Analysis of failure causes and countermeasures of automatic coagulation analyzer detection of thrombin time].

R Wang, M Y Yang, M L Wang, S Guo

Zhonghua yi xue za zhi 2022 Mar 22

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To study the failure alarm information displayed on the automatic coagulation analyzer (coagulation method) of thrombin time (TT), and formulate the coping strategies combined with clinical information. Methods: A total of 233 failed TT blood samples [132 males, 101 females, with a median age of 73 (66, 79) years] were selected from 21 359 inpatients in Peking University First Hospital from January to June 2021. The statistical analysis was made and the failure causes and solutions were summarized according to the coagulation curve and the error codes displayed on the coagulation instrument, in combination with the clinical information, sample characteristics, medication status and other reasons. Meanwhile, a total of 96 TT detection failed lipid blood samples [56 males, 40 females, with a median age of 72 (65, 79) years] were analyzed from the inpatients in Peking University First Hospital from July to November 2021. TT results were obtained by artificial coagulation curve interpretation method, magnetic bead method and high-speed centrifugal re-detection method, respectively. The TT results of the three methods were compared. Results: The proportion of 233 failed TT tests from the total number of samples was 1.1% (233/21 359). There were 41.2% (96/233) samples with lipids, 23.2% (54/233) samples with heparin interference, 22.3% (52/233) samples with oral anticoagulant, and 13.3% (31/233) samples with micro-coagulation or insufficient plasma volume among these test failure samples. The classifications for these alarm information of coagulation curves showed on the instrument were as follows: 32.6% (76/233) of samples with higher changes in absorbance at baseline (SD>2 mAbs), 30.5% (71/233) of samples without peak values of second derivative, 25.8% (60/233) of samples with absorbance difference<35 mAbs between baseline and plateau period, 8.6% (20/233) samples with too low starting point or no starting point, and 2.6% (6/233) samples without coagulation curves. Among these 233 samples, there were 55.8% (130/233) samples that could be manually judged according to the reaction principle and standard coagulation curve pattern. Among the 96 samples that failed in coagulation method due to lipemia, there were 78 samples with sufficient blood volume tested by magnetic bead method. The TT results of the high-speed centrifugal redetection method, artificial coagulation curve interpretation method and magnetic bead method were 14.10 (14.80, 13.38) s, 14.30 (14.99, 13.60) s, and 15.65 (17.25, 14.65) s, respectively, but the difference was not statistically significant (P=0.055). For 78 lipid samples, there was a correlation between the results of the artificial coagulation curve interpretation method and the results of magnetic bead method (r=0.99,P=0.001). Conclusions: For those samples failed in TT detection by coagulation method on automatic coagulation instrument, the cause of failure can be analyzed through coagulation curve and alarm information. For the lipid samples, TT results can be obtained by manual interpretation method, high-speed centrifugation method and magnetic bead method.

Citation

R Wang, M Y Yang, M L Wang, S Guo. Analysis of failure causes and countermeasures of automatic coagulation analyzer detection of thrombin time]. Zhonghua yi xue za zhi. 2022 Mar 22;102(11):808-812