Healthcare staff come into the professions, in general, to help others. It is a sad fact that sometimes, in the course of their work, they are themselves put at risk of harm. Some are threatened or injured by violent patients but a much more insidious risk is that of damage from the products or substances that they handle. Over the past 15 years there has been a growing understanding of the risks posed by cytotoxic drugs and there have been a number of revisions of guidance on good practice in this field.
In this issue we carry two articles about topics that are closely related to this – one concerns the testing of protective gloves (see page 59) and the other concerns a number of issues relating to the handling of cytotoxic drugs, including evidence of chromosomal damage in healthcare personnel who handle cytotoxic drugs (see page 22).
In October 2010 a cohort study was published that reported the occurrence of abnormalities in chromosomes 5 and 7 in nurses, pharmacists and pharmacy technicians who routinely handled cytotoxic drugs. These specific abnormalities are of interest because they are the same as those that are seen in patients who are treated with anti-cancer agents and who subsequently develop treatment-related myelodysplastic syndrome and treatment-related acute myeloid leukaemia. In many ways, this was the missing piece in the jigsaw – the risk of carcinogenesis was postulated in the past, now we have the nearest piece of evidence yet to confirming the link.
The highest risk was shown with alkylating agents, but this is not surprising as alkylating agents made up a far larger proportion of the materials handled than did other types of cytotoxic agent.
It is perhaps most salutary to note that the study was conducted in institutions that reported full compliance with up-to-date safe-handling guidelines. And yet, despite these measures, biologically important exposure to genotoxic agents was occurring.
These findings serve to underline the importance of adherence to validated safehandling guidelines including both measures to minimise the risk of drug leakage (such as containment devices) and measures to protect staff from contact with the drugs (such as protective clothing).
One key protective measure is the use of gloves during manipulation or administration of cytotoxic drugs. Current guidelines recommend changing of gloves every 30 minutes to minimise the risk of dermal exposure resulting from drug permeation of the glove material. However, studies conducted in Belgium have shown that gloves differ in their permeability characteristics (see page 59). All protective gloves have to conform to international permeation-testing standards, but this is not a reliable safety net because there are several different standards in use in Europe and the USA. Only one of these standards specifies permeation by chemotherapy drugs and this may have critical shortcomings in that it does not reflect the ways in which the glove are used in healthcare practice. Clearly, one of the things we might usefully do is to demand a new, meaningful standard for permeability of gloves to cytotoxic drugs.
Hazardous substances will not go away but as our understanding increases, we have the opportunity to manage occupational exposure more effectively – it should not be missed.