Brachial Artery Peak Velocity Variation to Predict Fluid Responsiveness

Study Overview
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Brief Summary
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The investigators designed this study to determine the predictive value for predicting fluid responsiveness of noninvasive evaluation of respiratory variation of peak velocity in brachial artery, in mechanically ventilated patients with acute circulatory failure.

Detailed Description
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Predicting the hemodynamic response to fluid administration (or fluid responsiveness) in critical ill patients is still a matter of concern, since fluid overload could worse the clinical situation of these patients. Parameters of fluid responsiveness usually require an invasive monitoring (like arterial pulse pressure variation). We hypothesize that noninvasive evaluation of respiratory variation of peak velocity in brachial artery using Doppler ultrasound could provide a feasible estimation on fluid responsiveness in mechanically ventilated patients with acute circulatory failure.

Official Title
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Brachial Artery Peak Velocity Variation to Predict Fluid Responsiveness in Mechanically Ventilated Patients

Conditions
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Hypotension, Shock

Intervention / Treatment
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* Other: Fluid administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with controlled mechanical ventilation, equipped with an indwelling radial artery catheter and for whom the decision to give fluids will be taken because the presence of one or more clinical signs of acute circulatory failure: systolic blood pressure <90 mmHg (or a decrease >50 mmHg in previously hypertensive patients) the need of vasopressor drugs oliguria (urine output <0.5 ml/kg/min for at least 2 h) tachycardia delayed capillary refilling the presence of skin mottling Exclusion Criteria: Contraindication for the volume administration: evidence of fluid overload and/or of hydrostatic pulmonary edema Patients with instable cardiac rhythm

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 |
| --- | --- |
| Acute circulatory failure<br>Patients for whom the decision to give fluids was taken because the presence of one or more clinical signs of acute circulatory failure. | Other: Fluid administration<br>* 500 ml of synthetic colloid (Voluven®, hydroxyethylstarch 6%; Fresenius, Bad Homburg, Germany) infused over 30 minutes<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Predictive value of respiratory variation in brachial artery peak velocity before volume expansion assessed by ROC curve. We defined responser as patients that increased stroke volume index equal or more than 15% after fluid administration. |  | immediately after volume expansion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the predictive value of pulse pressure variation for predicting hemodynamic response to fluid administration, comparing with the predictive value of respiratory variation of brachial artery peak velocity. |  | immediately after fluid administration | 
| Evaluate the predictive value of stroke volume variation for predicting hemodynamic response to fluid administration, comparing with the predictive value of respiratory variation of brachial artery peak velocity. |  | immediately after volume expansion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Fluid responsiveness, Ultrasound, Cardiac output