To Condition or Not to Condition … That is the Question

You already know that irreversible blood temperature indicators help ensure that the blood products you dispense stay within the appropriate temperature range. This can ultimately save money by reducing blood wastage, while also maintaining quality control.

The problem? Not all indicators on the market are created equal. The ones that require conditioning in some way don’t always meet the needs of today’s busy, fast-paced blood banks. Those I’ve spoken with say that ease-of-use is as high a priority as accuracy and reliability. That’s what Safe-T-Vue delivers.

Once our indicators are stored with your blood for 24 hours, the Safe-T-Vue 6 and Safe-T-Vue 10 do not need any conditioning. I’m often asked if the indicator needs to be heated prior to use or if it needs to go back into the refrigerator prior to use once it’s been applied to a blood bag. The answer to both these questions is no.

Safe-T-Vue indicators need only be stored in the refrigerator along with Red Blood Cells (RBCs). When RBCs are needed, a staff member simply removes an indicator and blood bag from the refrigerator and places the Safe-T-Vue on the blood bag.

It’s easily activated by folding over the “rounds” and snapping them together.

That’s it.

Other indicators on the market say they require “no conditioning” – but that’s simply not the case. One in particular has to be heated to a specified temperature for 60 seconds prior to activation. Another maps out “best practices,” which recommend putting the blood bag back into the refrigerator for 15 minutes once the indicator has been activated. The problem here is that the activation process can be delicate in the former example – and waiting for blood as in the latter, even for just 15 minutes, is very often not an option.

Here’s how it all breaks down.

To save even more time, inactivated Safe-T-Vue indicators can be adhered to blood bags as they are received – then put back into the refrigerator until needed for quick dispensing. You can then simply activate the indicator when blood product is requisitioned. And once activated, Safe-T-Vue indicators are good for 42 days compared to the other indicators that must come off the blood bag after each reissue.  This makes the Safe-T-Vue the only indicator that can be reissued multiple times on the same unit of blood.Safe-T-Vue 10 Blood temperature indicator for blood transport and temporary storage

If you have questions about how Safe-T-Vue works – and how it can save you valuable time compared to others on the market, please contact us. We’d also be happy to send you some Safe-T-Vue samples so you can see for yourself how easy they are to use.

Jeffrey Gutkind


The Blood Supply Chain

Learning about the points of failure

We recently came across a white paper published by MaxQ Research LLC that breaks down the transfusion blood supply chain into “7 critical steps,” as illustrated in their infographic.  What was interesting to us is that the white paper discusses how in each of these steps “possible points of failure where any delays, miscommunications, or procedural issues can cause serious problems.”

Over the years, based on what we’ve learned from you, many past VUEPOINTs have focused on the fact that it’s the time blood products are out of your (blood bank) control where these delays or procedural issues can result in problems.  It’s for this very reason that many of you believe using an irreversible temperature indicator is the only way to know for certain that temperatures never exceed the 6oC or 10oC standard.

Before you dive into the entire white paper, which we encourage you to do, here are some key sections in the white paper’s introductory pages that we’d like to highlight, particularly when considering temperature indicators like Safe-T-Vue:

p. 5: Returned Blood and Blood Components

“Often there will be a need to return blood, blood components, to the blood bank/transfusion service.  This is possible only if:…

  • The appropriate temperature has been maintained….
  • The records indicate that the blood, blood component, tissue or derivatives have been inspected and that they are acceptable for reissue.”

While a qualified and validated storage/transport container validated for up to 24 hours may be used, there are well-known “points of failure in the blood supply chain” caused by human error.  If the blood product is removed from the storage container or cooler and left at room temperature, which happens in both the ER and OR, the blood could reach unsafe temperatures.  An irreversible temperature indicator like Safe-T-Vue is the only way to know if this exposure has occurred.  Use of an infrared thermometer or other temperature measuring device is not an adequate inspection method as the blood product may have been returned to the cooler and re-cooled – after having exceeded temperature standards.

p. 8: Cost of Blood Wastage is Significant

“Not only are blood products costly, but unnecessary losses or spoilage can result in shortages and put human lives at risk.  A more reliable and cost-effective solution is needed.”

Need we say more?

As the white paper points out, in 2010 the estimated direct cost of one unit of RBCs was $225.42, and this doesn’t account for overhead costs.  And then there is the truly unquantifiable cost and risk of a unit of temperature-compromised blood being transfused into a patient.

Learn more about blood transport packaging

You can download the white paper PDF and learn more about what hospitals and blood banks are using for shipping and storage today as well as the science behind these containers.

Many thanks to MaxQ Research for authoring and sharing this white paper. They would be delighted to entertain your questions and hear your reactions to their work.

As always, we also welcome your comments and questions, and appreciate the work that you do to maintain quality and integrity in your blood supply chain.


Jeffrey Gutkind

p.s. The bibliography on the last page of the white paper is an excellent resource, be sure to check it out.

Make a New Year’s Resolution: Keep track of blood losses in your blood bank

Preserve precious resources, save money and optimize patient outcomes

I recently had the opportunity to visit a large metropolitan hospital that uses about 200 units of RBCs in the OR and ER every day. They were interested in learning about how temperature indicators might help them preserve their blood supplies, which is why I was there.

When I asked the blood bank supervisor how many units they lose each day she responded “zero.” A little further into the conversation, I asked her again and she said, “maybe a few per month.” Next, I asked her how many of those were lost because of temperature exposure. She didn’t know.

While a number as “low” as five units a month may not seem significant, particularly for a large institution, the costs can mount up quickly.  If one unit of RBCs is estimated at $250, for example, then losing “only a few” units each month can mean $15,000 to $20,000 a year.  And for smaller hospitals, losing even one or two units a month adds up to $2500 to $5000 annually.

And, as Dr. Robert A. DeSimone said in an interview with Medical Lab Management in 2017, “Blood products are a precious resource…we have tremendous respect for our blood donors and their provision of this valuable resource to our hospitals and patients.”  His point? Monetary cost aside, every unit of blood lost is the loss of a truly precious resource.

How can you determine what you are losing if you don’t keep track?

Some blood banks use a log to track blood losses.  Here’s an example of a simple grid that might help you get started:

Reviewing the grid regularly gives you the opportunity to tally your monthly losses, as well as look for any trends.  This can help you uncover the REASONS for the losses, which may give you insight into what measures can be taken to reduce or prevent those losses from happening. Download PDF of the Blood Disposal Log.

What improvements can be made when you do log blood losses?

One outcome of this logging exercise is evaluating whether or not you should actually be disposing of blood.  Is it safe to return to inventory, or not?

Scenario #1: Blood is not returned to the blood bank based on the 30-minute rule.

  • Result: There is no proof that the unit actually exceeded the recommended transport/temporary storage temperature. You could be disposing of a perfectly good unit of blood.

Scenario #2: Blood is measured with an infrared thermometer upon return to the blood bank and deemed viable.

  • Result: There is no proof that the unit didn’t exceed temperature guidelines during the period it was out of the blood bank (you can read more about infrared thermometers here). It may not be safe to return to inventory.

Scenario #3: Using an irreversible temperature indicator provides proof as to whether the blood should or should not be returned to inventory based on temperature exposure.

  • Result: You only return blood that has not been exposed to excessive heat to the blood bank, assuring patient safety and minimizing risk. Plus, you may be able to avoid disposing of some units of blood you may have otherwise – saving a valuable resource and money over the long term.

Are temperature indicators worth the expense?

Simply put, using an irreversible temperature indicator is the only way to have confidence that blood is safe to return to inventory – potentially preventing unnecessary disposal.  While there is an associated cost to using indicators, if you are able to save even one unit of blood each month, valued at $250, the cost of temperature indicators is quickly offset by the savings. Costs are also justified by the added peace of mind and your ability to preserve valuable blood supplies.

Jeffrey Gutkind
Jeffg@temptimecorp.comBlood Loss - Disposal Log Sheet


Is there a single irreversible indicator that works for both 6 and 10 degrees C?

It’s that time of year, so let’s talk turkey!

We get this question from blood banks a lot when helping them select and validate indicators. Our answer? No, there is not one irreversible indicator that works for two temperatures. Yet at the 2017 AABB Annual Meeting, we heard from a number of blood banks who said they are using ONE.

There are two problems with a “one size fits both” indicator: (1) the indicator is reversible up until it reaches endpoint and (2) the inability to validate the indicator.

Why Blood Banks Use Indicators

When blood is in the blood bank, under your control, you have a reasonable assurance that it is being maintained below the AABB guideline temperatures of 6oC for storage and 10oC for transport.  But when blood is out of your control, and then returned to the blood bank, an indicator is critical for confirming that it never exceeded the temperature endpoint. If the blood product reaches endpoint, an IRREVERSIBLE indicator gives you a visual cue – even if it has cooled down to an acceptable temperature by the time it arrives back in the blood bank.

Problem #1- Reversible indication up through 9oC

As noted, some blood banks are currently using a single product for both 6oC and 10oC requirements.  Let’s call it “Indicator A.” While it is true that this indicator gives you a real-time visual of the blood product temperature between 1oC to 9oC, indication is only irreversible at 10oC.

So, in the case of 10oC applications, if the endpoint “flower” hasn’t changed color when Indicator A arrives back to the blood bank, the blood is considered safe and can be returned to inventory.

This isn’t the case for 6oC applications, however, because the indicator does not provide irreversible indication until the blood reaches 10oC.  That means if the temperature of the blood rose above 6oC for a period of time, but still stayed below 10oC and then fell below 6oC before returning to the blood bank – there would be NO visual indication that exposure over 6oC had occurred.

The assumption that Indicator A is irreversible for BOTH 6oC and 10oC indication is false.  It is not.

Comparison of Temperature indicators: 6oC Irreversible Indicator vs. and 10oC Reversible IndicatorIndicator comparison chart

Problem #2 – Validation at 6oC

Validating a temperature indicator is an iterative process that involves measuring blood product temperature with a calibrated thermometer, and then recording the temperature at which the indicator reaches its irreversible visual indication state.

Indicator A can be accurately validated for 10oC applications, similar to our Safe-T-Vue 10.  Both will provide irreversible indication when the 10oC endpoint is reached – with Indicator A’s flower changing colors and Safe-T-Vue’s dot turning red.

If the intent is to use Indicator A for 6oC applications, however, it is impossible to validate it.  Indicator A provides no irreversible visual indication if the blood exceeded 6oC at any point during the time it was out of control of the blood bank.

Let’s Get Back to the Meat of It

Think about cooking a turkey. You set your oven to 450 degrees for 5 hours and wait for the plastic thermometer to pop to let you know the bird is done. You don’t care if the oven dipped to 350 when you opened the door to check it, you just care that your turkey is thoroughly cooked. The pop-up thermometer gives you an irreversible visual indication, but with no record of the actual temperature as it’s cooking.

The same applies to blood indicators:

  • A blood temperature indicator can provide irreversible indication of only one temperature, not two
  • There is no value in the “reversible” scale on an indicator; it doesn’t capture the temperature history – it only indicates real-time temperature
  • As a result, validation of a reversible indicator is impossible

This is why Temptime recommends using Safe-T-Vue 6 for 6oC applications and Safe-T-Vue 10 for 10oC applications.  Both are irreversible and can be validated for the indication temperature.

If you have questions about the difference between reversible and irreversible temperature indicators, and the importance of irreversible indicators, please contact us.  You can also read these validation procedures to get a better understanding of how a reversible indicator cannot be validated.  Or, request Safe-T-Vue samples and see for yourself.

Jeffrey Gutkind

“Clinical Temperature Management of Blood Products”

An interview with Robert A. DeSimone, MD as published in Medical Lab Management, July/August 2017

In this article by Transfusion Medicine Fellow, Dr. Robert A. DeSimone, he shares his experience with a small pilot study conducted at the New York Blood Center, and answers critical questions such as:

  • What are the risks and benefits of accepting and reissuing returned blood cell concentrates?
  • What has been the historical procedure when considering acceptance of RBCs without temperature maintenance?
  • What are the weaknesses with the 30-minute rule?
  • What method would you recommend the lab follow for accepting returned blood products?
  • What implications does your study have for blood bank practice?

The article may also be viewed online at Medical Lab Management.

Visit us at AABB booth #2447 to learn more about Safe-T-Vue temperature sensitive indicators for blood products.

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).


  • 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

Does the “30-minute rule” still apply?

Making sense of storage, transport, time and temperature

Recent conversations on PathLab Talk surrounding the 30-minute rule are drawing new attention from blood banks, whose interpretations of the AABB, FDA and CAP guidelines are ever-evolving.

The title of a presentation made at AABB 2015 (9108-QE) in Anaheim says it all:

“Making Sense of the Reissue Standard: Storage, Transport, 30-minute Rule, Coolers, Continuous Monitoring, USBs, Wireless Systems….How to Best Meet It Without Pulling Your Hair Out!”

transport_cooler_validationAnd as recently as last week at AABB 2016 in Orlando, the “word on the street” was that while AABB still allows the 30-minute rule, the new requirement is that the process must be validated and documented.

In this VUEPOINT, we will present information on blood reissue, based on content from this AABB presentation, CAP and AABB guidelines, and our work with two major U.S. hospitals. Specifically, we took into consideration information these hospitals have shared relative to interpreting return requirements and validation criteria to maintain compliance and safety for their patients.

The Guidelines

Simply stated, AABB Standard 5.26 and FDA Regulation 21 CFR 640.2 establish these return requirements relative to temperature:

  • Appropriate temperature
    – – – has been maintained (AABB)
    – – – blood has been continuously stored 1-6oC or transported 1-10oC
  • Records indicate the temperature inspection was performed and was acceptable

CAP TRM.42470 states:
“Acceptance Back Into Inventory: There is a written procedure validated by the laboratory, for accepting blood/blood components back into inventory after they have been issued.

NOTE: The procedure must include steps to verify the integrity and appearance of the container and maintenance at appropriate temperatures.  The steps and criteria defined in the procedure for acceptance of units back into inventory, such as the “30 minutes” rule, must be validated by the laboratory.”1

AABB Technical Manual, 18th Edition:
“Validation is used to demonstrate that a process is capable of consistently and reliably achieving planned results.”2

The Common Theme:Validation of the Process

As pointed out in the AABB 2015 presentation, “return criteria for temperature is directly related to the validation….”. With the “30-minute rule” the focus has been on TIME. In contrast, all of the guidelines focus on TEMPERATURE. And it is the documented validation of your process(es) that proves the consistent maintenance of temperature, continuously, for the life of the process.

It may sound easy, but can you accurately validate your process(es) – specifically, continuous temperature maintenance, from the time blood is dispensed until it is returned? Let’s consider all the points in the process that may require validation.

Validation Points

Let’s assume you dispense blood in validated coolers. Great! But have you validated the PROCESS for each (possible) step? Have you validated for every possible scenario – each validation point? For example:

  • Every blood product
  • All sizes/volumes of blood products
  • All possible packing scenarios – one bag, 3 bags, more?
  • All possible transport scenarios or “paths” and the time/environment associated with each – hand-carry, pick-up, cooler, pneumatic tube system
  • Recipients or destinations – each OR, ED, patient rooms, floors, nursing stations

Validation Points GraphYour validation documentation must show that your process is (1) consistent over time and (2) with exact temperatures. One of the hospitals we spoke with said this would be virtually impossible for them, since there are so many scenarios in their institution due to the hospital size, and the number of ORs and patient rooms.

Thinking of it this way, is it POSSIBLE to validate the “30 minute rule” in your institution? More important, can you actually capture and document a wide enough range of scenarios in your process, taking into consideration all the variables? Are your processes that consistent? And would it be worth the time it takes to validate all of the potential scenarios?

So, what about the “30-minute rule”?

The latest interpretation is that the 30-minute rule can be used, but only if the entire process was validated. When you can validate your process per CAP, AABB or FDA guidelines, “30-minutes” becomes a non-issue. As long as you have validated the process to prove that the temperature can be consistently and continuously maintained at acceptable storage/transport temperatures, the time factor is no longer applicable.

Is there an easier or more efficient way to validate process (es)?

Processes incorporating temperature indicators require fewer validation steps – AND provide more reliable indication of the temperature “history” of the blood product for the entire time it is out of blood bank control. Because the indicator is validated, using an indicator shows if the blood is kept at an acceptable temperature from the time it leaves the blood bank until it is returned.

Clearly, using a temperature indicator such as Safe-T-Vue is more time efficient and reliable at validating the entire process. And, if a unit is out longer than its time limit (whether it’s 30 minutes or 4 hours), the unit can be deemed acceptable on return if the indicator shows that its temperature has been continuously maintained, thus resulting in less waste and overall more cost-effectiveness.

1. CAP Guideline TRM.42470
2. AABB Technical Manual, 18th Edition

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 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.


Jeff Gutkind