Carotid Doppler Peak Velocity as Volume Response Predictor in Patients with AKI

Background: Prediction of fluid responsiveness in the context of acute kidney injury (AKI) is a topic of interest. Currently, non-invasive hemodynamic tests have been proposed to identify fluid responders (10-15% increase in cardiac output after passive leg elevation or fluid loading) and non-responders. In this study we evaluated whether a simpler measure such as delta of carotid doppler peak velocity (CDPV) is a good option compared to the standard measurement of cardiac output through the calculation of velocity time integral (VTI). Methods: In this descriptive, cross-sectional, prospective cohort study, 54 patients over 18 years of age were included who were admitted to the emergency department, with a diagnosis of AKI KDIGO I-III, with clinical and ultrasonographic suspicion of volume depletion, in the period between april through october 2023. In all cases, CDPV and VTI were measured with ultrasound before and after passive leg elevation. The type of sampling carried out was not probabilistic for convenience. Statistical analysis used: Stata statistical package version 13.1. Results: The average age was 53 years, 54% were male, 41 patients (75.9%) were responders and 13 (24.1%) were non-responders. The increase of more than 10% in CDPV was a good predictor of response to volume, compared to the VTI calculation, with a sensitivity of 97.5% and specificity of 100% with AUC 0.98 (the two tests being equally effective). Conclusion: The measurement of CDPV is a good tool to determine volume response, since similar effectiveness was observed compared to the reference standard. It also has the advantage of requiring a shorter learning curve and being more reproducible.