Laurence A Goldberg
HPE Editorial Consultant
Traditionally, intravenous doses have been prepared using syringe and needle systems. However, these expose healthcare personnel to the risks of accidental exposure to the drug and to the risk of needlestick injury.
Cytotoxic drugs: detection and protection
Cytotoxic drugs are highly reactive compounds that can cause irritation to the skin, eyes and mucous membranes. They are also carcinogenic. As a result, they are a cause for concern to regulatory bodies in many countries, explained Olle Nygren (Swedish National Institute for Working Life).
Some people are exposed directly to cytotoxic drugs, but many more are exposed indirectly through contact with contaminated equipment or packaging, patients’ excretions or garbage and laundry. In these situations, cytotoxic drugs can enter the body through the airways and the skin.
Pharmacy staff can be exposed to cytotoxic drugs when handling vials, during preparation of doses, handling of the finished product and whilst cleaning the working areas.
In recent years a number of sensitive test methods have been developed to detect spills and leakage. Radiolabelled technetium ((99m)Tc) can be used to detect leakage during a specific procedure. This method can detect leak volumes as small as 1 nanolitre/cm(2). Fluorescein can be used in a similar way. In this case, leakages fluoresce under ultraviolet light. The method is only semiquantitative, but it is useful for showing the extent of leakage or spillage. Surface contamination with cyclophosphamide, ifosfamide and 5-fluorouracil can be measured directly during routine working. The urine of staff can also be monitored for these products.
In many countries, cylophosphamide, ifosfamide and 5-fluorouracil have been detected inside and outside biological safety cabinets and also in the urine of staff. Cytotoxic drugs have been found on the exterior surfaces of drug vials. Elevated plasma platinum levels have been found in staff who handle cisplatin. In the Netherlands, an increase in the frequency of low-birthweight babies has been reported amongst people who handle cytotoxic drugs.
Cylophosphamide in the gas phase has a high affinity for surfaces, and for this reason it is not detected in air but is found on surfaces. Gloves are worn during the preparation of cytotoxic injections, and some will resist penetration for longer than others, but most will eventually be penetrated. If spills occur, gloves should be changed and hands washed immediately.
All groups of staff who are potentially exposed to cytotoxic drugs should be given adequate information on how to protect themselves. This is particularly important for stores personnel and cleaners, said Dr Nygren. Standard operating procedures help to reduce the risk of exposure, he added.
Cleaning and maintenance of the biological safety cabinets are essential. Most cleaning procedures have been designed with microbial contamination in mind and therefore specify cleaning from the preparation point outwards. For cytotoxic protection, the cleaning process should work from the outside towards the preparation point. The two techniques need to be combined in order to avoid spreading the drugs further. Cleaning staff usually just spread drugs around and so they need to be taught correctly.
When incidents occur, there must be a routine procedure to follow. Spills should be removed immediately to avoid the possibility of vaporisation, and the spill area should be washed several times. Clothes should be discarded, and the workers should shower to decontaminate themselves.
Approximately one million needlestick injuries occur in the EU each year, according to Albert Scius (Eucomed Eliminating Sharps Injuries Task Force). Even the tiniest drop of AIDS-infected blood from the smallest gauge needle contains about 100 times the amount required for seroconversion, he continued. In the UK, four healthcare workers have died as a result of AIDS contracted through needlestick injuries, and a further nine are living with the condition. In France, 52 people have developed hepatitis C as a result of needlestick injuries or blood splashes.
Bloodborne infection can also be passed from healthcare worker to patient, explained Mr Scius. Both AIDS and hepatitis C have been passed from surgeons to patients, and the problem of how to handle healthcare workers who have undergone seroconversion has not yet been solved.
In Europe, annual needlestick injury rates are 6.5–13 per 100 healthcare workers, or 12–30 per bed. The lowest rates occur in countries where drastic countermeasures have been taken. However, the reported injury rates are likely to be gross underestimates; surveys have shown that 60–80% of needlestick injuries go unreported.
Some devices are more likely to cause injury than others. Butterfly needles are the leading cause of needlestick injuries. Suture needles are less risky because they only have blood on the surface and much of this is likely to be removed when the needle pierces the glove. About 36% of injuries occur when the needle is in use, but 10% occur when putting the needle into the sharps disposal container. It is essential to have a procedure that specifies when a sharps container should be removed, as these are almost universally overfilled, and injuries often occur when trying to cram one more device into the container.
The consequences of needlestick injury can be grave – discovering that you are seropositive changes your life beyond recognition, said Mr Scius. Of those who are able to take postexposure prophylaxis in the golden hours after the incident, 80% will stop the treatment due to side-effects and in 10% it will not work, he noted.
The frequency of needlestick injuries can be reduced considerably through a combination of good practice and safe devices. Appropriate training and the creation of a safety culture are key steps in the process. Just doing the job better can reduce accident rates by up to 59%.The introduction of safety devices combined with monitoring of progress can reduce accident rates by 84–100%. Regular monitoring and feedback of results is vital to maintain interest and enthusiasm. Safety initiatives of this type could have a considerable impact. The avoidable costs of injury to healthcare workers combined with the costs of tracing patients who might have been infected by seropositive healthcare workers add up to large sums. It has been estimated that, in the UK, the National Health Service could save £280 million per annum. In Germany a 1,000-bed hospital could save €21,000 per annum, and liability insurance in Italy could be reduced by 5%. “Safety will be a good investment for you,” concluded Mr Scius.
In the handling of hazardous drugs, as in other areas of life, we should incorporate design features that prevent errors, said Rients Schootstra (Hospital Pharmacy Zorggroep Noordebreedte, Leeuwarden, The Netherlands). In his hospital, 20,000 cytotoxic doses are prepared each year. He is now planning to introduce the Tevadaptor to minimise the risk of exposure to cytotoxic drugs and to eliminate the risk of needlestick injuries during the compounding and administration of these products. The Tevadaptor conforms to the National Institute for Occupational Safety and Health (NIOSH) definition of a closed- system drug transfer device – that is, one that “mechanically prevents the escape of hazardous drug solution or vapour and the entry of environmental contaminants”, he explained.
Swedish National Institute for Working Life
National Institute for Occupational Safety and Health (NIOSH) W:www.cdc.gov/niosh/homepage.html