Scrubbing, gowning and gloving evidence for best practice part 2

Transcription

1 Vet Times The website for the veterinary profession Scrubbing, gowning and gloving evidence for best practice part 2 Author : James Gasson Categories : RVNs Date : January 1, 2010 James Gasson nursing manager and theatre supervisor, concludes his series with a look at the pros and cons of disposable versus reusable surgical scrubs, and at various aseptic gloving techniques IN part one of this series (VN Times 09.12; December 2009), the role of surgical hand preparation and its impact on surgical wound infection (SWI) rates was examined. In this article, the use of gowns and gloves within aseptic practices is detailed. In terms of personnel preparation, gowns and gloves provide the terminal barrier to the passage of microbes between non-sterile and sterile areas of the surgical field. In order to achieve this, gowns and gloves must be manufactured to a suitable standard and be donned in a manner that preserves their integrity; in use they must withstand the rigours of surgical activity. Gowns Short-sleeved surgical gowns were added to theatre garb at the end of the 19th century initially to protect the clothes of the wearer. Emphasis soon changed to protect the patient, but we now consider protection in both directions given the transmissible nature of pathogens. Reusable surgical gowns of 100 per cent cotton were the norm for many years; however, several decades ago it became apparent that fabrics failed to establish a barrier neither when wet nor dry. Intrinsically, woven fabrics have interstices, or pores, of considerable size, sometimes up to 80 µm 1 / 6

2 diameter this compares to microbes, which have a diameter of µm. Bacterial barrier The pores increase in size after laundering and sterilisation processes and, hence, older surgical fabrics have reduced barrier properties compared to new. Microbes do not migrate on free will and are carried on vectors, such as shed skin squames, either from the patient or theatre personnel. Loose-weave cotton of 140 thread count was soon replaced with more tightly woven fabrics; however, when wet, as is usual within surgery, woven fabrics still failed to establish a barrier. Capillary action causes wicking of fluids through fabrics, which can facilitate the transfer of microbes between surfaces ( Figure 1 ). Over the past 40 years, greater emphasis on establishing barriers has led to the evolution of non-woven, disposable fabrics. Non-woven fabrics are those that are formed by a method that does not involve tufting or weaving, and typically the interstices of such fabrics do not facilitate the passage of microbes when wet or dry. Non-woven fabrics are fluid resistant; truly impervious fabrics, such as those commonly used for equine colic surgeries and wet procedures, are plasticised. Most non-woven fabrics are used for disposable, single-patient-use items. However, within recent years, greater emphasis has been given to reusable/reposable items due to the perceived environmental impact of single-use disposable items. Environmental impact Modern reusable fabrics that fulfil the criteria for surgical barriers do exist; however, reprocessing such fabrics is, by and large, an industrial process not available to the veterinary sector. Typically, they consist of multi-laminates of tightly woven polyester and Gore-Tex-type fabrics. The environmental impact of both systems is considerable. Reusable items use massive amounts of water, chemicals and energy during reprocessing, while disposable items are frequently a result of waste crude oil processing that result in CO 2 emissions during manufacture and disposal. To date, the impact of these systems is not fully understood it is worth noting that reposable items have limited life, typically 50 uses, before significant deterioration will have occurred. The competitive market for disposable items has driven down cost considerably disposable gowns for less than 1 per item are a reality, depending on quantities purchased. With re-use, human costs need to be factored into the equation is it cost effective to use a nurse to wash, inspect, pack, sterilise and handle reusable linens? Both systems have been compared in a limited number of trials, although the studies appear weak in design and the statistical power is low. In my opinion, when studying microbial contamination of the surgical site and SWI rates, non-woven fabrics seem to out perform reusable woven fabrics. 2 / 6

3 Properties of gowns The properties of an ideal gown include: fluid resistance; stretch, pressure and friction resistance to defects; non-linting (lint acts as a contaminant and vector for microbial transfer); comfortable for the wearer; wide collar to prevent friction at the neck, leading to vertical shedding of skin squames; long, wide sleeves to facilitate gloving and for maximum movement; soft, flexible cuffs; and enclosing, wrap-around back panel. Reusable gowns must be packaged so that only the inner surfaces are handled during donning, and the neck portion must be easily identifiable to ensure the gown is unfolded in the correct orientation. Gowns of porous materials are not efficiently sterilised in gravity displacement autoclaves, especially those using short flash cycles. A vacuum-assisted autoclave with fractional air removal is recommended for all porous loads. Suitable areas Sufficient room should be available to allow for donning the sterile gown without risk of inadvertent contamination. Once scrubbed, it is acceptable for hands to be dried and gowns/ gloves donned in an area of the scrub room a separate substerile room adjacent to theatre or within the theatre itself. A separate sterile field should be used within theatre; gowning and gloving from the prepared instrument table is not acceptable due to the risk of contaminating sterile supplies with water splashes etc. Although the whole gown is sterile on presentation, it is zoned into sterile areas when in place ( Figure 2 ). These are: front of gown, from top of chest to waist; and sleeves up to two inches above the elbow. The back of the gown is not considered sterile, even if wraparound in style. It is not visible to the 3 / 6

4 wearer and inadvertent contamination may go unnoticed and, for this reason, a sterile team member should not turn his or her back on the sterile field. Members should move around while facing the sterile field and, if necessary, pass each other either back-to-back or front-to-front. Gloves Sterile gloves complete the attire for sterile members and permit the wearer to handle sterile equipment and tissues of the surgical wound, while protecting the wearer against potential zoonotic disease. Disposable gloves have been available since The first use of surgical gloves is described by William Halstead s nurse (and wife) Caroline Hampton, whose hands were damaged by the repetitive use of harsh antiseptic chemicals, circa Modern gloves can typically be made of: natural latex rubber; synthetic rubber; thermoplastic elastomers; neoprene; vinyl; or polyethylene. Latex is the most commonnly used material and is a polymeric membrane of natural rubber with an infinite number of holes between lattices and, therefore, not completely impermeable to moisture and viral particles. Latex contains protein antigen and may cause an allergic dermatitis or systemic anaphylaxis in the sensitised individual; latex-free alternatives should be available. Traditionally, surgical gloves were coated in maize starch prior to sterilisation to facilitate donning; however, maize starch is now considered to be detrimental to the wearer and patient due to the following: causes inflammatory response; granuloma; peritonitis; abscessation; 4 / 6

5 irritant to wearer; disseminates natural rubber proteins into the environment; and creates contamination of the surgical environment and is difficult to remove through routine cleaning. Silicone-based hydrogel coatings are considered safe and are recommended. Surgical gloves from a reputable manufacturer are rigorously tested and quality assured; however, new gloves may still have detectable punctures and up to 60 per cent are said to be punctured at the end of surgery. Double gloving reduces the incidence of inner glove puncture and is suitable for heavy duty surgery involving cut bone surfaces and metallic implants. Wearing a half size larger glove as the under glove improves comfort. Methods of gloving Three techniques of donning sterile gloves are described: open; closed; and assisted (plunge). Closed gloving ( Figure 3 ) is described as the gold standard, whereby the hands remain inside the gown during the gloving process to minimise contamination to the exterior surfaces. However, two small studies have shown that both open and closed methods of gloving produce similar amounts of contamination of the glove/gown surfaces while assisted gloving results in the least amount. It is not known how significant the resulting contamination is ( Figures 4 ). It is commonplace for newly worn gloves to be donned using the closed technique and sufficiently long gown sleeves are essential for minimising contamination. For intraoperative glove changes it is essential to use an open technique and so the nurse must be familiar with all methods. During the course of surgery, contamination from the wearer s axilla and arms accumulates within the sleeve portion of the gown, and withdrawing the hand back inside the gown to perform closed gloving of new gloves results in contamination of the hands and gloves. Similarly, the portion of cuff in direct contact with the exterior of the glove during closed gloving is not impervious to moisture, or an effective barrier. The cuffs should not be repositioned once in place and should remain covered by the surgical gloves at all times. 5 / 6

6 Powered by TCPDF ( During assisted gloving, the assistant must be proficient in the technique and roll the glove cuff back over their own hands to avoid contamination ( Figure 5 ). At the completion of surgery, gowns are removed first followed by gloves, using a glove-to-glove and skin-to-skin technique to minimise self contamination. 6 / 6