Hemostatic Variables In Snakebite Study (HISS)

Haemostatic Variables in Snakebite: a Regional Prospective Cohort to Identify the Role of Global Coagulation Assays and Serial Laboratory Testing in the Management of Snakebite Coagulopathy

Background

Novelty The global assays of coagulation, namely the viscoelastometric tests and clot waveform has never been studied in detail before in snakebite victims.

The pathophysiology of VICC including specific factor deficiencies and serial trend in blood cell indices amongst various hematotoxic snakebite in the region is not known.

No Indian study to date has systematically examined the changes in early laboratory tests results in envenomed and non envenomed snakebite victims.

Study Overview

• Status: Completed
• Conditions: Snake Bites; Coagulopathy, Consumption

Detailed Description

The problem:

Snakebite is a neglected disease of the poor in India. Nearly 50,000 individuals die of snake bite every year in the country, making it the region with most number of snakebite related deaths in the world.

Snakebite though is one of the leading cause of mortality and morbidity globally, it is in fact a "local" problem which warrants a regionalized approach. The venom characteristics of snakes and their response to treatment vary across geographical regions, even within the same species.

Therefore the venom sourcing for antivenom production, to clinical characterization of snakebites needs to be regionalized.

Clinical profiling of snakebite has been done in many observational studies across the region but a comprehensive prospective regional profiling of laboratory parameters including the global assays have not been done to date.

The health care in India is mostly out of one's own pocket, and the victims are of the lower socio economic strata the health care costs are seldom affordable. Research in the field is also sparse due to lack of funding for the same. The investigators through this research aim to study the clinical and laboratory profile of snakebite victims presenting to a tertiary care snakebite treatment centre in central Kerala and the role of global coagulation assays in the management of the same.

Once answered, the research question, would provide a better understanding of the hematotoxic snakebite in the region.

It could aid in better patient care strategies, including possible determination of a better test for coagulopathy, judicious antivenom and blood product usage.

Its relevance in local, national and international context:.

Snakebite being region specific warrants a region specific approach to the problem. Venomous species like Humpnosed pit viper (Hypnale hypnale) envenomation which is the second most common snakebite (first being Daboia russelli ) in the region is a serious problem that needs better understanding.

This would be a model which can be replicated in selected tertiary care snakebite centers across the country. Answering these research questions across the country would lead to better understanding of coagulopathy in snakebite, its response to antivenom and blood products in India.

It may also lead to quantifying the need for region specific antivenom in the country.

No Indian study has systematically examined the changes in early laboratory tests results in envenomed and non envenomed snakebite victims to date.

With the exception of a few case reports there has been no studies that has looked at the performance of global coagulation assays in the country.

The country that becomes the largest contributor of global burden of snake bite in terms of mortality is India.

This model if applicable in India, should be replicable elsewhere too. Ten years back, the investigators would not have been able to envision this study, since the understanding of the process of snake bite related coagulopathy was limited, and it was national projects like the Australian snake bite project implemented elsewhere that form the basis for the current understanding of the problem of snakebite.

In the international context many other low and middle income countries that are burdened by snake bites would benefit from any result in terms of a better bedside coagulation test (like CWA or MLW) or a cheaper blood indices (DNI) to prognosticate snake envenomation.

The understanding of coagulopathy in snakebite is now changing. Conventionally, although this coagulopathy is likened to disseminated intravascular coagulation (DIC), in the recent years, it has been described as venom-induced consumptive coagulopathy (VICC).

VICC defers from DIC in its rapidity of both onset and resolution. It used to be compared to Disseminated Intravascular Coagulation, but now the understanding of the same is changing and more recently the term VICC- Venom induced consumptive coagulopathy has been introduced. The snake venom in India are known to contain Factor V activators (D russelli), Factor X activators (D russelli), prothrombin activators (PTA) (Echis sp.), thrombin like enzymes (TLE) and fibrinogenases (Trimeresurus sp,. Hypnale hypnale). The above mentioned findings are mostly from studies in Srilanka, with assays done in samples frozen and sent to Australia, by the same team of investigators.

There are not many properly conducted study from any region of India that helps understand the pathophysiology better.

• Study Type: Observational
• Enrollment (Actual): 96

Contacts and Locations

Study Locations

• India
  • Kerala
    • Thrissur, Kerala, India, 680005
      • Jubilee Mission Medical College and Research Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All patients with history suggestive of snakebite presenting within 6 hours of snakebite and providing a written informed consent and/or assent would be included in the study

Definitions:

'Snakebite' OR 'History suggestive of snakebite' would be defined as, patients or their bystander claiming in sound mind not and not under the influence of any inebriants, to have witnessed being bitten by a snake, OR, patient with clinical features of snakebite as suspected by the clinician on floor

Description

Inclusion Criteria:

1. All patients with history suggestive of snakebite presenting within 6 hours of snakebite AND
2. All providing a written informed consent and/or assent

Exclusion Criteria:

1. All patients of stings or bites other than snakes
2. All patients who received antivenom or blood products at another institute
3. All patients with known hematological malignancies, coagulation disorders, chronic liver or renal failure.
4. All patients known to be on warfarin, heparin or any newer oral or injectable anticoagulants
5. All withdrawing a consent later on, or withdrawing assent later on-

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To study the serial change in CT of snakebite victims	Change from baseline (sample taken at admission) for clotting time would be recorded in minutes and seconds assessed at 1 hour (post admission), 1 hour 30 mins (post admission), 3 hours (post admission), 6 hours (post bite), 6 hours post antivenom, 6 hours after blood products or 12 hours after antivenom and at discharge or at 30 days (whichever is earlier)	up to 30 days
To study the serial change in fibrinogen levels of snakebite victims	The change in fibrinogen levels from baseline (sample taken at admission, 0 hour), 6 hour post bite, 6 hours post antivenom,12 hours post antivenom, 6 hours after blood products and at discharge or at 30 days (whichever occurs earlier), measured in weight per volume (milligram per decilitre).	up to 30 days
To study the serial change in D dimer levels of snakebite victims	The change D dimer from baseline (sample taken at admission, 0 hour), 6 hour post bite, 6 hours post antivenom,12 hours post antivenom, 6 hours after blood products and at discharge or at 30 days (whichever occurs earlier) measured in weight per volume ( micrograms per decilitre respectively).	up to 30 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy of Clotting Time in detecting coagulopathy	Sensitivity and specificity of Clotting Time (minutes) done using Modified Lee and White method (MLW) in detecting coagulopathy compared to conventional coagulation test (PT, aPTT)	48 hours
Diagnostic accuracy of 20'WBCT, MLW, Delayed reading of 20'WBCT in detecting coagulopathy	Sensitivity, specificity of; 20'WBCT (minutes); Delayed reading of 20'WBCT (30'WBCT) in detecting coagulopathy compared to conventional coagulation test (PT, aPTT)	48 hours
Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of the bedside coagulation tests.	Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of bedside coagulation tests (20'WBCT, MLW Clotting time, Delayed reading of 20'WBCT, Activated Clotting Time) (before and after antivenom)	48 hours
Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation conventional coagulation tests	Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of conventional coagulation tests PT/INR and aPTT (before and after antivenom)	48 hours
To study the serial change in PT and aPTT-clot waveform of snakebite victims	The change of PT and aPTT-clot waveform from baseline (sample taken at admission; 0 Hours) would be recorded in milli absorption (mabs) per second, 6 hours (post bite), 6 hours post antivenom, 12 hours post antivenom ,6 hours after blood products and at discharge or 7 days whichever is earlier	up to 7 days
To describe the clinical characteristics of snakebite victims measured as per a pre set proforma	The clinical characteristics of snakebite victims, including systemic manifestation and local manifestations would be measured as per a pre set proforma	up to 30 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to envenomation in hematotoxic snakebites in the region	time taken from snakebite, to development of signs or symptoms suggestive of envenomation in the first 7 days post bite measured in days, hours and minutes	7 days
Time to envenomation in Russells viper snake bite in the region	time taken from snakebite, to development of signs or symptoms suggestive of envenomation in the event of a Russells viper (Daboia russellii) bite measured in hours and minutes	48 hours
Time to envenomation in pitviper (crotaline) snake bite in the region	time taken from snakebite, to development of signs or symptoms suggestive of envenomation in the event of a pit viper bite Crotaline snakes, like humpnosed pitviper, large scaled pitviper, green pit viper and horseshoe pitviper measured in hours and minutes	48 hours
To study the serial change in ROTEM waveform of snakebite victims	The change in ROTEM waveform would be recorded from baseline (sample taken at admission; 0 Hours) in amplitude (mm) per time (minutes), 6 hours, 6 hours post antivenom,12 hours post antivenom, 6 hours after blood products and thereafter every 6th hourly upto seven days.	up to 7 days
To study the serial change in PT, aPTT of snakebite victims	Change from baseline (sample taken at admission) for prothrombin time, activated partial thromboplastin time would be recorded in minutes and seconds assessed 6 hours (post bite), 6 hours post antivenom, 6 hours after blood products or 12 hours after antivenom and at discharge or at 30 days (whichever is earlier)	up to 30 days
To study the serial change in coagulation factor assays of snakebite victims	The change of coagulation factor assays from baseline (sample taken at admission; 0 Hours) would be recorded in international units (IU) per volume (millilitre, decilitre) and at 12 hours post antivenom.	up to 7 days
Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of coagulation factor assays.	Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of coagulation factor assays (before and after antivenom)	48 hours
Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of Clot Waveform analysis (CWA) and Rotational Thromobelastometry	Change in coagulopathy in snakebite victims, after antivenom administration as measured by normalisation of the waveforms in CWA and ROTEM (before and after antivenom)	48 hours
To study the serial change in myoglobin levels of snakebite victims	The change serum myoglobin from baseline (sample taken at admission, 0 hour), 6 hour post bite, 6 hours post antivenom,12 hours post antivenom, 6 hours after blood products and at discharge or at 7 days (whichever occurs earlier) measured in weight per volume ( nanogram per millitre respectively).	7 days
To study the correlation of admission proteinuria and incidence of renal failure in 30 days	To study the correlation of proteinuria measured using urine dipstick, within 6 hours of envenomation with development of acute kidney injury measured as per RIFLE criteria, within 30 days	up to 7 days
To describe the peripheral smear changes in hematotoxic snakebite victims	To qualitatively describe the peripheral smear from baseline (sample taken at admission, 0 hour), with 6 hour post bite, 6 hours post antivenom,12 hours post antivenom, 6 hours after blood products and at discharge or at 7 days (whichever occurs earlier)	up to 7 days

Collaborators and Investigators

• Sponsor: Jubilee Mission Medical College and Research Institute
• Investigators: Principal Investigator: Siju V Abraham, M D, Jubilee Mission Medical College and Research Institute

Publications and helpful links

General Publications

• Abraham SV, Rafi AM, Krishnan SV, Palatty BU, Innah SJ, Johny J, Varghese S. Utility of Clot Waveform Analysis in Russell's Viper Bite Victims with Hematotoxicity. J Emerg Trauma Shock. 2018 Jul-Sep;11(3):211-216. doi: 10.4103/JETS.JETS_43_17.

Study record dates

Study Major Dates

• Study Start (Actual): March 15, 2022
• Primary Completion (Actual): July 31, 2023
• Study Completion (Actual): August 9, 2023

Study Registration Dates

• First Submitted: May 31, 2020
• First Submitted That Met QC Criteria: August 14, 2020
• First Posted (Actual): August 20, 2020

Study Record Updates

• Last Update Posted (Actual): March 7, 2024
• Last Update Submitted That Met QC Criteria: March 6, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: thromboelastometry; coagulopathy; ROTEM; global coagulation assay; hemostatic variables; VICC; DIC; Venom induced consumptive coagulopathy; Disseminated intravascular coagulation; CWA; clot waveform analysis; 20'WBCT; Clotting time; viscoelastometry; blood cell indices; snakebite; hematotoxic
• Additional Relevant MeSH Terms: Chemically-Induced Disorders; Cardiovascular Diseases; Vascular Diseases; Wounds and Injuries; Hematologic Diseases; Hemorrhagic Disorders; Thrombophilia; Poisoning; Bites and Stings; Hemostatic Disorders; Blood Coagulation Disorders; Snake Bites; Disseminated Intravascular Coagulation
• Other Study ID Numbers: 01/20/IEC/JMMC&RI; U1111-1252-7998 (Other Identifier: World Health Organisation)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No