Gonzalez, FilipeVarudo, RitaLeote, JoãoMartins, CristinaBacariza, JacoboFernandes, AnteroMichard, Frederic2022-10-262022-10-262022Br J Anaesth. 2022 Nov;129(5):e116-e1190007-0912http://hdl.handle.net/10451/54923© 2022 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Point-of-care ultrasound techniques are increasingly used for the bedside assessment of cardiac function and haemodynamics in critically ill patients. The sub-aortic or left ventricular outflow tract velocity time integral (VTI) can be measured using pulsed-Doppler ultrasonography from a transthoracic apical 5-chamber view. Quantifying VTI is useful to discriminate between vasoplegic states (hypotension with normal/high VTI) and low flow states (low VTI). Measuring VTI is also useful to predict fluid responsiveness, either by quantifying the respiratory swings in VTI when patients are mechanically ventilated, or by quantifying VTI changes during a passive leg raising manoeuvre or a fluid challenge.engArtificial intelligenceAutomationCardiac outputCritical careEchocardiographyVelocity time integraljournal article10.1016/j.bja.2022.07.0371471-6771