Study of Clot Waveform Analysis in Various Clinical Conditions

Tabbu, S (2020) Study of Clot Waveform Analysis in Various Clinical Conditions. Masters thesis, PSG Institute of Medical Sciences and Research, Coimbatore.


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INTRODUCTION: Coagulation is a complex mechanism involving the vessel wall, platelets and multiple plasma proteins. The traditional coagulation tests frequently performed in the laboratory are the APTT, PT and Thrombin time. Recently, global coagulation assays like Thromboelastogram (TEG/ROTEM), Thrombin Generation Test (TGT) and Clot waveform analysis are gaining more clinical importance. Clot waveform analysis is one such assay which gives information on the entire process of coagulation. It is an optical waveform which depicts the clot formation process by measuring changes in transmittance or absorbance of light beam through the analysed sample. In this study we propose to study the clot waveform pattern in various clinical conditions like DIC, liver disorders, sepsis, APLA and bleeding disorders such as Haemophilia. Since the early detection of clot formation in the above conditions helps in early diagnosis and prognosis of the patients especially with reference to sepsis and DIC, we propose to evaluate the various patterns of clot waveform which plays an important role in the prognosis of the patient. AIMS AND OBJECTIVES: To analyze the clot waveforms generated by the automated blood coagulation analyzer CS-2400 in: DIC, Sepsis, Liver diseases, Haemophilia, Other bleeding disorders and Antiphospholipid Syndrome. MATERIALS AND METHODS: This is a cross sectional study. Blood samples received in the Clinical Pathology section of the Department of Pathology, PSGIMS & R for prothrombin time (PT) and activated partial thromboplastin time (APTT) during the period starting from December 2017 to June 2019 were taken into consideration for this study. Sample size: 200 Samples APTT samples received for monitoring of heparin therapy or PT samples received for monitoring of oral anticoagulant therapy were excluded from the study. 1. Centrifuge the sample at 2000 g for 15 minutes. 2. Obtain platelet poor plasma (PPP). 3. Perform PT/ APTT. 4. Analsye corresponding clot waveform in various conditions. 5.Interpret results. Coagulation analyser CS 2400: The CS-2400 system – A high performance coagulation station measures multiple parameters with a maximum throughput of 180 tests / hour. RESULTS AND OBSERVATIONS: The clotting process is categorized into three parts; the pre-coagulation phase (a-b), coagulation phase (b-d) and post-coagulation phase (d-e). Pre-coagulation is described as the first segment of the trace, from the beginning of the signal to the onset of coagulation. Usually, this phase is horizontal. After the onset of coagulation, light transmittance is decreased by the formation of fibrin and is defined by a slope in the waveform (b-d). At the end of coagulation, light transmittance tends to stabilize and is characterized again by a linear segment (d-e). Of the 200 cases in our study, 90 cases (45%) were liver diseases, 70 cases (35%) were APLA, 27 cases (14%) were sepsis and Disseminated Intravascular Coagulation (DIC) and 13 cases (6%) were diagnosed as bleeding disorders. In Antiphospholipid syndrome, 70 patients were analysed & sigmoid wave pattern was maintained in 62 cases (89%) with prolonged precoagulation phase in 61 cases. Biphasic wave pattern was seen in 7 cases & an altered pattern in 1 case. Clot wave pattern of APTT in 13 patients of Haemophilia & other bleeding disorders studied, 10 cases (77%) maintained sigmoid pattern with prolonged precorrelation phase. 4 cases of Haemophilia A showed dose-dependent change to factor VIII level. Of the 27 cases of DIC studied, 2 cases showed biphasic pattern of which 1 case was in overt & the other in Non-Overt DIC. An altered wave pattern with small downward deflection in the pre-coagulation phase was seen in 3 cases & 1 case showed long plateau with no distinction of the phases of coagulation. Of the 90 cases of liver disease studies, 67 cases (75%) maintained sigmoid pattern with prolonged pre-coagulation phase in 41 cases. Biphasic pattern was seen in 3 cases (3%) & altered pattern in 20 cases on (22%) PT wave. Of the 90 cases of liver disease, 27 cases showed slow slope in coagulation phase. CONCLUSION: In our study clot waveform analysis gave important data on global hemostasis & data corelated well with factor levels in Haemophilia A patients. This study revealed that CWA has significant clinical potential. However the limitation of our study was the paucity of the number of cases in each clinical entity especially DIC and bleeding disorders. This may have lesd to results that did not conform to what is reported in the limited literature on this topic. Hence the utility of this innovative global coagulation test will have to be explored further with more patient numbers for definitive results.

Item Type: Thesis (Masters)
Additional Information: 201713404
Uncontrolled Keywords: Prothrombin time, Activated partial thromboplastin time, Clot waveform, Coagulation.
Subjects: MEDICAL > Pathology
Depositing User: Subramani R
Date Deposited: 29 Jan 2021 18:37
Last Modified: 29 Jan 2021 18:37

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