Carotid Artery Corrected Flow Time and Fluid Responsiveness in Geriatric Patients

Doppler ultrasound of the common carotid artery has begun to be used as a potential non-invasive tool for assessing hemodynamic status. Its non-invasive nature, ability to be applied independently of the patient's position, ease of application due to the superficial location of the carotid artery, and resistance to intrathoracic pressure changes are among its advantages. Carotid blood flow and corrected carotid flow time (Carotid Flow Time (FTc)) provide information about left ventricular preload and inversely correlate with systemic vascular resistance. Additionally, the velocity time integral (VTI) measuring blood flow through the carotid artery during systole, when multiplied by the cross-sectional area of the carotid artery, allows for the determination of flow within the carotid artery. The reliability in assessing fluid responsiveness has been demonstrated in studies involving invasive cardiac output measurements. In the elderly patient population where arterial elasticity can be compromised, there is no existing data in literature that determines the reliability and predictive value of FTc after general anesthesia induction.