Cold chain storage – the link to wider public health

In an interview back in October 2013 Professor Steve Field, Chief Inspector of General Practice at the Care Quality Commission highlighted the problems caused by inadequate medicines management and how this could have extremely serious implications for patient and public health. Professor Field was quoted by The Guardian as stating that patients who received vaccine that was out of date or stored badly could become ‘very, very poorly and then die’, and added ‘That could affect many hundreds of patients in single surgeries. If they’ve not tracked it for years, that’s a major problem. You’re talking about problems which can damage this generation and the next generation’.

There is currently anxiety about a measles outbreak in the south east of England and a study led by researchers at Emory University in Atlanta suggests that the recent outbreaks of measles and whooping cough in the USA, including the well publicised one at Disneyland, could have been the result of vaccine ‘refusers’. Furthermore, not only did these people get ill themselves, they caused pockets of ‘disease susceptibility that caused others to fall ill’.

These ‘refusers’ have consciously decided not to get vaccinated, so it is probably not surprising that they get ill. Although vaccines do not offer complete protection a child is 35 times more likely to get measles if not vaccinated, but in order to work that vaccine has to be live a the point of delivery but correct refrigerated storage is of extreme importance all the way along the supply chain.

The state of healthcare and adult social care in England 2011/2012, by the Care Quality Commission claimed that the ‘management of medicines was the single most common reason for providers across all care sectors in failing to meet all the essential standards’ and one of the three main reasons for this was ‘inappropriate storage facilities’ including the ‘lack of provision to store medicines within the correct temperature range’(p53).

Medicines cost the NHS billions of pounds every year and are a significant part of the overall budget. Vaccine programs also play an important role in public health as 2013’s Swansea measles outbreak and the research from the USA has shown. It is therefore vital that everything is done to maintain vaccine integrity, especially storage at the correct temperature.

All medicines have a manufacturers’ summary of product characteristics. This states at what temperature the product must be kept to ensure efficacy. In the case of most vaccines this is 2°C to 8°C. The DH Green Book Chapter 3 guidelines state that products like this should be kept in specialist pharmacy refrigerators because not only do they have tighter temperature tolerances when compared to domestic models, but they also come with a range of features designed to help health professionals and pharmacists manage the fridge efficiently.

The first thing professional pharmacy fridges are good at is maintaining their set point temperature and ensuring that temperature recovery is as quick as possible. This is why they are fitted with internal fans to ensure forced airflow through the cabinet. Internal temperature fluctuations can be caused by door openings or adding new stock so this is a vital feature. They also need to be fitted with an external temperature display. This should show the air temperature because if there is an issue in the fridge the air temperature will be the first to react. Load temperatures are slower to react as they are buffered to simulate the product, but by the time the load alarm is activated the user has no time to try to sort the problem before they need to move the product. The load probe is sometimes located in a bottle that may or may not be the size of the vaccine and placed on the side of the fridge. However, most of the product is actually located in the middle of the fridge where it is insulated by product so will be warmer that this bottle. This is why the MHRA advise that load temperature probes in wholesale pharmacies are put with the product in the centre of the fridge. In addition, the MHRA has recently said in response to a question on its blog in reference to wholesale pharmacy regulations that ‘any use of a liquid to simulate the load of the refrigerator rather than monitor air temperature should be supported by a risk assessment’, so while wholesale pharmacies have to record the load temperature, for peace of mind the one you want to display and for the fridge to alarm on is the air temperature.

Talking of alarms, professional pharmacy fridges are fitted with high and low temperature alarms. Most also have a door open alarm and the Labcold IntelliCold© range comes with alarm battery back up, so they will alarm if they experience a mains failure. They also record the minimum and maximum temperature and will hold this value until reset. Both in a healthcare and wholesale setting this has to be recorded on a daily basis, however, the Labcold IntelliCold© range records temperature data 24/7, automatically. This data can be transferred to a PC for permanent storage. In Scotland for example, pharmacy refrigerator temperature logs have to be stored for a number of years and many trusts want them kept for a few months at least, so not only is this an objective recording of temperatures it is convenient to store and easy to locate should it be required.

Externally pharmacy fridges are usually fitted with a lock and for extra security Labcold can offer customers the choice of a digital lock. A digital lock is a good way to control access as most manufacturers pharmacy refrigerators can all be opened with a generic key. Digital locks mean that access can be restricted to those who have the code only and can be changed when teams change to keep the contents secure.

All pharmacy refrigerators should be calibrated. There is no point in having a temperature display if it is not showing the temperature inside the fridge. This is recommended by the DH Green Book and the MHRA requires wholesale pharmacies to use calibrated temperature probes. Although not stated in the regulations, it makes sense to have these calibrated by a UKAS calibration lab so you can be sure that everything is in order and everything is traceable. Pharmaceuticals are expensive and a failure in documentation could be costly.

Amazingly, there is no standard for a professional pharmacy refrigerators, the advice is just that domestic refrigerators should not be used. However, pharmacy fridges are an important part of the cold chain all the way from development to testing, manufacture and wholesaling to dispensing. Choosing the right one and ensuring it is monitored and calibrated to UKAS standards will protect the viability of the contents. As Professor Field argued in primary care, any prolonged temperature incursion anywhere along the cold chain could have profound health implications, possibly for generations to come.