Plethysmographic Pulse-contour and Pulse-wave-transit-times for Haemodynamic Evaluation in Bleeding Simulation

Study Overview
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Brief Summary
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The evaluation of haemodynamic changes is still challenging in clinically relevant situations (e.g. in bleeding, septic and postoperative patients) with the conventional monitoring routinely used including heart rate and mean arterial pressure. If the arterial pressure drops and the heart increases, the haemodynamic state is already decompensated and a therapy is at risk being indicated too late. Prior to decompensation - still in the state of compensated shock - it would be desirable to detect the shock already. The compensated shock is characterized by an occult drop of cardiac output and a hypoperfusion of vital organs like e.g. the splanchnic region. Due to these pathophysiological characteristics, a therapy would be indicated already in this stadium of shock progression. The available monitoring tools to detect compensated shock are on the one hand side invasive (intravascular catheter), cost-intensive (cost of the catheter systems), or need extensive training (echocardiography). Consequently, the implementation of advanced haemodynamic monitoring is still low despite the high clinical relevance for the patients. It is the goal of this project to evaluate in healthy volunteers the routinely implemented technology of photo-plethysmography in its ability to detect haemodynamic changes by extended signal analysis of the pulse-contour and the pulse-wave-transit-times in relation to the gold-standard echocardiography. Secondary goal of this study is to analyse the physiological and haemodynamic changes during progressive central hypovolaemia displayed by non-invasive or minimal-invasive monitoring devices and associate the changes to each other.

Official Title
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Plethysmographic Pulse-contour and Pulse-wave-transit-times for Haemodynamic Evaluation in Bleeding Simulation

Conditions
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Health, Subjective

Intervention / Treatment
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* Device: Lower-body-low-pressure chamber


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Offered patient information and written informed consent Existence of valid health insurance Male gender Exclusion Criteria: Patients aged less than 18 years or more than 40 years Inability of German language use Lacking willingness to save and hand out data within the study Evidence of a chronic disease (cardio-vascular, renal, pulmonary, neurological, metabolic, gastro-intestinal) Chronic medication Signs of a reduced cardiorespiratory capacity Signs of an acute illness Participation in a prospective intervention trial during the study period Anamnestic hints for syncope or disposition to hypotension Signs of arterial hypertension Signs of inguinal hernia Relevant pathologies in the baseline examination of the transthoracic echocardiography For the bio-impedance measurements: heart defibrillator

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Progressive bleeding simulation<br>The study intervention by a lower-body-low-pressure chamber is performed in this group of healthy volunteers with progressive increase of negative pressure by a step-wise approach (-15mmHg, -30mmHg, -45mmHg). | Device: Lower-body-low-pressure chamber<br>* The lower-body-low-pressure chamber administers a negative pressure to the lower part of the body (below the waist) to induce a central hypovolaemia by pooling of blood in the legs according to Tymko, M. FACETS, Bd. 1, Nr. 1, S. 225-244, März 2017 and Esch, B.T.A. et al. AJP Adv. Physiol. Educ., Bd. 31, Nr. 1, S. 76-81, März 2007.<br>|
| Prolonged bleeding simulation<br>The study intervention by a lower-body-low-pressure chamber is performed in this group of healthy volunteers with prolonged exposure to a negative pressure of -15mmHg. | Device: Lower-body-low-pressure chamber<br>* The lower-body-low-pressure chamber administers a negative pressure to the lower part of the body (below the waist) to induce a central hypovolaemia by pooling of blood in the legs according to Tymko, M. FACETS, Bd. 1, Nr. 1, S. 225-244, März 2017 and Esch, B.T.A. et al. AJP Adv. Physiol. Educ., Bd. 31, Nr. 1, S. 76-81, März 2007.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in the pulse-contour-analysis of the plethysmographic signal | The pulse-contour of the plethysmographic signal will be analyzed to detect morphological changes over time in relation to the initial baseline recording | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Changes the pulse-wave-transit-times of the plethysmographic signal | The pulse-wave-transit-times of the plethysmographic signal will be analyzed to detect changes over time in relation to the initial baseline recording | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial blood pressure | Arterial blood pressure determined by non-invasive monitoring | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Heart rate | Heart rate determined by non-invasive monitoring | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Echocardiographic parameter to determine the cardiac performance of the left ventricle | The performance of the left ventricle will be analyzed by a transthoracic echocardiography by a physician certified by the European Society of Cardiology | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Echocardiographic parameter to determine the cardiac performance of the left atrium | The performance of the left atrium will be analyzed by a transthoracic echocardiography by a physician certified by the European Society of Cardiology | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Echocardiographic parameter to determine the cardiac performance of the right ventricle | The performance of the right ventricle will be analyzed by a transthoracic echocardiography by a physician certified by the European Society of Cardiology | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Echocardiographic parameter to determine the cardiac performance of the right atrium | The performance of the right atrium will be analyzed by a transthoracic echocardiography by a physician certified by the European Society of Cardiology | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Echocardiographic parameter to analyze the vena cava inferior | The analysis will be assessed by a subcostal approach by transthoracic echocardiography | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Heart rate variability | Heart rate variability calculated from raw biosignals Bioelectrical signals by standardized analysis algorithms | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Haemodynamic parameter of the bio-impedance monitoring | The parameter will be determined by the electrical cardiometry/bio-impedance monitoring device of Osypka Medical | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Shock indices of the bio-impedance monitoring | The parameter will be determined by the electrical cardiometry/bio-impedance monitoring device of Osypka Medical | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Heart sounds | Heart sounds measured by vibration sensors | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Tonometric arterial blood pressure | Tonometric arterial blood pressure measured by applanation tonometer | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Haemodynamic parameter of the tonometric pulse-contour method | The parameter will be determined by the non-invasive monitoring device Finapress | Time course of 40 minutes (at study baseline, at study intervention level 1, 2 and 3 and recovery time) | 
| Mean systemic filling pressure | The parameters describing the characteristics of the venous return determined by the stop-flow method | At baseline (up to minute 7 after starting the study protocol), during the study intervention level 1, 2 and 3 (between minute 8 up to minute 28 after starting study protocol) and recovery after finishing the study intervention (between minute 30 and 40) | 
| Questionnaire regarding alimentation | The questionnaire directs to characterize the intake of fluid and solid alimentation prior to the study protocol | Immediately prior to the start of the study protocol | 
| Bio-impedance analysis of the body fluid | The bio-impedance analysis of the body fluid directs to determine the water content of the body | Immediately prior to the start of the study protocol |