Surgical gowns are available as both single-use, made of non-woven materials and reusable, made of cotton or synthetic based materials. As their main purpose is to prevent the transmission of infectious agents between the clinical staff and the patient, surgical gowns are classed as medical devices.
An essential requirement for all medical devices is that they should be free from microbial contamination [1]. In addition, to avoid foreign body reactions, medical devices should be clean from foreign bodies or particulate matter [2]. Although it is possible to see objects as small as 50 μm with the naked eye, a microscope is required to detect anything smaller. In this study, surgical gowns, single use of standard performance (SP) and high performance (HP) material and reusables made of cotton and synthetic material, were evaluated to explore their cleanliness at a microscopic level using scanning electron microscopy (SEM).
RESULTS
A wide variety of particulates could be seen on all the surgical gowns with SEM.The particulate matter on the single use gowns was confirmed to be integrated in the material. All SEM analyses of the non-woven gowns of both SP and HP materials were consistent and showed that the non-woven material looked clean (Figure 1A and B). In contrast, all samples of the reusable gowns revealed a wide variety of unidentified structures. Figure 1C indicates that the materials of the synthetic reusable gowns may be coated and that this could potentially become detached. It was also observed that reusable synthetic and cotton gowns harbored particulate matters that appeared foreign, i.e. not part
of the gown material, and some of them resembled microbial structures (Figure 2A and B).
DISCUSSION
For reusable surgical gowns to be fit for purpose, they must be processed by cleaning, disinfection and sterilization to ensure the gown is free from foreign materials, such as soil and contaminating microbes that could come loose during a procedure [2]. However, the product will not be fit for use unless it has been processed effectively. Multiple factors, such as the level of soiling, organic contamination (e.g. microbes body fluids and tissue), the hardness and temperature of water, and type and amount of detergent and disinfectant affect the efficacy of each process. If contaminants on reusables are not properly removed, they will remain and could go unnoticed, especially if they are of microscopic size.
Particulate matter
While some of the foreign materials detected on the reusable gowns could be contaminants, they could also be residue from disinfectants or other impregnating chemicals. Such particulate matter,may not be a problem while adhered to the material. However, if it becomes detached, there could be an inflammatory reaction in the surgical wound causing the formation of granulomas and adhesion [3]; or catheter lines could be accidentally contaminated, causing emboli [4].
Microbial like particulate matters
It is intriguing to speculate that reusable surgical gowns ready to be worn could harbor microbes. Recently, Kramer et al summarized reports where inanimate surfaces have been incriminated as the source for outbreaks of nosocomial infections [5]. Both gram-negative and gram-positive bacteria, fungi and viruses were found to survive on different surfaces at hospitals for an extensive length of time.
In an experimental study, it was also shown that bacteria can survive for months on hospital fabrics and plastics [6]. In yet another experimental study, confined to surfaces in the operating room, gloves and surgical gowns were studied to see if they could be a source of many biomaterials-related infections [7]. It was shown that bacteria can adhere to and be transferred between different surfaces in varying degrees, depending on the bacterial species, the presence of moisture and the friction and characteristics of both the donating and receiving surfaces. As microbes can survive on inanimate surfaces and be transferred, it is clear that these surfaces must be properly disinfected before a subsequent use. Numerous studies have reported on bacterial survival after the laundry process [8].
There have been reports where linen has been the incriminating source of surgical site infections, even though the products have been washed and disinfected [9]. This was due to the linen harboring Bacillus spores that were not efficiently washed away. The ordinary washing temperature and disinfectants did not have any effect on the spores. There is, therefore, a potential risk that reusable surgical gowns will harbor microbes that are not effectively removed and killed between uses [10]. Furthermore, in a drive to reduce energy consumption, the use of lower washing temperatures may diminish laundry efficacy [11]. Lower temperatures are also used because mixed materials in synthetic reusable gowns cannot withstand high washing temperatures [10].
CONCLUSION
This study revealed that single use surgical gowns appeared to be clean at a microscopic level. In contrast, reusable
surgical gowns, both synthetic and cotton, did not look clean, and appeared to harbor foreign particulate matter. These resembled microbial structures
and/or possibly chemicals applied to recondition the gowns. Such foreign particulates could potentially have a
negative clinical impact, which has been highlighted by others [3, 4, 10].
Acknowledgement
We would like to thank Prof. Bengt Johansson at the Institute for Biomedicine, Sahlgrenska Academy, University of Göteborg, Sweden who guided us in the use of scanning electron microscopy.
Foto: Catarina Alenius Jensen
References:
1. EU (1993). Medical Device Directive 93/42/EEC.
2. Barrie, D. (1994). How hospital linen and laundry services are provided. J Hosp Infect 27, 219-235.
3. Duron, J.J., and Olivier, L. (1997). Foreign bodies and intraperitoneal post-operative adhesions. J Long Term Eff Med Implants 7, 235-242.
4. Konwaler, B.E. (1950). Pulmonary emboli of cotton fibers. Am J Clin Pathol 20, 385-389.
5. Kramer, A., Schwebke, I., and Kampf, G. (2006). How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infect Dis 6, 130.
6. Neely, A.N., and Maley, M.P. (2000). Survival of enterococci and staphylococci on hospital fabrics and plastic. J
Clin Microbiol 38, 724-726.
7. Knobben, B.A., van der Mei, H.C., van Horn, J.R., and Busscher, H.J.
(2007). Transfer of bacteria between biomaterials surfaces in the operating room – an experimental study. J
Biomed Mater Res A 80, 790-799.
8. Jaska, J.M., and Fredell, D.L. (1980).Impact of detergent systems on bacterial
survival on laundered fabrics. Appl Environ Microbiol 39, 743-748.
9. Barrie, D., Hoffman, P.N., Wilson, J.A., and Kramer, J.M. (1994). Contamination of hospital linen by Bacillus cereus. Epidemiol Infect 113, 297-306.
10. Fijan, S., Koren, S., Cencic, A., and Sostar-Turk, S. (2007). Antimicrobial disinfection effect of a laundering procedure for hospital textiles against various indicator bacteria and fungi using different substrates for simulating human excrements. Diagn Microbiol Infect Dis 57, 251-257.
11. Christian, R.R., Manchester, J.T., and Mellor, M.T. (1983). Bacteriological quality of fabrics washed at lower-than-standard temperatures in a hospital laundry facility. Appl Environ Microbiol 45, 591-597.