Haemostasis and Therapeutic Hypothermia

Study Overview
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Brief Summary
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The purpose of this study is to investigate, if the haemostasis is impaired in cardiac arrest patients during therapeutic hypothermia compared with normothermia.

Detailed Description
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Treatment with mild therapeutic hypothermia, 32-34 °C for 12-24 hours, has shown to improve the neurologic outcome in comatose survivors of out-of-hospital cardiac arrest. Hypothermia is suspected to inhibit haemostasis and therefore cardiac arrest patients with a risk of bleeding are not treated with therapeutic hypothermia. However, the impact on the coagulation system during mild therapeutic hypothermia, has not yet been fully investigated. The investigators aim to investigate if mild therapeutic hypothermia influences haemostasis. We are including survivors of cardiac arrest, who are treated with hypothermia for 24-48 hours. Blood will be sampled during hypothermia and secondly during normothermia. 30 minutes after the blood are sampled it will be analyzed using a sensitive low-tissue-factor assay with rotational thromboelastometry (ROTEM®). All the dynamic coagulation parameters obtained on the ROTEM® at hypothermia and normothermia, respectively, will be compared.

Official Title
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Is Haemostasis Impaired in Cardiac Arrest Patients During Therapeutic Hypothermia?

Conditions
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Hypothermia, Heart Arrest

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Treatment with therapeutic hypothermia, for minimum 24 and up to 48 hours, due to cardiac arrest. Exclusion Criteria: age <18 years.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To detect changes in clotting time in seconds (s), during the first 3 days after target temperature (34 °C) is reached. | Clotting time will be measured by thromboelastometry on the ROTEM-analyzer using a low-tissue-factor assay. | 22, 46 and 70 hours after target temperature (34 °C) is reached (+/- 2 hours). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To detect changes in the clot formation time (s), during the first 3 days after target temperature (34 °C) is reached. | Coagulation parameters will be measured by thromboelastometry on the ROTEM® using a low-tissue-factor assay. | 22, 46 and 70 hours after target temperature (34 °C) is reached (+/- 2 hours). | 
| To detect changes in maximum clot firmness (mm), during the first 3 days after target temperature (34 °C) is reached. | Coagulation parameters will be measured by thromboelastometry on the ROTEM® using a low-tissue-factor assay. | 22, 46 and 70 hours after hypothermia is reached. (+/- 2 hours) | 
| To detect changes in time to maximum velocity (s), during the first 3 days after target temperature (34 °C) is reached. | Coagulation parameters will be measured by thromboelastometry on the ROTEM® using a low-tissue-factor assay. | 22, 46 and 70 hours after target temperature (34 °C) is reached (+/- 2 hours). | 
| To detect changes in maximum velocity (mm/min.), during the first 3 days after target temperature (34 °C) is reached. | Coagulation parameters will be measured by thromboelastometry on the ROTEM® using a low-tissue-factor assay. | 22, 46 and 70 hours after target temperature (34 °C) is reached (+/- 2 hours). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Thromboelastometry, Haemostasis, Hypothermia, Heart arrest