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


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.

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.


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

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.