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Published on 18 September 2008

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Safety and hygiene aspects of contrast media administration in Germany

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A roundtable discussion held in Berlin concluded that an economic evaluation of prefilled syringes of contrast media taking into account time savings and costs of treating infections is needed

Christine Clark

PhD

Contributing Editor
HPE

Hospital Pharmacy Europe recently hosted a roundtable discussion in Berlin to review the safety and hygiene aspects of contrast media administration in Germany. The discussion involved a multidisciplinary panel of leading pharmacists, microbiologists and radiology staff. Topics included pharmacovigilance, microbiological considerations, and a review
of the potential advantages and disadvantages of prefilled
contrast media syringes in the German healthcare system. There was also a demonstration of the Covidien injector system, which uses prefilled syringes.

In Germany, a number of pharmaceutical and medical organisations are involved in pharmacovigilance at national level, explained Martin Hug (Pharmacy Department, University Hospital, Freiburg, Germany). In Freiburg the pharmacy department is at the centre of a local pharmacovigilance network that is strongly focused on risk minimisation. The network collects reports of adverse reactions and incidents.

A 2005 study of medication errors in intravenous drug preparation reported that the most common errors in German hospitals were selection of the incorrect diluents and failure to mix properly. However, one memorable incident showed that even correct selection and mixing does not always guarantee success. A batch of 0.9% saline injection turned out to have a pH value of 10, instead of the usual value of 7. When used to
reconstitute clarithromycin, the alkalinity was such that the antibiotic rapidly precipitated, making the solution cloudy.

One of the most common questions for the pharmacy is about compatibility of intravenous drugs when more than one product is mixed together. This issue is rarely raised in relation to contrast media, although there is an incredibly large number of contrast media that are not compatible with medicines, noted Dr Hug. The multidose systems for contrast media that are most commonly used in Germany comprise a multidose bottle of contrast media, a bag or bottle of saline, and injector equipment that automatically fills the syringes as required. The “stock bottles” can hang for up to a day before being replaced. A three-way tap links the loaded syringes with the administration tube leading to the patient. Retrograde flow is prevented by a nonreturn valve. The administration tube is changed for each
patient, but the other tubing and connectors remain in place for the day.

In Freiburg, more than half the contrast media were used in 100–200 ml volumes. However, the most common pack sizes were 50 ml and 30 ml.

Concerning patient safety, a relatively new feature in the German healthcare arena is the Patient Safety Campaign Alliance (Aktionsbuendis Patientensicherheit). There are similar bodies in other European countries concerned with collecting information about adverse incidents and near misses. “We need to build a reporting culture in Germany,” said Dr Hug. However, he said that there are practical problems – doctors are reluctant
to make reports because of the paperwork.

In discussion, participants pointed out that the system described is susceptible to bacterial contamination because of frequent handling of connections. The risks are increased by the long hang-time that is permitted for the saline solution – this is a maximum of eight hours in Freiburg, but in other hospitals it varies between two hours and 24 hours. Another possible route of contamination is air vents that do not have filters. The reliability of the non-return valve was also questioned; if it fails there is a possibility that blood-borne contaminants could be
transmitted from one patient to the next.

Prefilled syringes of contrast media are much easier to use and have many other advantages, according to Ines Freude (head radiography technician, Traunstein Hospital, Germany). In her department, 40–50 CT scans are performed daily, and prefilled syringes (Opti-Ray; Covidien) have now been in use for some time. Fresh syringes and tubing are used for each patient. The system is closed, and container sizes are selected to minimise wastage. The use of the prefilled syringes has made workflow more efficient, and she estimates that a time-saving equivalent to one technician has been made. Staffing has not been reduced, but there is more flexibility, and technicians have more time with patients, providing explanations and putting them at ease.

Ms Freude demonstrated the setup procedure for the OptiVantage CT injector system and explained that the system had been easy for staff of all ages – “from 22 to 60 years of age” – to put into operation. “At first we had a poster on the wall, but everyone learned the routine quickly and they keep to it no matter whether it is three o’clock in the morning or four o’clock in the afternoon. It is simple and much easier than drawing up syringes as we did before,” she said.

Participants queried the 125ml maximum volume that this system can deliver. Some large patients need 180ml of contrast medium for liver imaging. Contrast media are now relatively cheap, but the packaging can be expensive. The costs of a prefilled syringe system need to be balanced against potential time savings and reduced infection risks.

Multidose vials are a source of infection control problems, and there is ample evidence in the literature to show this, Markus Dettenkofer (Institute for Environmental Medicine and Hospital Hygiene, University Hospital, Freiburg, Germany) explained to the group.

Infections have been traced to contaminated injection products: in one case, a three-year-old girl died after receiving an injection of bacterially contaminated anaesthetic. The product was designed for single use. Another report concerned an outbreak of septicaemia in surgical outpatients caused by intravenous propofol infusion contaminated with Enterobacter cloacae.

“We can conclude from these episodes that we must undertake hand disinfection – the single most important infection control measure,” said Professor Dettenkofer. “It is important to use 5ml of hand-sanitising product and rub for five minutes,” he added.

Handwashing can create more problems than hand sanitisation with disinfectant (alcohol) rubs, and so the latter method is preferred. When it comes to surface disinfection, there is no point in swabbing surfaces with 70% alcohol three times a day – one hour later surfaces are contaminated again. Sterile gloves must also be used correctly – they should be changed when
each patient episode is finished, and care must be taken not to spread infection through careless handling techniques.

Turning to X-ray contrast media administration systems, he warned that “a non-return valve and long tubing do not constitute a reliable barrier against infection”.

Infections have been traced to contaminated X-ray contrast media: in a German hospital two patients died from Pseudomonas aeruginosa meningitis as a result of receiving contaminated X-ray contrast medium. The source of infection was found to be a contaminated vial that was used over a period of eight days.

A subsequent study of 227 multidose vials found that 114 (50%) were labelled with the date/time of opening, but 15 had already passed their expiry time; only 44 (19%) were stored in a fridge.

The probability of infection is small but depends on the level of contamination and the immune status of the patient. Interestingly, surveillance studies show that there are quite a number of unexplained fevers, especially in intensive care areas.

A systematic review of 128 reports of hospital acquired infections (HAIs) showed that in 64 cases products had been used for multiple doses contrary to the manufacturer’s instructions. The authors of this review concluded that the majority of medication-related HAIs could have been prevented by the use of singledose vials. A multidose vial must contain a preservative, otherwise it is a single-dose product, Professor
Dettenkofer reminded the group.

The preparation of two injections at the same time to avoid re-use of a single-dose vial is not a satisfactory solution because the second injection could be left sitting around for some time. Single-use or prefilled products are always the better option.

Reports of blood-borne infections related to contaminated
catheters and contrast media underline the risks associated with some equipment and procedures. One report concerned an outbreak of malaria associated with contaminated catheters and CT contrast medium.

A report from Spain in 2005 illustrated the importance of single-use equipment. Four patients developed hepatitis C after undergoing CT scans with injections of contrast medium. An anonymous commentator had said, “We do not change the syringes of the injector or the antireflux valves for each patient – just the catheter that goes directly to the patient.”

In conclusion, Professor Dettenkofer drew attention
to two points in a chapter in a recent book on hospital
hygiene concerning the use of injectors and contrast
media for multiple patients:

  • The use of the infusion system for several patients in a row cannot, in general, be relied upon from the hospital hygiene point of view without validation from the manufacturer.
  • The current system (perfusor and tubing with antireflux valves) needs to be monitored to ensure that there is no possibility of back-diffusion of small particles.

Frauke Mattner (Institute for Medical Microbiology and Hygiene, Luebeck, Germany) has recently conducted an observational study on the use of contrast media in her hospital. The results show that hand hygiene was generally poor, contrast media were drawn up from open bottles, the ends of lines were left uncovered, and on one occasion a line was primed over an open rubbish bin.

Reviewing the potential advantages and disadvantages
of prefilled contrast media syringes, Irene Krämer (director of pharmacy, Johannes Gutenberg University Hospital, Mainz, Germany) said that issues of practicality and cost had to be considered.

Labelling of prepared injections is important so that they can be easily identified, and, in practice, prepared syringes of contrast media are often unlabelled. One option is to have prepared labels that only need have a few details added, she suggested.

Potential “dose-failure” with the existing systems should be taken into account. Underdosing would result in poor or non-existent images, but the patient would need to be re-X-rayed and could end up receiving more radiation than was necessary.

More procedures can be carried out in the same time period when using prefilled syringes of contrast media, and so efficiency is increased. This is an important consideration for hospitals such as the university hospital in Mainz, which has four CT scanners.

However, the accessories for prefilled syringe systems are expensive, and the overall cost-effectiveness of the product has to be considered. Linkage of the equipment to specific contrast media products would be a drawback. If a hospital is restricted to using only one company’s contrast media, then it loses the opportunity to negotiate good prices on the contrast media of
its choice. This is not a problem with the Covidien injector
systems, as they can be configured to use either prefilled Covidien products or others (using empty syringes).

These systems require preloaded syringes of sodium chloride, which can be bulky – there may not always be enough room to store these. In Professor Krämer’s experience, ready-to-use systems always require more storage space, although some participants felt that this system actually requires less storage space than conventional systems.

The disposal of waste is an important issue for hospitals today. Clear information on disposal requirements is needed for the used syringes and tubes.

Finally, participants agreed that there could be benefits
to staff through increased job satisfaction – a finding
mentioned in a report from the USA. They also agreed:

Microbiological risks
There are potential microbiological risks associated with the multidose systems currently the most commonly used systems in Germany. The risks are variable, depending partly on the hang-time that is permitted, particularly for saline, ranging from two hours to 48 hours.

The following recommendations were agreed:

  • For each patient there should be an individual system – re-use of tubing and syringes should not occur.
  • Open systems for injection preparation should not be used.
  • Prefilled syringes should be part of the solution.
  • Any safety measures must consider the hang-time of both the contrast medium and the saline.
  • Intensive education of all staff involved in handling intravenous injections about hygiene measures – especially hand hygiene (including hand disinfection and correct use of gloves) – needs to be put in place. Regular reinforcement is important because of staff turnover and the tendency for good habits to be forgotten over time.
  • The feasibility of including an inline bacterial filter for administration of contrast media should be explored.

Labelling
Labelling of prepared contrast media is not believed to be a major problem. It is important to label products with the time and date of opening to avoid the risk of use beyond recommended expiry times.

Barcoding of products would be useful, but to fit with current working practices this would need to be on the outer packing, not on the syringes themselves. RFID would offer further advantages.

Use of prefilled syringes of contrast media
The main advantages are that it reduces hygiene problems and could increase efficiency in some departments, depending on workload and current working practices. Costs and the maximum fill volume of 125ml were seen to be the main disadvantages.

The group recommended that an economic evaluation should be undertaken to compare the use of prefilled syringes of contrast media with the most widely used system in Germany (which relies on the filling of syringes from multidose vials and bags). The analysis should take into account the costs of treating occasional episodes of sepsis and the potential time savings.

Quality management
Quality management measures, such as the introduction
of standard operating procedures in radiology departments,
could help to improve the safe use of injectable contrast media.



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