Development of a rapid emergency hemorrhage panel

Abstract

Background: Evaluation of hemostasis in bleeding patients requires both accuracy and speed.

Study design and methods: As an alternative to point-of-care testing, we developed an emergency hemorrhage panel (EHP: prothrombin time [PT], fibrinogen, platelet count, hematocrit) for use in making transfusion decisions on bleeding patients with a goal of less than 20-minute turnaround time (TAT) when performed in the clinical laboratory on automated instruments. Because point-of-care samples are not checked for clotting or hemolysis, we evaluated their effect on automated testing.

Results: TAT was reduced by moving the sample immediately to testing and shortening centrifugation times. Clotting in samples was rare (1.1%) and shortened the PT by only 0.7 seconds. It lowered fibrinogen on average 18%, but resulted in only one of 2300 samples changing from normal to low fibrinogen. Hemolysis had no clinically significant effect on the PT or fibrinogen. Therefore, hemolysis checks were eliminated and clot checks minimized. Initially TAT averaged 15±4 minutes (range, 8-30min), but 9% of samples exceeded the 20-minute goal due to low fibrinogens that slowed testing. A revised fibrinogen assay with expanded calibration range resulted in a TAT of 14±3 minutes (range, 6-28min) with only 2% of samples exceeding the 20-minute goal. By limiting EHPs to patients that were actively bleeding, EHPs accounted for only 8 of 243 coagulation samples per day.

Conclusion: Limiting EHPs to bleeding patients and modifications to the process and assays used for hemostasis testing lead to TATs of less than 20 minutes for critical testing in the clinical laboratory.