar disposable plaster available on the market, for speed of application and improvement of safety against the risk of infection by breakdown of asepsis. Materials and methods The plasters The new plaster (NP) [Figure 1(a)] consists of a protective gauze placed on an adhesive strip. Its aseptic application is facilitated by the presence of two protective sheets of glossy paper.
Received 21 March 2001; revised manuscript accepted 19 September 2001; published online 14 November 2001. Author for Correspondence: Dr M. Perraud, Unite d'HygieÁne B1 (Environmental Laboratory), HoÃpital Edouard Herriot, 5 place d'Arsonval, 69437 LYON cedex 03, France. Fax: 33 4 72 11 07 26; E-mail:
[email protected]
1090-3801/01/040293 + 03 $35.00/0
The plaster is positioned in three steps: 1 Removal of sheet 1; 2 Fixation of the freed adhesive extremity on healthy skin close to the wound or area to be protected; 3 Removal of sheet 2, freeing the gauze and the other adhesive extremity, which is then applied to the skin or wound. The fingers of the operator remain at a distance from the critical zones (the patient's wound, the plaster's gauze), since all manipulations occur at the extremities of the plaster. The entire procedure can be done easily with only one hand after the removal of sheet 1. The standard control plaster (SCP) [Figure 1(b)] represented the type of plaster presently available. Its application followed the same steps as the prototype NP, but since the protective sheets are much shorter, the operator's fingers come close to the critical zones, increasing the risk of compromising asepsis through contact. Application with only one hand is more difficult and increases the risk of touching one of the critical zones. The test materials Plexiglass (methacrylate) plates (110 50 cm) with 10 wells (two series of five wells) were constructed to & 2001 The Hospital Infection Society
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M. Perraud and F. Tissot Guerraz
Gauze
Adhesive strip
Protective sheet 1 Protective sheet 2 (a)
Gauze
Protective sheet 2
Adhesive sheet
Protective sheet 1 (b)
Gauze
Lid Scalpel
Plexiglass support plate Rodac dish
Agar medium (c)
Figure 1 (a) New plaster, (b) standard control plaster, (c) diagram of a test unit showing a plexiglass plate well supporting a Rodac dish and plaster.
hold 10 Rodac dishes3 (Becton Dickinson and Co., Lincoln Park, NJ, USA) containing trypticase soy agar (bioMeÂrieux SA, 69280 Marcy l'Etoile, France) with 0.01% of 2,3,5-triphenyl tetrazolium chloride according to a standard production technique. The geometric features of the apparatus were defined so that the agar surface was levelled with the higher surface of the perforated plexiglass plate [details of one well are shown in Figure 1(c)]. The entire unit was conceived to represent the cutaneous surface carrying a wound destined to receive the plaster. The two extremities of the plaster adhered to the plexiglass surface. Breakdown of asepsis was analysed by the appearance of red colonies on the agar. The operator The operator positioned the NP and SCP according to the procedures described below, after
contaminating his/her hands by immersion, up to the wrist, in a sterile bag containing a suspension titrated with 3.5 106 Staphylococcus epidermidis/mL prepared from a strain isolated beforehand from his/her own cutaneous flora and cultured on trypticase soy agar for 48 h at 37 C. After immersion, the hands were withdrawn, the liquid dripped off in the same bag, and then dried under a laminar flow hood. The volume of suspension retained by the hands was estimated (by weighing) at 3 mL (presumed mass volume 1) i.e. approximately 104 bacteria/cm2 of the hands, the front/back surface of a hand estimated to be 300±500 cm2.4 All manipulations were performed under the laminar flow hood. The 10-well plexiglass plate was disinfected before use. Each unit contained 10 Rodac dishes, five to be used for testing of the NP, and the other five for testing of the SCP. After application, the part of the plasters facing the agar was separated from the adhering extremities with the help of a sterile scalpel and using the lid as a guide [Figure 1(c)]. The lid was then clamped down and the Rodac dishes were recovered from under the plexiglass plate. The lid was kept closed with adhesive tape. The Rodac dishes were incubated for 72 h at 37 C. Two parameters were studied. Firstly, Bacterial contamination was expressed as the number of colony-forming units. The count was limited to 20. Above this number, the count of 20 was analysed for the results. Three series of tests were performed, that is, 15 tests with the NP and 15 with the SCP. Secondly, speed of application was studied. For each unit tested earlier (qualitative tests), the duration of plaster application was timed by an observer. The chronometer was started and the operator applied a series of five plasters (NP or SCP) to the specified locations; the chronometer was stopped as soon as the fifth plaster was placed. Three timings were undertaken for the SCP and NP respectively (three series of five plasters).
Results The raw data are presented in Table I. Comparison testing of bacterial contamination revealed a very significant difference in favour of the NP (paired values of 15 SCP and 15 NP tests: 12 133 vs. 1133, P 0.001). Comparison testing by time demonstrated a significant difference favouring NP (paired values of three SCP and three NP tests: 1.71 vs. 1.27, P 0.021).
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Table I Comparison of bacterial contamination of the new plaster and standard control plaster Series 1 Contamination in CFU
NP SCP
Duration of application in minutes
NP SCP
10 5
1 20
Series 2 2 20
1 20
0 20
0 20
1.51 2.05
2 3
Series 3 1 20 1.17 1.49
0 2
0 3
0 1
0 3
0 20
0 5
0 20
1.13 1.59
CFU: colony-forming units; NP: new plaster; SCP: standard control plaster. 20 means `20 or more'.
Discussion The microbiological tests revealed that the SCP was more often and more markedly contaminated than the NP. It is noteworthy that contamination was globally elevated because the experimental conditions were deliberately extreme (contamination of the hands to 104 bacteria/cm2) for sensitivity of the method and for each asepsis breakdown shown by a positive culture. The chronometric tests demonstrated that, while being safer, application of the NP was also more rapid. According to Centers for Disease Control (CDC) guidelines, `avoiding touch contamination of the catheter insertion site (CIS) when the plaster is replaced' is classified as IA, i.e. proven.1 Our NP should improve the nosocomial infection incidence rate for sites of catheter insertion, especially in wards where such infections are significant. This is the case in parenteral nutrition wards5 and chronic haemodialysis centres,6,7 for which the CDC has recently created a new national survey system. Conclusion Simple changes made to presently available adhesive plasters on the market produce highly significant improvements to maintain asepsis during application, with a lower risk of contamination and a quantitative decrease in contamination when it occurs. Placement is more rapid and much easier; in particular, the plaster may be applied with only one hand while respecting aseptic control. The
advantageous features of the new system may be adopted for any plaster, no matter what its size or therapeutic properties. Acknowledgements The authors thank Vincent Perraud for the technical drawings. References 1. Pearson ML. Hospital Infection Control Practices Advisory Committee. Guidelines for prevention of intravascular device-related infections. Infect Control Hosp Epidemiol 1996; 17: 438±473. 2. MinisteÁre francËais de l'emploi et de la solidariteÂ. 100 recommendations pour la surveillance et la preÂvention des infections nosocomiales. CTIN, 1999. 3. Hall LB, Harnett MJ. Measurement of bacterial contamination on surfaces in hospitals. Publ Health Rep 1964; 79: 1021±1024. 4. Rossiter ND, Chapman P, Haywood IA. How big is a hand? Burns 1996; 22: 230±231. 5. Ryan JA Jr, Abel RM, Abboth WM et al. Catheter complications in total parental nutrition. A prospective study of 200 consecutive patients. N Engl J Med 1974; 290: 757±761. 6. Bonomo RA, Rice D, Whalen C, Linn D, Eckstein E, Shlaes DM. Risk factors associated with permanent acces-site infections in chronic hemodialysis patients. Infect Control Hosp Epidemiol 1997; 18: 757±761. 7. Stevenson KB, Adcox MJ, Mallea MC, Narasimhan N, Wagnild JP. Standardized surveillance of hemodialysis vascular access infections: 18-month experience at an outpatient, multifacility hemodialysis center. Infect Control Hosp Epidemiol 2000; 21: 200±203.