Role of gloves in tackling SSI

At the Reducing HCAIs conference, Professor David Walker, Deputy Chief Medical Officer, Department of Health warned that we are ‘down to our last class of antibiotics’ for a number of infections. In the future, the risks associated with SSI could become much greater and the outcomes poorer, if we do not act now on antibiotic resistance. The event highlighted the importance of overcoming barriers to the development of new classes of antibiotics, while ensuring effective stewardship to safeguard the drugs that remain in our armoury. Strategies for minimising the risk of infection were also high on the agenda. Professor David Leaper, visiting professor, Imperial College, London, discussed The role of surgical gloves in prevention of surgical site infection, while highlighting the latest research and updates to NICE guidance. “Fleming first noted that Penicillium notatum inhibited Staphylococcus aureus, in 1928. Since then, we have overused antibiotics and become too dependent on them,” commented Prof. Leaper. He pointed out that patients continue to demand antibiotics from their GP for sore throats and other minor ailments, while at least 15% of wounds after clean wound surgery are treated with antibiotics. “Half of these haven’t even been looked at,” he exclaimed. Prof. Leaper described the situation as ‘worrying’, pointing out that Alexander Fleming predicted that if we did not look after antibiotics, ‘we would be sorry’. “Fleming was concerned that people might under-dose themselves – in fact, we have gone the other way. As a result, we are seeing a rise in antibiotic resistant organisms,” he explained. Prof. Leaper went on to highlight the fact that just a 10% reduction in healthcare-associated infections (HCAIs) could save e150 million per year. He warned that hospitals cannot afford not to tackle the issue. SSIs are the third most common HCAI and contribute greatly to the economic costs of surgical procedures. UK hospitals also risk financial penalties for having too many C. difficile infections, for example, and fines have the potential to be as high as £1 m in some cases. Community-acquired infection also needs to be addressed – some 30%-40% community pressure sores have MRSA and patients are bringing this into the hospital setting when they require admission. The Panton Valentine Leukocidin gene (PVL) is also becoming a concern. Strains of Staphylococcus aureus encoding the PVL genes (PVL-SA) have been recognised as a cause of infection in community and healthcare settings worldwide for over 60 years. However, interest in PVL-SA has increased, since the 1990s, with the emergence of methicillin resistant strains, which have become known as PVL-MRSA or community-associated MRSA (CAMRSA). 1

Prevention

“New antibiotics are running out. If we do not improve antibiotic stewardship we are going to have nothing on the shelves – so is there an alternative? In the face of increasing antibiotic resistance could we return to antiseptics?” said Prof. Leaper. He described the mechanism of action of antiseptics, pointing out that they target every part of the microorganism, by: blocking cell respiratory processes and membrane proteins, blocking efflux pumps, denaturation of proteins and enzymes, as well as changing the DNA. He pointed out that Lister’s development of antiseptic surgery had a major impact on mortality. Mortality rates following surgery, from 1864 to 1866, were 45.7%. From 1867 to 1870, this was reduced to 15.0%, following the introduction of phenol. There are now a wide range of antiseptics available – such as chlorhexidine, polyhexamethylene biguanide, povidone iodine, triclosan and silver. There are various interventions that are considered effective in preventing SSI and the NICE guidelines highlight the role of antiseptics, as well as other aspects of best practice care – before, during and after surgery. Prof. Leaper previously chaired the NICE guidelines on surgical site infection, published in 2008, and highlighted the latest evidence updates.2 “Antiobiotic prophylaxis is still level one evidence but it is not being administered appropriately,” commented Prof. Leaper. “It is being given either too late or after the tourniquet, or for five days – then we wonder why we get resistance in patients. Keeping patients warm is important and is also supported by level-one evidence. “However, the management of sugar levels in diabetics is also increasingly being rolled out to non-diabetic patients, as the metabolic response raises sugar levels. If you control this, you will reduce surgical site infection. This has been well demonstrated in cardiac surgery. In addition, if you are going to use incise drapes, you should ensure they are impregnated, as they can increase the risk of SSIs, while there is still a need for further work to investigate intra-cavity wound lavage with antiseptics.” Originally, the NICE guidance stated that the skin should be prepared at the surgical site immediately before incision using an (aqueous or alcohol based) antiseptic preparation using povidoneiodine or chlorhexidine. Since the guidance, a paper was published by Darouiche et al,3 which compared chlorhexidine-alcohol versus povidoneiodine for surgical site antisepsis. The overall rate of surgical-site infection was significantly lower in the chlorhexidine–alcohol group than in the povidone–iodine group (9.5% vs 16.1%; P=0.004; relative risk, 0.59; 95% confidence interval, 0.41 to 0.85). Chlorhexidine–alcohol was significantly more protective than povidone–iodine against both superficial incisional infections (4.2% vs 8.6%, P=0.008) and deep incisional infections (1% vs 3%, P=0.05) but not against organ-space infections (4.4% vs 4.5%).3 Prof. Leaper commented that he did not know any surgical colleagues that were not using this approach now, adding that there are currently other studies underway which should shed light on the most appropriate skin antisepsis. He went on to discuss the problem of biofilm formation, which protects bacteria from the host-defences and antibiotics. “I am sure you have seen surgical wounds where there is not much smell or discharge, but they fall apart. This could be due an acute biofilm,” explained Prof. Leaper. He commented that the formation of biofilm is a particular problem on implants such as prosthetic joints and sutures. However, a meta-analysis of RCTs of sutures coated in Triclosan has shown that there is a statistically significant advantage in using antimicrobial sutures.4 Surgical gloves are also designed to protect both the clinician from infection as well as the patient in terms of prevention of surgical site infection (SSI). However, research suggests that the rate of glove perforation is a cause for concern. A paper by Parteke et al5 examined the glove perforation rate by type of surgery and found that for cardiothoracic surgery the rate was as high as 32.3%, 22.3% for vascular surgery, 20.3% for major abdominal surgery, 12.3% for moderate abdominal surgery, 17.3% for minor abdominal surgery and 15.3% for laparoscopic surgery. Parteke et al also looked at the perforation rate by duration of wear. The study found that when the duration of wear was greater than or equal to 151 minutes, the rate of perforation was significantly higher at 23.7% compared to 0.7% for the control period of 90 minutes (the study examined 898 pairs of gloves in total). “These figures are frightening,” said Prof. Leaper. “This is a very common problem – particularly in cardiothoracic surgery. It is the non-dominant index finger that is usually affected and it is most commonly the first assistant. Does this reflect their inexperience? I am not sure… However, it is typically the finger that you stitch on. You may have forgotten that you have pricked your finger, but when you have finished the operation and taken off your glove, you will find blood on the inside of your glove. Not many surgeons will own up to this and they often hate double gloving,” he continued. Prof. Leaper pointed out that wearing rings, dirty fingernails and inflamed skin are also causes for concern, highlighting figures which showed that: