• Aortic valve stenosis
• Cerebrovascular circulation
• Cognition
• Hemodynamics
• Magnetic resonance imaging
• Neuropsychological tests
• Transcatheter aortic valve replacement

• Cardiac output
• Color Doppler
• Doppler
• Echocardiography
• Point-of-care
• Pulsed Doppler
• Spectral analysis
• Ultrasound

• Humans
• Ultrasonography, Doppler/methods
• Point-of-Care Systems
• Ultrasonography, Doppler, Color/methods
• Cardiac Output/physiology

• Aortic valve stenosis
• Cerebrovascular circulation
• Cognition
• Magnetic resonance imaging
• Neuropsychological tests
• Transcatheter aortic valve replacement

• CVON 2018-28, 2012-06 Heart Brain Connection Hartstichting
• Nederlandse Federatie van Universitair Medische Centra
• ZonMw
• Netherlands Heart Institute

• Agreement
• Inferior vena cava
• Jugular vein
• Time velocity integral
• Venous excess ultrasound

• Humans
• Reproducibility of Results
• Point-of-Care Systems
• Ultrasonography/methods
• Critical Care
• Vena Cava, Inferior/diagnostic imaging

• Adult
• Humans
• Male
• Middle Aged
• Aged
• Female
• Stroke Volume
• Ventricular Function, Left/physiology
• Critical Illness
• Prospective Studies
• Cardiac Output/physiology
• Shock

• Brain injury
• cardiac dysfunction
• hypoxic-ischaemic encephalopathy
• speckle-tracking echocardiography
• therapeutic hypothermia

• Humans
• Infant, Newborn
• Case-Control Studies
• Retrospective Studies
• Hypoxia-Ischemia, Brain/complications
• Hypoxia-Ischemia, Brain/diagnostic imaging
• Ventricular Dysfunction, Right/diagnostic imaging
• Ventricular Dysfunction, Right/etiology
• Echocardiography
• Heart Ventricles/diagnostic imaging
• Ventricular Function, Right

• Blood infusion test
• Blood return
• Cardiac output
• Fluid responsiveness
• Passive leg raise
• Velocity time integral

• colchicine
• echocardiography
• emergency medicine
• internal medicine
• ultrasonography
• ultrasound

• Humans
• Cardiovascular Diseases
• Echocardiography
• Acute Disease
• Hospitals

• artificial intelligence
• critical care
• left ventricular outflow tract velocity time integral
• point of care ultrasound training

• Artificial Intelligence
• Humans
• Intensive Care Units
• Lactic Acid
• Stroke Volume
• Ventricular Function, Left

• 2019-1-QN-40 China-Japan Friendship Hospital Youth Science and Technology Project
• 10023201902301 Peking Union Medical College Teaching Reform Project

• Cardiac Output
• Catheterization, Swan-Ganz/methods
• Critical Illness/therapy
• Humans
• Monitoring, Physiologic/methods
• Thermodilution/methods

• intermediate risk
• left ventricular outflow tract
• pulmonary embolism
• right ventricle dysfunction
• velocity time integral

The coronavirus disease 2019 (COVID-19) pandemic has stretched our healthcare system to the brink, highlighting the importance of efficient resource utilization without compromising healthcare provider safety. While advanced imaging is a great resource for diagnostic purposes, the risk of contamination and infection transmission is high and requires extensive logistical planning for intrahospital patient transport, healthcare provider safety, and post-imaging decontamination. This dilemma has necessitated the transition to more bedside imaging. More so than ever, during the current pandemic, the clinical utility and importance of point-of-care ultrasound (POCUS) cannot be overstressed. It allows for safe and efficient beside procedural guidance and provides front line providers with valuable diagnostic information that can be acted upon in real-time for immediate clinical decision-making. The authors have been routinely using POCUS for the management of COVID-19 patients both in the emergency department and in intensive care units turned into “COVID-units.” In this article, we review the nuances of using POCUS in a pandemic situation and maximizing diagnostic output from this bedside technology. Additionally, we review various methods and diagnostic uses of POCUS which can replace conventional imaging and bridge current literature and common clinical practices in critically ill patients. We discuss practical guidance and pertinent review of the literature for the most relevant procedural and diagnostic guidance of respiratory illness, hemodynamic decompensation, renal failure, and gastrointestinal disorders experienced by many patients admitted to COVID-units.

• COVID-19
• SARS-CoV-2
• Point-of-care ultrasound
• COVID-intensive care units
• COVID-unit
• Critical care
• Decontamination
• Pandemic
• Imaging in COVID-19
• Point-of-care ultrasound in a pandemic

Resuscitative fluid therapy aims to increase stroke volume (SV) and cardiac output (CO) and restore/improve tissue oxygen delivery in patients with circulatory failure. In individualized goal-directed fluid therapy (GDFT), fluids are titrated based on the assessment of responsiveness status (i.e., the ability of an individual to increase SV and CO in response to volume expansion). Fluid administration may increase venous return, SV and CO, but these effects may not be predictable in the clinical setting. The fluid challenge (FC) approach, which consists on the intravenous administration of small aliquots of fluids, over a relatively short period of time, to test if a patient has a preload reserve (i.e., the relative position on the Frank-Starling curve), has been used to guide fluid administration in critically ill humans. In responders to volume expansion (defined as individuals where SV or CO increases ≥10–15% from pre FC values), FC administration is repeated until the individual no longer presents a preload reserve (i.e., until increases in SV or CO are <10–15% from values preceding each FC) or until other signs of shock are resolved (e.g., hypotension). Even with the most recent technological developments, reliable and practical measurement of the response variable (SV or CO changes induced by a FC) has posed a challenge in GDFT. Among the methods used to evaluate fluid responsiveness in the human medical field, measurement of aortic flow velocity time integral by point-of-care echocardiography has been implemented as a surrogate of SV changes induced by a FC and seems a promising non-invasive tool to guide FC administration in animals with signs of circulatory failure. This narrative review discusses the development of GDFT based on the FC approach and the response variables used to assess fluid responsiveness status in humans and animals, aiming to open new perspectives on the application of this concept to the veterinary field.

• cardiac output
• fluid challenge
• fluid responsiveness
• goal-directed fluid therapy
• shock

This study was designed to evaluate the hemodynamic effect of norepinephrine (NE) on the peak systolic velocity (PSV), diameter, and blood flow of the common carotid artery (CCA) using the point-of-care ultrasound (POCUS) in patients with septic shock. The study involved patients above 18 years old with septic shock. Arterial monitoring, carotid ultrasonography, and transthoracic echocardiography were performed before NE administration (T₀). When the mean arterial pressure exceeded 65 mmHg after NE administration (T₁), the measurement was repeated. Twenty-four patients (median age 67 [interquartile range: 54–77] years; 42% female) with septic shock were examined in this study. Before (T₀) and after (T₁) NE administration, the PSV (mean, standard deviation [SD]) changed from 85.3 (21.1) cm/s to 83.5 (23.5) cm/s (p = 0.417); this change was not significant. However, the diameter and blood flow of the CCA increased significantly from 0.6 (0.09) cm and 0.75 (0.27) L/min to 0.66 (0.09) cm and 0.85 (0.27) L/min, respectively (p < 0.001). The diameter of the left ventricular outflow tract (LVOT) remained unchanged, but the velocity time integral of the LVOT increased significantly from 21.7 (4.39) cm to 23.6 (5.14) cm. There was no significant correlation between changes in blood flow of the CCA and changes in cardiac output (coefficient −0.365, p = 0.079). In conclusion, NE increased the diameter and blood flow of the CCA significantly, without changing the PSV in patients with septic shock.

• Echocardiography, aortic blood flow
• Extreme prematurity
• Near infrared spectroscopy
• Regional saturation

• echocardiography
• right ventricle
• right ventricular dysfunction
• right ventricular failure

• bioimpedance cardiography
• cardiac output monitoring
• fluid responsiveness
• passive leg raising

• Adult
• Aged
• Area Under Curve
• Cardiac Output/physiology
• Cardiography, Impedance/instrumentation
• Cardiography, Impedance/methods
• China
• Critical Illness
• Echocardiography/methods
• Female
• Hemodynamics/physiology
• Humans
• Intensive Care Units/organization & administration
• Intensive Care Units/trends
• Male
• Middle Aged
• Prospective Studies
• ROC Curve
• Statistics, Nonparametric

• Pulmonary acceleration time
• Pulmonary hypertension
• Pulmonary vascular reserve
• Stress echocardiography
• Tricuspid regurgitant velocity

Stroke volume (SV) and cardiac output (CO) are basic hemodynamic parameters which aid in targeting organ perfusion and oxygen delivery in critically ill patients with hemodynamic instability. While there are several methods for obtaining this data, the use of transthoracic echocardiography (TTE) is gaining acceptance among intensivists and emergency physicians. With TTE, there are several points that practitioners should consider to make estimations of the SV/CO as simplest as possible and avoid confounders.

With TTE, the SV is usually obtained as the product of the left ventricular outflow tract (LVOT) cross-sectional area (CSA) by the LVOT velocity–time integral (LVOT VTI); the CO results as the product of the SV and the heart rate (HR). However, there are important drawbacks, especially when obtaining the LVOT CSA and thus the impaction in the calculated SV and CO. Given that the LVOT CSA is constant, any change in the SV and CO is highly dependent on variations in the LVOT VTI; the HR contributes to CO as well. Therefore, the LVOT VTI aids in monitoring the SV without the need to calculate the LVOT CSA; the minute distance (i.e., SV × HR) aids in monitoring the CO. This approach is useful for ongoing assessment of the CO status and the patient’s response to interventions, such as fluid challenges or inotropic stimulation. When the LVOT VTI is not accurate or cannot be obtained, the mitral valve or right ventricular outflow tract VTI can also be used in the same fashion as LVOT VTI. Besides its pivotal role in hemodynamic monitoring, the LVOT VTI has been shown to predict outcomes in selected populations, such as in patients with acute decompensated HF and pulmonary embolism, where a low LVOT VTI is associated with a worse prognosis.

The VTI and minute distance are simple, feasible and reproducible measurements to serially track the SV and CO and thus their high value in the hemodynamic monitoring of critically ill patients in point-of-care settings. In addition, the LVOT VTI is able to predict outcomes in selected populations.

• Cardiac output
• Doppler
• Echocardiography
• Point-of-care
• Shock
• Stroke volume
• Ultrasonography

• Cardiac output
• Critical care
• Intensive care unit
• Medical students
• Ultrasonography

In critical care medicine, the use of transthoracic echo (TTE) is expanding. TTE can be used to measure dynamic parameters such as cardiac output (CO). An important asset of TTE is that it is a non-invasive technique. The Probefix is an external ultrasound holder strapped to the patient which makes it possible to measure CO using TTE in a fixed position possibly making the CO measurements more accurate compared to separate TTE CO measurements. The feasibility of the use of the Probefix to measure CO before and after a passive leg raising test (PLR) was studied. Intensive care patients were included after detection of hypovolemia using Flotrac. Endpoints were the possibility to use Probefix. Also CO measurements with and without the use of Probefix, before and after a PLR were compared to the CO measurements using Flotrac. Side effects in terms of skin alterations after the use of Probefix and patient’s comments on (dis)comfort were evaluated.

Ten patients were included; in eight patients, sufficient recordings with the use of Probefix could be obtained. Using Bland–Altman plots, no difference was found in accuracy of measurements of CO with or without the use of Probefix before and after a PLR compared to Flotrac generated CO. There were only mild and temporary skin effects of the use of Probefix.

In this small feasibility study, the Probefix could be used in eight out of ten intensive care patients. The use of Probefix did not result in more or less accurate CO measurements compared to manually recorded TTE CO measurements. We suggest that larger studies on the use of Probefix in intensive care patients are needed.

• Cardiac output
• Cardiac ultrasound
• External
• Intensive care
• Passive leg raising test