Assessment of volume responsiveness by ultrasound parameters of carotid blood flow in patients with cardiogenic shock

Abstract

Introduction There is no noninvasive method that can reliably and accurately identify fluid responsiveness. As such, in patients with undifferentiated shock, treatment often involves empiric fluid administration, in the hope that volume expansion will increase preload, which will then serve to increase cardiac output. However, for patients on the flat portion of the Starling curve, aggressive fluid administration results in no appreciable increase in cardiac output and may be detrimental to hemodynamically unstable patients. Objective The aim of this study was to compare the sensitivity and specificity of cardiac output measurement using bedside ultrasound on carotid artery and Transthoracic Echocardiogram(TTE) while assessing volume responsiveness in cardiogenic shock patients. Patients and methods In this prospective observational study, 40 cardiogenic shock patients were enrolled. Carotid artery Doppler ultrasound was performed where carotid blood flow (CBF) was calculated and TTE where cardiac output was calculated before and after passive leg-raising test to assess volume responsiveness. Results CBF measurements in comparison with cardiac output for assessment of fluid responsiveness had a sensitivity of 83.33% and specificity of 100%. Conclusion Carotid Doppler ultrasound and calculation of CBF is a reliable predictor to fluid responsiveness in patients with cardiogenic shock where transthoracic echocardiography is the gold standard in dynamic monitoring of the change in stroke volume after a maneuver that increases venous return (preload).