The amount of aero-allergens in areas where powdered gloves are worn can increase 5-10 fold when compared to those where only powder-free gloves are used.
Glove manufacturing has changed dramatically in the last 20 years with the advent of powder free gloves technology. This technology was developed due to the issues arising with the use of powder in gloves as well as the changing needs of the end-users such as the need for double gloving and intra-operative donning.
Powder free gloves are seen by many as a more expensive choice than powdered gloves. However, this is not true when the need for washing powdered gloves prior to use is considered. The US Food and Drug Administration made mandatory for manufacturers to place a warning label on the glove packaging to indicate the need for washing off the glove powder. Unfortunately, studies have shown that washing of powdered gloves prior to use is inefficient in totally removing glove powder and can lead to clumping of the powder particles, creating even less absorbable aggregates1. It has also been reported that the cost of washing powdered gloves can be at least seven times higher than the cost of using powder free gloves .
Unfortunately, some surgeons do not wash powdered gloves prior to use, which can lead to complications. Exposure to starch powder from both surgical and examination gloves can cause a number of undesirable reactions for both patients and the healthcare workers, which vary from well-known allergy symptoms and upper respiratory-tract disorders to adhesions, granulomas, pleuritis, myocarditis, irritation of the central nervous system or even carcinoma or tuberculosis misdiagnosis1 2 3. These complications can lead to an increase of the hospitalisation time or even require extra surgery4.
A well documented consequence of the use of starch powder in gloves is its capacity to bind with natural rubber latex (NRL) protein antigens. These allergen/protein coated powder particles can be aerosolised when the gloves are donned or removed, thus hospital environment. Inhalation or ingestion of these powders can lead to sensitisation and many diverse allergic reactions to NRL (e.g. upper respiratory tract symptoms or eye irritation). It is estimated that the use of powdered gloves within a theatre will deposit in excess of 2kg of glove powder within the theatre environment per year. The amount of these aero-allergens in areas where powdered gloves are worn can increase 5-10 fold when compared to those where only powder-free gloves are used. However, glove powder acts not only as a vehicle for NRL antigens but can also be a vehicle for opportunistic and pathogenic micro-organisms, which increases the occupational risks to both healthcare workers and patients.
Another common problem that can arise from the use of starch glove powder is the development of adhesions, which are likely to occur after most surgical procedures and granulomas4. These effects have been very well documented concerning the peritoneal cavity, but they have also been reported in almost every anatomical site including the oral region. Despite glove washing with saline, the glove powder can enter the body during surgery5, which may trigger an inflammatory response by the immune system, leading to the formation of fibrous bands and post-operative adhesions. Adhesions are the major cause of post-operative intestinal obstruction (more than 40 per cent of all causes with 60-70 per cent of cases involving the small bowel). Uterine and fallopian tube adhesions, resulting from glove powder, are a significant risk to female fertility, with papers advising that powder free gloves should be used even for routine vaginal examination. Analysis of adhesions occurrence showed that between 69-93%, were due to foreign micro-bodies, which include starch powder6.
Researchers have also shown powdered gloves to be a risk factor for post-operative wound infections. As with most foreign bodies, glove powder decreases the inoculum of bacteria required to produce abscesses, being reduced in this case by a factor of at least 10 fold7. In addition, powder also delays wound healing and alters the normal reparative process while at the same time increasing the wound’s inflammatory response8. Surgical Site Infections (SSI) are the second most common cause of hospital-associated infections, with studies showing that compared to similar risk patients undergoing the same surgery, a patient who develops a SSI is twice as likely to die, 5-6 times more likely to require re-admission, and likely to stay in the hospital twice as long. For major orthopedic or cardiac surgery, the costs of these complications may range from US$ 30,000-US$ 50,0009.
All these problems, together with the lack of an efficient removal of the glove powder by means of washing, prompted the development and adoption of new powder free technologies.
Chlorinated powder free gloves
The first generation of powder free gloves were the double-sided chlorinated gloves, where both the inside and outside surfaces are chlorinated. Untreated latex gloves (both NRL and synthetic latex), are too tacky to be donned without any further treatment, therefore a surface treatment is required if the powder, which acts as a lubricant is removed. The first powder free gloves were treated with a chlorine solution which modifies the surface texture and reduces the natural tackiness. However, over chlorination can deteriorate the gloves and can affect the grip properties during use. As such the chlorination process has to be optimised and controlled with great care.
There are two main methods of chlorination: “Batch Chlorination” and “Piece by Piece Chlorination”. Batch chlorination is more economical, however it will produce a product with more grip variability as the chlorine contact with each of the glove cannot be controlled as precisely. On the other hand, piece by piece chlorination is more precise as it ensures glove chlorine contact equally on all the glove surface for a predetermined amount of time, ensuring a more reproducible result and less variability amongst batches or even gloves within a same batch.
Polymer coating powder free gloves
Another alternative to powdered gloves is a NRL glove having a synthetic polymer lining on the internal surface of the glove. The slippery surface of such a lining facilitates donning of the glove. Due to its low coefficient of friction, the lining facilitates donning with either damp or dry hands.
This is the technology used in the Gammex Powder Free family of products, which uses a hydrophobic/hydrophilic polymer lining in order to ensure improved donning qualities and undergoes external carousel chlorination to guarantee a consistent grip.
Recent advances in NRL manufacture
Manufacturers of NRL medical gloves have also investigated and implemented manufacturing processes to reduce the NRL protein allergen and chemical accelerators content of their products.
Some manufacturers have developed leaching/washing processes either on-line or in the post processing of the gloves, which reduce the NRL protein allergen content of the gloves.
The on-line leaching process reduces the protein allergen content considerably, however, the leaching only occurs from one side of the film. In order to ensure a more complete reduction of the extractable proteins, Ansell uses a unique high temperature post-washing process called P.E.A.R.L (Protein and Endogenous Allergen Reduction Leaching Process). This process can eliminate more of the extractable proteins as both sides of the film are exposed to the cleaning process. The hot water also hydrates the rubber film and as the film’s intersticial spaces are enlarged the allergens are easily extracted. As a result, the final film has a lower protein allergen content than the film formed using other processes such as ‘de-proteinised’ natural rubber latex.
Ansell’s P.E.A.R.L. process not only reduces the extractable proteins levels but also decreases the chemical residues, another cause of contact dermatitis. This is an area where manufacturers have focused their efforts not only to develop processes aimed at decreasing the overall content of accelerator residues, but also developing new processes aimed at eliminating the use of some accelerators, such as thiurams, which is the accelerator most frequently linked to contact dermatitis. Ansell, not only has discontinued the use of Thiurams in its powder free range, but it has also developed alternative options for healthcare workers suffering from accelerators sensitivity, such as the use of PV100, an accelerator that becomes volatile gases completely consumed during vulcanisation therefore minimising the risks of contact dermatitis and the complete elimination of accelerators in Ansell’s DermaPrene Ultra, a neoprene latex free glove.
Powder free gloves are a more cost effective and safer alternative to powdered gloves. Today’s manufacturing technology ensures powder free options with similar comfort, donnability, tactile properties and grip than the powder equivalent but with the advantage of less post-operative complication and allergy problems.
1U.S. Food and Drug Administration. Centre for Devices and Radiological Health. Medical Glove Powder Report. 1997. http://www.fda.gov/cdrh/glvpwd.html
2Moriber-Katz, S. et al. Contamination of perfused donor kidneys by starch from surgical gloves. Am. J. Clin. Pathol.1998; vol. 90(1):81-84.
3Edelstam, J. et al. glove powder in the hospital environment- consequences for healthcare workers. Int. Arch. Environ. Health 2002; vol. 75:267-271.
4Sjosten, A.C.E. et al. Post-operative consequences of glove powder used pre-operatively in the vagina in the rabbit model. Human Reproduction. 2000; vol. 15:1573-1577.
5Hunt, T.K. et al. Starch powder contamination of surgical wounds. Arch. Surg. 1994; vol 129(8):825-827.
6Duron, J.J. et al. Post-operative peritoneal adhesions and foreign bodies. Eur. J. Surg. Suppl. 1997; vol. 579:15-16.
7Emerson, M. Chairman’s conclusions. Eur J Surg. 1997.
8Odum, B.C. et al. Influence of absorbable dusting powders on wound infection. J. Emerg. Med. 1998; vol. 16(6):875-9.
9The American Health Quality Association. Many Hospitals Show Gains Fighting Surgical Infections. 2005.