Prediction Of Coagulation Testing In Underfilled Patient Samples

SUMMARY

• The global market size for coagulation testing is expected to grow at  a CAGR of 7.7% and reach US$3.5 billion by 2027 from US$2.1 billion in year 2020. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are the most frequently performed coagulation tests with estimated annual test volumes of 65.9 million and 45.6 million, respectively.
• The Clinical & Laboratory Standards Institute (CLSI) recommends that blood samples used for coagulation testing have a 9:1 ratio of sample to anticoagulant. Those that are <90% filled are rejected since underfilled samples may lead to inaccurate measurements. Up to 10% of samples drawn in the ER are rejected due to under-filling. The rejections present difficulties such as the need for another sample to be sent, potentially resulting in additional needle sticks, increased risk of complications  and patient discomfort, increased time used  and a delay in treatment of critical health conditions (e.g., ischemic stroke)  thus impacting treatment decisions/outcomes.   
• While using real underfilled patient samples, this technology corrects the sample (topping up) with an imidazole buffer to adjust the sample-to-anticoagulant ratio. Measurements  can be used to correct PT, aPTT and fibrinogen levels, which allow for the accurate prediction of these coagulation test values in underfilled patient samples. 

ADVANTAGES

ADVANTAGES

• Samples filled up to and over 50% can be filled with buffer solution to obtain reliable results in comparison to true results.  This means that the threshold for acceptance can be lowered to 50% volume fill from the current value of 90%. 

APPLICATIONS

• Feasibility of expansion of rules for acceptance of underfilled tubes for coagulation testing
• With the advent of sophisticated coagulation analyzers, this approach may potentially be incorporated in an automated system that would:
  • l) accurately measure the actual blood volume in the tube,
  • 2) automatically pipette in the amount of imidazole-buffered saline required to bring the total volume up to the proper, fully-filled level,
  • 3) keep track of the specimen’s underfilled status, and
  • 4) employ an algorithmic approach for estimating the values had the specimen been properly filled at the outset, together with cautionary statements as to limitations of this approach.

February 10, 2022

Proof of concept

Patent Issued

Licensing

Johnathan Miller

• Patent No. US 10,976,305