Keeping Blood Products Cold During Dispensing

Tests show that gel blankets significantly help maintain temps below 6oC

Test Blood Bag Warming using reusable ice packsOn a recent visit to a blood bank customer who uses Safe-T-Vue 6, we learned something that we felt was worth sharing. During the approximate 10 minutes that it often took to do paperwork and cross-matching, they sometimes experienced the Safe-T-Vue 6 (STV-6) “tripping.” This caused concern that the blood product may have been compromised by room temperature exposure, even for a seemingly short time period.

To address this problem, they began using refrigerated gel blankets (reusable ice pack sheets) to keep the blood product cool. Taking this simple step of placing the blanket around the blood bag(s) during preparation and before transport to the ER/OR has given them confidence that the blood product has been kept cool, and the STV-6 provides visual indication and reassurance that 6°C has not been exceeded.

Wanting to learn just how much the gel blanket helped, we turned to Marielle Smith, Technical Service Scientist in our Temptime Lab, to do some testing. You may be surprised by what we learned.

Read this VUEPOINT to see the test procedure and learn from the detailed data we gathered. It may inspire you to try gel blankets in your blood bank!

Tests to compare blood bag warming with and without refrigerated gel blankets

When blood banks are preparing refrigerated blood bags for transport to the OR/ER, there is limited time for blood bank personnel to record the necessary patient information (cross-check, paperwork, etc.) before the blood approaches critical temperatures. Many blood banks use Safe-T-Vue 6 for exactly this reason.

Previous studies have shown that bags warm quickly to temperatures (6.0°C in less than 10 minutes) rendering the blood unsuitable for use. Results from this new study, however, demonstrate that using a refrigerated gel blanket (such as the Thermafreeze Reusable Ice Pack Sheet) makes a significant difference in slowing the warming rate when the blood product is removed from refrigeration to typical room temperature conditions.

Test procedure setup

A test was performed to assess whether using a refrigerated gel blanket can add to the longevity of the blood bags upon removal from refrigerated storage (1°C – 4°C).

The test was setup to collect temperature data as follows:

1. Control, single bag with no gel blanket
2. Single bag with small gel blanket, cutout window (to view Safe-T-Vue 6)
3. Three bags with larger gel blanket

Six (6) bags of 350 mL simulated red blood cells volume were used for scenarios 1 and 2, and 18 bags were used for scenario 3.

Reusable Ice Pack Sheets (e.g., gel blanket) were obtained and cut into different dimensions to allow for testing either a single bag (with a window cut-out to view the Safe-T-Vue 6 indicator) or 3 bags side-by-side.

Small gel blanket with viewing window for 1 bag

Large gel blanket for 3 bags

Temperature measurement

Calibrated temperature probes were inserted into each of the simulated blood bags. Calibrated electronic thermometers (accuracy of at least ±0.1°C) were used to record the temperature of the fluid inside the filled blood bags.

After pre-conditioning in the refrigerator (maintained between 1°C to 4°C) for at least 24 hours, the bags and the gel blankets were removed and placed lying flat on a counter-top at room temperature conditions (19°C ± 1°C with 50% R.H). A timer was set to count-up mode and temperature readings were recorded at one minute intervals until the temperature inside the bag reached 6°C.

Test results

The data points on the graph below show the gradual warming of the bags as the refrigerated blood bags warm to 6.0°C in room temperature conditions when the blood bag is either wrapped in a refrigerated gel blanket, or left as is upon removal from refrigerated storage (control).

Summary

  • Without using a gel blanket, blood bags warmed from 3.2°C to 6.0°C in approximately 9 minutes
  • Using a small gel blanket (with a window cut out to allow for visual interpretation of the Safe-T-Vue 6 indicator), blood bags warmed to 6.0°C in approximately 25 minutes
  • Using a large gel blanket for testing up to 3 bags side-by-side, blood bags warmed to 6.0°C in approximately 32 minutes

Conclusions and recommendations

The results presented in this report support that a pre-conditioned refrigerated gel blanket can be wrapped around blood products to keep the blood below 6°C for an extended period of time – while blood bank personnel are preparing the blood for transport to the ER/OR.

When a simulated blood bag was wrapped in a refrigerated gel blanket upon removal from refrigerated storage (1°C to 4°C), the bag warmed to 6.0°C within about 25 to 32 minutes on a counter at room temperature conditions. As an added precaution, a Safe-T-Vue 6 indicator can be used to provide irreversible visual indication of temperature excursions beyond 6.0°C.

Order free samples of Safe-T-Vue 6

What is “stop temperature?”

Return to Refrigerator Challenge” generates new questions from blood banks

This was the most common question we received from blood bankers in an unprecedented response to our January 2017 VUEPOINT.  In that issue of VUEPOINT, we shared the results of a “Return to Refrigerator Challenge” – where a major university hospital conducted a test to compare two blood temperature indicators.  Their intention was to evaluate indicator performance when unused blood was returned to the blood bank.

Although this was the first time we discussed stop temperature in a VUEPOINT, it’s not the first time we’ve received questions about it from our blood bank contacts. To address those issues, we researched what stop temperature means for indicator manufacturers who use this specification. We found that stop temperature appears to relate to the chemical indication behavior.  This means that if the blood product temperature is below the stop temperature, the indicator does not change color.

How does a 10oC indicator with an 8oC stop temperature behave?

The 10oC indicator used in the challenge has a specified stop temperature of 8oC.  If the blood product begins to exceed the stop temperature (8oC), the 10oC indicator’s chemical indication material melts back to its liquid state. This melting reaction gives users a visual indication that the blood product is no longer in compliance. This type of indicator may signal that the blood product is out of compliance once it exceeds 8oC, even if it never reaches 10oC, as shown in this example.

What does this mean to blood banks using a stop temperature type indicator?

Now that we understand what stop temperature is, the question is what does the specification – and indicator performance – mean to blood banks?  Specifically, what happens if the blood product is hovering around the 8oC stop temperature for any period?

Tests shared by blood banks, combined with our studies, have shown that under a wide range of exposures and times – once the indicator exceeds its stop temperature of 8oC, the indicator may be irreversibly tripped.  In multiple tests, the blood product temperature was being internally monitored to confirm that it remained below the indication temperature of 10oC before being returned to the blood bank refrigerator.  After the blood bags were returned to the refrigerator for reissue, many indicators had tripped during the refrigeration period.

Comments and questions from blood banks based on findings

  • “Doesn’t this make it an 8oC indicator?”
  • “We have many bags that are returned to the blood bank at 8oC and they look OK. We put them in the refrigerator and they show overheated.  This is an 8oC indicator.  We are throwing out good blood.”
  • “This did not show up in the standard validation, and it never occurred to us to try this while performing the validation. After performing the ‘return to refrigerator challenge’ we found that the indicator just did not perform”.

We are grateful for comments and questions like these because they help fuel our blood indicator knowledge and testing.  Clearly, the “stop temperature” specification may be new to many blood banks and is something to be further explored.  Please share your experiences and observations so we can continue learning together.

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

HELP not HYPE: Being truly useful to blood banks

VUEPOINT posts and website top-ranking pages prove that delivering blood bank help is timeless and valuable

The Williams Labs web site was created with a single goal – provide a place where people involved in blood banking can find information to help them perform their jobs more easily and with better results.

We are delighted that blood bankers from around the world – some who are Safe-T-Vue users and some who are not – routinely visit williamlabs.com and read our VUEPOINT posts because we are providing relevant, useful and helpful information for blood banks.

AABB_Temperature_Standards_2016We’ve also been flattered to learn that blood bank inspectors point blood banks to our website as an easy source of information regarding transport and storage of blood products.

In this VUEPOINT, we share the links to these pages and posts as a quick guide to these informational resources. Maybe they are handy to bookmark for your daily blood bank operations – or perhaps in orienting a new employee? Whatever your reason, it’s here for you and your blood bank staff – with our continued focus on helping you do your best.

Top 5 Useful and Helpful Pages

1. AABB Temperature Standards for Blood Products: Storage and Transport
This table provides fast access to the newest 2016 AABB Reference Standard 5.1.8.A for storage and transport temperatures of blood components.

2. Simulated Blood Product RecipesSimulated_Blood_Products_Validation
We first published this VUEPOINT almost 4 years ago, and based on the web statistics, it continues to be a valuable resource for blood banks. Did you know that 10% glycerol in water is NOT “one size fits all?” You might want to read this one and learn more.

 

3. QA Documents
It doesn’t sound glamorous or intriguing, but the incredibly useful nature of having QA documents for the Safe-T-Vue products easily accessible 24/7/365 has proven to be a winner. No hype, just help.Safe-T-Vue_QA_Docs

4. Category: Storage of Blood Components
This page provides titles and excerpts of all the VUEPOINT posts in the category “Storage of Blood Components” that we’ve published over the years. Scroll down the page and you’ll quickly find information on IR Thermometers, Cooler Validation, Refrigerator Setpoints, Indicator Comparisons and more.

5. Tags: Blood Temperature
Similar to #4 “Storage of Blood Components” this page presents almost 5 years of VUEPOINT posts that have something to do with blood temperature – measuring, monitoring, and managing.

We are always looking to learn from you – about how we can be more helpful and genuinely useful by providing valuable information to blood bankers worldwide. If you have suggestions for VUEPOINT topics or questions you’d like for us to explore – and share – we would be delighted to hear from you.

Sincerely,

Jeff Gutkind

3 Things You Need to Know

About Blood Temperature Indicators

Do you trust a product to protect your blood supplies that may “auto activate?” Would you be discarding expensive blood products because of an unreliable indicator?

1. Accuracy Matters

Of the indicators on the market, one is clearly less accurate. “Indicator A” can reach endpoint at 9o, resulting in wasted blood – blood that may actually be in compliance.

2. Performance Varies Greatly

The fine print for a competing indicator clearly states that AFTER ACTIVATION, the temperature of the blood needs to be brough back down to its 8oC “Stop Temperature” to avoid premature indication.

This means that the indicator could prematurely indicate at a temperature as low as 8oC if the blood bank doesn’t take the extra step to ensure that the blood – after attaching an activated indicator – is cooled below this “stop temperature.”

3. Lower Price May Not Be Lowest Cost

Comparing indicator purchase price may make it seem like an easy choice.  however, the actual COST of an indicator that is:

  • poor performing
  • less accurate, or
  • unreliable

is dramatic in comparison to the cost of wasted blood products.

Knowing that, on average:

  • blood banks receive a significant amount of issued blood back
  • ONE unit of wasted blood may cost the blood bank $250
It only makes sense that a more reliable indicator that reaches endpoint at 9.6oC (and not as low as 8.0oC) is a more cost effective choice.

Handy Tip

Safe-T-Vue lot-by-lot QA documents are posted here on our website for easy customer access – and prove that Safe-T-Vue is manufactured to quality standards.

 

IR Thermometers: Determining Blood Product Temperature on Return to Blood Bank

Learn as we explore common misconceptions about IR thermometers and surface temperature vs. core temperature

The following PathLabTalk post describes something we encounter repeatedly in blood banks – and illustrates several problematic misconceptions about determining blood product temperature on return to the blood bank. At the same time, this post demonstrates a reliable, good practice!

“Our transfusion service is looking for an infrared thermometer that we can use to determine the internal temperature of our donor units. We issue products in validated coolers to surgery, ED, and other locations and sometimes we receive the products back that have not been used. Currently, we attach a temperature indicator to the unit, but want something more accurate that is not difficult to operate, calibrate, etc….”1

First, we congratulate this PathLabTalk poster for reaching out to the blood bank community for ideas and support. She/he has realistic, everyday needs that many may identify with. In this VUEPOINT, we present some problems and misconceptions, along with this blood banker’s good practices, that are communicated in the post.

Problem #1
Infrared Thermometers (a.k.a. Infrared “Guns”) do not measure “internal temperature”

Infrared thermometers are used to measure surface temperature without contacting the product being measured. Most specifications for these devices state “non-contact surface temperature measurement.” They do not measure “core temperature” of any product, including blood. Infrared thermometers are used in many different applications ranging from food service, to residential heating/cooling, to industrial. Typically they are used for “hard to reach” areas where contact temperature measurement is difficult/impossible.

Problem #2
A one-time temperature reading of a returned blood product provides little assurance that the blood was kept at the correct storage or transport temperature over the entire time period that it was out of blood bank control.

No matter how well everyone is trained and how conscientious they are, we all know that once the blood product leaves the blood bank, anything can happen. For example, in the OR or ED there are many critical functions being performed at once, and often over long periods of time. Blood can be taken from the cooler and left on a table for hours – and then returned to the blood bank, having had time to “cool” to what may appear to be an acceptable temperature.

The precariousness of this situation is compounded when an IR thermometer is used to check SURFACE temperature when the product is returned.
• Perhaps the blood bag was placed on an OR table for 6 hours during a long procedure, but was placed back in the cooler just long enough for the SURFACE to cool to a seemingly “acceptable” temperature…?
• Is it safe to assume that the blood temperature never reached unsafe temperatures?

Problem #3
Accuracy of IR Thermometers is affected by how they are used – due to “Distance to Target” A.K.A. FOV (Field of View) or D/S Ratio (Distance to Spot)

Accuracy specifications for most IR thermometers range from +/- 1.0oC to +/- 2oC. Looking at a few models from major manufacturers, their D/S specifications are documented as: 1 meter, 1.5 meters and 2 meters – which might surprise blood bankers using IR thermometers. The distance between the device and the target (blood product) affects the reading accuracy – and also means that the dependability and repeatability of temperature readings is “user dependent” in how they use the IR thermometer from variable distances (you’ll read about this problem in the PathLabTalk post responses). If you’d like to learn more about this particular characteristic, Grainger (industrial and facilities maintenance equipment resource) has an excellent “Quick Tip” on IR thermometers.

Good Practice

Temperature indicators provide irreversible visual evidence if the blood product exceeds its specified temperature, even if the product is “re-cooled” prior to return to the blood bank.
Attaching an irreversible temperature indicator to the blood product, as done by the PathLabTalk poster, IS one way to know if the blood was maintained at correct storage/transport temperatures. When the blood product reaches the indication temperature (typically 6oC or 10oC), the indicator provides “irreversible” visual evidence of the temperature excursion – even if the blood product is “re-cooled” after being out of blood bank control.

This elicits a similar question that we raised regarding IR thermometers – do temperature indicators that adhere to the surface of the blood product provide indication of the surface temperature or core temperature?

Safe-T-Vue indicators (Temptime Corporation) are chemical indicators, and the algorithms that are used to formulate them are based on thousands of laboratory tests that incorporate the CORE blood product temperature. While the indicator may be applied to the surface, its color response is correlated to core temperature.

Why this all matters

Bacteria are very rarely transmitted during blood component transfusion, but if they are, they usually cause severe, life-threatening adverse reactions, with the mortality rate of 20-30%.2

Periodically, there are reports of incidents likely to have caused serious injury or death, that have been linked to bacterial sepsis from blood products that were dispensed for extremely long surgeries, and returned to the blood bank unused.3 Those very products could be returned to inventory after checking the temperature with an IR thermometer, and reissued to another patient. Unbeknownst to the blood bank, the blood products may have reached temperatures that allowed for contaminants to thrive. When that unit is then reissued and transfused to the next patient, the results can be catastrophic.

Kudos to the PathLabTalk poster for good practice

In summary, we understand that it’s unrealistic to assume that blood products will be handled outside of the blood bank with the same watchful eye and expertise that trained, focused blood bankers have. And there is little certainty of blood product maintenance at appropriate storage/transport temperatures, even when using a temperature sensing device to check the product on return to the blood bank.

The most sure way to know that the blood did not reach non-compliant temperatures – that could result in bacterial sepsis – is to use an irreversible temperature indicator that stays with the blood product during its entire time out of the blood bank – as the PathLabTalk post noted.

References
1. http://www.pathlabtalk.com/forum/index.php?/topic/6436-infrared-thermometer/

2. http://cdn.intechopen.com/pdfs-wm/27955.pdf

3.  http://www.jsonline.com/watchdog/watchdogreports/problems-at-hospital-lab-show-lax-regulation-hidden-mistakes-b99585186z1-330324081.html

The Results are in: Platelet Indicator Survey

65% would definitely use a platelet indicator, and another 12% said “maybe” or in special situations

Thank you to the 115 of you who participated in our October survey about platelet management and provided your feedback on a platelet temperature indicator. We’re excited to share what we learned….. and even more excited to tell you what we plan to do about it!

A few fast facts from the survey:

  • 65% would definitely use a platelet indicator and another 12% said “maybe” or in special situations

  • 80% of those who would use an indicator want a dual range indicator (20-24oC)

  • Reasons for not returning unused platelets to inventory (most common comments): (1) Time out of blood bank, (2) Uncontrolled/unmonitored environment, including temperature and lack of agitation and (3) Spiked bags, defaced labels

  • 75% of respondents take platelet temperature on return to the blood bank (but few have temperature monitoring during the time period the platelets are out of blood bank control)

The complete Survey Results are presented at the end of this VUEPOINT post.

Interest confirmed at AABB

To further explore the topic, we had a chance to talk about platelet management with many of the blood bankers at AABB. What they told us only validated what we learned in the survey – with patient safety always at the forefront, blood bankers need a better way to both (1) assure temperature compliance and (2) preserve precious platelet supplies. A temperature indicator would monitor platelet “temperature history” for the entire period it is out of blood bank control.

You’ve spoken and we’ve heard you

These recent interactions have revealed a potential new product need in the market. At Temptime, we have initiated the first steps of our new product development process focusing on a dual-range indicator for platelets. We are working to develop a deeper understanding of your needs and identifying potential product and technology solutions..

Get involved!

Temptime’s product development process depends on user input and field trials. If you’d be interested in providing input to the initial design and specifications for this new product development, we welcome your participation. Please email us and we will be in touch with you.

Survey Results

Q1: “Comments” Summary

  • 5-6 responses relative to time away from blood bank, lack of monitoring
  • 3 responses specific to agitation

Q1: “Other” Summary

  • 11 relative to time out of blood bank
  • 7 storage/uncontrolled environment
  • 7 spiked or modified bag/label
  • 5 “no swirling” observed
  • 4 noted “agitation” concerns

Q2: “Other” Summary:

  • 13 relative to time away and/or lack of monitoring/controlled environment (some specified >30 mins, > 2 hours)
  • 11 expired

Q3: Most common Text Responses summary:

  • 36 take temp with thermometer or temperature plate
  • 20 take temperature with IR thermometer
  • 16 “take temperature” (unknown how)
  • 13 use “touch/feel”
  • 7 report platelets returned in cooler, on ice or from fridge
  • 5 report that temp is monitored every 4 hours or constantly, or kept in temperature controlled chamber
  • 4 discard due to time

Q6: Most common Text Responses summary:

  • 6 report low usage or returns
  • 5 reference cost
  • 3 indicate would take temperature if unsure, indicator not needed 

Q8: Most common Text Responses summary:

  • 17 expired/outdated
  • 10 wrong/poor storage, including use of coolers
  • 7 time away from blood bank/control
  • 3 agitation concerns
  • 3 spiking bag and returned

Blood Bank Refrigerator Setpoints Matter

Learn about these important time/temperature correlations relative to your day-to-day blood bank operations.

Understanding the time pressures of busy blood banks, it would be fair to say that ANY time/temperature “advantages” – such as revisiting the refrigerator setpoint – might be worth consideration. Learn more in this VUEPOINT.

by Jeffrey Gutkind, Temptime

Over the past several months I’ve had the opportunity to visit some of the largest blood banks across the nation. In the course of talking with blood bankers about maintaining blood temperatures during storage, issue and transport, I observed a wide range of refrigeration setpoints, anywhere from 1.5oC to 4.7oC.

Reviewing my observations from these visits and reflecting on the AABB standard of 1.0oC to 6.0oC for storage, it brought me back to the “starting” temperature for blood when it’s removed from the refrigerator.

    • How does even a degree or two at a higher or lower storage temperature affect the blood temperature as it is dispensed and issued from the blood bank?
    • More importantly, how does the refrigerator setpoint affect how much TIME you have before the blood reaches 6oC?

To answer these questions, we asked Marielle Smith, Technical Service Scientist, to run a simple test in our lab.

How long does it take for refrigerated blood products to reach 6oC?

Blood Storage Temperature: 2°C vs. 4°C

The following table and graph show the time it takes for the core temperature of a refrigerated blood bag to warm to 6°C when removed from refrigerated conditions (2°C or 4°C) and placed on a counter-top at room temperature.1

The graph demonstrates that the lower the refrigerated storage temperature, the more time it takes for the blood bag to reach 6°C when warming at room temperature conditions. While these results are specific to the test method and setup used, they should be typical.

In terms of practical, day-to-day blood bank operations, what does this tell us?

Based on this test data, it suggests that blood bankers have over twice as much time to get blood issued and dispensed when the refrigerator setpoint is lower (2oC vs. 4oC). This represents a significant advantage for refrigerating blood at lower temperatures and longer times out of refrigeration before the blood goes out of specification.

Knowing that AABB guidelines state blood can be stored at 6oC for up to 42 days and transported between facilities below 10oC, and at the same time understanding the time pressures of busy blood banks, it would be fair to say that ANY time/temperature “advantages” such as revisiting the refrigerator setpoint might be worth consideration.

What do the blood refrigeration experts have to say?

After researching refrigerator setpoint specifications for a number of different vendors, we found that the factory setpoint is typically 4.0oC. Not being a refrigerator expert, I decided to reach out to Colleen Holtkamp Market Manager from Helmer® Scientific, to learn more. Colleen graciously provided these thorough answers to my questions, as well as thoughtful guidance for your consideration on setpoints, alarms and refrigerator specifications. (Colleen’s responses are in blue following the questions).

1. What is the typical factory setpoint temperature of your refrigerators when they go into the field? Are these setpoints easily changed, or does it have to be reset by the factory?

“The typical setpoint for Blood Bank Refrigerators is 4oC. Per AABB Standards, the acceptable temperature for storage of whole blood and most red cell components is 1oC to 6oC. Setting the temperature to 4ºC, close to the middle of the range, is standard practice for blood bank refrigeration.

It should be noted that the alarm setpoints are important, as well. AABB Standards state that alarms should be set to activate before blood components are exposed to unacceptable conditions. For example, since the lower limit for blood storage is 1oC, it makes sense to set the low alarm to 1.5oC (and since the upper limit is 6oC, a high alarm setting of 5.5oC is appropriate).

The ability to change the temperature setpoint depends on the manufacturer/brand of the refrigerator, as does the process for changing the alarm settings (instructions should be included in the refrigerator’s user manual).

Helmer Scientific Blood Bank Refrigerators enable the operating setpoint and alarm settings to be changed at the facility (they do not have to be reset by the factory). With temperature and alarm settings, it’s important to remember that while it should be reasonably convenient to modify them, it shouldn’t be so easy that they tend to be changed by mistake. A safeguard such as password protection for the refrigerator settings offers the best of both worlds – security and ease of use.”

2. Is there some type of statistic that you would use to say if the door is open for 3 minutes per hour; it will take XX minutes to get back down to the original setpoint?
As an example: If the refrigerator is set to 3.0oC and the door is open for 2 minutes, how long will it take for the refrigerator to get back down to the 3.0oC setpoint?

“There isn’t a standard method for measuring temperature recovery after a door opening. It can be impacted by variables such as ambient temperature and how much cold product is stored in the refrigerator at the time. What is important is that the unit has a heavy-duty, forced air refrigeration system and that the fan stops running while the door is open so that it does not blow out the cold air. In addition, the refrigeration system should be powerful enough to circulate the air inside the cabinet multiple times shortly after the door is closed, ensuring quick temperature recovery.

Another consideration is the importance of alarms. Having both a door open alarm and a high temperature alarm provides two layers of protection against temperature excursions due to door openings.”

3. What is the typical tolerance for blood bank refrigerators? (we found this information difficult to find in our online research).

“Blood Bank requires the tightest temperature uniformity of any cold storage application. The typical temperature uniformity specification for Blood Bank Refrigerators is +/-1oC. While not necessarily a regulatory requirement, many Blood Banks have written this specification into their internal protocols/SOPs. Therefore, it has become a community standard that drives performance expectations for Blood Bank Refrigerators.

Before a Blood Bank considers changing refrigerator setpoints from 4oC to 2oC, it is critical to think about the following information. If a blood refrigerator is set to 2oC, with uniformity of +/-1oC, the temperature inside the unit might reach the lower limit of the acceptable range (1oC). Also, if the low alarm is set to 1.5oC (which is advisable because AABB standards state that alarms should activate before blood is exposed to unacceptable conditions), it may be triggered by operation at 2oC. Helmer Scientific’s priority is to optimize the temperature of the blood bag while it is stored in our units. The setpoints and alarms are established to protect the blood while it is in the refrigerator.”

When it comes to blood bank refrigeration setpoints, what have we learned?

• The typical factory setpoint for blood bank refrigerators when delivered from the manufacturer is 4.0oC
• The ability to change the refrigerator setpoint at the blood bank varies by manufacturer
• Blood that is stored at 2oC takes over twice as long (approximate, based on our test) to reach 6oC at ambient, when compared to blood stored at 4oC
• Temperature recovery of refrigerators is affected by a number of variables (door opening, amount of stored cold product, ambient operating temperature)
• Low and high alarms, as well as open door alarms, are important and recommended by the manufacturers

If you have any recommendations, experiences, questions or ideas relative to refrigerator storage temperatures and your blood bank, we’d love to hear from you. Please POST A COMMENT or email us.

Jeffrey Gutkind
jeffg@temptimecorp.com

1Test Details
At each storage temperature, a total of six (6) simulated blood bags were tested. Each 600mL PVC blood bag (Charter Medical) was filled with 350mL of a mixture of 10% glycerol and 90% water, to simulate red blood cell volume. The bags were removed from refrigerated storage (at 2°C and 4°C) and then placed lying flat on a counter-top at room temperature (at approximately 21°C with 30% R.H). The temperature was measured by placing a calibrated temperature-sensing probe in the center of the simulated blood mixture inside the bag and the temperature was monitored using a calibrated Oakton Thermistor Thermometer. Temperature readings were recorded at 1 minute intervals. The data represents the time needed for the simulated blood mixture (10% glycerol with 90% water) to warm to 6°C.

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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.