Validating Temperature Indicators: The “Return to Refrigerator” Challenge

Learn more in this VUEPOINT about indicator comparison tests we conducted based on reports from blood banks experiencing indicators “tripping” after returning blood products to the refrigerator

by Jeffrey Gutkind, Temptime

We are often called on by blood banks to answer questions about temperature indicators and support their validation requirements.  They also interface with us when they are having “issues” with an indicator, whether it’s Safe-T-Vue or a competing product, and are looking for insight and possible solutions.

Temperature indicators “tripping” after return to refrigerator

Several times over the past year we’ve interacted with blood banks experiencing a specific temperature indicator problem.  Here’s how it goes – the unused blood is returned to the blood bank and the indicator shows that it is still in compliance, that it hasn’t exceeded its 10oC indication temperature.   Great!  So, the blood is returned to the blood bank refrigerator for future reissue.

Then, at a later time, the when the blood is removed from the refrigerator for reissue –the indicator has “tripped” or turned color.  How could this be?  If the temperature was in compliance going IN to the refrigerator, how could it then be out of compliance AFTER being refrigerated?

The “Return to Refrigerator Challenge”

Blood Temperature Indicator Comparison

Figure 1: “Return to Refrigerator Challenge” Temperature Indicator Test Setup

In response to this influx of concern from blood banks, we decided to conduct a comparison test.  Fortunately, we had an opportunity to work with a major university medical center to gather validation data focused specifically on the “return to refrigerator” portion of the blood product’s journey. We refer to this test as the “Return to Refrigerator Challenge.”

The purpose of the challenge was to simulate a typical blood product journey – blood being issued to another department, such as the OR, and removed from the cooler for a brief period of time, and then returned to the blood bank.   A temperature probe would be placed in the blood bag, and the performance of two types of 10oC indicators would be compared.

  1. A probe was inserted into a (simulated glycerol-water) blood bag, which was placed in the refrigerator until it reached 4.2oC.
  1. The bag was removed from the refrigerator. Five Safe-T-Vue 10 indicators and five ‘Indicator A’ were affixed to the blood bag. (Figure 1)
  1. The blood temperature was allowed to reach 8.5oC. The indicators were observed and observations recorded (Figure 2).
  1. The blood bag was placed back in the refrigerator at 4.2oC (to simulate blood being returned to the blood bank for reissue) for 30 minutes.
  1. After 30 minutes, the blood bag was removed from the refrigerator. The indicators were observed and observations recorded (see Figure 2).

Figure 2: “Return to Refrigerator Challenge” Indicator Pass and Fail Data

*Note: Accuracy of Safe-T-Vue 10 is +/- 0.4oC and published accuracy of Indicator A is +/- 0.5oC

Challenge proves need to validate indicator performance throughout journey

Comparing the performance of the two indicators (Figure 2), it was apparent that the Safe-T-Vue indicator had accurately performed as expected and within the specifications.   Two of five ‘Indicator A’ had prematurely indicated (at 8.5oC) prior to refrigeration, and all five had failed to perform to specification after refrigeration at 4.2oC for 30 minutes.

Based on the manufacturer’s published accuracy specifications, Safe-T-Vue performed successfully, whereas ‘Indicator A’ failed to perform to specification.  Not only did 2 out of 5 ‘Indicator As’ “trip” at 8.5oC, all five of the indicators had tripped within 30 minutes of being refrigerated at 4.2oC.   This may be due to Indicator A’s published “stop temperature” of 8.0oC.

Is it necessary for you to conduct your own “challenge?”

This “return to refrigerator challenge” proved that the Safe-T-Vue indicator could be validated for returning blood products to the blood bank. If you have confidence in the performance (to specification) of the indicators you are using, then you probably don’t need to conduct your own “challenge.”  But, if you’ve had issues like we described early in this VUEPOINT, where indicators are mysteriously changing while under refrigeration, you may want to conduct the “challenge” to be certain that the indicators are performing as specified.

Validate critical points in your process to confirm indicator performance

The typical, standard validation should help you identify indicators that do not perform to specification (for example the two Indicator A’s that tripped at 8.5oC, which does not meet the published specification of +/- 0.5oC).   The closer look of the “challenge” could be used to confirm additional failure to perform to specification, particularly in situations where the indicator performance seems odd or questionable.

As always, we welcome your feedback on this topic.  And if we can provide validation support or help you address any temperature indicator issues, please contact me.

Jeffrey Gutkind

Blood Banks: Get “Inspection-Ready” with these Tips and Resources

Avoid panic! 3 Tips to make your inspection a proactive, collaborative, and educational experience

While the purpose of a blood bank inspection is ultimately educational, does the mere mention of it invoke anxiety in your staff? We’d like to help put some of that to rest with solid resources and some sound advice.

In this VUEPOINT, we guide you to two journal articles that are educational about the “who, when and why” of lab inspections, giving practical advice and resource links.

We were also fortunate to speak with Jim Baldridge, MT (ASCP) SBB, who is the Manager of Blood Bank Pathology at Providence – Little Company of Mary Medical Center in Torrance, California. Jim has been involved in the business of blood banks for almost 35 years, has performed AABB assessments, and currently conducts CAP (College of American Pathologists) inspections. And, you’ll find that Jim’s real-life experience supports the recommendations provided in the two articles.

3 Things you can do to prepare and get the most from your inspection

Jim Baldridge’s suggestions mirrored some of those you’ll see in both articles – including “locate, review and complete the reference guide (or checklist) that the inspector will use.” Here are three tips from Jim:

Tip #1
“Prior to the inspection, go through the checklist and have everything located and notated for the inspector,” said Jim. “This will allow the inspector to get to exactly what they are looking for, and move on. Use the checklist like a script.”

He also noted that this method of preparation allows the lab to have a permanent checklist that you can “roll forward” to the next inspection. “When revisions to the checklist are published you can address those new requirements, but you’ve already laid the groundwork for your inspection by completing the bulk of the work.”

Tip #2
Start a folder and keep copies of questions asked and documents requested during the inspection. “As the inspection progresses, it’s helpful to make a list of any questions that are asked, and make yourself a copy of any records the inspector requests – and put them in a folder. At the end of the day, you can go through the folder and debrief yourself – and prepare for the next day.” He also noted that it’s a good time to make notes for future inspections – – and this takes the pressure off of you to trust your memory!

Tip #3 
Look at the inspection as a collaborative process and expect positive outcomes. “I’ve found that in most inspections I’ve learned things and gotten good ideas. I’ve been able to borrow procedures and forms from others, and incorporate them into my policies. This is particularly true with CAP inspections, since they are peer reviews,” he added. “Preparation respects the time of the inspector, and a positive, collaborative attitude can help you get the most from the experience.”

Helpful journal articles

They’re Here! How to Prepare Your Blood Bank for Inspection was published in the April 24, 2015 issue of LabMedicine1, and provides a wealth of information. It’s a valuable resource, with helpful links at the end. In the article you’ll find:
• Overview of Agencies that perform inspections – CMS, FDA, AABB and CAP
• Explanation of terms used in inspections
• Practical Advice from 3 individuals – a QA specialist, a blood bank manager and an assessor
Click here for PDF

Is it an inspection, audit or assessment?

Per the article, while the agencies use different terminology, these terms are often used interchangeably, as are the terms ‘checklist’ and ‘assessment tool.’ You’ll find explanations of all of these terms in the article.

“Is Your Lab Inspection Ready?”
This article appeared in Medical Laboratory Observer2, June 2013, and provides a comprehensive list of the various organizations, and includes detailed information about their purposes, resources and checklists (assessment tools), where applicable. (Please note that since this article was published in 2013, some links may be invalid).

 

Cooler Validation: Comparison of “Manual” Thermometer vs. “Automated” Data Logger Methods

In our March 2012 survey of over 70 blood banks, many respondents generally described cooler validation as a “pain,” characterizing it as time-consuming, frustrating and even primitive.

Most blood banks revalidate their transport coolers annually. And although it is only once a year, there never seems to be a good time or resource-efficient way to do it.


Using multiple data loggers allows more accurate temperature mapping of the cooler interior.

The three key factors we hear repeated most often are:
1. Time Efficiency (technician’s time)
2. Data Accuracy
3. Simplifying Documentation

At the SCABB/CBBS meeting last month, we entertained compelling discussions with blood bankers who have switched from manual cooler validations with thermometers, to using data loggers (electronic temperature recorders). Some of them are using the Val-A-SureTM Cooler Validation Kit.

If you’ve ever considered switching to an automated validation process, we thought it might be helpful to share what we’ve learned from blood bankers across the country. In the following table (next page) we compare the traditional “manual” thermometer method to the “automated” data logger method – and capture how it has changed their validation experiences.

This graph displays temperature of the top bag vs. the bottom bag. The data is downloaded from data loggers and printed for permanent validation documentation, eliminating handwritten and transcribed data.

We’ll be giving away a Val-A-Sure Cooler Validation Kit at AABB 2015, so if you’re interested in a “free” chance to change your cooler validation method, be sure to stop by and see us!

Jeffrey Gutkind
jeffg@temptimecorp.com

P.S. For more on Transport and Storage Coolers, check out our Tips, Helpful Ideas and AABB Standards References on www.williamlabs.com.

COMZ VUEPOINT – Cooler Validation-Comparison of Manual Thermometer vs. Automated Data Logger Methods – web version (doc. 2341)

Are all temperature indicators created equal?

When it comes to cost and performance, how do you choose?

by Jeffrey Gutkind

In today’s cost-conscious healthcare environment, our immediate reaction when making a buying decision is to minimize purchase cost.   The temperature indicators currently on the market have different costs.  And there are questions you may be asking:

  • is the “cheapest” purchase price going to save the blood bank money overall?
  • are all indicators equal in terms of performance?
  • how do you know which indicator to choose?

To answer these questions, let’s take a step back and question WHY we even use temperature indicators.

Temperature indicators for blood products were originally designed to provide assurance that blood product temperatures had not exceeded AABB temperature guidelines when the blood is out of the blood bank’s control. The temperature indicator provides proof that the blood product has been maintained at proper temperature while out of the blood bank control.

Numerous visitors to our AABB booth a few weeks ago stated that 40-50% of the blood issued from their blood banks is not used. To further illustrate the challenge, a journal article recently published in Transfusion (shared in our August 2014 VUEPOINT), described a study by a blood bank that stated how most of their blood waste was from either temperature or time (away from the blood bank) excursions, and that 70% of those losses came from blood products issued to the OR in coolers.  Temperature indicators are used by blood banks worldwide for exactly this reason – to provide assurance that the blood products at no time exceeded temperature thresholds, to help maintain blood product quality and to minimize blood waste.

So, other than cost, what matters when choosing an indicator?

Let’s circle back to our initial questions of the temperature indicator cost and the temperature indicator performance.  Since the job of a temperature indicator is to provide temperature information back to the blood bank, the indicator’s temperature ACCURACY (also referred to as “tolerance”) is critical.

As an example, of the three most popular 10o C temperature indicators on the market today, each publishes a different accuracy specification:

  • Safe-T-Vue 10  +/- 0.4 o C
  • Indicator A +/- 0.5 o C
  • Indicator B +/- 1.0 o C

How does indicator accuracy influence blood product waste?

In this illustration, you can see that a 10oC indicator with an accuracy of  +/- 1.0 may actually “trip” at 9 o C, thus falsely indicating that the temperature of the blood is out of specification.  And, as we all know, the cost of wasted blood itself far exceeds the purchase price of an indicator – and minimizing blood waste (not indicator cost) is the primary objective behind using a temperature indicator.

Using an average cost of $250.00 for a single wasted blood unit, it’s easy to calculate the potential savings of using a more accurate temperature indicator.   The cost difference in temperature indicators is minimal in comparison to the cost of one wasted unit of blood.

When comparing temperature indicators to make a buying decision, be sure to make ACCURACY comparison a key factor in your selection process.  Safe-T-Vue indicators are available in 6°C and 10°C temperature indications, both accurate within +/-0.4°C.  *

As always, we welcome your comments and feedback on the ideas presented in this VUEPOINT.

Sincerely,

Jeffrey Gutkind
jeffg@temptimecorp.com

* Refer to AABB standards for blood banks and transfusion services, 21 CFR 640.2, 21 CFR 640.4, and 21 CFR 600.15.

Reduce RBC and FFP Waste, Improve ROI

Learn more from this Blood Transport and Storage Initiative that resulted in significant ROI

by Jeff Gutkind, Business Development Manager

I recently read an article in the journal Transfusion1 in reference to reducing red blood cell (RBC) and plasma (FFP) waste.  The study showed significant reduction in RBC and FFP waste by using a new blood transport and storage system, and a significant return on their investment in the new system (estimated savings of $9000/month for their institution).

While the article doesn’t speak to temperature indicators, it does seem to validate that there is a trend toward cooler storage in the OR being considered “intraoperative storage,” which is significant.

For those of us sensitive to blood waste (and associated costs) due to time-temperature issues, this study has a wealth of valuable information and powerful messages:The article cites a national waste rate for hospital-issued blood products ranging from 0% to 6%, and a common reason for blood waste being inadequate intraoperative storage.2

  • The article describes how most of their blood waste was from either temperature or time (away from the blood bank) excursions, and that 70% of those losses came from blood product issued to the OR in coolers.
  • In the second paragraph they state that “AABB standards require red blood cell and plasma units to be maintained at a temperature of 1-10°C during transport and 1-6°C during intraoperative storage.
  • They go on to state (under Materials and Methods) that “holding product in the OR represents a storage condition“….. and “the storage (1-6°C), not the more lenient transport (1-10°C) temperature range needed to be maintained.”

Their previous procedure was to issue blood products to the OR in off-the-shelf commercial coolers that were validated to hold product at 1-10°C for 8 hours. They changed to a new, more expensive cooler that incorporated specialty phase change material that is validated to hold 1-6°C for 18 hours. As a result of the new system and strategy, they have improved their “storage” compliance to 1-6°C and reduced waste from 1.20% to 0.06%, which they calculate to save the $9,000 per MONTH.

The result of this study suggests that incorporating a new, longer duration blood shipping and storage container has allowed the OR to store blood for up to 18 hours at 1-6°C while meeting AABB’s more strict guidelines and has produced significant cost savings and notable return on investment 

It would be interesting to see the savings if they incorporated a Safe-T-Vue 6 indicator in this study.

REFERENCES:

1. Brown MJ, Button LM, Badjie KS, Guyer JM, Dhanaroker SR, Brach EJ, Johnson PM, Stubbs JR. Implementation of an intraoperative blood transport and storage initiative and its effect on reducing red blood cell and plasma waste, Transfusion 2014;54: 710-07.

2. Heltimiller ES, Hill RB, Marshall CE, Parsons FJ, Berkow LC, Barrasso CA, Zink EK, Ness PM. Blood wastage reduction using Lean Sigma methodology. Transufions 2010;50: 1887-96.

Tips for Better Blood Handling

Lessons you’ve taught us – and why they work!

Keeping blood cold can be a challenge. Here we present a few EASY handling procedures that can be readily incorporated into the day-to-day receiving and dispensing of blood in your blood bank – and make a significant difference.

You told us in our late 2013 survey what topics were of most interest to you and your colleagues in the blood bank. The most popular choices – by a large margin – were:

  1. Proper handling of blood products, and
  2. Use of temperature sensors in blood transport to the OR and ER/Trauma

Reflecting on the conversations and comments from visitors to our booth at the 2013 AABB in Denver, this survey validated what many of you have told us about keeping blood cold and proper handling.

In this VUEPOINT we are summarizing some of the handling procedures and ideas that blood bankers from around the world have shared with us over the years.

Tip #1

Handling blood bag by edges to prevent warming blood product Always handle blood bags by the ends where there is no blood that may be warmed by normal handling.

Why?

Holding a typical 300 – 400 cc blood bag in warm human hands for even 20-30 seconds may raise the core temperature by up to 2°C. The temperature rise is faster in smaller bags (< 350 cc) so extra care should be taken to handle small bags only by parts of the bag where no blood may be warmed by handling.

Tip #2

Always keep cold packs in the blood refrigerator. Place blood bags on a cold pack immediately when removing blood from the refrigerator – MAKE IT A HABIT!

Why?

A 350 cc blood bag that starts at 3.5 °C will reach 6.0°C in approximately 6 minutes and approximately 10°C in approximately 19 minutes depending on the temperature of its environment, and the temperature of any surface it comes into contact with (hands, lab bench, etc.).

The same bag on a cold pack, where both blood and cold pack are at 3.5°C and placed on a bench at 20°C will keep the blood below 6.0°C for approximately 14 minutes and below 10.0°C for approximately 36 minutes.

This is a no-brainer! USE COLD PACKS.

350 cc Blood Bag, temperature change with and without cold pack
3.5 °C 6.0°C 10°C
Without Cold Pack START 6 minutes 19 minutes
With Cold Pack START 14 minutes 36 minutes

Tip #3

Using an adhesive temperature indicator on the blood bag is one way to monitor – and be assured – that the blood temperature has not exceeded the upper compliance temperature of 6.0° C or 10.0°C.

Why?

Adhesive temperature indicator on blood product gives visual indication

Indicators give visual indication when the blood is approaching the 6°C or 10° C compliance temperature, and then confirm if the blood exceeded temperatures – even if the blood is “re-cooled” to a compliance temperature.

QUICK ACTIVATION TIP

Temperature indicators on blood bags in blood bank refrigerator

Some blood banks have adopted a procedure to apply the indicators to blood bags as they are put in blood bank refrigerator storage – then they can quickly activate the indicator immediately when the blood is dispensed, or activate it at the same time it is applied.

VALIDATION TIP – When validating a blood indicator be certain to use a temperature recorder that measures and indicates to within 1/10th of 1°C accuracy (0.1 °C).

 

SELECTION TIP – When choosing an indicator, be sure to pay attention to and ASK FOR proof that the product has been cleared through the 510(k) process by the FDA. This can be verified by receiving the product’s FDA 510(k) registration number from your supplier. To learn more about FDA 510(k) registration, read this VUEPOINT.

 

Do You Have Any Tips To Share?

  • Are there other procedures or ideas from your blood bank that we can share?
  • Do you have unanswered questions that we can help you get answers to?

Your peers, in hundreds of blood banks around the globe, are always eager to learn from each other. Please pass on your Tips for better blood handling, and we will be sure to post them in the next VUEPOINT.

When should I use a probe for temperature validations?

Here are a few guidelines for validation with or without a probe, based on what you told us

With our daily giveaway contest of a Val-A-Sure Cooler Validation Kit at AABB, we had the opportunity to talk with many of you about the validation procedures in your blood banks. Hands down, the most frequently asked question was “when do I use temperature recorders with external temperature probes – and when should I use temperature recorders with built-in sensors?”  Our Advantage Kit is configured with both types, since our research showed us that it’s done both ways for a number of reasons.

When we conducted product development beta tests and interviews with your peers, we learned a lot.  Here are a few guidelines for validation with or without a probe, based on what you told us.

Using Built-In Sensor Temperature Recorders

  1. When temperature among, around or between the bags in the cooler are to be recorded
  2. When several points within the cooler need to be recorded
  3. Where the compactness of the built-in sensor makes it easier to fit into the cooler/space
  4. In a larger cooler with six or more bags and numerous areas within the cooler need to be recorded, such as near top, near bottom, sides and ends
  5. General monitoring of all sizes of refrigerators, freezers, and ovens

Using Temperature Recorders with Probes

  1. When core temperature of blood bags is to be recorded
  2. For larger coolers where specific, more pin-point locations need to be temperature-monitored
  3. General monitoring of all sizes of refrigerators, freezers, and ovens where the probe may or may not be in a liquid

The Val-A-Sure Advantage Kit is supplied with 2 TRIX-8 Recorders (built-in sensors) and 2 TREX-8 Recorders with Bag-Sealer Probes. For those of you who prefer different recorder configurations, the Custom Kit allows you to select exactly the type and quantity of temperature recorders that will work best for your needs.

The temperature recorders have a range of +85 to -40°C, and we’re learning that some labs are using them for validations beyond transport coolers.  Every recorder is supplied with calibration document identifying instruments used for calibration and their traceability to a NIST standard.

If you have any other guidelines or suggestions to share, please feel free to Comment on this post (below) and we’ll be sure to pass it on to your peers!

And don’t forget, we have validation procedure videos here on the William Labs website.

Blood Temperature Compliance at 6°C … is it safe to re-inventory?


When blood products are issued from the blood bank in a packed cooler and are later returned to the blood bank, how do you know if the blood was maintained at the compliance temperature of 6°C? In this 90 second video, you’ll see how Safe-T-Vue® 6 from William Laboratories (www.williamlabs.com) can be used throughout the transport and temporary storage process to provide easy visual indication if the blood temperature exceeds 6°C.

Val-A-Sure Cooler Validation Kit Overview & Introduction

The Val-A-Sure™ Cooler Validation Kit from William Labs (williamlabs.com) combines everything you need in one simple kit for temperature validation of blood transport coolers. All of the necessary components, instructions and documentation for validation are conveniently included in the kit, and have been tested to work together efficiently and accurately.Hands-on trials and feedback from blood banks and laboratories provided the guidance for the Val-A-Sure™ kit development. It delivers the simplicity, accuracy, standardization and speed of process that blood banks and labs told us that they need — in one integrated kit.

Recommended SOPs, temperature recorders and software provide options for an accurate validation process, regardless of your blood bank size. Using electronic recording equipment and following the SOPs, and using the supporting documentation, helps ensure consistent measurement and recording for each validation.

The DVD and documentation supplied with the kit contain:

– QuickStart Guide
– Easy-to-follow 3 minute video instructions of 3 different recommended validation procedures
– Validation SOPs (4 included)
– Validation Log Sheet
– Cooler Label format/template
– Validation Tips

Simulating Platelets for Validations

Guidance in using an average density to simulate platelets for validations

After reading our VUEPOINT post – “Simulated Blood Products: 10% Glycerol in water may NOT be “One Size Fits All” – that presented “recipes” for simulated blood products (Red Blood Cells, Whole Blood and Plasma) – one of our VUEPOINT readers recently  posted a comment on our website. The question was about platelets, asking for the water-glycerol mixture for simulating them, just like we had done for the other blood products. Great question and we’re glad you asked!

How do we calculate an accurate mixture based on varying platelet densities?

Because of the density range of platelets, if you were striving to be highly, highly accurate, you would need to know what group the platelets fall into. Various professional papers discuss high, low and other density groups. Here is a reference from the University of Virginia School of medicine that classifies platelets into three Density Classes, with an average density for each class.

Another platelet density analysis reported “…normal platelets layered onto Percoll formed a band extending from 1.0625 g/ml to 1.0925 g/ml, with a mean platelet density of 1.0775 g/ml:…”.1

In response to our VUEPOINT reader’s inquiry, we have modified our graph and recommended water-glycerol mixture (1.066, 26%) to include a formula for platelets. This graph plots the % Glycerol (y-axis) to Density / Specific Gravity (x-axis), which reflects density, for Plasma, Whole Blood, Platelets and RBCs.

Recommended “Recipes” for simulated blood products

Based on the data presented in this VUEPOINT, we recommend that you consider using the following mixtures for blood product simulation.

Stir for a few minutes to assure a homogeneous solution. Be sure to follow any precautions supplied by the glycerol manufacturer for handling pure glycerol.

Other Sources for Platelet Density Information

For those of you who are interested in digging a little deeper into platelet density, here is a link to another reference that reports blood density determination:
Blood. 1977 Jan;49(1):71-87. Heterogeneity of human whole blood platelet subpopulations. I. Relationship between buoyant density, cell volume, and ultrastructure. Corash L, Tan H, Gralnick HR.

Please Share Your Questions and Feedback

We always appreciate questions like these that give us an opportunity to do some research and share more valuable information, with the goal of making your job a little easier if we can. Please don’t hesitate to post a COMMENT to any of our VUEPOINT articles if you have something to share, or would like to us to “dig a little deeper” for our mutual learning.
info@williamlabs.com
1-800-767-7643

1 Platelet-Density Analysis and Intraplatelet Granule Content in Young Insulin Dependent Diabetics, A. Collier, H.H. K Watson, D.M. Matthews, L. Strain, C.A. Ludlam, and D.F. Clarke, Diabetes, Vol. 35, October 1986.