An observational study in Snakebite and Coagulopathy, Consumption, sponsored by Jubilee Mission Medical College and Research Institute. Completed at 1 site in India. Per ClinicalTrials.gov, last updated 2023-07-17.
Sponsored by Jubilee Mission Medical College and Research Institute · Observational
In hematotoxic snakebites, due to the lack of a better alternative, 20 minute whole blood clotting test (20'WBCT) or Clotting time remains the standard test in developing countries even though its reliability and sensitivity has been shown to be low.
Activated partial thromboplastin time (aPTT) based Clot Waveform Analysis (CWA) is an optic absorbance assay that can be used as a global clotting test.
It essentially detects the change in colour of the plasma as coagulation progresses and quantifies the change in the form of a waveform.
In this study, the investigators intend to study prospectively the behaviour of clot wave (CW) in hematotoxic bites.
A pilot observational study was initially conducted (IEC Ref No. 42/16/IEC/JMMC and RI) and CWA showed changes which provided information earlier than the conventional coagulation studies in the snakebite victims studied.
While aPTT or WBCT reflects clotting time, CWA conveys the dynamic process of clot formation. CWA may reveal disorders of clotting in snakebite victims before the conventional tests become abnormal.
Here the investigators aim to study the changes in CWA in snakebite victims who develop coagulation disorders in blood
Viperidae bites are quite common in India and are notorious to cause hematotoxicity.
In hematotoxic bites, the test recommended to ascertain the development of coagulopathy is a whole blood clotting test (WBCT) as per the current guidelines.
Eventhough the reliability and sensitivity of WBCT has been shown to be low, it still remains the standard test.
There exists a need to explore other coagulation studies in snakebite to look for a better and efficient alternative.
Clot waveform analysis (CWA) is an activated partial thromboplastin time (aPTT)-based optic absorbance assay that can be used as a global clotting test.
It has been shown useful in identifying disseminated intravascular coagulation (DIC) in sepsis with high specificity (97.6%) and sensitivity (98%), and the test is recommended by the British Committee for Standards in Hematology guidelines for the diagnosis and treatment of DIC.
CWA is based on the traditional aPTT assay. On assessing aPTT with light transmission, a change in the light absorbance is observed as the clot stabilizes by fibrin polymerization.
Plotting the milliabsorbance (mAbs) of the sample to time, a curve is obtained which reflects the optical profile that is generated as a clot is formed.
This tracing against time gives a qualitative assessment of fibrin polymerization.
The delta in absorbance (dAbs) is based on the change in mAbs value from the baseline to the endpoint (plateau) along the Y-axis of the clot curve. The dAbs values of \<100 mAbs denote low fibrinogen samples
The normal clot waveform has five main phases: delay, baseline, acceleration, deceleration, and end point.
The "delay" period begins at 0 and precedes the "baseline." which denotes the mixing of the reagents and system optimization of light intensity.
The "baseline" is the portion of the curve which appears after all reagents have been added to the time and the clot formation begins.
The aPTT value is noted at this point (vertical red line). The "acceleration" phase denotes fibrin clot formation, whereas "deceleration" denotes decreasing rate of clot formation.
There are two more curves that are plotted in CWA, the first derivative and the second derivatives. They are both derivatives of the absorbance curves. The first derivative reflects the coagulation velocity, whereas the second derivative reflects the acceleration of coagulation.
The investigators in this study aim to assess the changes in the CW form in viper-envenomated victims and to compare CWA with standard tests such as prothrombin time (PT) with the international normalized ratio (INR), aPTT, clotting time (CT) (modified Lee and White method) and 20'WBCT( twenty minute whole blood clotting test)
38 studies on the registry are indexed under Snake Bites; 11 are open to participants now.
This study's enrollment of 96 is close to the median of 99 across 19 observational studies indexed under Snake Bites.
Browse Snake Bites studies →Jubilee Mission Medical College and Research Institute is the lead sponsor of 25 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
All victims of snakebite consenting to be part of the study presenting to the emergency department at Jubilee Mission Medical College and Research Institute Thrissur, Kerala, India
Snake bite registry would be established All consecutive cases would be enrolled in the study if they consent to be part of it.
Sub group analysis excluding the dry bites,would be done Sub group analysis of the victims of hematotoxic snakebite would be done
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
-snakebite victims were (aPTT) sample has been sent
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Snakebite victims in whom the snake has been brought and positively identified as Viperidae AND simultaneous aPTT has been sent AND consenting to be part of the study
age and gender matched victims of snake bite in whom the culprit snake brought along has been identified as a non venomous one. AND consenting to be part of the study
Clot wave form 1st derivative changes
Changes in the 1 st derivative
Time frame: For all aPTT samples done at admission, just prior to antivenom administration, 6 hours after antivenom administration completion and 6 hours after blood product administration, upto 7 days post admission.
Clot wave form 2nd derivative changes
Changes in the 2nd derivative
Time frame: For all aPTT samples done at admission, just prior to antivenom administration, 6 hours after antivenom administration completion and 6 hours after blood product administration, up to 7 days post admission.
changes in delay phase, baseline, acceleration, deceleration and end point phases of CWA
Changes in the predefined Clot wave segments
Time frame: For all aPTT samples done at admission, just prior to antivenom administration, 6 hours after antivenom administration completion and 6 hours after blood product administration, up to 7 days post admission.
Clotting time (CT)
The absolute clotting time by modified lee white method done for all samples as per institutional protocol
Time frame: For all CT samples done at admission, just prior to antivenom administration, 6 hours after antivenom administration completion and 6 hours after blood product administration, up to 7 days post admission..
maximum coagulation velocity
maximum coagulation velocity
Time frame: For all aPTT samples done at admission, just prior to antivenom administration, 6 hours after antivenom administration completion and 6 hours after blood product administration, up to 7 days post admission.
sensitivity and specificity of CWA in detecting envenomation compared to 20'WBCT and MLW (Modified Lee and White) method
To test how sensitive and specific changes in CWA is in detecting coagulopathy in snakebite victims compared to the World Health Organisation Recommended twenty minute whole blood clotting test and the modified lee white clotting time done as per institute protocol
Time frame: from admission till time of objective detection of coagulopathy, or up to 48 hours of admission, whichever is earliest
correlation of CWA with serum fibrinogen levels
For all serum Fibrinogen and aPTT sample sent simultaneously correlation of CWA parameters with serum fibrinogen levels
Time frame: For all serum Fibrinogen and aPTT sample sent simultaneously upto 48 hours of admission.
Plan to share: Undecided
This study is completed, as verified in Jul 2023. You cannot join it, but the record below documents what was studied.
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Jubilee Mission Medical College and Research Institute