Transthoracic Echocardiographic Assessment of the Superior Vena Cava Flow Respiratory Variation in ICU Intubated Patients
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Intubated Patients
- Sponsor
- Hospices Civils de Lyon
- Enrollment
- 188
- Locations
- 1
- Primary Endpoint
- ventricular outflow tract velocity time index (LVOT TVI)
- Last Updated
- 7 years ago
Overview
Brief Summary
Acute circulatory failure is frequent, affecting up to one-third of patients admitted to intensive care units (ICU). Monitoring hemodynamics and cardiac function is therefore a major concern. Analysis of respiratory diameter variations of the superior vena cava (SVC) is easily obtained with transesophageal echocardiography (TEE) and is helpful to assess fluid responsiveness.
Transthoracic echocardiography (TTE) exploration of the SVC is not used in routine. Recently, micro-convex ultrasound transducers have been marketed and these may be of use for non-invasive SVC flow examination. However, analysis of diameter variations of the SVC with TTE does not seem to be possible since the approach from the supraclavicular fossa does not allow for a good visualization of the SVC walls.
It was recently demonstrated in a short pilot study that TTE examination of the SVC flow with a micro-convex ultrasound transducer (GE 8C-RS) seems both easy to learn and to use (feasibility = 84.9%), and is reproducible in most ventilated ICU patients with an intraclass correlation coefficient for the systolic fraction of the superior vena cava flow of 0.90 (95% confidence interval [0.86-0.93]).
The hypothesis is that cardio-respiratory interactions in intubated-ventilated patients are responsible of SVC flow variations and that the analysis of the SVC flow respiratory variations could be a new predictive tool of fluid responsiveness.
Investigators
Eligibility Criteria
Inclusion Criteria
- •Adult patients (≥ 18 years old)
- •Admission in ICU after tracheal intubation or tracheal intubation during the ICU stay
- •Volume-controlled ventilation with a tidal volume of 8 mL/kg
- •Patient or family agreement for the inclusion
Exclusion Criteria
- •Persistence of spontaneous breathing
- •Cardiac arrhythmia
- •Severe Acute Respiratory Distress Syndrome, defined as PaO2/FIO2 ratio \< 100
- •Acute right ventricular failure defined by S'VD \< 10 cm or Tricuspid Annular Plane Systolic Excursion (TAPSE) \< 10 mm measured with Transthoracic Echocardiography (TTE)
Outcomes
Primary Outcomes
ventricular outflow tract velocity time index (LVOT TVI)
Time Frame: The day of inclusion
Echo-Doppler measurements are performed with Vivid S6 model (GE Healthcare France, Lyon, France). All measurements are recorded at the end of expiration. Echo-Doppler measurements are performed in the upper part of the SVC, approximately 1 to 2 cm below the brachiocephalic vein. From this view, pulse Doppler is performed. Pulse Doppler waves obtained in the SVC are used to obtain velocity time integrals (VTI). Expiratory VTI is named VTImax and inspiratory VTI is named VTImin. These values will allow the calculation of Respiratory variations of the superior vena cava flow (ΔSVCf). ΔSVCf is calculated as(VTImax- VTImin )/(1/2(VTImax+ VTImin))
Secondary Outcomes
- optimal cut-off value of ΔSVCf to predict fluid-responsiveness(The day of inclusion)
- proportion of patients in which measurement of ΔSVCf is not possible(The day of inclusion)