The Conundrum of Volume Status Assessment: Revisiting Current and Future Tools Available for Physicians at the Bedside

Venous excess ultrasonography (VExUS) captures dynamic changes in volume status surrounding hemodialysis: A multicenter prospective observational study

Background

The evaluation of volume status is essential to clinical decision-making, yet multiple studies have shown that physical exam does not reliably estimate a patient's intravascular volume. Venous excess ultrasound score (VExUS) is an emerging volume assessment tool that utilizes inferior vena cava (IVC) diameter and pulse-wave Doppler waveforms of the portal, hepatic and renal veins to evaluate venous congestion. A point-of-care ultrasound exam initially developed by Beaubein-Souligny et al., VExUS represents a reproducible, non-invasive and accurate means of assessing intravascular congestion. VExUS has recently been validated against RHC-the gold-standard of hemodynamic evaluation for volume assessment. While VExUS scores were shown to correlate with elevated cardiac filling pressures (i.e., right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP)) at a static point in time, the ability of VExUS to capture dynamic changes in volume status has yet to be elucidated. We hypothesized that paired VExUS examinations performed before and after hemodialysis (HD) would reflect changes in venous congestion in a diverse patient population.

Methods

Inpatients with end-stage renal disease undergoing intermittent HD were evaluated with transabdominal VExUS and lung ultrasonography before and following HD. Paired t-tests were conducted to assess differences between pre-HD and post-HD VExUS scores, B-line scores and dyspnea scores.

Results

Fifty-six patients were screened for inclusion in this study. Ten were excluded due to insufficient image quality or incomplete exams, and forty-six patients (ninety-two paired ultrasound exams) were included in the final analysis. Paired t-test analysis of pre-HD and post-HD VExUS scores revealed a mean VExUS grade change of 0.82 (p<0.001) on a VExUS scale ranging from 0 to 4. The mean difference in B-line score following HD was 0.8 (p=0.001). There was no statistically significant difference in subjective dyspnea score (p=0.41).

Conclusions

Large-volume fluid removal with HD was represented by changes in VExUS score, highlighting the utility of the VExUS exam to capture dynamic shifts in intravascular volume status. Future studies should evaluate change in VExUS grade with intravenous fluid or diuretic administration, with the ultimate goal of evaluating the capacity of a standardized bedside ultrasound protocol to guide inpatient volume optimization.

Hyponatremia and Identification of Seniors at Risk (ISAR) Score in Geriatric Patients: An Analytical Cross-Sectional Study

Aim and objective Hyponatremia is the most common electrolyte abnormality in hospitalized patients. Age is an important, strong independent factor for hyponatremia. Geriatric at-risk groups are identified with six straightforward dichotomous questions. The research aims to determine the incidence of hyponatremia and correlate the identification of seniors at risk (ISAR) score with electrolytes in elderly individuals.  Materials and methods The 334 geriatric population of elderly men and women were recruited based on age cut-off as more than 70 to 75, 76 to 80, and more than 80. Patients were categorized based on serum sodium levels as severe hyponatremia group A (< 125 mEq/L), moderate hyponatremia B (126 to 130 mEq/L), mild hyponatremia C (131 to 135 mEq/L) and normonatremia D (136 to 145 mEq/L). At the time of admission, the ISAR Tool was utilized to identify the participants with hyponatremia at risk. Electrolytes sodium, potassium, and chloride were analyzed in the Beckman Coulter AU480 autoanalyzer by indirect ISE method. The mean of the data was compared with ANOVA, and the ISAR risk score was correlated with electrolytes by Pearson correlation analysis; p < 0.5 is considered significant.  Results and discussion About 16.76 % (56 patients) had severe hyponatremia (Serum sodium 119.14± 4.14 mEq/L) with a high ISAR score (6.0) and were reported as critical alert results by the central laboratory. Based on age-wise category, 70 to 75 yrs had serum sodium levels of 133.82 mEq/L, 76 to 80 yrs had 128.4 mEq/L, and more than 80 years had serum hyponatremia 119.17 mEq/L. Geriatrics with normonatremia had a 1.22 ISAR score, whereas geriatrics with severe hyponatremia had a 6.0 ISAR score. Correlation analysis of the ISAR score revealed a statistically significant negative correlation with sodium (r = - 0.53), potassium (r = - 0.34), and chloride (r = - 0.30) levels. Likewise, the length of hospital stay of the geriatrics with severe hyponatremia was prolonged (19 days), which contributed to the deterioration of health status; thereby, better healthcare follow-up is encouraged.  Conclusion Hyponatremia is a critical alert analyte that is common in hospitalized geriatric patients. The ISAR score system points towards the individuals who are at risk and need immediate correction. Thereby, correction of sodium levels and close monitoring of the elderly patient enables quick recovery, and the consequences of hyponatremia are circumvented.

Systemic Venous Congestion Reviewed

Accurate determination of intravascular volume status is challenging in acutely ill patients. Favorable patient outcome is vital to correctly identify intravascular volume depletion and avoid systemic venous congestion. Most of the conventional means of hemodynamic monitoring in the acute healthcare setting are geared toward addressing the cardiac output and maintaining an optimum mean arterial pressure. While assessing and maintaining cardiac output in an acutely ill patient is very important, a venous congestion cascade is often overlooked, which can negatively affect the intraabdominal end organs. The prospect of using point-of-care ultrasound (POCUS) to determine systemic venous congestion could be a potentially handy tool for clinicians. Venous excess ultrasound score (VExUS) has also been utilized by clinicians as a semi-quantitative assessment tool to assess fluid status. This review aims to discuss the potential role of POCUS and VExUS scores in determining systemic venous congestion through a narrative review of recently published literature.

Intrarenal Doppler approaches in hemodynamics: A major application in critical care

The treatment of severe cases usually requires multimodality hemodynamic monitoring approaches, particularly for tissue and organ perfusion tracking. Currently, only a few studies have investigated renal perfusion status at the bedside. Ultrasound has become increasingly utilized to guide the hemodynamic management of severe patients. Similarly, intrarenal Doppler (IRD) is widely used to assess renal perfusion from both the intrarenal artery and vein perspectives. The renal resistive index (RRI), which reflects the renal arterial blood flow profile, is often applied to predict the reversibility of renal dysfunction and to titrate hemodynamic support. Intrarenal venous flow (IRVF) patterns and the renal venous stasis index (RVSI), which reflects the intrarenal vein blood flow profile, are now being used to assess intravenous congestion. They may also be useful in predicting the risk of acute kidney injury and avoiding fluid overload. IRD can provide diverse and supplemental information on renal perfusion and may help to establish the early diagnosis in severe patients. This review focused on the specific operational methods, influencing factors, and applications of IRD in hemodynamics.

A Case of Severe Tricuspid Valve Regurgitation in a Patient Undergoing Orthotopic Liver Transplantation: Whether to Proceed, or Not

A 38-year-old male presented for orthotopic liver transplantation complicated by new-onset torrential tricuspid regurgitation before incision. Subclinical volume overload and functional tricuspid regurgitation created a challenging scenario in which the benefits of expeditious transplant were weighed against the risks of allograft congestion and failure. Intraoperative transesophageal echocardiography proved critical in diagnosing severe tricuspid regurgitation and guided clinical decision making. In this article, we describe the intraoperative presentation of acutely elevated right heart pressures and the subsequent management of this patient prior to ultimately successful liver transplantation.