Maximum Inferior Vena Cava Diameter Research Articles

#2058 IVC diameter and collapsibility via point-of-care ultrasound among clinically euvolemic Filipinos in Victoriano Luna Medical Center, Philippines

Abstract Background and Aims History, physical findings, and laboratory tests have limited sensitivity and specificity to assess relative intravascular volume or volume responsiveness. Inferior vena cava (IVC) ultrasound provides a direct assessment of relative intravascular volume status. The Journal of the American Society of Echocardiography (2010), recommended that an IVC diameter of <2.1 cm and collapsibility of >50% with a sniff indicates normal right atrial pressure of 3 mmHg (0-5 mmHg), while an IVC diameter of >2.1 cm with <50% inspiratory collapse indicates high right atrial pressure of 15 mmHg (10-20 mmHg). However, there have been occasions in the hospital setting wherein clinically hypervolemic Filipino patients were observed to have inferior vena cava diameters of less than 2.0 cm. This study aims to determine the average IVC diameter among clinically euvolemic Filipinos and to evaluate the applicability of standardized ultrasonographic IVC measurements in the Filipino population. Method This is a prospective observational study that included 45 clinically euvolemic patients and staff of Victoriano Luna Medical Center from 01 September 2023 to 01 November 2023. The demographic profile and anthropometric measurements of the volunteers were obtained. Ultrasound assessment was performed bedside and the IVC diameter was measured during passive respiration without sniff test 1 to 2 cm distal to the hepatic vein or 3 to 4 cm distal to the junction of the right atrium and inferior vena cava. The maximum and minimum diameters of the inferior vena cava was also measured using M-mode, and its collapsibility index was computed using the following formula: collapsibility index (CI) = (IVC max – IVC min) / IVC max. Categorical variables such as sex and comorbidities will be presented as frequencies and percentages while continuous variables such as age, body mass index, and inferior vena cava diameter and collapsibility will be presented as mean and standard deviation or median and interquartile range. Results The study group mainly consisted of males aged 65 years and below with normal body mass index for Asians. Cut-off values for the maximum inferior vena cava diameter were based on the venous excess ultrasound grading system, or VEXUS score, by Beaubien-Souligny et al. (2020) wherein congestion was considered at IVC diameters more than or equal to 2.0 cm. Of the 45 participants, 33 had maximum inferior vena cava diameter of less than 2.0 cm. Twenty-eight (28) out of 45 participants had a collapsibility index of more than 50%, which is indicative of normal right atrial pressure. Of the 33 with a maximum inferior vena cava diameter of less than 2.0 cm, 11 of which had a collapsibility index between 20 and 50%, and 22 with more than 50%. The remaining 12 participants had a maximum IVC diameter of more than or equal to 2.0 cm, with five having a collapsibility index between 20 and 50% and six with more than 50%. The mean maximum IVC diameter in the 45 volunteers on quiet respiration was 1.79 cm (+0.47), with an average computed collapsibility index of 54.43% (+19.78). Conclusion Thirty-three participants (73.33%) had a maximum inferior vena cava diameter of less than 2.0 cm, 22 of which have a collapsibility index of more than 50%. Among the 45 volunteers, the mean IVC maximum diameter on quiet respiration was 1.79 cm (+0.47), with an average computed collapsibility index of 54.43% (+19.78). Based on the results, standardized ultrasonographic IVC measurements can be applied on the Filipino population. Considering the Filipinos’ petite stature, the average IVC diameter among Filipinos is smaller and further investigation is warranted to establish clear cut-off values to identify plethoric IVCs in the Filipino setting.

Preoperative Ultrasound for the Prediction of Postinduction Hypotension: A Systematic Review and Meta-Analysis.

Postinduction hypotension (PIH) is closely associated with postoperative adverse outcomes. Preoperative hypovolemia is a key risk factor, and many parameters are available from ultrasound to detect hypovolemia, but the accuracy of PIH from ultrasound remains unclear. This systematic review and meta-analysis aimed to evaluate the commonly used measurements from ultrasound to predict PIH. We searched the PubMed, Cochrane Library, Embase, CNKI, and Web of Science databases from their inception to December 2023. Thirty-six studies were included for quantitative analysis. The pooled sensitivities for the inferior vena cava collapsibility index (IVC-CI), maximum inferior vena cava diameter (DIVCmax), minimum inferior vena cava diameter (DIVCmin), and carotid artery corrected flow time (FTc) were 0.73 (95% CI = 0.65, 0.79), 0.66 (95% CI = 0.54, 0.77), 0.74 (95% CI = 0.60, 0.85), and 0.81 (95% CI = 0.72, 0.88). The pooled specificities for the IVC-CI, DIVCmax, DIVCmin, and carotid artery FTc were 0.82 (95% CI = 0.75, 0.87), 0.75 (95% CI = 0.66, 0.82), 0.76 (95% CI = 0.65, 0.84), and 0.87 (95% CI = 0.77, 0.93). The AUC for the IVC-CI, DIVCmax, DIVCmin, and carotid artery FTc were 0.84 (95% CI = 0.81, 0.87), 0.77 (95% CI = 0.73, 0.81), 0.82 (95% CI = 0.78, 0.85), and 0.91 (95% CI = 0.88, 0.93). Our study demonstrated that ultrasound indices are reliable predictors for PIH. The carotid artery FTc is probably the optimal ultrasound measurement for identifying patients who will develop PIH in our study.

The use of lung ultrasound in evaluation of extravascular lung water in hemodialysis patients: Systematic review and meta-analysis.

Determining dry weight is crucial for optimizing hemodialysis, influencing efficacy, cardiovascular outcomes, and overall survival. Traditional clinical assessment methods for dry weight, relying on factors such as blood pressure and edema, frequently lack reliability. Lung ultrasound stands out as a promising tool for assessing volume status, given its non-invasiveness and reproducibility. This study aims to explore the role of Lung ultrasound in evaluating the impact of hemodialysis and ultrafiltration on extravascular lung water, with a specific focus on changes in B-lines post-hemodialysis compared to pre-hemodialysis. The research encompassed searches across PubMed, WOS, and Scopus databases for studies related to lung ultrasound and hemodialysis. A meta-analysis was then performed to determine the mean differences in various parameters before compared to after, hemodialysis, including the number of B-lines, indexed end-inspiratory and end-expiratory inferior vena cava diameters, inferior vena cava collapsibility index, weight, blood pressure, and serum levels of NT-pro-BNP. Our meta-analysis, included 33 studies with 2301 hemodialysis patients, revealed a significant decrease in the number of B-lines post-hemodialysis (mean difference = 8.30, 95% CI [3.55 to 13.05]). Furthermore, there was a noteworthy reduction in inspiratory and expiratory inferior vena cava diameters post-hemodialysis (mean difference = 2.32, 95% CI [0.31 to 4.33]; mean difference = 4.05, 95% CI [2.44 to 5.65], respectively). Additionally, a significant positive correlation was observed between B-lines and the maximum inferior vena cava diameter both pre- and post-hemodialysis (correlation coefficient = 0.39; correlation coefficient = 0.32, respectively). These findings indicate the effectiveness of lung ultrasound in detection of volume overload and assessment of response to ultrafiltration in hemodialysis patients.

Diagnostic accuracy of venous system ultrasound for subtypes of acute kidney injury

BackgroundManagement of acute kidney injury (AKI) in the ED can be difficult due to uncertainty regarding the aetiology. This study investigated the diagnostic value of venous system ultrasound for determining...

Correlation of Ultrasound Guided Inferior Vena Cava Collapsibility Index with Central Venous Pressure to Assess the Volume Status in Postoperative Intensive Care Unit Patients: A Prospective Observational Study

Background: Accurate assessment of intravascular volume status is a vital aspect of management of intensive care unit (ICU) patients. Inferior vena cava (IVC) diameter and IVC collapsibility index have surfaced as promising methods to accurately predict hypovolemia. But no such study has evaluated it’s their utility in postoperative patients.
 Methods: The study aimed to assess the correlation between ultrasound guided IVC collapsibility index (IVC CI) and CVP for volume status in intensive care unit patients. Hundred spontaneously breathing patients receiving postoperative care in our surgical ICU between November 2019 to march 2021were enrolled into the study. Maximum IVC diameter (IVCdmax) at end-expiration, minimum IVC diameter at end-inspiration (IVCdmin) and IVC CI were measured. Simultaneous CVP recordings were obtained.
 Results: A positive correlation was noted between IVC maximum diameter and CVP (p = <0.001) and between IVC Minimum Diameter and CVP. (p = <0.001) A negative correlation between IVC CI and CVP was seen (p = <0.001). Mean IVC CI was highest in the hypovolemic group. The area under the ROC curve (AUROC) for IVC CI predicting hypovolemia was 0.943 (95% CI: 0.9 - 0.986), thus demonstrating excellent diagnostic performance. At a cut off of ≥58.416%, IVC CI predicts hypovolemia with a sensitivity of 93.8%, and a specificity of 84%.
 Conclusion: IVC CI can be used to guide fluid therapy due to its excellent diagnostic accuracy in predicting hypovolemia in postoperative patients in ICU.

Coronary sinus diameter to estimate congestion and predict survival

BackgroundCongestion predicts a poor prognosis, but its assessment is challenging in clinical practice and requires a multiparametric approach. We investigated if the coronary sinus (CS) diameter can predict mortality in a human model of rapid fluid unloading. MethodsWe measured by echocardiography the CS, and the inferior vena cava (IVC) for comparison, in 60 patients with end-stage chronic kidney disease (ESKD) immediately before and after hemodialysis (HD; age 76 [57–81] years, 40% female, left ventricular ejection fraction 57 [53–56]%). Patients were prospectively followed up for all-cause mortality. ResultsHD-induced decongestion decreased the maximum diameters of both CS and IVC (p ≤ 0.001 for all). The maximum diameter of the CS (CSmax) was as accurate as the IVC maximum diameter and collapsibility for the identification of congestion, defined as pre-hemodialysis status (AUROC CSmax = 0.902 vs IVC = 0.895, p = n.s.). A CSmax diameter after hemodialysis > 9 mm predicted all-cause mortality at 12 months (Log-rank Chi square = 11.49, p < 0.001). ConclusionsA persistently dilated CS after hemodialysis is a marker of residual congestion and predicts death at one year in high-risk ESKD patients.

Association of infraclavicular axillary vein diameter and collapsibility index with general anesthesia-induced hypotension in elderly patients undergoing gastrointestinal surgery: an observational study

BackgroundThe collapse index of inferior Vena Cava (IVC) and its diameter are important predictive tools for fluid responsiveness in patients, especially critically ones. The collapsibility of infraclavicular axillary vein (AXV) can be used as an alternative to the collapsibility of IVC (IVC-CI) to assess the patient’s blood volume.MethodsA total of 188 elderly patients aged between 65 and 85 years were recruited for gastrointestinal surgery under general anesthesia. Ultrasound measurements AXV and IVC were performed before induction of general anesthesia. Patients were grouped in accordance to the hypotension after induction. ROC curves were used to analyze the predictive value of ultrasound measurements of AXV and IVC for hypotension after induction of anesthesia. Pearson linear correlation was used to assess the correlation of ultrasound measurements and decrease in mean arterial blood pressure (MAP).ResultsThe maximum diameter of AXV(dAXVmax) and the maximum diameter of IVC (dIVCmax) were not related to the percentage decrease in MAP; the collapsibility of AXV (AXV-CI) and IVC-CI were positively correlated with MAP changes (correlation coefficients:0.475, 0.577, respectively, p < 0.001). The areas under the curve (AUC) was 0.824 (0.759–0.889) for AXV-CI, and 0.874 (0.820–0.928) for IVC-CI. The optimal threshold for AXV-CI was 31.25% (sensitivity 71.7%, specificity 90.1%), while for IVC-CI was 36.60% (sensitivity 85.9%, specificity 79.0%). Hypotension and down-regulation of MAP during induction can be accurately predicted by AXV-Cl after correction for confounding variables.ConclusionInfraclavicular axillary vein diameter has no significant correlation with postanesthesia hypotension, whereas AXV-CI may predict postanesthesia hypotension during gastrointestinal surgery of the elderly.Trial registrationThis study was registered in the Clinical Trial Registry of China on 05/06/2022 (ChiCTR2200060596).

Expiratory Diameter of the Inferior Vena Cava Diameter IVC Across Age Groups in CCF Subjects

Background: Dilatation of the Inferior Vena Cava (IVC) is used as the ultrasonic diagnostic feature in patients suspected of congestive heart failure. The IVC diameter has being reported to vary among the various age ranges. Knowledge of these variations is useful in precision diagnoses of CHF by imaging scientists. Aim: The study aimed to determining the ultrasonic mean expiratory diameter of the IVC across the various age ranges with CCF in Azare, Bauchi State-Nigeria. Methods: One hundred and ninety-nine subjects of both sexes diagnosed with Congestive Cardiac Failure were randomly grouped into six age groups. A structured questionnaire was used to rule out those that fell within the exclusion criteria. Their informed consent was sought for abdominal ultrasound scan. The probe was placed on the mid line of the body, half-way between the xiphoid process and the umbilicus with the marker on the probe directed towards the patient`s head to obtain a longitudinal view of the IVC. The maximum IVC diameter was measured from the subcostal view using the electronic caliper of the scan machine during expiration on a B mode. The mean value of each group was obtained and analyzed statistically. Results: It was observed that, the mean expiratory diameter of the IVC across the age group (18-27, 28-37, 38-47, 48-57, 58-67 and 68-77) years were (1.89, 1.96, 1.94, 2.06, 1.91, 1.97 and 1.94) cm, respectively P-value ≤ 0.05. Conclusion: In conclusion, the normal cutoff values for indicating a dilated IVC across the different age strata in the populace has been established.

Point of care transthoracic echocardiography for the prediction of post – spinal anesthesia hypotension in elderly patients with cardiac diseases and left ventricular dysfunction

In elderly patients with cardiac diseases, changes in cardiovascular physiology diminish cardiovascular reserve and predispose to hemodynamic instability after spinal anesthesia; hence, such patients could be at risk of postoperative complications. Additionally, transthoracic echocardiography (TTE) is used in clinical practice to evaluate cardiovascular hemodynamics. Therefore, we hypothesized that echocardiographic measurements could display significant diagnostic power in the prediction of post - spinal anesthesia hypotension in elderly patients with cardiac diseases and reduced left ventricular ejection fraction (LV-EF). Therefore, sixty-one elderly orthopedic-trauma patients were recruited. Prior to spinal anesthesia a TTE examination was performed. The LV-EF, the stroke volume index (SVI), the peripheral vascular resistance (PVR), the LV filling pressures (E/Em ratio), the right ventricular function [tricuspid annular plane systolic excursion (TAPSE), tricuspid annular systolic velocity (TASV) and fractional area change (FAC)], as well as inferior vena cava (IVC) measurements, such as IVCCI (collapsibility index of the IVC) and dIVCmax (maximum diameter of IVC)-to-IVCCI ratio were assessed. Twenty-six out of sixty-one patients manifested hypotension. Preoperative dIVCmax-to-IVCCI ratio demonstrated the greatest performance amongst echocardiographic indices in predicting post - spinal anesthesia hypotension. The dIVCmax-to-IVCCI ratio < 48 had significantly higher diagnostic power than IVCCI > 0.28, FAC > 42, E/Em ratio < 9 and SVI < 32 (receiver operator characteristic curve analysis). The gray zone for the dIVCmax-to-IVCCI ratio (40–49) showed the lowest number of inconclusive measurements among echocardiographic variables. The preoperative dIVCmax-to-IVCCI ratio could be a reliable echocardiographic index to predict post - spinal anesthesia hypotension in elderly patients with left ventricular dysfunction.

Correlation of Baseline Inferior Vena Cava Diameter and Collapsibility with Age and Sex in Normovolaemic Children: A Cross-sectional Study

Introduction: Ultrasound measurement of Inferior Vena Cava (IVC) diameter and collapsibility is increasingly used for volume status assessment and fluid responsiveness in paediatric and adult population. There is a wide variation in the age specific IVC diameters in paediatric population, whereas age specific variation in IVC collapsibility in euvolaemic children is not much known. Aim: To analyse the correlation of baseline IVC diameter and collapsibility with age and sex in euvolaemic children. Materials and Methods: This cross-sectional study was conducted at Kerala Institute of Medical Sciences, a tertiary care hospital in south Kerala, India, over a study period from June 2014 to May 2016. A total of 80 children in the age group of one month to 15 years, who presented without evidence of volume depletion were enrolled. The IVC was assessed approximately 2 cm distal to IVC-hepatic vein junction, Motion mode (M-mode) measurement of maximum (expiratory) and minimum (inspiratory) width of IVC diameter was measured. Collapsibility Index was also calculated for each subject by measuring difference between the maximum and minimum IVC diameters divided by the maximum diameter. The statistical data was analysed using the statistical software Statistical Package for Social Sciences (SPSS) version 16. All the numerical data was expressed as mean±Standard Deviation (SD). Quantitative analysis was performed using Analysis of Variance (ANOVA) and t-test. The correlation of IVC parameters were assessed using Karl Pearson correlation coefficient. The p-value less than 0.05 was considered as significant. Results: Eighty euvolaemic children between the age one month and 15 years were enrolled in the study. The mean age of study group was 5±4 years. Males 41 (51.3%) and females 39 (48.8%) were almost equally distributed. A significant strong positive correlation was found between IVC expiratory and inspiratory diameter with age using Karl Pearson correlation, r= 0.912, p&lt;0.001; r=0.876, p&lt;0.001, respectively. No significant correlation was found between IVC collapsibility and age, Karl Pearson correlation, r=0.079, p=0.485. No correlation was found between sex and the IVC parameters. Conclusion: According to the present study results, IVC diameter showed a positive correlation with age but not with sex. The IVC collapsibility had no correlation with either age or sex.

Prognostic significance of pulmonary arterial wedge pressure estimated by deep learning in acute heart failure.

Acute decompensated heart failure (ADHF) presents with pulmonary congestion, which is caused by an increased pulmonary arterial wedge pressure (PAWP). PAWP is strongly associated with prognosis, but its quantitative evaluation is often difficult. Our prior work demonstrated that a deep learning approach based on chest radiographs can calculate estimated PAWP (ePAWP) in patients with cardiovascular disease. Therefore, the present study aimed to assess the prognostic value of ePAWP and compare it with other indices of haemodynamic congestion. We conducted a post hoc analysis of a single-centre, prospective, observational heart failure registry and analysed data from 534 patients admitted for ADHF between January 2018 and December 2019. The deep learning approach was used to calculate ePAWP from chest radiographs at admission and discharge. Patients were divided into three groups based on the ePAWP tertiles at discharge, as follows: first tertile group (ePAWP≤11.2mm Hg, n=178), second tertile group (11.2<ePAWP<13.5mm Hg, n=170), and third tertile group (ePAWP≥13.5mm Hg, n=186). The third tertile group had a higher prevalence of atrial fibrillation and lower systolic blood pressure at admission; a lower platelet count and higher total bilirubin at both admission and discharge; and a higher left atrial diameter, peak early diastolic transmitral flow velocity, right ventricular end-diastolic diameter, and maximal inferior vena cava diameter at discharge. During the median follow-up period of 289days, 223 (41.7%) patients reached the primary endpoint (a composite of all-cause mortality or rehospitalization for heart failure). Kaplan-Meier analysis revealed a significantly higher composite event rate in the third tertile group (log-rank test, P=0.006). Even when adjusted for clinically relevant factors, a higher ePAWP at discharge and a smaller decrease in ePAWP from admission to discharge were significantly associated with higher event rates [ePAWP at discharge: hazard ratio, 1.10; 95% confidence interval (CI), 1.02-1.19; P=0.010; and size of ePAWP decrease: hazard ratio, 0.94; 95% CI, 0.89-0.99; P=0.038]. Our study suggests that ePAWP calculated by a deep learning approach may be useful for identifying and monitoring pulmonary congestion during hospitalization for ADHF.

ROLE OF ULTRASONOGRAPHIC INFERIOR VENACAVAL ASSESSMENT IN SURGERIES CONDUCTED UNDER GENERAL ANAESTHESIA-A PROSPECTIVE OBSERVATIONAL STUDY

Background: One of the most frequent side effects following the induction of general anaesthesia during surgery is hypotension. The goal of our study was to determine if there was a connection between the maximum inferior vena cava (IVC) diameter prior to induction, the collapsibility index (CI), and the post-induction decrease in mean arterial blood pressure in patients undergoing operations under general anaesthesia. Materials and Methods: Eighty patients who underwent procedures under general anaesthesia at Gandhi Medical College Bhopal and associated tertiary care hospital were included in a prospective observational research. Prior to starting general anaesthesia, the IVC was evaluated. For each surgical patient, the maximum and minimum IVC diameters (IVCD max and IVCD min) as well as the CI were assessed. Results: According to the criteria of hypotension as defined, 31(38.75%) of the patients developed post-induction hypotension. Four patients had MAP &lt;60 mmHg after induction of anesthesia. Post-induction hypotension was seen in patients with increased age. Patients with smaller IVCD max (P = 0.02), smaller IVCD min (P = 0.003), and higher CI% (P = 0.004) developed hypotension after induction of anesthesia. Percentage drop in MAP was 33.7 ± 4.48% (P = 0.002) in patients who developed post-induction hypotension. Conclusion: Predicting post-induction hypotension caused by hypovolemia in surgical patients with IVC measurement using ultrasound is a reliable strategy.

Clinical utility of ultrasonography, pulse oximetry and arterial line derived hemodynamic parameters for predicting post-induction hypotension in patients undergoing elective craniotomy for excision of brain tumors - A prospective observational study

BackgroundHypotension, which is a common adverse effect of induction of anesthesia, may be especially detrimental in neurosurgical patients. Hence, it is important to investigate hemodynamic parameters which may be useful in identifying patients at risk of hypotension, following induction. Our study was designed to assess the utility of parameters derived from ultrasonography, pulse oximeter and arterial line for predicting post-induction hypotension. MethodsThe study was designed as a prospective, observational trial. Written informed consent was obtained from 100 American Society of Anesthesiologists (ASA) 1 and 2 patients, between 18-60 years of age, scheduled for elective craniotomy for brain tumors. Arterial cannula was inserted before induction of anesthesia and connected to Vigileo cardiac output monitor. Baseline stroke volume variation (SVV), stroke volume (SV), cardiac index (Ci), cardiac output (CO) and pulse pressure variation (PPV) were recorded. Plethysmography variability index (PVI) and perfusion index (PI) were obtained from the Masimo rainbow SET® Radical-7® pulse oximeter. Ultrasonographic assessment of the inferior vena cava (IVC) was performed before induction of anesthesia and again within 15 min after induction. Maximum and minimum IVC diameters (dIVCmax and dIVCmin) and collapsibility index (CI) were measured. All the other aforementioned parameters were recorded every minute starting at induction, until the 15th minute following induction. ResultsPI, CI and dIVCmax were found to have the largest AUCROC for the prediction of post-induction hypotension (AUCROC 0.852, 0.823 and 0.781 respectively). Multiple logistic regression analysis revealed CI to be the most significant independent factor for the prediction of post-induction hypotension. ConclusionNon-invasively derived hemodynamic parameters like dIVCmax, CI and PI were more accurate for the prediction of post-induction hypotension, compared to invasively derived parameters.

Maximum inferior vena cava diameter predicts post-induction hypotension in hypertensive patients undergoing non-cardiac surgery under general anesthesia: A prospective cohort study.

BackgroundInferior vena cava (IVC) ultrasonography is a reliable variable that predicts post-induction hypotension (PIH) in patients undergoing surgery under general anesthesia. However, in patients with hypertension, the predictive performance of ultrasound IVC measurements needs further exploration.MethodsThis is a prospective cohort study. Adult patients with existing hypertension scheduled to undergo non-cardiac surgery under general anesthesia were eligible. An abdominal ultrasound examination was conducted immediately prior to anesthesia induction (0.03 mg kg–1 midazolam, 0.3 mg kg–1 etomidate, 0.4 μg kg–1 sufentanil, and 0.6 mg kg–1 rocuronium). IVC collapsibility index (IVC-CI) was calculated as (dIVCmax–dIVCmin)/dIVCmax, where dIVCmax and dIVCmin represent the maximum and minimum IVC diameters at the end of expiration and inspiration, respectively. PIH was defined as a reduction of mean arterial pressure (MAP) by >30% of the baseline or to <60 mmHg within 10 min after endotracheal intubation. The diagnostic performance of IVC-CI, dIVCmax, and dIVCmin in predicting PIH was also examined in a group of normotensive patients receiving non-cardiac surgery under the same anesthesia protocol.ResultsA total of 51 hypertensive patients (61 ± 13 years of age, 31 women) and 52 normotensive patients (42 ± 13 years of age, 35 women) were included in the final analysis. PIH occurred in 33 (64.7%) hypertensive patients and 19 (36.5%) normotensive patients. In normotensive patients, the area under the receiver operating curve (AUC) in predicting PIH was 0.896 (95% confidence interval [CI]: 0.804–0.987) for IVC-CI, 0.770 (95% CI: 0.633–0.908) for dIVCmax, and 0.868 (95% CI: 0.773–0.963) for dIVCmin. In hypertensive patients, the AUC in predicting PIH was 0.523 (95% CI: 0.354–0.691) for IVC-CI, 0.752 (95% CI: 0.621–0.883) for dIVCmax, and 0.715 (95% CI: 0.571–0.858) for dIVCmin. At the optimal cutoff (1.24 cm), dIVCmax had 54.5% (18/33) sensitivity and 94.4% (17/18) specificity.ConclusionIn hypertensive patients, IVC-CI is unsuitable for predicting PIH, and dIVCmax is an alternative measure with promising performance.Clinical trial registration[http://www.chictr.org.cn/], identifier [ChiCTR2000034853].

Accuracy of Multi-organ Point-of-Care Ultrasound for Acute Kidney Injury Etiologies.

This study investigated the diagnostic performance of point-of-care ultrasound (POCUS) for acute kidney injury (AKI) etiological subgroups in emergency department (ED) patients. Multi-organ POCUS including kidney, bladder, inferior vena cava (IVC), lung and cardiac examinations were used to identify five AKI subgroups: hypovolemia, reduced cardiac output, systemic vasodilatation and renal vasomodulation, renal and post-renal. One hundred sixty-five AKI patients were included in the study. The most diagnostic parameter in the post-renal group was the presence of any hydronephrosis, with a sensitivity of 93.3% (95% confidence interval [CI]: 68.1-99.8) and specificity of 85.9% (95% CI: 79.3-91.1). For the reduced cardiac output group, the most diagnostic parameter was IVC maximum diameter &gt;17 mm with a sensitivity of 100% (95% CI: 83.2-100) and specificity of 70.2% (95% CI: 61.6-77.7). For the hypovolemia group, the most diagnostic parameter was IVC maximum diameter ≤17.9 mm with a sensitivity of 81.2% (95% CI: 71.2-88.8) and specificity of 56.5% (95% CI: 44-68.4). For the systemic vasodilatation and renal vasomodulation group, the most diagnostic parameter was diffuse ascites with a sensitivity of 56.3% (95% CI: 29.9-80.2) and specificity of 89.9% (95% CI: 83.8-94.2). None of the parameters were significant for the renal group. We concluded that multi-organ POCUS is of diagnostic value for AKI subgroups.

Correlation between transhepatic and subcostal inferior vena cava ultrasonographic images for evaluating fluid responsiveness after cardiac surgery.

Echocardiographic monitoring during the postoperative period following cardiac surgery is essential because patients often develop hemodynamic instability from hypovolemia and other causes. Therefore, predicting fluid responsiveness by measuring respirophasic variation in the inferior vena cava (IVC) is essential in this population. Yet it is not always possible to evaluate using the traditional subcostal view. This cross-sectional study of 36 consecutive adult patients who underwent cardiac surgery included those in whom it was possible to adequately visualize the IVC in both the subcostal and transhepatic views. The maximum and minimum diameters and respirophasic variation were measured in each view. These views were then correlated and the capacity of the transhepatic view to predict fluid responsiveness was evaluated. There was a strong positive correlation between IVC maximum and minimum diameters and respirophasic variation according to subcostal and transhepatic views. Evaluation of IVC respirophasic variation indices using the transhepatic view also showed high sensitivity for predicting fluid responsiveness. There is a correlation between the transhepatic and subcostal views for determining maximum and minimum IVC diameters, and distensibility and variability indices for predicting fluid responsiveness in postoperative cardiac surgery patients.

Lack of correlation between different congestion markers in acute decompensated heart failure

BackgroundHospitalizations for acute decompensated heart failure (ADHF) are commonly associated with congestion-related signs and symptoms. Objective and quantitative markers of congestion have been identified, but there is limited knowledge regarding the correlation between these markers.MethodsPatients hospitalized for ADHF irrespective of left ventricular ejection fraction were included in a prospective registry. Assessment of congestion markers (e.g., NT-proBNP, maximum inferior vena cava diameter, dyspnea using visual analogue scale, and a clinical congestion score) was performed systematically on admission and at discharge. Telephone interviews were performed to assess clinical events, i.e., all-cause death or readmission for cardiovascular cause, after discharge. Missing values were handled by multiple imputation.ResultsIn total, 130 patients were prospectively enrolled. Median length of hospitalization was 9 days (interquartile range 6 to 16). All congestion markers declined from admission to discharge (p < 0.001). No correlation between the congestion markers could be identified, neither on admission nor at discharge. The composite endpoint of all-cause death or readmission for cardiovascular cause occurred in 46.2% of patients. Only NT-proBNP at discharge was predictive for this outcome (hazard ratio 1.48, 95% confidence interval 1.15 to 1.90, p = 0.002).ConclusionNo correlation between quantitative congestion markers was observed. Only NT-proBNP at discharge was significantly associated with the composite endpoint of all-cause death or readmission for cardiovascular cause. Findings indicate that the studied congestion markers reflect different aspects of congestion.Graphical abstract

The Sonographic Measurement of the Inferior Vena Cava Diameter versus the Central Venous Pressure in Assessing Fluid Responsiveness in Patients after Coronary Artery Bypass Graft Surgery

Background: Fluid status assessment and management post coronary artery bypass grafting (CABG) is a clinical challenge. The study aimed to establish whether central venous pressure (CVP) and ultrasound measures of respiratory variability of inferior vena cava (IVC) diameter might predict fluid responsiveness in mechanically ventilated patients after CABG.&#x0D; Methods: This comparative study included 200 consecutive adult patients who underwent elective CABG. We recorded the following parameters: heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), central venous pressure (CVP), inferior vena cava maximum (IVCmax), and minimum (IVCmin) diameters, left ventricular ejection fraction (LVEF), and velocity-time integral in the left ventricular outflow tract (VTI-LVOT).&#x0D; Results: The age of the patients ranged from 45 to 71 years, and 147 were males (73.5%). Patients were grouped into fluid responders (n= 135), defined as stroke volume variation (SVV) of 15% or greater following fluid bolus administration, and fluid non-responders (n= 65), defined SVV of less than 15% following fluid bolus administration. There was no statistically significant difference between the groups regarding their CVP, maximum and minimum IVC diameters, inferior vena cava distensibility index (IVC-DI), and other markers of fluid responsiveness (p-value 0.47, 0.34, 0.59, and 0.64, respectively). There was a significant difference in SVV between fluid responders (18.33±2.767) and non-responders (10.95±1.940) (p-value &lt;0.001).&#x0D; Conclusion: Neither CVP nor sonographic measures of IVC diameter respiratory variability provided an accurate method to distinguish between fluid responders and non-responders in the early postoperative period after CABG.

IVC measurement for the noninvasive evaluation of central venous pressure.

Central venous pressure (CVP) is one of only a handful of variables that can be used to assess a patient's volume status to attempt to optimize stroke volume. The gold standard method for assessing CVP is though pulmonary artery catheterization, which is invasive and risks severe complications such as pneumothorax and cardiac conduction abnormalities. Current noninvasive methods for estimating CVP such as jugular venous pressure assessment are imperfect with wide inter-examiner variability. The inferior vena cava (IVC) is a highly compliant vessel that uniquely does not constrict in response to hypovolemia, making it an ideal, noninvasive surrogate for the estimation of CVP. A range of IVC indices including minimum and maximum IVC diameter and fraction of IVC collapse with inspiration (known as collapsibility index) have been studied with highly variable results that range from excellent to poor correlation between these values and CVP. Despite this inconsistency in findings, multiple schemes have been proposed to attempt to estimate CVP from IVC measurements, but when prospectively tested, none has been shown to be accurate. Since the most recent 2015 American Society of Echocardiography guidelines, multiple studies have identified unique ways of improving the accuracy of IVC measurement, which could translate into better CVP estimation. The goal of this review is to summarize the many, often conflicting studies that exist in this area, and provide recommendations for future studies based on our findings.

Can vena cava ultrasound-guided volume repletion prevent general induced hypotension in elderly patients? A mini-fluid challenge

BackgroundHypotension is often occurring after induction of general anesthesia (IGA) and can cause organ hypoperfusion and ischemia which associated with adverse outcomes in patients having both cardiac and non-cardiac surgery. Elderly patients are particularly more vulnerable and at increased risk to the depressant effect of anesthetic drugs. So, recognition and prevention of such event are of clinical importance. This study recruited patients aged above 60 years, with ASA physical status classification I-II-III who were scheduled for surgery under general anesthesia with the aim to assess the effectiveness of preoperative IVC ultrasonography in predicting hypotension which develops following IGA and its association with the volume status in elderly patients receiving general anesthesia, through measurements of the maximum inferior vena cava diameter (dIVCmax), minimum inferior vena cava diameter (dIVCmin), inferior vena cava collapsibility index (IVC-CI), and basal and post-induction mean arterial pressure (MAP).ResultsThirty-nine (44.3%) of the 88 patients developed hypotension after IGA, and it was significantly more in patients who did not receive preoperative fluid (p = 0.045). The cut-off for dIVCmax was found as 16.250 mm with the ROC analysis. Specificity and sensitivity for the cut-off value of 16.250 mm were calculated as 61.2% and 76.9%, respectively. The cut-off for IVC-CI was found as 33.600% with the ROC analysis. Specificity and sensitivity for the cut-off value of 33.600% were calculated as 68.7% and 87.2%, respectively.ConclusionsIVC ultrasonography may be helpful in the prediction of preoperative hypovolemia in elderly patients in the form of high IVC-CI and low dIVCmax. The incidence of hypotension was lower in patients who received fluid infusion before IGA.