Accurate Assessment Of Volume Status Research Articles

Transesophageal echocardiographic acquisition of the venous excess ultrasound exam—a case series and technical description

PurposeObtaining an objective, reproducible, and accurate assessment of volume status is one of the more difficult tasks in the perioperative arena. Since its advent in 2020, the Venous Excess Ultrasound (VExUS) score has gained popularity in the minimally invasive assessment of venous congestion. The VExUS exam has been well described as an additional series of images (hepatic vein, portal vein, and intrarenal vein) obtained with a phased-array probe during a transthoracic echocardiogram. Nevertheless, there are no descriptions of comprehensive VExUS exams performed using transesophageal echocardiography (TEE)—a modality that is routinely employed in patients undergoing cardiac surgery. Clinical featuresWe describe techniques to acquire and interpret a comprehensive TEE-supported VexUS exam, which may be used to optimize the perioperative care of cardiac surgical patients.ConclusionGiven the risks of fluid overload in critically ill cardiac surgery patients, TEE-supported VExUS examination may be a way to reduce morbidity in this population.

Perioperative Fluid Management and Volume Assessment

Fluid therapy is an integral component of perioperative care and helps maintain or restore effective circulating blood volume. The principal goal of fluid management is to optimize cardiac preload, maximize stroke volume, and maintain adequate organ perfusion. Accurate assessment of volume status and volume responsiveness is necessary for appropriate and judicious utilization of fluid therapy. To accomplish this, static and dynamic indicators of fluid responsiveness have been widely studied. This review discusses the overarching goals of perioperative fluid management, reviews the physiology and parameters used to assess fluid responsiveness, and provides evidence-based recommendations on intraoperative fluid management.

Noninvasive Monitoring of Simulated Hemorrhage and Whole Blood Resuscitation

Hemorrhage is the leading cause of preventable death from trauma. Accurate monitoring of hemorrhage and resuscitation can significantly reduce mortality and morbidity but remains a challenge due to the low sensitivity of traditional vital signs in detecting blood loss and possible hemorrhagic shock. Vital signs are not reliable early indicators because of physiological mechanisms that compensate for blood loss and thus do not provide an accurate assessment of volume status. As an alternative, machine learning (ML) algorithms that operate on an arterial blood pressure (ABP) waveform have been shown to provide an effective early indicator. However, these ML approaches lack physiological interpretability. In this paper, we evaluate and compare the performance of ML models trained on nine ABP-derived features that provide physiological insight, using a database of 13 human subjects from a lower-body negative pressure (LBNP) model of progressive central hypovolemia and subsequent progressive restoration to normovolemia (i.e., simulated hemorrhage and whole blood resuscitation). Data were acquired at multiple repressurization rates for each subject to simulate varying resuscitation rates, resulting in 52 total LBNP collections. This work is the first to use a single ABP-based algorithm to monitor both simulated hemorrhage and resuscitation. A gradient-boosted regression tree model trained on only the half-rise to dicrotic notch (HRDN) feature achieved a root-mean-square error (RMSE) of 13%, an R2 of 0.82, and area under the receiver operating characteristic curve of 0.97 for detecting decompensation. This single-feature model's performance compares favorably to previously reported results from more-complex black box machine learning models. This model further provides physiological insight because HRDN represents an approximate measure of the delay between the ABP ejected and reflected wave and therefore is an indication of cardiac and peripheral vascular mechanisms that contribute to the compensatory response to blood loss and replacement.

Chest Ultrasound as a New Tool for Assessment of Volume Status in Hemodialysis Patients.

Accurate assessment of volume status (VS) in hemodialysis (HD) patients is challenging. The use of chest ultrasound (CUS) for detection of extravascular lung water has recently gained wide acceptance. The aim of this study was to evaluate the use of CUS in VS assessment in HD patients in comparison to clinical and inferior vena cava (IVC) indices and to assess their relation with volume displacement after ultrafiltration. This prospective cohort study was carried out on 38 patients on regular HD. VS was assessed using a 13-point clinical score, and IVC indices and CUS score were measured pre- and post-ultrafiltration. Correlation between these parameters and with ultrafiltration volume was tested. There was a statistically significant reduction in post-ultrafiltration CUS score and the 13-point clinical score (P < 0.01). Moreover, reduction in all the IVC indices (inspiratory and expiratory diameters and collapsing index) was detected, but did not reach statistical significance (P = 0.185, P = 0.296, and P = 0.194, respectively). CUS score had statistically significant correlations with ultrafiltration volume and New York Heart Association classes (P < 0.001 and <0.001, respectively). Neither clinical signs nor IVC indices can be used independently for the assessment of VS in HD patients. CUS is a useful guide in VS assessment, and we recommend its routine use in the management of HD patients. Concomitant use of bio- impedance analysis (BIA) may be needed in addition to CUS for more accurate assessment of VS in HD patients.

Advances in assessment of volume status and perioperative fluid management for surgical patients

Rational perioperative fluid management is one of the key determinants responsible for enhanced recovery of patients after surgery. Hypovolemic condition or hypervolemia is closely associated with an increased postoperative mortality or morbidity. Optimal fluid administration facilitates the improvement of tissue perfusion and oxygen supply, so as to avoid microcirculation dysfunction, unnecessary fluid loading, and reduce patient mortality and hospitalization stay. Therefore, accurate assessment of volume status is one of important issues in perioperative management for these patients. In the paper, diverse methods of assessing perioperative volume status of patients including static and dynamic parameters as well as noninvasive transthoracic ultrasound are critically reviewed. The advancements in assessment of the volume status of patients and perioperative fluid management are reviewed to provide new thoughts in fluid therapy of the surgical patients in this article. Key words: Perioperative period; Volume status; Fluid management

The Role of Hand Carried Ultrasound in Guiding Management of Challenging Heart Failure Patients

Purpose Accurate assessment of volume status and estimation of central venous pressure is critical in directing management of acute heart failure (HF) patients . We evaluated the impact of hand carried ultrasound (US) in guiding therapy for HF patients with uncertain volume status on physical examination (PE) or with worsening serum creatinine (Cr). Methods We prospectively included patients admitted to the hospital with acute HF exacerbation and had uncertain volume status or worsening Cr to undergo US-guided management between January 2017 to October 2018. HF team provided initial management plan based on standard of care (PE, symptoms and lab results), then they were provided with US estimation of intravascular volume (by assessing inferior vena cava size and respiratory variation, right and left jugular veins size, respiratory variation and compressibility). Primary outcome was percent change of initial plan after providing US results. Logistic regression was used to compare the percent change in plan by HF type. Results A total of 151 (Age 64±15,46% females, 78% white) patients were included during study duration. 47(31%) patients had HF with preserved ejection fraction (HFpEF), and 104 (69%) patients had HF with reduced ejection fraction (HFrEF). A change in plan was observed in 77.5% of the patients after using ultrasound. No difference in percent change of plan between HFrEF (81%) and HFpEF patients (70%), (OR 1.7, 95% CI: 0.73, 3.9, p= 0.2). Conclusion Ultrasound management of patients with HF and uncertain volume status or worsening Cr may significantly impact management decisions regardless of HF type, Further studies are needed to explore whether these changes improve outcomes of this population.

Abstract 264: Accuracy and Indication of Emergency Department Echocardiography, What Needs to Be Improved? A Single Center Experience

Background: Focused echocardiographic (FE) assessment of left and right ventricular (LV and RV) size and function, pericardial and aortic pathology and inferior vena caval (IVC) size and respiratory variation) has become a valuable part of the assessment of patients (pts) in the emergency department (ED). However, there are no head to head comparisons on the accuracy of FE as compared with a full formal study in the echo department. We compare the accuracy of these two echo modalities in a busy university-affiliated community hospital. Methods: The electronic medical record (EMR) was used to screen patients admitted between 9/1/2017 to 12/31/2017. Only patients with FE in ED, as well as a formal study on the same admission were included. A board-certified cardiologist finalized the findings of departmental echo. A total of 1913 pts were reviewed with 222 patients having both FE and formal studies. There was no report documented for FE in 161 pts, leaving 61 patients with both studies available to analyze. Result: The main indications for FE were shortness of breath (46%), tachycardia (16%), and chest pain (15%), while syncope and hypotension comprised 4% each. As compared to a formal echo: FE accurately estimated IVC dimension in 88%. Evaluation of LV ejection fraction (EF) (normal vs abnormal) was concordant in 85% of pts with consistent underestimation of EF by &gt;10% in the other 15% of pts by FE. Concordance in the assessment of pericardial effusion was 90% with no significant effusions missed by FE. FE assessment of the RV missed 3 cases of significant RV enlargement, 2 of which were associated with acute pulmonary emboli. Finally, the FE reported aortic root size as indeterminate in 25% of cases and missed 4 cases of enlarged aortic roots. Of particular concern was lack of documentation of FE findings in the EMR in 73%. Conclusion: In general, FE is a valuable tool which provides accurate assessment of volume status (IVC dimension) and for the most part accurately assessed EF and the presence of a pericardial effusion. However, FE may significantly underestimate EF in 15% of patients. Both LV and RV function and size may be difficult to assess based on time constraints, inadequate echo windows or technical issues with imaging. FE was unable to assess the aortic root accurately in 25% of cases. Despite the limitations of FE (acuity of medical conditions, the relative brevity of the study and modest training in echocardiography undertaken by most ED providers), FE remains a valuable tool which can be improved upon to enhance diagnostic accuracy. To improve ED FE utility and accuracy we suggest education surrounding appropriate use criteria, improved report documentation in the EMR, rotation of ED residents through the echo department for enhanced training, and rapid consultation with a dedicated echo technician in ED to aid with difficult studies. A prospective collaborative quality improvement initiative is planned.

Retrospective analysis of inferior vena cava collapsibility with point of care ultrasound and urine sodium and FENa in patients with early stage acute kidney injury

ABSTRACTEarly stage acute kidney injury (AKI) is an independent risk factor for an increase in mortality. Accurate assessment of volume status is a major challenge during the early stages of acute renal injury. Determining volume status based on the history and physical exam lacks accuracy. Urine sodium and free excretion of sodium (FENa) provide objective evidence of intravascular volume status when interpreted carefully and is helpful to delineate prerenal from intrinsic renal failure. In recent years point of care ultrasound has been used to assess volume status. Our team conducted a retrospective chart review to assess the association of inferior vena cava collapsibility by point of care ultrasound (POCUS) and urine electrolytes (urine sodium, fractional excretion of sodium) during early stage AKI (Stage 1–2 of KDIGO guidelines). We reviewed 150 cases based on the provisional diagnosis. 36 patients met the criteria for further review. Using bivariate analysis, we found a strong association between >50% IVC collapsibility with FENa < 0.4% with an odds ratio 5.3 (CI 1.1–24.5, p = 0.04), and urine sodium <20 meq/dl with an odds ratio of 6.7 (Cl 1.5–30, p = 0.02). Subsequently, multivariate analysis and Spearman correlation showed an inverse relation between IVC collapsibility and fractional excretion of sodium FENa (β = −0.4, p = 0.001) and (r = −0.44, p = 0.01). These findings suggest the role of POCUS and urinary markers in determining the intravascular volume status in AKI. POCUS is also valuable to assess volume status in cases of renal failure where urine studies are difficult to interpret.

175 - Readiness for Discharge of Heart Failure Patients Based on ReDS Lung Fluid Measurement

Background: Accurate assessment of volume status is a key factor in the management of patients with heart failure (HF). Inadequate inpatient decongestion is considered to be a contributing factor in HF readmissions. The ReDS system is an FDA-approved vest that can rapidly and non-invasively measure lung fluid. Methods: The ReDS Discharge trial is a single-center randomized trial designed to investigate the efficacy and safety of using the ReDS system to guide the timing of HF discharge. The primary outcome of the study is to determine the percentage of HF patients deemed ready for discharge who have persistent lung congestion (ReDS ≥ 39%, normal 25–35%). Important secondary endpoints include length of stay, volume of additional diuresis, change in renal function, and readmission rates.To date, 100/120 patients have been enrolled. All trial patients underwent a ReDS assessment on the day the primary team deemed them ready for discharge. Readings for patients in the intervention arm were provided to the care team. Patients with readings ≥ 39% were considered to be inadequately decongested and, per protocol, required a HF Team consultation to direct care prior to discharge. Readings for patients in the usual care arm were blinded and once these readings were obtained the patients were discharged home. Results:Tabled 1% patients in intervention arm with ReDS ≥ 39%32% (15/47)Mean wt loss from initial ReDS reading to actual d/c3 kgMean added LOS in intervention arm2.3d% patients with rise SCr > 0.5 g/dl after additional diuresis7.2% (1/14)30 & 90 day readmission rates intervention vs controlpending Open table in a new tab Conclusion: A non-invasive lung fluid measurement performed at the time of proposed HF discharge led to improved decongestion in over 30% of hospitalized HF patients without adversely affecting renal function. The effect on HF readmission rates will be reported at the completion of the study.

Outpatient Use of Focused Cardiac Ultrasound to Assess the Inferior Vena Cava in Patients With Heart Failure

Accurate assessment of volume status is critical in the management of patients with heart failure (HF). We studied the utility of a pocket-sized ultrasound device in an outpatient cardiology clinic as a tool to guide volume assessment. Inferior vena cava (IVC) size and collapsibility were assessed in 95 patients by residents briefly trained in focused cardiac ultrasound (FCU). Cardiologist assessment of volume status and changes in diuretic medication were also recorded. Patients were followed for occurrence of 30-day events. There was a 94% success rate ofobtaining IVC size and collapsibility, and agreement between visual and calculated IVC parameters was excellent. Most patients were euvolemic by both FCU IVC and clinical bedside assessment (51%) and had no change in diuretic dose. Thirty-two percent had discrepant FCU IVC and clinical volume assessments. In clinically hypervolemic patients, the FCU evaluation of the IVC suggested that the wrong diuretic management plan might have been made 46% of the time. At 30days, 14 events occurred. The incidence of events increased significantly with FCU IVC imaging categorization, from 11% to 23% to 36% in patients with normal, intermediate, and plethoric IVCs. By comparison, when grouped in a binary manner, there was no significant difference in event rates for patients who were deemed to be clinically volume overloaded. Assessment of volume status in an outpatient cardiology clinic using FCU imaging of the IVC is feasible in a high percentage of patients. A group of patients were identified with volume status discordant between FCU IVC and routine clinic assessment, suggesting that IVC parameters may provide a valuable supplement to the in-office physical examination.

Role of telephone monitoring in patients with chronic heart failure: theory and practical implications

With the aging of the world's population and the rise of chronic illness such as heart failure (HF), the economic burden, number of hospitalizations, and penalties imposed for failure to meet hospital readmission expectations will continue to rise, thus increasing pressure on clinicians to utilize successful HF monitoring interventions to improve these measures. Telephone monitoring in patients with chronic HF utilizes a proactive approach in the care of such patients, and for this review is grouped into three categories, ie, structured telephone support, telemonitoring, and remote implantable device monitoring. Earlier studies on structured telephone support and telemonitoring suggested a clear benefit on mortality and HF admissions, although several recent large, randomized controlled studies have been neutral. Optimizing medical therapy requires an accurate assessment of volume status by the clinician; therefore, symptom report and weight monitoring alone are often challenging in the identification of true HF decompensation because they are not very sensitive markers. The use of remote monitoring technology for follow-up of patients with implantable devices, including implantable cardiac defibrillators and cardiac resynchronization therapy devices, can aid in identifying HF decompensation. Self-care or self-management is an essential component of a chronic illness such as HF, and it is important for such patients to be engaged in their health care to best utilize the telephone monitoring intervention. System design, adequate staffing, patient satisfaction, and treatment adherence are important for success of the telemonitoring system. Telephone monitoring seems to be an effective approach in the chronic HF population. In the future, large-scale telemonitoring programs may come into place as well as additional remote implantable monitoring devices.

Focused Cardiac Ultrasound as an Outpatient Tool To Assess Volume Status

Introduction: Accurate assessment of volume status is critical in the management of patients with congestive heart failure (CHF). We studied the utility of a pocket sized ultrasound device (Vscan; GE) in an outpatient cardiology clinic as a tool to guide volume assessment and reduce CHF admissions. Hypothesis: Use of pocket ultrasound to assess IVC parameters will help clinicians titrate diuretic medications and decrease hospital admissions. Methods: Inferior vena cava (IVC) maximum size and collapsibility were assessed in 95 patients by two internal medicine residents briefly trained in focused cardiac ultrasound (FCU). Both visual estimation and quantification of IVC size and collapsibility were performed during passive respiration and inspiratory sniff. Patients with IVC size O2cm and collapsibility !50% were deemed volume overloaded. Cardiologist assessment of volume status (blinded to imaging data) and changes in diuretic medication were also recorded. Patients were followed by means of chart review and telephone inquiry for occurrence of 30 day events (ER visit or hospital admission). Results: There was a 95% success rate of obtaining IVC size and collapsibility. Agreement between the visual and calculated IVC assessments of collapsibility and size were excellent, kappa 0.96 (95% CI: 0.89-1.00) and 0.87 (95% CI: 0.745-0.99), respectively, resulting in a 93% concordance for volume status assessment. Comparison of visual IVC and clinician ability to detect volume overload yielded a kappa statistic of 0.25 (95% CI: -0.01 0.51). Most patients were euvolemic by both IVC and clinician assessment (83%); only 2% were overloaded by both techniques. In 14% of patients there was discordance in volume status between visual IVC and clinician assessment, most of whom (11/ 12) were volume overloaded by IVC. In these 11 patients, 10 did not have their diuretic dose increased. At 30 days, 14 events occurred, with volume assessment discordant in 4. Two events were CHF-related and volume assessment was not discordant in either case. Of the other 12 events, half were cardiovascular and half were non-cardiovascular. Conclusion: Assessment of volume status in an outpatient cardiology clinic using FCU imaging of the IVC is feasible in a high percentage of patients. The strong agreement between visually assessed and measured IVC parameters validates FCU as a quick subjective bedside tool. Most patients in this outpatient cohort were euvolemic by both IVC and clinician. A group of patients was identified as volume overloaded by IVC yet euvolemic by clinician, suggesting that FCU in an outpatient setting may be a valuable adjunct to the physical exam. Whether FCU can help prevent hospital admission warrants further study in a larger patient population.

A Rational Approach to Assess Volume Status in Patients with Decompensated Heart Failure

Although the past few decades have yielded significant improvements in the management of cardiomyopathy, heart failure remains a leading cause of hospitalization as well as readmissions, both in the United States and worldwide. Accurate assessment of volume status in these patients is of great importance because it guides initial therapies and aids in determining suitability for discharge. However, this assessment can prove to be challenging and, therefore, must be based on multiple data points and techniques. This review examines the various modalities of volume assessment in the patient with decompensated heart failure.

Role of Bioimpedance Vectorial Analysis in Cardio-Renal Syndromes

The cardio-renal syndromes (CRS) are the result of complex bidirectional organ cross-talk between the heart and kidney, with tremendous overlap of diseases such as coronary heart disease, heart failure (HF), and renal dysfunction in the same patient. Volume overload plays an important role in the pathophysiology of CRS. The appropriate treatment of overhydration, particularly in HF and in chronic kidney disease, has been associated with improved outcomes and blood pressure control. Clinical examination alone is often insufficient for accurate assessment of volume status because significant volume overload can exist even in the absence of peripheral or pulmonary edema on physical examination or radiography. Bioelectrical impedance techniques increasingly are being used in the management of patients with HF and those on chronic dialysis. These methods provide more objective estimates of volume status in such patients. Used in conjunction with standard clinical assessment and biomarkers such as the natriuretic peptides, bioimpedance analysis may be useful in guiding pharmacologic and ultrafiltration therapies and subsequently restoring such patients to a euvolemic or optivolemic state. In this article, we review the use of these techniques in CRS.

Hemodynamic Monitoring and Treatment Strategy of Acute Heart Failure

Acute heart failure (AHF) has emerged as a major public health problem over the past 2 decades and AHF represents a period of high risk for patients, during which time the patients are more susceptible to have fatal outcomes or be re-hospitalized, compared to periods of chronic stable heart failure. The goals of AHF treatment are symptomatic relief and hemodynamic stabilization, which need accurate assessment of volume status and cardiac function of patients. Until now, there is a paucity of controlled clinical data to define optimal treatment for patients with AHF and most guidelines published by the American Heart Association or European Society of Cardiology have been generated by the consensus opinions of experts. In these guidelines, routine invasive hemodynamic monitoring of AHF patients is not recommended because there have not been any reports showing survival benefit in patients monitored with pulmonary artery catheters. At present, treatment strategies based on clinical characteristics such as pulmonary congestion and tissue hypoperfusion rather than invasive hemodynamic monitoring is widely accepted. In this article, we discuss an optimal management plan including appropriate assessment of the hemodynamic status of patients and treatment of AHF.

Measurement of Blood Volume at Bedside: New Era in Critical Care Medicine

Accurate assessment of volume status of the critically care ill patients in the intensive care unit is a challenging task facing intensivits each day. Failure to correct the volume deficit in patients with shock is known to significantly increase the morbidity and mortality in these patients 1 . On the other hand, fluid overload may cause worsening pulmonary edema, worsening hypoxemia, and deleterious effect in patients with acute respiratory distress syndrome 2 . Assessment of volume status becomes even more complicated when caring for patients with congestive heart failure, pulmonary arterial hypertension, renal failure, and cirrhosis.

The Valsalva Maneuver: A Bedside “Biomarker” for Heart Failure

Accurate assessment of volume status remains an important clinical goal in the management of patients with heart failure. Although physical examination can provide clues to volume status, its sensitivity and reproducibility are limited. Other noninvasive methods, such as measurement of natriuretic peptides or the use of impedance cardiography, are not well validated. The cardiovascular response to the Valsalva maneuver had been proposed as a simple, inexpensive bedside test for estimating filling pressures in patients with heart failure. Our objective was to summarize and critically evaluate the evidence for the use of the Valsalva maneuver in evaluating volume status in patients with heart failure. Studies have demonstrated a significant correlation between the cardiovascular response to the Valsalva maneuver and invasively measured ventricular filling pressures in patients with clinical heart failure. Although often overlooked in clinical training and practice, the cardiovascular response to the Valsalva maneuver is a potentially useful, noninvasive means of evaluating filling pressures in patients with heart failure.