Correlation Between End-tidal CO2 and Degree of Compression of Heart During CPR Measured by Ultrasound

Study Overview
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Brief Summary
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Individual optimization of cardiopulmonary resuscitation (CPR) in real time may increase the success rate of the procedure. End-tidal CO2 (EtCO2) levels reflect cardiac output induced by CPR. Other potential marker of haemodynamic efficacy of CPR is direct measurement of the extent of induced compression of left ventricle (LV), right ventricle (RV) and inferior caval vein (IVC) by ultrasound. We plane to evaluate whether these ultrasound parameters correlate with EtCO2 levels during CPR for out-of-hospital cardiac arrest (OHCA) of non-traumatic origin.

Detailed Description
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Pre-hospital observational study will be realized in the setting of physician-based Emergency Medical System in the Czech republic. 20 patients resuscitated for OHCA of nontraumatic origin are planned to be included to the study. Transthoracic echocardiography will be performed from subcostal view during ongoing chest compressions in all of them and in the time of this investigation EtCO2 level will be recorded. This will be repeated three times during CPR in each patient if possible. Later on, maximal and minimal diameter of LV, RV and IVC will be obtained from the recorded loops and compression index (%) of LV (LVCI), RV (RVCI) and IVC (IVCCI) will be calculated as (maximal-minimal/maximal cavital diameter)x100. Correlations between EtCO2 and LVCI, RVCI and IVCI and CImax will be expressed as Spearman's correlation coefficient. The results of the study will answer the question whether echocardiographic evaluation of compression of heart cavities during CPR reflect haemodynamic efficacy of CPR. If so, this study will be followed by an interventional clinical trial evaluating the effect of compression depth changes as a response to measured compression of the heart.

Official Title
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Correlation Between End-tidal CO2 and Degree of Compression of Heart Cavities Measured by Transthoracic Ultrasound During Cardiopulmonary Resuscitation for Out-of-hospital Cardiac Arrest

Conditions
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Cardiopulmonary Resuscitation, Echocardiography

Intervention / Treatment
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* Diagnostic Test: Intra-arrest echocardiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patient resuscitated for out-of-hospital cardiac arrest of non-traumatic origin. Exclusion Criteria: Technical unavailability of intra-arrest ultrasonography and capnography.

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| OHCA patients<br>Patients resuscitated for out-of-hospital cardiac arrest of non-traumatic origin and investigated by intra-arrest echocardiography. | Diagnostic Test: Intra-arrest echocardiography<br>* Intra-arrest echocardiography performed by portable ultrasound device during ongoing chest compressions.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of EtCO2 level and compression index of left ventricle, right ventricle and inferior caval vein | Compression index of left ventricle, right ventricle and inferior caval vein measured by intra-arrest echocardiography and EtCO2 measured by side stream approach during cardiopulmonary resuscitation. | Participant will be repeatedly evaluated during cardiopulmonary resuscitation. Therefore, anticipated time frame the time interval will fluctuate from 5 minutes to 120 minutes |