Fluid Responsiveness in Septic Shock Evaluated by Caval Ultrasound Doppler Examination

Study Overview
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Brief Summary
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The study aims at clarification of venous collapsibility measures with real venous flow measurements during dynamic maneuver testing fluid responsiveness in septic shock patients.

Detailed Description
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Sedated and mechanically ventilated patients in septic shock will be enrolled in the study. A fine catheter with ultrasound doppler probe will be introduced into the central venous catheter already in place in superior vena cava. Doppler signal will be evaluated by console prototype (NILUS Medical) and continuous analysis of blood flow velocity respiratory variation will be performed. These values will be compared to standard hemodynamic monitoring parameters (central venous and arterial pressures) and to parameters acquired by transoesophageal (TOE) and transthoracic echocardiography.

Official Title
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Fluid Responsiveness in Septic Shock Evaluated by Caval Ultrasound Doppler Examination - FRIEND Study

Conditions
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Septic Shock, Vein Collapsibility, Intravascular Doppler, Volume Responsiveness in Septic Shock

Intervention / Treatment
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* Procedure: passive leg raising


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients in severe sepsis or septic shock intubation and mechanical ventilation sedated patient without spontaneous respiratory efforts central venous catheter in place inserted via right internal jugular vein signed informed consent by family members Exclusion Criteria: superior vena cava vascular anomaly irradiation of neck or mediastinum in medical history thrombosis of superior vena cava in medical history atrial fibrillation or other irregular rhythm permanent or external pacemaker aggressive mechanical ventilation (PEEP above 10 cm H2O, Pmax above 30 cm H2O) TOE contraindication (oesophageal varices, stricture, tumour, upper gastrointestinal bleeding) Pericardial effusion, constrictive pericarditis Moderate or severe valvular lesion Severe systolic dysfunction of the left (EF less than 30%) or right ventricle (FAC less than 25%) Intraabdominal pressure above 20 mmHg Open chest Obvious severe hypovolemia ( LVEDA<5.5cm2/m2BSA)

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

| Intervention/Treatment |
| --- |
|Procedure: passive leg raising|passive leg raising under echocardiographic monitoring with intravascular doppler in place|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fluid responsiveness | Evaluation of fluid responsiveness, defined as 15% increase of cardiac output after reversible fluid challenge (using PLR - passive leg raise maneuver), by ultrasound doppler evaluation of superior vena caval blood flow respiratory variation. | through the study, data collection during 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of flow | Evaluation of fluid responsiveness by measuring a change of blood flow velocity after PLR maneuver. | through the study, data collection during 1 year | 
| Respiratory variation of flow velocity | Evaluation of fluid responsiveness by measuring respiratory variation of blood flow velocity in left ventricular outflow tract after PLR maneuver | through the study, data collection during 1 year | 
| Respiratory collapsibility | Evaluation of fluid responsiveness by measuring respiratory collapsibility of inferior vena cava after PLR maneuver. | through the study, data collection during 1 year | 
| Respiratory collapsibility | Evaluation of fluid responsiveness by measuring respiratory collapsibility of superior vena cava after PLR maneuver | through the study, data collection during 1 year |