Brachial Artery Peak Velocity Variation to Predict Fluid Responsiveness
Brachial Artery Peak Velocity Variation to Predict Fluid Responsiveness
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.
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.
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