Laboratory Management: Monitoring the cold chain

Given the potentially massive movement of vaccines around the globe in 2021, this means interest in temperature monitoring systems is increasing exponentially and exciting new developments in ‘in transit’ monitoring options will undoubtedly play a role in the months to come. Of course, the benefits of these technological developments will expand to include not just human health products but also veterinary medicines, pharmaceutical products, tissue samples and blood and plasma products.

The financial benefits of maintaining the cold chain correctly are significant. A country level World Health Organization report (www.who.int/vaccines-documents/) estimates worldwide vaccine wastage at an astonishing 50%. Although some of the wastage is attributed to breakage, missing inventory and theft, the report attributes the majority of wastage in unopened vials to cold chain and stock management problems which can therefore be minimised.

Maintaining the cold chain is dependent upon cooperation between manufacturers, distributors and retailers in order to retain the stability and efficiency of the products

Regulations require regular recording

It is true that different drugs, medicines and other biologics have different attributes, but all need to be maintained within a temperature range as defined by their manufacturer and many are subject to requirements and regulations which also demand an accurate audit trail.

Maintaining the cold chain is dependent upon cooperation between manufacturers, distributors and retailers in order to retain the stability and efficiency of the products. Unfortunately, experience shows that this can still be a somewhat haphazard process.

Regulatory requirements place a considerable burden on individual organisations and businesses, most commonly necessitating the collection and recording of temperature information from refrigerators several times a day.

This has led to loopholes in the process. Where manual systems are used, typically these processes simply don’t happen outside working hours. They are time consuming, subject to human error and not produced in a format that can be manipulated to meet regulatory requirements. They cost both time and money and do not include an ability to raise the alarm in the event of failure.

More and more, regulatory bodies and businesses are looking at how technology can provide a more reliable solution.

Temperature control of drugs and biologics

The temperature control of drugs and other products can be divided into three key areas:

1. Product manufacture
2. Transport from manufacturer to distributor, and from there on to point of use
3. Storage at point of use

At the product manufacturing stage, manufacturers who have specified correct storage temperatures will ensure the products remain within these limitations.

During the logistics and transportation stage, monitoring becomes a more challenging issue subject to a variety of potential complications and problems – all of which can be overcome by a reliable online monitoring system.

Once at the point of use, products are typically subject to a variety of monitoring systems, which may be manual or varying degrees of electronic.

These staged solutions can be identified as follows:

• Manual/paper-based recording systems
• Fridges with a temperature display and audible alarm in the event of over/under temperature
• Simple dataloggers
• Dataloggers with an ability to report via the internet
• Online monitoring systems cloud data storage and real time alarm capacity

To achieve the best, most reliable results, anything that involves manual checks and recording should ideally be rejected. It is not the route to precise data, is subject to human error, is time consuming and yields a poor audit trail.

Minimising human error

Sadly, the most common faults are caused by users failing to close the fridge door properly, by fridge temperatures accidentally set too high or too low, or by staff inadvertently disconnecting equipment.

There is very real potential for sensor-led technologies to make a massive contribution to the correct and safe storage of medicines.

A good online monitoring system will immediately alert on the resultant temperature fluctuations, eliminating the potential for stock losses or, even more damaging, causing products to lose some of their efficacy. An online system with its own database will provide continuous, accurate data, usually accessible via a clear dashboard and the ability to produce tailored reports, together with a totally accurate audit trail in line with regulatory requirements. Another significant benefit of online monitoring is to allow users to see patterns emerging which enable processes to be improved, such as fridges turned up too high or going over/under temperature regularly.

Any powered system will have a clear Achilles heel if it relies on a local power supply, Wi-Fi or Ethernet connection

But beware internet dropout

Any powered system will have a clear Achilles heel if it relies on a local power supply, Wi-Fi or Ethernet connection. If you’re opting for an online monitoring system, you should examine the potential for more resilient systems.

Wi-Fi reliant options may mean that you lose all relevant data completely. Some systems may save data for when you’re back online again, which means that you can still access data and make informed decisions based on this data, but they will not alert users in real time to a power failure and allow them to take corrective action before valuable stock is lost or damaged. The consequences are often not just financial but also disruptive. Take as a simple example a school vaccination programme, with teams in place to deliver shots, all cancelled due to non-availability of the essential vaccines due to an overnight power failure and equipment outage.

Some of the best solutions, such as Remote Monitoring’s RemoteM solution, provide a stand-alone configuration, consisting of a base station and small wireless sensors placed in each fridge. These systems will continue to operate irrespective of whether issues are caused by a fridge failure, power circuit or utility outage. (You could argue that the most robust solution sees the node communicating directly to the cloud.)

Typically, these wireless, battery-powered and retrofit options are easy and quick to self-install and use network resilient SIMs on the mobile network, removing reliance on internet and local power availability, connecting automatically to the strongest network in the area.

They can provide real time customised reporting, alarming to one or multiple recipients, using email, automated voice calls or SMS, ensuring that corrective action can be taken before any losses are incurred. Notably, the systems can be set to many different parameters and are equally effective in monitoring temperatures in freezers or ambient temperatures in storage cupboards.

When developing our system, the key objective was to use sensor technology to provide a solution capable of not just recording and monitoring but also playing a role in alerting in the event of temperature excursions. Coupled with this, the system provides a reliable audit trail to demonstrate that drugs and other temperature sensitive products are and have been kept at within the correct storage temperature ranges.

‘In transit’ real time temperature monitoring

Recent developments include a new ‘in transit’ option, using either a simple transportable node to log temperatures and upload back at base, or a ‘real time’ in transit monitoring solution, involving a battery-powered base station and temperature monitoring nodes. Subject to cellular coverage (now over 95% of the UK landmass) this product uploads temperature storage data regularly over each 24-hour period and will alert in real time if products are being stored at incorrect temperatures.

The systems are designed to provide a complete and accurate picture of the storage of medicines, whenever and wherever it may be.

Monitoring outside a healthcare infrastructure

The most pressing challenge is undoubtedly the scale of the proposed vaccination programme, already acknowledged in the UK as one of the greatest civilian projects the country has ever faced.

If this project is daunting here in the UK, imagine stepping outside the infrastructure of an established healthcare delivery system, using vaccines which require chilling (and in some cases extreme chilling) in remote areas of sub-Saharan Africa. Maintaining the quality and efficacy of those vaccines represents a totally different challenge.

Electronic monitoring systems will have an important role to play in to ensure that vaccines reach end users in the best possible condition to maintain the best levels of effectiveness into the future.

Author: Matt Feeny is co-director of Remote Monitoring and co-inventor of the RemoteM temperature monitoring system