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.

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.

How can you monitor CORE blood bag temperature with adhesive temperature indicators?

With several indicators on the market, it’s increasingly confusing to know what to use – or who to trust.

There’s been a lot of “buzz” lately about measuring core temperature of blood units during temporary storage and transport.  Do the adhesive temperature indicators on the market, including Safe-T-Vue, measure core temperature?

The simple answer is NO.

Since all of the available temperature indicators are applied to the blood bag surface, they do not measure core temperature. As most of you know, there is no way to measure core temperature of a blood unit during temporary storage and transport without inserting a temperature probe into the “core” of the bag.

So, if the indicators aren’t sensing core temperature, what are they sensing?

These adhesive temperature indicators are actually measuring the surface temperature of the bag, not core temperature.  Safe-T-Vue also measures the surface temperature of the bag. However, through over 20,000 laboratory tests, we have developed direct correlations between blood bag surface temperature and core blood product temperatures.  This process allows us to formulate a consistently performing adhesive surface indicator, and assures that Safe-T-Vue indicator response is accurately correlated to actual core temperatures.

How can you trust the performance of a temperature indicator?

1. Published product specifications

Suppliers, like William Labs, publish the temperature accuracy of their products, usually in their product literature and on their websites.

Safe-T-Vue has correlated temperature indication to core blood bag temperature supported by over 20,000 test data results that quantitatively support the consistency, predictability and repeatability of its indicator performance.

2. QA Documentation

Some suppliers take the “proof” of temperature accuracy a step farther, by supplying their customers with QA documents and procedures, documenting the temperature data for that product, for each lot, to prove that testing was performed and the product performs to specification.  Safe-T-Vue is shipped with accompanying QA documents, which can also be accessed anytime from our website.

For added confidence and convenience, the validation procedures for Safe-T-Vue are published on the website, for those users who would like to perform their validations and replicate our work in their own labs.

3. FDA 510(k) and Quality Audits

As you know, the purpose of the FDA is to oversee safety.  Section 510(k) helps the FDA make sure new medical devices are safe and effective. New medical devices submitted under 510(k) rules must also be “substantially equivalent” to other similar marketed products.

This FDA regulation that applies to medical devices, including temperature indicators, is of critical importance.  It assures that the supplier of the product you are trusting to “do its job” is both safe and effective.  510(k) ensures the product is as safe and as effective as other 510(k) devices already on the market.

Just because a product is being sold into the healthcare market, do not assume it has been cleared by FDA 510(k).  Ask your supplier – and make them prove it.

Additionally, credible suppliers have a quality plan to support the process and accuracy claims of their products.  For example, actual and statistical verification of Safe-T-Vue data supports the product claims.  As part of the quality plan, this data is reviewed by the company’s QC staff and annually by external auditors.

What’s next?

We’ve been so stimulated by the recent conversation about core temperature, that we’re making plans now for comparative studies in early 2014, which we will be sharing with you.  Our new partnership with Temptime has expanded our time-temperature testing capabilities and laboratory expertise in healthcare, so look forward to these and other test results in the coming year.

As always, if you have any thoughts on core temperature measurement and adhesive temperature indicators, we always appreciate hearing from you.  Feel free to post a comment on the VUEPOINT post, or email us.

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.