Coexistence of a fluid responsive state and venous congestion signals in critically ill patients: a multicenter observational proof-of-concept study

Point of care ultrasound for monitoring and resuscitation in patients with shock

Point-of-Care Ultrasound (POCUS), when used by experienced physicians, is a valuable diagnostic tool for the initial minutes of shock management and subsequent monitoring. It enables early diagnosis with high sensitivity (Sn) and specificity (Sp). Published protocols have advanced towards true multi-organ ultrasonographic exploration, with the RUSH (Rapid Ultrasound in Shock) protocol likely being the most well-known nowadays. Although there is no established order, cardiac evaluation, as well as vascular system assessments including intra- and extravascular volume, should be explored. Additionally, there are ultrasonographic evaluations particularly useful for diagnosing and monitoring response/tolerance to volume. Both the identification of B lines and the increase in left ventricular pressures bring us closer to a diagnosis of fluid overload in these patients. Velocity-time integral (VTI) of the left ventricle (LV) outflow tract (LVOT, LVOTVTI) or right ventricular outflow tract (RVOT, RVOTVTI) can be indicative of distributive shock if elevated, and help identifying volume responders through leg-raising manoeuvres or crystalloid bolus administration. Several index of the inferior vena cava (IVC) can also be helpful. In addition, different parameters to establish fluid responsiveness are being investigated at the carotid level. Venous congestion parameters have not yet been proven to identify volume responders but can identify patients with poor tolerance. Currently, it is essential that physicians treating critical patients use POCUS to enhance clinical outcomes.

Venous excess ultrasound score association with acute kidney injury in critically ill patients: a systematic review and meta-analysis of observational studies

BACKGROUND

Systemic venous congestion assessed by the venous excess ultrasound score (VExUS), has been associated with acute kidney injury (AKI) in patients undergoing cardiac surgery. However, there is a lack of evidence of this association in the general critically ill patients.

STUDY DESIGN AND METHODS

PubMed, Embase, and Cochrane databases were searched for observational prospective studies that included critically ill patients and analyzed VExUS score on the first day of admission to the ICU. The main outcome was occurrence of AKI. Secondary outcome was all-cause mortality. Statistical analysis was performed using Review Manager 5.4.1. Odds ratios (OR) with 95% confidence interval were pooled using a random-effects model. The Quality in Prognosis Studies (QUIPS) tool was used to assess risk of bias. Publication bias was assessed via funnel plot and heterogeneity was examined with I2 statistics.

RESULTS

Our analysis included 1036 patients from nine studies, of whom 17.4% presented venous congestion according to VExUS definition. In critically ill patients presenting with venous congestion (VExUS score ≥ 2), the incidence of AKI was significantly higher as compared with those without congestion (OR 2.63, 95% CI 1.06-6.54; p = 0.04; I2 = 74%). The association was notably stronger in cardiac surgery patients (OR 3.86, 95% CI 2.32-6.42; p < 0.00001; i2 = 0%). There was no significant association between venous congestion and all-cause mortality (OR 1.25, 95% CI 0.71-2.19; p = 0.44; i2 = 8%).

CONCLUSIONS

These findings suggest that VExUS score may correlate with an elevation in the incidence AKI in critically ill patients, with a more pronounced effect observed within the subgroup of patients undergoing cardiac surgery. There was no statistically significant association between VExUS score and all-cause mortality.

CLINICAL TRIAL REGISTRATION

PROSPERO under protocol number CRD535513.

VExUS Score: Making Waves in an Ocean but Still a Mirage in the Desert

Kumar V. VExUS Score: Making Waves in an Ocean but Still a Mirage in the Desert. Indian J Crit Care Med 2025;29(3):205-207.

How I Teach: Heart-Lung Interactions during Mechanical Ventilation. Positive Pressure and the Right Ventricle

The provision of positive pressure ventilation has the potential to provoke hemodynamic deterioration. The subject of heart-lung interactions is both complex and critical yet often obscure and fraught with misconception among trainees and seasoned clinicians alike. In this article, we focus on the impact of positive pressure ventilation on the right heart, providing a teaching approach composed of didactic sessions and simulated cases. We split our didactics and cases into two 30-minute sessions: "How the right heart fills" and "How the right heart empties." Within each session, our framework highlights key concepts with respect to circulatory physiology, respiratory system mechanics, and an amalgam of the two subjects as it pertains to managing clinical scenarios encountered during a trainee's intensive care unit rotation.

Point-of-Care Ultrasonography in the Critical Care Unit: An Update

PURPOSE OF REVIEW

This article outlines updates in point of care ultrasonography.

RECENT FINDINGS

Improving diagnostic accuracy and image quality is continuing to evolve in Point-of-care ultrasonography (POCUS). This include incorporating Artificial Intelligence (AI) and use of other modalities such as Doppler in lung ultrasonography. Transesophageal echocardiography is an emerging option when imaging is difficult to obtain via transthoracic echocardiography. POCUS is becoming instrumental when used during cardiac arrest. Ultrasound (VExUS) Grading System is a promising measurement to assess a patient's volume status. Given the multiple advantages of POCUS usage, competency in POCUS became a requirement of Critical Care fellowship training. POCUS is an important diagnostic modality and guide to medical management. New technological advances such as AI, can serve as a guide to enhance image quality and help accurately obtain quantitative assessments. POCUS has a major role during cardiac arrest and advanced cardiac life support. The clinical utility of POCUS was further substantiated during the COVID-19 pandemic. The Accreditation Council for Graduate Medical Education (ACGME) requires critical care programs to include competency in POCUS as part of their training.

Hepatocardiorenal Syndrome: Integrating Pathophysiology with Clinical Decision-Making via Point-Of-Care Ultrasound

BACKGROUND

Accumulating evidence has challenged the traditional model of the liver-kidney connection in hepatorenal syndrome. Cirrhosis can significantly impact cardiac function, leading to cirrhotic cardiomyopathy. Recent understanding reveals how cardiac dysfunction plays a pivotal role in the development of renal dysfunction in this setting, suggesting that disturbances traditionally categorized under hepatorenal syndrome may actually represent a hepatic form of cardiorenal syndrome - hepatocardiorenal syndrome - where the liver affects the kidney through cardiorenal pathways.

SUMMARY

Effective management of hepatocardiorenal syndrome and acute kidney injury in cirrhosis relies on accurately assessing a patient's hemodynamic and volume status. Point-of-care ultrasound, including lung and focused cardiac ultrasound, is a valuable diagnostic tool that provides crucial data on fluid tolerance, subclinical pulmonary congestion, and left ventricular filling pressures. This objective, bedside approach offers a comprehensive assessment that directly influences patient management and therapeutic decisions.

KEY MESSAGES

Point-of-care ultrasound plays an essential role in evaluating and managing hepatocardiorenal syndrome, providing insights into the underlying pathophysiology. By assessing hemodynamic parameters, it helps guide therapy and monitor patient responses, ensuring more accurate and effective treatment of patients with cirrhosis and acute kidney injury.

Fluid management of acute kidney injury

PURPOSE OF REVIEW

Acute kidney injury (AKI) is commonly encountered in critical care medicine as is intravenous fluid therapy. It is accepted that there is interplay between fluid use and AKI, both potentially positive and negative. An understanding of the physiological rationale for fluid is important to help clinicians when considering fluid therapy in patients with, or at risk for AKI; this includes understanding choice of fluid, method of monitoring, administration and clinical sequelae.

RECENT FINDINGS

There is increasing interest in combining both static and dynamic measures to assess fluid balance, fluid responsiveness effects of fluid therapy, which are areas requiring ongoing study to translate this theory into clinically useful practice at the bedside. Whilst the debate of choice of crystalloid in ICU practice continues, further evidence for benefits for balanced solutions emerges in the form of international guidelines and patient data meta-analysis of previously performed trials.

SUMMARY

This review assesses the physiological rationale for fluid use in ICU cohorts with AKI of various types, as well as a systematic approach for choice of fluid therapy using a number of different variables, which aims to help guide clinicians in managing fluid use and fluid balance in critically ill patients with AKI.

Fluid management in the septic peri-operative patient

PURPOSE OF REVIEW

This review provides insight into recent clinical studies involving septic peri-operative patients and highlights gaps in understanding fluid management. The aim is to enhance the understanding of safe fluid resuscitation to optimize peri-operative outcomes and reduce complications.

RECENT FINDINGS

Recent research shows adverse surgical and clinical outcomes with both under- and over-hydration of peri-operative patients. The kinetic of intravenous fluids varies significantly during surgery, general anaesthesia, and sepsis with damage to endothelial glycocalyx (EG), which increases vascular permeability and interstitial oedema. Among clinical anaesthesia, neuraxial anaesthesia and sevoflurane have less effect on EG. Hypervolemia and the speed and volume of fluid infusion are also linked to EG shedding. Despite improvement in the antisepsis strategies, peri-operative sepsis is not uncommon. Fluid resuscitation is the cornerstone of sepsis management. However, overzealous fluid resuscitation is associated with increased mortality in patients with sepsis and septic shock. Personalized fluid resuscitation based on a careful assessment of intravascular volume status, dynamic haemodynamic variables and fluid tolerance appears to be a safe approach. Balanced solutions (BS) are preferred over 0.9% saline in patients with sepsis and septic shock due to a potential reduction in mortality, when exclusive BS are used and/or large volume of fluids are required for fluid resuscitation. Peri-operative goal-directed fluid therapy (GDFT) using dynamic haemodynamic variables remains an area of interest in reducing postoperative complications and can be considered for sepsis management (Supplementary Digital Content).

SUMMARY

Optimization of peri-operative fluid management is crucial for improving surgical outcomes and reducing postoperative complications in patients with sepsis. Individualized and GDFT using BS is the preferred approach for fluid resuscitation in septic peri-operative patients. Future research should evaluate the interaction between clinical anaesthesia and EG, its implications on fluid resuscitation, and the impact of GDFT in septic peri-operative patients.

Critical care management of hantavirus cardiopulmonary syndrome. A narrative review

Hantaviruses, members of the Bunyaviridae family, can cause two patterns of disease in humans, hantavirus hemorrhagic fever with renal syndrome (HFRS) and cardiopulmonary syndrome (HCPS), being the latter hegemonic on the American continent. Andesvirus is one of the strains that can cause HCPS and is endemic in Chile. Its transmission occurs through direct or indirect contact with infected rodents' urine, saliva, or feces and inhalation of aerosol particles containing the virus. HCPS rapidly evolves into acute but reversible multiorgan dysfunction. The hemodynamic pattern of HCPS is not identical to that of cardiogenic or septic shock, being characterized by hypovolemia, systolic dysfunction, and pulmonary edema secondary to increased permeability. Given the lack of specific effective therapies to treat this viral infection, the focus of treatment lies in the timely provision of intensive care, specifically hemodynamic and respiratory support, which often requires veno-arterial extracorporeal membrane oxygenation (VA-ECMO). This narrative review aims to provide insights into specific ICU management of HCPS based on the available evidence and gathered experience in Chile and South America including perspectives of pathophysiology, organ dysfunction kinetics, timely life support provision, safe patient transportation, and key challenges for the future.

A nursing-led sepsis response team guiding resuscitation with point-of-care ultrasound: A review and model for improving bundle compliance while individualizing sepsis care

A dysregulated host response to infection resulting in life-threatening organ dysfunction defines the onset of sepsis. Unfortunately, sepsis is common, costly, and deadly. The Surviving Sepsis Campaign publishes regularly updated, evidence-informed, detection, and treatment guidelines culminating in time-sensitive care "bundles." The goal of these bundles is to expedite sepsis recognition because it is widely held that early treatment is life-saving. Hospitals are mandated to publicly report their bundle compliance, and this will soon be tied to hospital reimbursement. For these reasons, hospitals are creating sepsis emergency response teams which are a form of a rapid response team consisting of dedicated medical professionals who evaluate patients with suspected sepsis and initiate therapy when appropriate. Evidence to date support sepsis emergency response teams as a mechanism to improve bundle compliance, and potentially, patient outcome. Nevertheless, some elements of bundled sepsis care are controversial (e.g., intravenous fluid administration) as some argue that mandated treatment precludes personalized care. Herein, we briefly describe general sepsis emergency response team structure, review evidence supporting sepsis emergency response teams to improve bundle compliance and patient outcome and report our unique experience incorporating point of care ultrasound-to guide intravenous fluid-into a nursing-led sepsis team. We propose that our sepsis emergency response team approach allays concern that sepsis care is either bundled or personalized. Instead, incorporating point of care ultrasound into a nursing-led sepsis emergency response team increases bundle compliance and individualizes care.

Changes in portal pulsatility index induced by a fluid challenge in patients with haemodynamic instability and systemic venous congestion: a prospective cohort study

BACKGROUND

It is uncertain whether fluid administration can improve patients with systemic venous congestion and haemodynamic instability. This study aimed to describe the changes in systemic venous congestion and peripheral perfusion parameters induced by a fluid challenge in these patients, and to analyse the influence of the fluid responsiveness status on these changes.

METHODS

The study is a single-centre prospective cohort study of 36 critically ill ICU patients with haemodynamic instability and a maximum vena cava diameter ≥ 20 mm. Changes in cardiac index during a fluid challenge (4 mL/kg of lactated Ringer's solution during 5 min) assessed by pulse contour analysis, central venous pressure, ultrasound systemic congestion parameters (portal venous flow pulsatility index, supra hepatic and intrarenal venous Doppler), and peripheral perfusion parameters (capillary refill time and peripheral perfusion index) were assessed in the overall population. All these data were compared between patients presenting a cardiac index increase > 10% during the fluid challenge (fluid responders) and the others (fluid non-responders).

RESULTS

Twenty-eight (78%) patients were admitted for postoperative care following cardiac surgery; their mean ± SD left ventricular ejection fraction was 42 ± 9% and right ventricular dysfunction was found in at least 61% of the patients. The mean ± SD SOFA score was 9 ± 3. Thirteen (36%) patients were fluid responders. The fluid challenge administration induced a significant increase in portal pulsatility index, VExUS score, and central venous pressure without significant difference of these changes between fluid responders and non-responders. No significant change in perfusion parameters was observed.

CONCLUSION

Fluid administration in patients with haemodynamic instability and systemic venous congestion worsens venous congestion regardless of the fluid responsiveness status, without improving perfusion parameters.

Fluid responsiveness in acute respiratory distress syndrome patients: a post hoc analysis of the HEMOPRED study

PURPOSE

Optimal fluid management in patients with acute respiratory distress syndrome (ARDS) is challenging due to risks associated with both circulatory failure and fluid overload. The performance of dynamic indices to predict fluid responsiveness (FR) in ARDS patients is uncertain.

METHODS

This post hoc analysis of the HEMOPRED study compared the performance of dynamic indices in mechanically ventilated patients with shock, with and without ARDS, to predict FR, defined as an increase in aortic velocity time integral (VTI)  > 10% after passive leg raising (PLR).

RESULTS

Among 540 patients, 117 (22%) had ARDS and were ventilated with a median tidal volume of 7.6 mL/kg [6.9-8.4] and a median positive end-expiratory pressure of 7 cmH2O [5-9]. FR was observed in 45 ARDS patients (39% vs 44% in non-ARDS patients, p = 0.384). Reliability of dynamic indices to predict FR remained consistent in ARDS patients, though with different thresholds. Collapsibility index of the superior vena cava (ΔSVC) showed the best predictive performance in both ARDS (area under the curve [AUC] = 0.763 [0.659-0.868]) and non-ARDS (AUC = 0.750 [0.698-0.802]) patients. A right to left ventricle end-diastolic area ratio  > 0.8 or paradoxical septal motion were strongly linked to the absence of FR (> 80% specificity). FR was not associated with intensive care unit (ICU) mortality (47% vs. 46%, p = 1). However, hypovolemia, defined as an aortic VTI increase  > 32% during PLR (median increase in patients with a partial SVC collapse) was independently associated with ICU mortality (odds ratio [OR] = 1.355 [1.077-1.705], p = 0.011), as well as pulse pressure variation (OR = 1.014 [1.001-1.026], p = 0.034).

CONCLUSION

Performance of dynamic indices to predict FR appears preserved in ARDS patients, albeit with distinct thresholds. Hypovolemia, indicated by a  > 32% increase in aortic VTI during PLR, rather than FR, was associated with ICU mortality in this population.

Incidence, predictability, and outcomes of systemic venous congestion following a fluid challenge in initially fluid-tolerant preload-responders after cardiac surgery: a pilot trial

BACKGROUND

Fluid administration has traditionally focused on preload responsiveness (PR). However, preventing fluid intolerance, particularly due to systemic venous congestion (VC), is equally important. This study evaluated the incidence and predictability of VC following a 7 ml/kg crystalloid infusion in fluid-tolerant preload-responders and its association with adverse outcomes.

METHODS

This single-center, prospective, observational study (May 2023-July 2024) included 40 consecutive patients who were mechanically ventilated within 6 h of intensive care unit (ICU) admission after elective open-heart surgery and had acute circulatory failure. Patients were eligible if they were both fluid-tolerant and preload-responsive. PR was defined as a ≥ 12% increase in left-ventricular outflow tract velocity time integral (LVOT-VTI) 1 min after a passive leg raising (PLR) test. VC was defined by a portal vein pulsatility index (PVPI) ≥ 50%. Patients received a 7 ml/kg Ringer's Lactate infusion over 10 min. The primary outcome was the incidence of VC 2 min post-infusion (early-VC). Secondary outcomes included VC at 20 min, the incidence of acute kidney injury (AKI) and severe AKI at 7 days, and ICU length of stay (LOS).

RESULTS

45% of patients developed early-VC, with VC persisting in only 5% at 20 min. One-third of patients developed AKI, with 17.5% progressing to severe AKI. The median ICU LOS was 4 days. Patients with early-VC had significantly higher central venous pressure, lower mean perfusion pressure, worse baseline right ventricular function, and a higher incidence of severe AKI. While LVOT-VTI returned to baseline by 20 min in both groups, PVPI remained elevated in early-VC patients (p < 0.001). The LVOT-VTI versus PVPI regression line showed similar slopes (p = 0.755) but different intercepts (p < 0.001), indicating that, despite fluid tolerance and PR at baseline, early-VC patients had reduced right ventricular diastolic reserve (RVDR). Post-PLR PVPI predicted early-VC with an area under the curve of 0.998, using a threshold of 44.3% (p < 0.001).

CONCLUSION

Post-PLR PVPI effectively predicts fluid-induced early-VC in fluid-tolerant preload-responders, identifying those with poor RVDR. Its use can guide fluid management in cardiac surgery patients, helping to prevent unnecessary fluid administration and associated complications.

TRIAL REGISTRATION

NCT06440772. Registered 30 May 2024. Retrospectively registered.

Inferior vena cava distensibility during pressure support ventilation: a prospective study evaluating interchangeability of subcostal and trans‑hepatic views, with both M‑mode and automatic border tracing

The Inferior Vena Cava (IVC) is commonly utilized to evaluate fluid status in the Intensive Care Unit (ICU),with more recent emphasis on the study of venous congestion. It is predominantly measured via subcostal approach (SC) or trans-hepatic (TH) views, and automated border tracking (ABT) software has been introduced to facilitate its assessment. Prospective observational study on patients ventilated in pressure support ventilation (PSV) with 2 × 2 factorial design. Primary outcome was to evaluate interchangeability of measurements of the IVC and the distensibility index (DI) obtained using both M-mode and ABT, across both SC and TH. Statistical analyses comprised Bland-Altman assessments for mean bias, limits of agreement (LoA), and the Spearman correlation coefficients. IVC visualization was 100% successful via SC, while TH view was unattainable in 17.4% of cases. As compared to the M-mode, the IVC-DI obtained through ABT approach showed divergences in both SC (mean bias 5.9%, LoA -18.4% to 30.2%, ICC = 0.52) and TH window (mean bias 6.2%, LoA -8.0% to 20.4%, ICC = 0.67). When comparing the IVC-DI measures obtained in the two anatomical sites, accuracy improved with a mean bias of 1.9% (M-mode) and 1.1% (ABT), but LoA remained wide (M-mode: -13.7% to 17.5%; AI: -19.6% to 21.9%). Correlation was generally suboptimal (r = 0.43 to 0.60). In PSV ventilated patients, we found that IVC-DI calculated with M-mode is not interchangeable with ABT measurements. Moreover, the IVC-DI gathered from SC or TH view produces not comparable results, mainly in terms of precision.

Optimising flow without congestion using the venous-arterial Doppler enhanced resuscitation framework

Introduction

Ultrasonography as a guide for intravenous (IV) fluid therapy is increasingly accepted within the spheres of acute care. Initial investigations and protocols often focused on measures of arterial flow as an objective approach for personalising organ 'perfusion.' More recently, and with literature associating excessive IV fluid with adverse outcomes, venous ultrasound as a measure of organ 'congestion' is taking hold. Yet, arterial (i.e., 'perfusion') and venous (i.e., 'congestion') Doppler ultrasound measures are often performed separately and can be time-consuming, especially for novices.

Methods

We report a case, wherein venous and arterial Doppler were simultaneously measured using a wireless, wearable ultrasound as a means to optimise flow without congestion.

Results

Before IV volume expansion, the patient had Doppler measures consistent with low central venous pressure (CVP) and stroke volume (SV). Following IV volume expansion, venous Doppler remained the same; however, carotid corrected flow time (ccFT) increased significantly.

Conclusion

A framework for venous-arterial Doppler enhanced resuscitation (VADER) can be used to guide IV volume in patients at risk for venous congestion.

The MINUTES bundle for the initial 30 min management of undifferentiated circulatory shock: an expert opinion

Acute circulatory shock is a life-threatening emergency requiring an efficient and timely management plan, which varies according to shock etiology and pathophysiology. Specific guidelines have been developed for each type of shock; however, there is a need for a clear timeline to promptly implement initial life-saving interventions during the early phase of shock recognition and management. A simple, easily memorable bundle of interventions could facilitate standardized management with clear targets and specified timeline. The authors propose the "MINUTES" acronym which summarizes essential interventions which should be performed within the first 30 min following shock recognition. All the interventions in the MINUTES bundle are suitable for any patient with undifferentiated shock. In addition to the acronym, we suggest a timeline for each step, balancing the feasibility and urgency of each intervention. The MINUTES acronym includes seven sequential steps which should be performed in the first 30 min following shock recognition: Maintain "ABCs", INfuse vasopressors and/or fluids (to support hemodynamic/perfusion) and INvestigate with simple blood tests, Ultrasound to detect the type of shock, Treat the underlying Etiology, and Stabilize organ perfusion.

Point-of-care ultrasonography in cirrhosis-related acute kidney injury: How I do it

Discerning the etiology of acute kidney injury (AKI) in cirrhotic patients remains a formidable challenge due to diverse and overlapping causes. The conventional approach of empiric albumin administration for suspected volume depletion may inadvertently lead to fluid overload. In the recent past, point-of-care ultrasonography (POCUS) has emerged as a valuable adjunct to clinical assessment, offering advantages in terms of diagnostic accuracy, rapidity, cost-effectiveness, and patient satisfaction. This review provides insights into the strategic use of POCUS in evaluating cirrhotic patients with AKI. The review distinguishes basic and advanced POCUS, emphasizing a 5-point basic POCUS protocol for efficient assessment. This protocol includes evaluations of the kidneys and urinary bladder for obstructive nephropathy, lung ultrasound for detecting extravascular lung water, inferior vena cava (IVC) ultrasound for estimating right atrial pressure, internal jugular vein ultrasound as an alternative to IVC assessment, and focused cardiac ultrasound for assessing left ventricular (LV) systolic function and identifying potential causes of a plethoric IVC. Advanced POCUS delves into additional Doppler parameters, including stroke volume and cardiac output, LV filling pressures and venous congestion assessment to diagnose or prevent iatrogenic fluid overload. POCUS, when employed judiciously, enhances the diagnostic precision in evaluating AKI in cirrhotic patients, guiding appropriate therapeutic interventions, and minimizing the risk of fluid-related complications.

Dynamic changes of hepatic vein Doppler velocities predict preload responsiveness in mechanically ventilated critically ill patients

BACKGROUND

Assessment of dynamic parameters to guide fluid administration is one of the mainstays of current resuscitation strategies. Each test has its own limitations, but passive leg raising (PLR) has emerged as one of the most versatile preload responsiveness tests. However, it requires real-time cardiac output (CO) measurement either through advanced monitoring devices, which are not routinely available, or echocardiography, which is not always feasible. Analysis of the hepatic vein Doppler waveform change, a simpler ultrasound-based assessment, during a dynamic test such as PLR could be useful in predicting preload responsiveness. The objective of this study was to assess the diagnostic accuracy of hepatic vein Doppler S and D-wave velocities during PLR as a predictor of preload responsiveness.

METHODS

Prospective observational study conducted in two medical-surgical ICUs in Chile. Patients in circulatory failure and connected to controlled mechanical ventilation were included from August to December 2023. A baseline ultrasound assessment of cardiac function was performed. Then, simultaneously, ultrasound measurements of hepatic vein Doppler S and D waves and cardiac output by continuous pulse contour analysis device were performed during a PLR maneuver.

RESULTS

Thirty-seven patients were analyzed. 63% of the patients were preload responsive defined by a 10% increase in CO after passive leg raising. A 20% increase in the maximum S wave velocity after PLR showed the best diagnostic accuracy with a sensitivity of 69.6% (49.1-84.4) and specificity of 92.8 (68.5-99.6) to detect preload responsiveness, with an area under curve of receiving operator characteristic (AUC-ROC) of 0.82 ± 0.07 (p = 0.001 vs. AUC-ROC of 0.5). D-wave velocities showed worse diagnostic accuracy.

CONCLUSIONS

Hepatic vein Doppler assessment emerges as a novel complementary technique with adequate predictive capacity to identify preload responsiveness in patients in mechanical ventilation and circulatory failure. This technique could become valuable in scenarios of basic hemodynamic monitoring and when echocardiography is not feasible. Future studies should confirm these results.