Fluid Responsiveness in Critically Ill Patients Using Carotid Peak Systolic Velocity Variability: A New Frontier

Area of Science:

• Critical care medicine
• Cardiovascular physiology
• Hemodynamic monitoring

Background:

• Fluid responsiveness assessment is crucial in critical care.
• Left Ventricular Outflow Tract (LVOT) velocity time integral (VTI) variability is a common but often difficult-to-obtain parameter for fluid responsiveness.
• Carotid Peak Systolic Velocity (CPSV) variation is explored as a potentially more accessible surrogate marker.

Purpose of the Study:

• To evaluate the utility of CPSV variation as a surrogate marker for fluid responsiveness.
• To assess changes in CPSV variation in patients already identified as fluid responders.

Main Methods:

• Adult patients receiving fluid bolus therapy were studied.
• LVOT VTI and CPSV variation were measured before and after a 6 ml/kg fluid bolus.
• Hemodynamic variables and breathing modes (spontaneous vs. mechanical ventilation) were recorded.

Main Results:

• CPSV variation significantly decreased post-fluid administration in both spontaneously breathing (14.1 ± 3.4 to 5.4 ± 2.6, p < 0.05) and mechanically ventilated patients (15 ± 5.3 to 6.5 ± 3.1, p < 0.005).
• A significant positive correlation was found between LVOT VTI variation and CPSV variation before fluid therapy (r=0.56, p=0.001) and a moderate positive correlation after (r=0.37, p=0.043).

Conclusions:

• CPSV variation decreases significantly after fluid administration in fluid responders.
• CPSV variation shows potential as a non-invasive, easily obtainable surrogate marker for assessing fluid responsiveness, complementing LVOT VTI.