“If we use a temperature indicator inside the cooler, can we eliminate the step of checking the temperature every 4 hours?”
At the Ask the FDA session at the 2010 AABB meeting, this was one of the questions asked referencing a new requirement1 to check the temperature of blood products every 4 hours when being transported in a validated cooler. The answer at the session was “yes,” if using a temperature indicator inside the cooler. As a manufacturer of blood bag temperature indicators, this was good news. However, our curiosity was piqued about ‘how difficult can it be to validate a cooler?’
Given the discussion around this topic, we asked blood bankers about their cooler validation practices and equipment, checked blogs, and generally surveyed how blood bank coolers were being validated. We learned some things. One of them being that there is a wide range in validation procedures, some using ‘good science’ that takes into consideration the real world uses of blood transport coolers. For example, we found validation procedures and practices that included:
- Taking into consideration the periodic removal of blood units during the transport time period
- Careful inspection of coolers during the annual validation procedure
- Temperature measurement of TWO bags – the top bag and the bottom bag – when multiple bags may be transported in the cooler
Establishing a ‘cold start’ for the bags before placing them in the cooler ( as low as possible).
Back in our lab at William Laboratories, we already knew that cooler packing is the key to keeping blood products cold as along as possible. Using a two-channel datalogger, we found that our ‘Igloo®-style’ validated cooler kept 2 bags at nearly identical temperatures for long periods of time. However, we were surprised at the results when there were 4 bags in the cooler. We found that the measured temperatures of the top and bottom bags of a 4 bag layer were dramatically different. The top bag measured 3°C higher than the bottom bag when the bottom bag reached 6°C. We are continuing this work to learn more, and plan to publish our findings for you in upcoming VUEPoint issues and via AABB regional meetings.
Given the range of validation procedures in use, we are in the process of combining the best practices and necessary equipment into a cooler Validation Kit with simple instructions. Our goal is to simplify and demystify this often frustrating validation requirement for busy blood banks, transfusion services and hospitals. The validation kit will have everything you need, in one easy-to-use kit.
We welcome your comments and ideas on cooler validation. In the coming weeks, we are providing test kits to a selected group of hospitals and blood banks for their evaluation.
If you are attending AABB next month in San Diego, and have questions or ideas about portable cooler validation please come see us at Booth 742.
See you in San Diego –
Ed Sharpless, VP Product Development William Laboratories, Inc.
1American Association of Blood Banks, Technical Manual (16th Edition), 22.214.171.124.2
American Association of Blood Banks, Standards for Blood Banks, (27th Edition)