Vet Times The website for the veterinary profession https://www.vettimes.co.uk Scrubbing, gowning and gloving evidence for best practice part 1 Author : James Gasson Categories : RVNs Date : December 1, 2009 James Gasson operating department manager, on the objectives of surgical hand antisepsis and methods to reduce wound infection SCRUBBING, gowning and gloving form the foundation of aseptic surgery and, in part one of this article we will examine the relevance of scrubbing to minimising surgical wound infection. Hand antisepsis Joseph Lister was a pioneer of antiseptic surgery, introducing his famous carbolic acid in the 1860s. William Halsted used carbolic acid and mercuric chloride to disinfect the hands of his operating team in the 1890s. Fortunately, modern antiseptics are less detrimental to the user and greater emphasis is placed on minimising harm. The objectives of surgical hand antisepsis are to: remove gross dirt and transient microorganisms; reduce the resident microbial population to a sub-pathogenic level in as short a period of time as possible and with the least amount of tissue irritation; and inhibit rapid rebound growth of microbes. 1 / 6
The ideal hand antiseptic solution is: rapid acting; broad spectrum in activity; residual in action; non-irritant; cost effective; and easy to apply. The iodophor povidone-iodine was one of the first antiseptics described followed by the introduction of chlorhexidine gluconate in the 1950s, both are in use today and have yet to be superseded ( Table 1 ). Others described, but falling out of favour, are hexachlorophene and parachlorometaxylonol. Up to 20 per cent of the resident microbial population of the hands and forearms are inaccessible to antisepsis, residing deep in the stratified corneum of the skin. Sterile gloves, which will be discussed in part two of the article, are the terminal barrier to transfer, but are not 100 per cent effective; it is assumed that correct hand antisepsis reduces the potential for microbial migration that may lead to a surgical wound infection. The overall successful act of surgical hand antisepsis may be thought of as being a combination of the agent used, the method of application and the contact time, to produce the desired effect. Aqueous scrubs Figure 1 shows the comparison between povidone-iodine and chlorhexidine gluconate. The efficacy of both agents has been compared in numerous studies investigating the ability to reduce colonyforming units (CFU), a measure of viable bacterial numbers. This is an example of a surrogate measure being used to imply significance to the objective outcome. We want to know which is superior in terms of reducing surgical wound infections, but rather than measure that, we look at the agent s ability to kill microbes. It is assumed there is a relationship between bacterial numbers on the hands and developing a surgical wound infection through a breakdown in the terminal glove barrier. This relationship has not been established. To measure the objective outcome of surgical wound infections (SWI), apart from being expensive, would require a huge amount of data collection to be statistically significant, given that the incidence is relatively small approximately 2.5 to five per cent for clean surgical procedures. Similarly, to design a study that is controlled and free of variance is almost impossible given the wide range of factors implicated in increasing the potential for developing a wound 2 / 6
infection. A Cochrane systematic review of surgical hand antisepsis, (Tanner et al, 2008), provides one of the most up-todate single collative references, with meta-analysis where appropriate 10 studies are included for retrospective analysis. Comparisons With respect to povidone-iodine (PI) versus chlorhexidine gluconate (CHG) the following conclusions can be made: Statistically, there is no significant difference between CFU immediately post-application with either PI or CHG. Compared to PI, CHG provides superior CFU reduction more than two hours post-application. There is no data to support the use of one agent over the other in a clinical setting with respect to reducing SWI. CHG may be superior in sustaining sub-pathogenic levels of resident flora. Clinically, either is acceptable as a presurgical hand antiseptic agent and the selection is ultimately down to personal preference; both CHG and PI may cause skin irritation. Materials for application The term surgical scrub would logically derive from the historical use of scrubbing brushes to clean the hands and forearms. Scrub brushes are now recognised to be detrimental to the process by causing micro-abrasions to the skin that result in a heavy rebound population of resident flora and excessive drying leading to irritation and excessive shedding of skin squames. Disposable scrub brushes combined with sponges and antiseptics are commonly found in scrub rooms; the bristled side must only be used to clean the fingernails where indicated ( Figure 2 ). The sponge portion may be used to cleanse the skin surfaces; however, sufficient friction is generated from skin-to-skin contact to effectively remove dirt and lose skin squames. Sponges are intended to be single-use: weak antiseptics can support microbial growth and the reused sponge may act as a reservoir of contamination. If the sponges are dirty, fingernails may be cleaned under running water using a nail pick and the brush/sponge can be eliminated completely a significant cost saving. Studies relating to surgical scrubbing brushes are few and far between but, in the most recent (Tanner, 2008) three protocols are used: CHG only; CHG plus nail pick; and CHG plus nail brush. 3 / 6
CFU counts from glove juice samples one hour post-application revealed no statistically significant difference between any two of the three protocols, suggesting that neither brushes nor picks add anything useful to the surgical scrub ( Figure 3 ). Methods of application Traditionally, two descriptions of surgical scrubbing are used: the anatomical timed and counted brush stroke methods. Both describe the systematic application of an aqueous antiseptic in a detergent using a scrubbing brush/sponge to achieve maximum efficacy and are still commonly taught in classrooms and from textbooks. The Association of Perioperative Practitioners (UK) does not recommend either technique. A standardised systematic technique does ensure consistency and the six-step Ayliffe method of hand washing is most commonly used. For surgical hand preparation this is extended to the elbow on the first pass and to mid-forearm on subsequent passes, using rotational hand movements around the arm. Each step is five strokes forwards and five strokes backwards; completing all steps is a pass. The steps are: Rub palm to palm. Right palm over left dorsum and left palm over right dorsum. Palm to palm fingers interlaced. Back of fingers to opposing palms with fingers interlaced. Rotational rubbing of right thumb clasped in left palm and vice versa. Rotational rubbing back and forwards with clasped fingers of right hand in left palm and vice versa. If using aqueous antiseptics, the hands and forearms are first wetted with water before dispensing the antiseptic into the hand, typically 5ml. The sequence is repeated after rinsing from fingertips to elbow under running water until an appropriate contact time with the antiseptic has been achieved ( Figure 4 ). Duration of application Initial scrubs of five minutes, reduced to three minutes for subsequent procedures, are frequently cited. Taking four suitable trials into account, Tanner s review concludes that the optimum duration 4 / 6
of surgical scrubbing is not known, although the following may be taken into consideration: Initial scrubs of shorter duration (two to three minutes) seem to be as effective in reducing CFU when compared to five-minute scrubs, both immediately and two hours postapplication. It is assumed that reduced CFU counts from a two-minute scrub will not increase SWI. Subsequent scrubs of 30 seconds duration resulted in higher CFU counts compared to three minutes, although the impact of SWI is not known. Poor compliance Compliance with long surgical scrub times is poor and this evidence suggests that anything more than an energetic hand wash of two to three minutes is not necessary. If hands are inadvertently contaminated during the procedure, the wash may be extended but there is no justification for starting from scratch. Aqueous vs alcohol antiseptics: rubbing vs scrubbing To date, aqueous antiseptics have formed the basis for recommended scrub routines in the UK and USA, but this practice is now questioned. Alcohol antiseptic rubs have many advantages over aqueous solutions. They do not require a dedicated area for their application, their use does not waste water, require brushes/ sponges or hand towels all offering considerable resource savings. Scrubbing with an aqueous solution is particularly wasteful of water and it is highly recommended that taps be upgraded to include infrared sensors, which are only activated when the hands are in close proximity. Elbow-operated taps are normal within scrub rooms and, when left running during the scrub, up to 25 litres of water are used. If using an on/off scenario (total rinsing time within a typical surgical scrub is 30-40 seconds), this is reduced to less than five litres of water. Alcohol antiseptics vary considerably between manufacturers; there has yet to be an ideal formulation established frequently, they are a combination of different types of alcohols and chlorhexidine gluconate. Differences The Cochrane review included five studies looking at the effectiveness of alcohol antiseptics versus aqueous solutions and highlighted the following: No statistically significant difference between aqueous or alcohol antiseptics with respect to SWI the objective outcome (one study). Alcohol rubs produced significantly fewer CFU as compared to aqueous scrubbing with either PI 5 / 6
Powered by TCPDF (www.tcpdf.org) or CHG (three studies) both initially and two hours post-application. Within the UK and USA, perioperative organisations recommend alcohol rubs as a suitable alternative to scrubbing for subsequent cases. However, within the four studies of Tanner s review, the alcohol antiseptics were used for all interventions, suggesting the application of alcohol rubs to clean hands is a suitable alternative to aqueous solutions for any case. Grossly soiled hands may be socially cleaned with soap/ water and dried with nonsterile supplies prior to terminal antisepsis with alcohol. Applying alcohol to wet hands negates the antibacterial effect of the alcohol, which achieves its maximal activity through evaporation water will dilute the alcohol and impede evaporation. Applying alcohol antiseptics follows the same multi-step routine of the Ayliffe hand wash technique. Initially, the alcohol is pooled within the palm of the hand to allow decontamination of the fingertips ( Figure 5 ). Rubbing of the hands and forearms until the alcohol has evaporated is the correct procedure; wafting hands in the air to facilitate drying is not recommended ( Figure 6 ). In part two of this article I will look at surgical gowns and gloves, and their impact on surgical wound infections. References Tanner J, Khan D, Walsh S et al (2009). Brushes and picks used on nails during the surgical scrub to reduce bacteria: a randomised trial, J Hosp Infect 71(3): 234-238. 6 / 6