Health professionals are constantly striving to eliminate unnecessary risk during surgery. The use of protective clothing, regular handwashing and the use of sterilised equipment, to choose three examples, are all intended to reduce the possibility that either the patient or the surgeon may be exposed to infection. One of the more controversial methods to combat infection is the use of double-gloving – whereby two pairs of surgical gloves are worn – during surgery.
It may seem like a simplistic, piecemeal response to the danger of sharps injuries and surgical glove tears but double-gloving has been endorsed by no less an authority than the American College of Surgeons (ACS). In a 2007 statement on sharps safety, it recommended "the universal adoption of the double-glove (or underglove) technique in order to reduce body fluid exposure caused by glove tears and sharps injuries in surgeons and scrub personnel. In certain delicate operations, and in situations where it may compromise the safe conduct of the operation or safety of the patient, the surgeon may decide to forgo this safety measure."
Despite a large body of data documenting the benefits of double-gloving, the ACS added, the technique has not received wide acceptance by surgeons. They have proposed a period of adaptation and "retraining" to ensure practitioners feel comfortable with the technique.
A report by Greco and Garza, published in Aesthetic Plastic Surgery in 1995, supports the ACS's position. They found that blood contact exposure during aesthetic surgery occurred in 32% of operations in which a single pair of surgical gloves is used: contact rates decreased by 70% when two pairs were used. Outer-glove perforations occurred in 25.6% of the cases, while inner-glove perforations occurred in only 10% of the cases. All of the inner-glove perforations occurred during procedures that lasted longer than two hours, and in no case was there an inner-glove defect without a corresponding outer-glove perforation. Double-gloving during aesthetic procedures reduced the operating room personnel's risk of blood contact exposure by 70% when compared with single-glove use.
Professor Judith Tanner, the joint chair in Clinical Nursing Research at De Montfort University and University Hospitals of Leicester, says there is plenty of evidence to support the use of double-gloving. "Double-gloving is one of the few medical interventions where there is a whole raft of overwhelming evidence to support its use," she says.
"There are around 14 high-quality single studies comparing single-gloving with double-gloving carried out in different surgical specialities all over the world. They overwhelmingly show that wearing two pairs of gloves statistically significantly reduces the number of perforations to your glove. If you wear two pairs of gloves, 3% of inside gloves have at least one perforation in them, compared to just wearing single gloves where 9% of gloves would have at least one perforation.
"If you think about how many gloves a surgeon typically wears each day – let's say 12 in one day (six pairs) – so reducing perforation rate from 9% to 3% is quite a big difference."
While there have been plenty of studies into the efficacy of double-gloving, there have been none which have been able to ascertain if the technique protects effectively against blood-borne pathogens – but there are good reasons why not. "There are no high-quality studies on how wearing two pairs of gloves impacts on how many people get hepatitis C, hepatitis B or HIV," says Tanner.
"To do a study like that would be prohibitively expensive: if you imagine how long it takes to develop hepatitis C, you'd have to follow up the surgical team and the patients for years and years and years. This is why we look at the number of perforations instead. Therefore we can say that double-gloving reduces the possibility of pathogens being transferred."
Some people claim that double-gloving has severe drawbacks, however. Barry Jones, one of the world's leading plastic surgeons working out of King Edward VII's Hospital Sister Agnes in London, believes that the reduction in tactile sensitivity produced by wearing two pairs of gloves make the technique a non-starter for plastic surgeons.
"Have you ever tried wearing two condoms?" he said. "It doesn't take a rocket scientist to work out that if the padding between you and whatever it is you are trying to manipulate is twice as thick, then your feedback is less and therefore your dexterity is less.
"If you are manipulating hammers and chisels and doing heavy work – like hip replacement, for example– then you may feel that it is a useful thing to do. But certainly for what I do as a plastic surgeon it is entirely negative. I wouldn't consider it unless somebody could prove to me that it had a value either to me or to the patient."
Tanner does not agree. She believes it is a matter of getting used to wearing two pairs of gloves. "Lots of articles have been published looking at dexterity, for example, how quickly someone can tie a knot if they've got two pairs of gloves on as opposed to one," she says.
"These articles have found that people wearing two pairs of gloves are less dextrous or have less perception sensitivity.
"But what these studies haven't done is long-term follow-ups. There's an American paper by Carolyn Twomey who talks about retraining your mind. She says that after 30 days [of double-gloving] any differences between those two groups [single-gloved and double-gloved] have gone. After wearing two pairs of gloves for 30 days it's as if you were just wearing one – your dexterity is the same, you get used to it.
"Surgical gloves are evolving all the time. The quality of latex is so much better that wearing two pairs now is not as difficult as when the gloves weren't as nice, say, ten years ago. My background is orthopaedic surgery, so I'm used to wearing two pairs of gloves. If I was scrubbing for a case and I only had one pair of gloves on I would feel a bit naked. It's just about retraining your mind and getting used to it."
Tanner argues that the decision to use two pairs of gloves is based on how willing a surgeon is to accept a 9% risk of a perforation. "The way that you would approach is: 'how high-risk is this case?'" she says.
"'What are the chances of me perforating my gloves and getting an infection, or the patient getting infected?' You classify each individual surgical procedure for risk and the main categories are anything that involves metal work – sawing, drilling, and wiring: that means practically all orthopaedic procedures, all cardiac procedures and all maxillofacial procedures. Those are considered to be the most high-risk and double gloving is routine.
"The fact is that it reduces the risk from 9% to 3% – that is a lot, if you consider you wear 12 gloves a day, and you do that every day. All those perforation studies were carried on in what we would call "low-risk" surgery, stuff like plastic surgery. You could say to a plastic surgeon: "are you happy to take the 9% risk?" That would be scary to me.
"Practices are different worldwide. I spoke to somebody recently who practised surgery in South Africa. The incidence of HIV among the population is very high there and there was no way the surgeon would operate wearing gloves with a perforation rate of 9%.
"In the UK, hepatitis C is the virus most likely to be transferred and the risk isn't that great, so people are happy to amble along with a 9% risk for a low-risk procedure. But if we suddenly had a massive influx of patients with hepatitis C, B or HIV then people might change their gloving practice."
Double-gloving can benefit the patient as well as the surgical team, Tanner points out. "Wearing two pairs of gloves to prevent blood-borne pathogens is probably for the benefit of the surgical team because they are putting their hands in a big mass of potentially infected blood – you need quite a bit of blood for a pathogen to be transferred.
The surgeon is not the one who is bleeding profusely during surgery, so he'd wear two pairs of gloves to protect himself.
"But reducing the number of glove perforations means that the patient is probably less likely to have a surgical site infection. Reducing the number of perforations means that bacteria from the hands of the surgical team are less likely to be transferred to the patient's wound where they can cause infections."
There are alternatives to double-gloving: orthopaedic gloves, knitted gloves and triple gloving. Tanner says: "In the UK, we are a bit traditional. It's really just single or double-gloving here. The Europeans and Americans have other products. The main ones are orthopaedic gloves, knitted gloves and triple gloves.
"Orthopaedic gloves are an alternative to wearing two pairs – you just wear one pair of really thick gloves. There's only one decent study on orthopaedic gloves, which shows they offer the same protection level as wearing two pairs of gloves.
"Knitted gloves are made of plastic polymers – like Kevlar. They are cut-resistant. You would wear a pair of latex gloves with the knitted gloves on top. They offer better protection then wearing just two pairs of latex gloves. "Triple-gloving is as it sounds: three pairs of latex gloves. The specialities that mainly use these three products are orthopaedic, cardiac and maxillofacial.
"The other thing you can use is a perforation-indicator system, which is in widespread use in the UK. That involves wearing a green coloured glove underneath and a beige glove on top. If you have a perforation in your outside glove, fluid from the surgical site will leak in through the hole and a green hole will stand out very brightly against a beige background. The perforation-indicator system doesn't offer additional protection but it does make you aware of a perforation.
"The normal awareness for identifying a hole is 25%. By wearing perforation-indicator gloves, your awareness increases to 75%. So you're three times more likely to spot a hole."
For now, double-gloving is not widespread. Concerns still remain over the sensitivity issues encountered, particularly in delicate operations, and many surgeons performing low-risk procedures in low-risk situations feel that it may be unnecessary. However, in high-risk areas such as part of Africa, where transmission of diseases such as HIV through a surgical incident is high, double-gloving is seeing increasingly further adoption.
As materials become more developed and newer technologies meet the healthcare market, the practice may become more standard, to the benefit of doctors and patients alike.