Does bedside sonographic measurement of the inferior vena cava diameter correlate with central venous pressure in the assessment of intravascular volume in children?

Hepatic vein Doppler ultrasound to estimate central venous pressure in mechanically ventilated children

Monitoring central venous pressure (CVP) is crucial for managing critically ill patients yet poses challenges in pediatric cases. This study aimed to correlate CVP with hepatic vein Doppler and IVC ultrasound variables in children. Mechanically ventilated children underwent simultaneous ultrasound and CVP measurements. Hepatic vein Doppler assessed peak velocities (A, S, V, D) and systolic filling fraction. IVC ultrasound included respiratory variability indices, IVC/aorta ratio, and IVC/body surface area ratio. Fifty-three children were included (median age of 8.3 months and weight of 6.3 kg). Significant correlations were found between CVP values and all hepatic vein Doppler-based variables. The strongest correlation was found between CVP and the sum of the absolute values of the A- and D-wave peak velocities (AD velocity), with a ρ = 0.61 (95% confidence interval [CI] of 0.40 to 0.75; p < 0.001). The AD velocity > 38.55 cm/s was able to discriminate patients with CPV > 12 mmHg with a sensitivity of 100%, specificity of 95.3%, positive predictive value of 83.3%, and negative predictive value of 100%. No correlations were observed between CVP and variables derived from IVC respiratory variability indices or the IVC/aorta ratio. Conclusion: Hepatic vein Doppler ultrasound provides variables that significantly correlate with CVP and may be useful for estimating cardiac preload in mechanically ventilated children. Indices derived from IVC ultrasound were not reliable for estimating CVP. What is known? • Increased central venous pressure (CVP) can cause interstitial edema and reduce vital organ perfusion, leading to organic dysfunctions, with encapsulated organs such as the kidneys and liver being at higher risk. • However, measuring CVP in children poses challenges due to the difficulties and risks of central venous catheterization, frequent partial or total luminal obstructions in venous catheters, and potential technical errors in measurements. What is new? • Variables obtained through hepatic vein Doppler ultrasonography outperformed those obtained by inferior vena cava ultrasound for estimating CVP in this population. • Hepatic vein Doppler ultrasonography holds potential as an accurate, safe, and non-invasive method for discriminating patients with increased cardiac preload.

Usefulness of Non-Invasive Parameters (Inferior Vena Cava Diameter, Inferior Vena Cava Collapsibility, Inferior Vena Cava-Aortic Ratio) for Hemodynamic Monitoring in Critically Ill Children: A Systematic Review

Purpose

Volume measurement in critically ill children can be conducted using invasive procedure such as Central Venous Pressure (CVP), or non-invasive procedure such as measurement of Inferior Vena Cava (IVC) indices using ultrasonography. However, their accuracy and efficacy are still under scrutiny. We aim to compare CVP and IVC indices as non-invasive parameters in assessing volume status in critically ill children.

Methods

We conducted a systematic review based on literature searching from four electronic databases which were PubMed, Cochrane, ScienceDirect, SpringerLink with keywords: "CENTRAL VENOUS PRESSURE", "INFERIOR VENA CAVA DIAMETER", "INFERIOR VENA CAVA COLLAPSIBILITY", "INFERIOR VENA CAVA AORTIC-RATIO", "VOLUME STATUS", "FLUID STATUS", "CRITICAL ILL", "CHILDREN", and "PEDIATRICS". We included relevant studies in English published from 2000 to 2023 on critically ill children aged 0-18 years. Comparison between CVP and IVC indices was resumed.

Results

Eight articles were included in this study. Majority of the studies showed a consistent correlation between CVP and IVC indices. IVC-CI was the most common parameter evaluated in the included studies. There was moderate to strong correlations using IVC-CI and IVC-DI, and moderate correlation using IVC-Ao ratio.

Conclusion

We found that non-invasive tools might have a potential role to measure volume in critically ill children equals to CVP. Further high-quality and longitudinal studies are needed to validate these findings and to establish a clear guideline for the non-invasive tool to be used in daily clinical practice.

Point-of-Care Ultrasonography for the Assessment of Dehydration in Children: A Systematic Review

OBJECTIVES

Accurate estimation of the degree of dehydration remains a diagnostic challenge. The primary objective was to systematically review the literature on the role of ultrasound in assessment of the degree of dehydration in children.

METHODS

Data sources included Ovid MEDLINE, Web of Science Core Collection, Current Index to Nursing and Allied Health Literature, Cochrane Library, ClinicalTrials.gov , and Trip Pro Database. Two independent reviewers used screening protocol to include articles on assessment of dehydration in children with the use of point-of-care ultrasonography (POCUS). The level of evidence was assessed in accordance with the "The Oxford 2011 Levels of Evidence." The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate risk of bias.

RESULTS

We identified 108 studies, and 8 studies met our inclusion criteria. All studies were prospective cohort studies (level of evidence, 3-4). The authors of 5 studies used difference between ill weight and weight after rehydration as the reference standard for dehydration, and the authors of 3 studies used clinical dehydration scale. Two studies from the United States showed acceptable areas under the curve for inferior vena cava to aorta (IVC/Ao) diameter ratio at 0.72 and 0.73 for prediction of significant dehydration (>5% weight loss). The IVC/Ao ratio with cut-off at 0.8 had sensitivity of 67% and 86% and specificity of 71% and 56% for prediction of significant dehydration. Studies from the resource-limited settings were more heterogeneous. One study with acceptable risk of biases reported poor sensitivity (67%) and specificity (49%) of Ao/IVC ratio with cut-off of 2.0 for predicting severe dehydration (>9% weight loss) with area under the curve at 0.6. Three studies showed increase in IVC diameter with fluid resuscitation with mean change in IVC diameter by 30% in children with significant dehydration (>5% weight loss) and by 22% without significant dehydration (<5% weight loss). Metaanalysis was not completed due to high heterogeneity.

CONCLUSIONS

This study showed that the quantity and quality of research on the application of POCUS for the assessment of dehydration in children is limited. There is no criterion standard for assessing the degree of dehydration and no universal definition of the degree of dehydration. Thus, more methodologically rigorous studies are required. Current systematic review does not support the routine use of US to determine the severity of dehydration in children. Despite these limitations, the use of POCUS in children with dehydration demonstrates potential. Given the clear increase in IVC size with rehydration, repeated IVC US scans may be helpful in guiding fluid resuscitation in children with dehydration. From different proposed US parameters, IVC/Ao ratio has better diagnostic accuracy in detecting significant dehydration than Ao/IVC ratio and IVC collapsibility index. Despite low to moderate diagnostic performance, US still showed better assessment of dehydration than physician gestalt and World Health Organization score.

Correlation between non-invasive to invasive right-heart data in paediatric heart transplant patients

BACKGROUND

Paediatric studies have shown serum N-terminal pro b-type natriuretic peptide levels to be a valuable tool in the surveillance of myocardial function and an early biomarker for rejection in transplant patients. The correlation between low mean right atrial pressure and increased inferior vena cava collapsibility index is well studied in adults. Our study aims to assess correlation between non-invasive measurements (serum N-terminal pro b-type natriuretic peptide, inferior vena cava dimensions collapsibility, tricuspid regurgitation, and left ventricular remodelling index to invasive mean right atrial pressure in paediatric heart transplant patients).

METHODS

A single centre, retrospective chart review of the paediatric transplant patients from 0 to 21 years of age was performed between 2015 and 2017. Thirty-nine patients had complete data which includes cardiac catheterisation, transthoracic echocardiogram, and serum N-terminal pro b-type natriuretic peptide levels done within a two weeks of interval.

RESULTS

A higher inferior vena cava collapsibility index correlated with a lower mean right atrial pressure (r = -0.21, p = 0.04) and a larger inferior vena cava diameter in expiration indexed to body surface area (IVCmax/BSA0.5) correlated with a higher mean right atrial pressure (r = 0.29, p = 0.01). There was a correlation between elevated N-terminal pro b-type natriuretic peptide and inferior vena cava collapsibility index (r = -0.38, p = 0.0001), IVCmax/BSA0.5 (r = 0.25, p = 0.0002), and mean right atrial pressure (r = 0.6, p = 0.0001).

CONCLUSION

Serum N-terminal pro b-type natriuretic peptide levels correlated to non-invasive measurements (inferior vena cava collapsibility index and IVCmax/BSA0.5) and to the invasive mean right atrial pressure. Non-invasive (IVC-CI IVCmax/BSA0.5) correlates with elevated mean right atrial pressure in this population. Together, these may serve as a reliable surveillance tool in assessing right heart filling pressures and cardiac function within the paediatric heart transplant patient.

Diagnostic Utility of Point-of-Care Ultrasound in the Pediatric Cardiac Intensive Care Unit

Purpose of Review

Recent Findings

Summary

Supplementary Information

Correlation of Ultrasound-Based Hydration Assessment Measures with CVP and Clinical Hydration Status among Children Admitted to the PICU: A Prospective Observational Study

Purpose This article assesses the correlation of respiratory variation in inferior vena cava (IVC) with central venous pressure (CVP) in children. Secondary objective was to evaluate IVC variability with clinical hydration status.

Methods IVC variability was assessed at the subcostal (SC) and right lateral (RL) region, and collapsibility index (CI) (spontaneously breathing) and distensibility index (DI) (positive pressure) and IVC/aortic ratio were calculated. Partial correlations were calculated between CI/DI with CVP adjusting for body mass index and age. Sensitivity of CI and DI to predict clinical dehydration was calculated using receiver operating characteristic curves.

Results A total of 145 ultrasounds were performed on 72 patients (41% positive pressure). Only RL CI in spontaneously breathing patients strongly correlated with CVP (r = –0.65, p < 0.001). A moderate correlation was observed between CI and DI from SC and RL regions (r's = 0.38 and 0.47). Among spontaneously breathing patients, a significant difference was observed in the SC CI based on hydration status. For patients on positive pressure, IVC/aortic ratio had a significant difference. SC CI had the highest area under the curve (0.82) to detect dehydration with 80% sensitivity/87% specificity for a cutoff of 40%.

Conclusion SC CI is the most reliable measure to assess the hydration status of spontaneously breathing children, while the IVC/aortic ratio performs well for patients under positive pressure. RL CI has strong negative correlation with CVP in spontaneously breathing patients.

Interobserver Agreement of Inferior Vena Cava Ultrasound Collapse Duration and Correlated Outcomes in Children With Dehydration

OBJECTIVE

Dehydration is a common concern in children presenting to pediatric emergency departments and other acute care settings. Ultrasound (US) of the inferior vena cava (IVC) may be a fast, noninvasive tool to gauge volume status, but its utility is unclear. Our objectives were to determine the interobserver agreement of IVC collapse and collapse duration, then correlate IVC collapse with the outcome of intravenous (IV) versus oral (PO) rehydration.

METHODS

We conducted a prospective study by enrolling patients 0 to 21 years old with emesis requiring ondansetron or diarrhea requiring IV hydration. Clinical operators interpreted US examinations in real time to determine whether the IVC was collapsed. Two blinded reviewers interpreted the US videos to determine IVC collapse and collapse duration. Cohen's kappa(κ) was calculated for reviewer-reviewer and reviewer-operator agreement. Primary outcomes were PO versus IV rehydration, and admitted versus discharged.

RESULTS

One hundred twelve patients were enrolled, and 102 had complete data for analysis. The mean age was 7.2 years with 51% female. Twenty-nine patients received IV hydration. The reviewer-operator agreement for IVC collapse was κ = 0.57 (95% confidence interval [CI], 0.38-0.75) and interreviewer agreement was κ = 0.93 (95% CI, 0.83-1.0). The interreviewer agreement for collapse duration was κ = 0.66 (95% CI, 0.51-0.82). All patients with noncollapsed IVCs tolerated PO hydration. The likelihood of receiving IV hydration was correlated with the duration of IVC collapse (P = 0.034).

CONCLUSIONS

Based on a novel dynamic measure of IVC collapse duration, children with increasing duration of IVC collapse correlated positively with the need for IV rehydration. Noncollapsing IVCs on US were associated with successful PO rehydration without need for IV fluids or emergency department revisits.

Comparison of vena cava distensibility index and pulse pressure variation for the evaluation of intravascular volume in critically ill children

OBJECTIVE

In this study, the authors aimed to evaluate the effectiveness of the vena cava distensibility index and pulse pressure variation as dynamic parameters for estimating intravascular volume in critically ill children.

METHODS

Patients aged 1 month to 18 years, who were hospitalized in the present study's pediatric intensive care unit, were included in the study. The patients were divided into two groups according to central venous pressure: hypovolemic (< 8 mmHg) and non-hypovolemic (central venous pressure ≥ 8 mmHg) groups. In both groups, vena cava distensibility index was measured using bedside ultrasound and pulse pressure variation. Measurements were recorded and evaluated under arterial monitoring.

RESULTS

In total, 19 (47.5%) of the 40 subjects included in the study were assigned to the central venous pressure ≥ 8 mmHg group, and 21 (52.5%) to the central venous pressure < 8 mmHg group. A moderate positive correlation was found between pulse pressure variation and vena cava distensibility index (r = 0.475, p < 0.01), while there were strong negative correlations of central venous pressure with pulse pressure variation and vena cava distensibility index (r = -0.628, p < 0.001 and r = -0.760, p < 0.001, respectively). In terms of predicting hypovolemia, the predictive power for vena cava distensibility index was > 16% (sensitivity, 90.5%; specificity, 94.7%) and that for pulse pressure variation was > 14% (sensitivity, 71.4%; specificity, 89.5%).

CONCLUSION

Vena cava distensibility index has higher sensitivity and specificity than pulse pressure variation for estimating intravascular volume, along with the advantage of non-invasive bedside application.

Non-invasive Assessment of Intravascular Volume Status for Postoperative Patients: The Correlation Between the Internal Jugular Vein/Common Carotid Artery Cross-sectional Area Ratio and the Inferior Vena Cava Diameter

Background

This study aimed to assess the correlation between the internal jugular vein/common carotid artery (IJV/CCA) cross-sectional area (CSA) ratio and the inferior vena cava (IVC) diameter as non-invasive techniques for the assessment of intravascular volume.

Methods

The study samples included 35 adult patients of both sexes (age range: 20 - 60 years) according to the criteria of the American Society of Anaesthesiology (ASA) physical status II - III, who were admitted to the surgical intensive care unit (SICU) after major surgeries for the assessment of intravascular volume status.

Results

There was a positive correlation between the IJV/CCA CSA ratio and the IVC maximum and minimum diameter before and after fluid infusion (r = 0.923, P < 0.001 and r = 0.390, P = 0.021, respectively) and between the IJV/CCA CSA ratio at inspiration and the IVC minimum diameter before and after fluid infusion (r = 0.605, P < 0.001 and r = 0.496, P < 0.001, respectively). The sensitivity and specificity analysis of the IJV/CCA CSA during inspiration after fluid correction to predict a central venous pressure (CVP) of 8 - 12 cmH₂O showed that at a ratio of 2.56, the highest sensitivity was 56.5%, and the specificity was 83.3%; at a ratio of 2.58, the highest sensitivity was 65.2% and the specificity was 75%. During expiration, at a ratio of 2.62, the highest sensitivity was 52.2%, and the specificity was 67%; and at a ratio of 2.65, the sensitivity was 56.5%, and the specificity was 50%.

Conclusions

The assessment of the IJV/CCA CSA ratio using bedside ultrasound could be a non-invasive tool for the evaluation of intravascular volume status in spontaneously breathing adult patients after major surgeries.

The Impact of Focused Cardiac Ultrasound Performed by Pediatric Intensivists: A Prospective Study

OBJECTIVES

Focused cardiac ultrasound is an echocardiographic method used by medical intensivists for fast and reliable hemodynamic assessment. Prospective studies and guidelines have defined its role in adult critical care. Data regarding its use in pediatric critical care are scarce. This is the first prospective study that aims to evaluate its impact in this setting.

METHODS

This is a single-center prospective study performed in a tertiary referral hospital pediatric intensive care unit (PICU). For a period of 6 months, when performing an echocardiogram, pediatric intensivists filled out a questionnaire that included the patient's clinical data and indication for the examination. The intensivists had to record both the clinical impression regarding that indication and therapeutic plan before and after the echocardiogram. All the patients with an echocardiogram performed by the pediatric intensive care unit medical staff were included.

RESULTS

There were 80 echocardiograms performed on 35 patients during the study period. The most common patient diagnostic groups were respiratory infections (38%, n = 30) and septic shock (21%, n = 17). The main indication for the examination was assessment of intravascular volume status and left ventricular systolic function. After the echocardiogram, the clinical impression was maintained in 49% (n = 39) and changed in 44% (n = 35). There were new findings unrelated to the initial evaluation in 7% (n = 6). The planned treatment was maintained in 55% (n = 44) and changed in 45% (n = 36).

CONCLUSIONS

The echocardiogram changed the clinical impression and therapeutic plan in almost half of the patients. These data show the value of focused cardiac ultrasound as a diagnostic and hemodynamic monitoring tool in pediatric intensive care and emphasize the importance of a rigorous training program.

Diagnostic Applications of Point-of-Care Ultrasound in Pediatric Emergency Medicine

Point-of-care ultrasound has become an essential part of pediatric emergency medicine training and practice. It can have significant clinical benefits, including improving diagnostic accuracy and decreasing length of stay, and does not require radiation exposure for patients. In this review, we summarize the current diagnostic point-of-care ultrasound applications in pediatric emergency medicine, their evidence, and techniques.

Point-of-care ultrasound to assess volume status and pulmonary oedema in malaria patients

PURPOSE

Fluid management is challenging in malaria patients given the risks associated with intravascular fluid depletion and iatrogenic fluid overload leading to pulmonary oedema. Given the limitations of the physical examination in guiding fluid therapy, we evaluated point-of-care ultrasound (POCUS) of the inferior vena cava (IVC) and lungs as a novel tool to assess volume status and detect early oedema in malaria patients.

METHODS

To assess the correlation between IVC and lung ultrasound (LUS) indices and clinical signs of hypovolaemia and pulmonary oedema, respectively, concurrent clinical and sonographic examinations were performed in an observational study of 48 malaria patients and 62 healthy participants across age groups in Gabon.

RESULTS

IVC collapsibility index (CI) ≥ 50% on enrolment reflecting intravascular fluid depletion was associated with an increased number of clinical signs of hypovolaemia in severe and uncomplicated malaria. With exception of dry mucous membranes, IVC-CI correlated with most clinical signs of hypovolaemia, most notably sunken eyes (r = 0.35, p = 0.0001) and prolonged capillary refill (r = 0.35, p = 0.001). IVC-to-aorta ratio ≤ 0.8 was not associated with any clinical signs of hypovolaemia on enrolment. Among malaria patients, a B-pattern on enrolment reflecting interstitial fluid was associated with dyspnoea (p = 0.0003), crepitations and SpO₂ ≤ 94% (both p < 0.0001), but not tachypnoea (p = 0.069). Severe malaria patients had increased IVC-CI (p < 0.0001) and more B-patterns (p = 0.004) on enrolment relative to uncomplicated malaria and controls.

CONCLUSION

In malaria patients, POCUS of the IVC and lungs may improve the assessment of volume status and detect early oedema, which could help to manage fluids in these patients.

Evaluation of a Focused Cardiac Ultrasound Protocol in a Pediatric Emergency Department

OBJECTIVES

The objective of this study was to evaluate the implementation of a focused cardiac ultrasound (FoCUS) protocol in a pediatric emergency department (PED).

METHODS

We conducted a cross-sectional, observational, quality improvement project in a PED of an urban tertiary care children's hospital. A FoCUS protocol was collaboratively developed by pediatric cardiology and pediatric emergency medicine. This included a reference document with definitions, indications, image acquisition guidelines, and interpretation expectations. We measured physician-sonographer performance against pediatric cardiologist interpretation of stored cine clips as our reference standard. Focused cardiac ultrasound interpretation was dichotomized for the presence or absence of pericardial effusion, depressed left ventricular function, and chamber size abnormalities. Run charts were used to compare the number FoCUS performed each month and the quality of captured cine clips with those from the previous year.

RESULTS

Ninety-two FoCUSs were performed by 34 different physician-sonographers from January to December 2016. The prevalence of FoCUS abnormalities was 18.5%. For pericardial effusion, sensitivity was 100% (95% confidence interval [CI], 48%-100%) and specificity was 99% (95% CI, 94%-100%). For depressed function, sensitivity was 100% (95% CI, 54%-100%) and specificity was 99% (95% CI, 94%-100%). For chamber size abnormalities, sensitivity was 100% (95% CI, 54%-100%) and specificity was 95% (95% CI, 89%-99%). The median number of monthly FoCUS increased from 1 (preprotocol) to 5 (postprotocol), and the median rate of adequate studies increased from 0% to 55%.

CONCLUSIONS

We report the collaborative development and successful implementation of a PED FoCUS protocol. Physician-sonographer interpretation of FoCUS yielded acceptable results. Improvements in FoCUS utilization and cine clip adequacy were observed.

Inferior Vena Cava Collapsibility Index to Assess Central Venous Pressure in Perioperative Period Following Cardiac Surgery in Children

The inferior vena cava collapsibility index (IVCCI) is an ultrasound method used to assess central venous pressure (CVP). Our objective was to evaluate the correlation between IVCCI and CVP in children during the early period following surgery for congenital heart disease (CHD). Prospective study performed in a single tertiary care center. Patients  ≤ 18 years old, who underwent cardiopulmonary bypass surgery for CHD, were enrolled. Ultrasound images of the inferior vena cava (IVC) were obtained at two time points; the first was within 2 h of arrival to the CICU and the second was 12-18 h from the first measurement. CVP measured by catheter placed during surgery was recorded within minutes of performing ultrasound. Maximum and minimum IVC diameters were measured by 2D images and M mode method. Seventy patients (47.1% males), with median age 7 months (IQR 4-47 months) and weight 6.9 kg (IQR 4.8-13.5 kg), were evaluated. The 2D IVCCI had inverse correlation with CVP in patients breathing spontaneously; r =  - 0.76 (p < 0.01) and r =  - 0.73 (p < 0.01), during the first and second measurements, respectively. The 2D IVCCI ≤ 0.24 had sensitivity, specificity, and negative predictive value of 94%, 79%, and 88.9% , respectively, to detect CVP ≥ 10 mmHg. No correlation was found between IVCCI and CVP during positive pressure ventilation. There is a significant inverse correlation between 2D IVCCI and CVP in spontaneously breathing children after surgery for CHD. Use of 2D IVCCI for monitoring CVP could reduce the frequency and duration of CVP catheters and their inherent complications.

Central Venous Pressure Estimation by Ultrasound Measurement of Inferior Vena Cava and Aorta Diameters in Pediatric Critical Patients: An Observational Study

OBJECTIVES

To evaluate the ability to predict central venous pressure by ultrasound measured inferior vena cava and aortic diameters in a PICU population and to assess interoperator concordance.

DESIGN

Noninterventional observational study.

SETTING

PICU of a tertiary-care academic center.

PATIENTS

Eighty-eight pediatric patients (0-16 yr old) with a central venous catheter in place were studied. Sixty-nine percent of the patients received positive-pressure ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An experienced and a nonexperienced operator used ultrasound to measure the maximal diameter of inferior vena cava and minimal diameter of the inferior vena cava and the maximum diameter of the abdominal aorta from the subxiphoid window. The inferior vena cava collapsibility index and the ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta were then derived. The central venous pressure was measured using a central venous catheter and recorded. Twenty-three patients had low central venous pressure values (≤ 4 mm Hg), 35 patients a value in the range of 5-9 mm Hg, and 30 patients high values (≥ 10 mm Hg). Both inferior vena cava collapsibility index and ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta were predictive of high (≥ 10 mm Hg) or low (≤ 4 mm Hg) central venous pressure. The test accuracy showed the best results in predicting low central venous pressure with an inferior vena cava collapsibility index greater than or equal to 35% and ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta less than or equal to 0.8, and in predicting high central venous pressure with an inferior vena cava collapsibility index less than or equal to 20% and ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta greater than or equal to 1.3. Inferior vena cava collapsibility index returned generally higher accuracy values than ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta. Lin's coefficient of concordance between the operators was 0.78 for inferior vena cava collapsibility index and 0.86 for ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta.

CONCLUSIONS

Inferior vena cava collapsibility index and ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta correlate well with central venous pressure measurements in this PICU population, and specific inferior vena cava collapsibility index or ratio of maximal diameter of inferior vena cava/maximum diameter of the abdominal aorta thresholds appear to be able to differentiate children with high or low central venous pressure. However, the actual clinical application of these statistically significant results remains limited, especially by the intrinsic flaws of the procedure.

The Relation Between Common Carotid Artery Diameter and Central Venous Pressure for Assessment of Intravascular Fluid Status after Major Surgeries; an Observational Study

Objectives

The current study aimed to find the relation between the changes in the common carotid artery (CCA) diameter and the central venous pressure (CVP) in response to a fluid challenge in spontaneously breathing adult patients.

Methods

This study included 65 adult patients aged 20 - 60 years who were admitted to the surgical ICU. The CCA diameter and CVP were measured before and after fluid challenge, and the percentage of increase in the CCA diameter and CVP were calculated. The correlation was assessed between changes in the CVP and CCA diameter.

Results

The CCA diameter before fluid administration had a significant strong positive correlation to the CVP (r = 0.8, P value < 0.001); the increase in the CCA diameter after fluid administration had a significant moderate positive correlation with the increase in the CVP (r = 0.4, P value < 0.001). The percentage of increase in CCA diameters was positively correlated to the percentage of increase in CVP (r = 0.589, P value = 0.001) following fluid administration. However, the Receiver Operating Characteristic (ROC) analysis was an invalid test (area under curve 0.513, P value = 0.885).

Conclusions

After major surgeries, the change in the CCA diameter was positively correlated with the change in the CVP values in response to fluid administration in the spontaneously breathing adult patients, but the cut-off limit cannot be reached.

Point-of-Care Ultrasound Assessment of the Inferior Vena Cava in Mechanically Ventilated Critically Ill Children

OBJECTIVES

The objective of this study was to compare the ultrasound-measured inferior vena cava distensibility index (IVCdi), inferior vena cava distensibility variability (IVCdv), and inferior vena cava-to-aorta ratio (IVC/Ao) to other common methods to assess fluid status in mechanically ventilated pediatric critically ill patients. These methods include central venous pressure (CVP), percent fluid overload by weight (%FOw), and percent fluid overload by volume (%FOv).

METHODS

This was a prospective observational study of a convenience sample of 50 mechanically ventilated pediatric patients. Ultrasound measurements of the inferior vena cava and aorta were obtained, and the IVCdi, IVCdv, and IVC/Ao were calculated and compared to CVP, %FOw, and %FOv.

RESULTS

The median %FOw was 5%, and the median %FOv was 10%. The mean CVP ± SD was 8.6 ± 4 mm Hg. The CVP had no significant correlation with %FOw or %FOv. There was no significant correlation of the IVCdi with CVP (r = -0.145; P = .325) or %FOv (r = 0.119; P = .420); however, the IVCdi had a significant correlation with %FOw (P = .012). There was also no significant relationship of the IVCdv with CVP (r = -0.135; P = .36) or %FOv (r = 0.128; P = .385); however, there was a significant correlation between the IVCdv and %FOw (P = .012). There was no relationship between the IVC/Ao and any other measures of fluid status.

CONCLUSIONS

In this cohort of mechanically ventilated pediatric intensive care unit patients, many commonly used markers of fluid status showed weak correlations with each other. The IVCdi and IVCdv significantly correlated with %FOw and may have potential as markers for fluid overload in this patient population.

Nonosmotic secretion of arginine vasopressin and salt loss in hyponatremia in Kawasaki disease

BACKGROUND

The precise mechanism of hyponatremia in Kawasaki disease (KD) remains elusive because assessment of volume status based on serial changes in body weight is lacking in previous reports.

METHODS

Seventeen patients who were diagnosed with KD and hyponatremia (serum sodium levels <135 mmol/L) were analyzed. Volume status was assessed based on serial changes in body weight. Plasma arginine vasopressin (ADH), urine electrolytes, and serum cytokine levels were measured on diagnosis of hyponatremia. An increase in body weight by >3% was defined as hypervolemia and a decrease in body weight by >3% was defined as hypovolemia.

RESULTS

The volume status was hypervolemic in three patients (18%), euvolemic in 14 (82%), and hypovolemic in none (0%). Five (29%) patients were diagnosed with "syndrome of inappropriate secretion of antidiuretic hormone" (SIADH) and no patients were diagnosed with hypotonic dehydration. The contribution of decreased total exchangeable cations (salt loss) to hyponatremia (5.9% [interquartile range, 4.3%, 6.7%]) was significantly larger than that of increased total body water (-0.7% [-1.8%, 3.1%]) (P = 0.004). Serum interleukin-6 levels were elevated in all of the nine patients who were evaluated. Among the 12 (71%) patients who did not meet the criteria of SIADH and hypotonic dehydration, plasma ADH levels were inappropriately high in ten patients. These patients were also characterized by euvolemic or hypervolemic hyponatremia and salt loss, which might be compatible with a diagnosis of SIADH.

CONCLUSIONS

Our study shows that hyponatremia in KD is euvolemic or hypervolemic and is associated with nonosmotic secretion of ADH and salt loss in the majority of patients.

Point-of-Care Ultrasound for the Pediatric Hospitalist's Practice

Point-of-care ultrasound (POCUS) has the potential to provide real-time valuable information that could alter diagnosis, treatment, and management practices in pediatric hospital medicine. We review the existing pediatric POCUS literature to identify potential clinical applications within the scope of pediatric hospital medicine. Diagnostic point-of-care applications most relevant to the pediatric hospitalist include lung ultrasound for pneumothorax, pleural effusion, pneumonia, and bronchiolitis; cardiac ultrasound for global cardiac function and hydration status; renal or bladder ultrasound for nephrolithiasis, hydronephrosis, and bladder volumes; soft tissue ultrasound for differentiating cellulitis from abscess; and procedural-guidance applications, including line placement, lumbar puncture, and abscess incision and drainage. We discuss POCUS applications with reviews of major pathologic findings, research gaps, the integration of POCUS into practice, and barriers to implementation.

Point-of-Care Ultrasound for Targeted Assessment of Shock: Remember HIPP in Children

The differential diagnosis for patients presenting in shock can be broad, making rapid diagnosis and management challenging. We present a case of a medically complex patient with presumed septic shock, diagnosed with a large pericardial effusion with evidence of tamponade using the rapid ultrasound in shock and hypotension protocol. The point-of-care ultrasound examination allowed for more timely and definitive management.

Inferior vena cava, abdominal aorta, and IVC-to-aorta ratio in healthy Caucasian children: Ultrasound Z-scores according to BSA and age

The pediatric ultrasound measurement of the inferior vena cava (IVC) and aorta (AO) with the study of the collapsibility index (CI) and of IVC-to-AO ratio (IVC/AO) can provide clinicians in the acute care setting with information on abnormal volume status but one of the major limitations is a lack of reference normal values by body surface area (BSA) and age. The aim of this study was to provide reference ranges for the sonographic measurement of IVC, AO, and IVC/AO ratio in healthy Caucasian Italian children.

METHODS

We enrolled prospectively 516 healthy Caucasian Italian children aged between 1 month and 16 years. Echocardiographic IVC and AO diameters were collected and presented separately for children aged ≤1 year and for children aged over 1 year. For children >1 year we categorized subjects into 3 years classes. CI and IVC/AO for the systolic aortic diameter were then calculated. For children over 1 year, age reference ranges were age-related or BSA-related; for children of ≤1 year, reference ranges were determined with their 90% confidence intervals regardless of age and of BSA.

RESULTS

Tables and charts with reference ranges for all the echocardiographic measurements are presented for children aged >1 year according to age and BSA. The equations to obtain percentile and Z-score for each echocardiographic measurement are provided. The reference ranges for children aged ≤1 year are shown considering the small 90% confidence intervals for upper and lower limits. CI was 30% (SD 17%) in children >1 year and 36% (SD 16%) in children <1 year. IVC/AOs showed age-dependent values from 0.83 (SD 0.20) age <1 year to 1.22 (SD 0.31) in older subjects.

CONCLUSIONS

We report reliable reference ranges for echocardiographic measurement of IVC, AO, CI, and IVC/AO for a Caucasian Italian healthy pediatric population.

Recent Advances in Technology and Its Applications to Pediatric Emergency Care

Advances in technology are continuously transforming medical care, including pediatric emergency medicine. The increasing adoption of point-of-care ultrasound examination can improve timely diagnoses without radiation and aids the performance of common procedures. The recent dramatic increase in electronic health record adoption offers an opportunity for enhanced clinical decision-making support. Simulation training and advances in technologies can provide continued proficiency training despite decreasing opportunities for pediatric procedures and cardiorespiratory resuscitation performance. This article reviews these and other recent advances in technology that have had the greatest impact on the current practice of pediatric emergency medicine.

A Retrospective Evaluation of Echocardiograms to Establish Normative Inferior Vena Cava and Aortic Measurements for Children Younger Than 6 Years

OBJECTIVES

The ability to plot the inferior vena cava (IVC) size on a normal curve for pediatric patients may prove beneficial. First, in patients with normal cardiac anatomy who present in shock, assessing IVC size may be valuable for evaluating the degree of dehydration. Second, in children with heart disease, understanding how a child's IVC size compares to normal could be particularly beneficial for patients with right heart disease. We sought to create normal curves for the IVC and aorta in children younger than 6 years.

METHODS

Data were gathered from 347 echocardiograms of healthy children younger than 6 years in a retrospective study at a quaternary care children's hospital. From the subcostal long- and short-axis images, maximum diameters in the transverse and longitudinal views were obtained for both the IVC and the aorta.

RESULTS

Both IVC and aortic dimensions increased in a linear fashion and had excellent correlations with the body surface area, body mass, and height (IVC, r = 0.78-0.81; P < .0001; aorta, r = 0.82-0.86; P < .0001).

CONCLUSIONS

In children younger than 6 years, the IVC and aorta increase linearly as the children grow. Such normal curves will be beneficial for assessing a pediatric patient's hydration status or right heart function in patients with congenital heart disease.

Point of care ultrasonography in the pediatric emergency department

IMPORTANCE

Point-of-care ultrasonography (POCUS) allows to obtain real-time images to correlate with the patient's presenting signs and symptoms. It can be used by various specialties and may be broadly divided into diagnostic and procedural applications.

OBJECTIVE

We aimed at reviewing current knowledge on the use of POCUS in Pediatric Emergency Departments (PEDs).

FINDINGS

US diagnostic capacity in paediatric patients with suspected pneumonia has been studied and debated whereas literature regarding the usefulness of point-of-care echocardiography in the pediatric setting is still limited. Similarly, Focused Assessment with Sonography for Trauma (FAST) has become a standard procedure in adult emergency medicine but it is still not well codified in the pediatric practice. Concerning procedural applications of POCUS we identified 4 main groups: peripheral vascular access, bladder catheterizations, identification and drainage of abnormal fluid collections and foreign body identification.

CONCLUSIONS AND RELEVANCE

Bedside emergency ultrasound is routinely used by adult emergency physicians and in the last 10 years its application is recognized and applied in PED. Pediatric emergency physicians are encouraged to familiarize with POCUS as it is a safe technology and can be extremely helpful in performing diagnosis, managing critical situations and guiding procedures, which results in globally improving pediatric patients care.

A Comparison between the Bedside Sonographic Measurements of the Inferior Vena Cava Indices and the Central Venous Pressure While Assessing the Decreased Intravascular Volume in Children

Background:

Hemodynamic monitoring is an essential part in the treatment of critically ill patients. Establishment of intravascular volume and creation of a normal systemic perfusion are the most important part to reduce the risk of organ failure and mortality. This study aimed to determine the correlation between the inferior vena cava (IVC) sonographic indices and the central venous pressure (CVP) to provide a useful guide for noninvasive intravascular volume status assessment in children.

Materials and Methods:

Target sample of children who were admitted to the pediatric critical care unit and required CVP monitoring were enrolled in this study. The collapsibility index (CI) and IVC/aorta (AO) ratio, from bedside ultrasonography measurement of the IVC, were calculated.

Results:

Of the 70 participants, 22 patients (31.4%) revealed a CVP of 8 mm/Hg or less and 48 patients (68.6%) revealed a CVP >8 mm/Hg. Fifty-six patients (80%) had an IVC-CI of 0.5 or greater and 17 patients (24.3%) had an IVC/AO of 0.8 or less. IVC-CI index is 45.5% sensitive and 91.7% specific with positive predictive value of 71.4 and negative predictive value of 78.6 to predict CVP <8, and the IVC/AO index is 50.8% sensitive and 87.5% specific with a positive predictive value of 64.7 and a negative predictive value of 79.2 to predict CVP <8.

Conclusion:

Based on the present finding, the IVC sonographic indices provide a useful guide for noninvasive intravascular volume status assessment in children.

New directions in point-of-care ultrasound at the crossroads of paediatric emergency and critical care

PURPOSE OF REVIEW

The diagnostic capability, efficiency and versatility of point-of-care ultrasound (POCUS) have enabled its use in paediatric emergency medicine (PEM) and paediatric critical care (PICU). This review highlights the current applications of POCUS for the critically ill child across PEM and PICU to identify areas of progress and standardized practice and to elucidate areas for future research.

RECENT FINDINGS

POCUS technology continues to evolve and advance bedside clinical care for critically ill children, with ongoing research extending its use for an array of clinical scenarios, including respiratory distress, trauma and dehydration. Rapidly evolving and upcoming applications include diagnosis of pneumonia and acute chest syndrome, identification of intra-abdominal injury via contrast-enhancement, guidance of resuscitation, monitoring of increased intracranial pressure and procedural guidance.

SUMMARY

POCUS is an effective and burgeoning method for both rapid diagnostics and guidance for interventions and procedures. It has clinical application for a variety of conditions that span PEM and PICU settings. Formal POCUS training is needed to standardize and expand use of this valuable technology by PICU and PEM providers alike.

Non-invasive Assessment of Significant Dehydration in Infants Using the Inferior Vena Cava to Aortic Ratio: Is it Useful?

OBJECTIVES

The aim of the study was to assess the accuracy of the inferior vena cava to aorta (IVC/Ao) diameter ratio for predicting significant dehydration in infants relative to their percentage weight change and the clinical diagnosis by a physician.

METHODS

A prospective observational study was performed on 200 infants presented with acute diarrhea and clinical evidence of significant dehydration whose treatment required intravenous (IV) fluids as determined by the attending physician at the pediatric emergency department of Tanta University Hospital. Weight was recorded at admission before IV fluid treatment and at hospital discharge. The percentage of dehydration was determined using the following formula: (discharge weight - admission weight)/discharge weight × 100%. Patients with a percentage weight change of <5% were considered to be nonsignificantly dehydrated, whereas patients with a percentage weight change >5% were considered significantly dehydrated. The IVC/Ao diameter ratio was measured for all patients before IV fluid rehydration and again at discharge.

RESULTS

Only 134 out of 200 dehydrated infants were found to be significantly dehydrated using the gold standard, percentage weight change. Receiver operating characteristics (ROC) curve analysis of the prehydration IVC/Ao ratio showed a sensitivity of 82%, a specificity of 91%, and an accuracy of 87% for predicting significant dehydration in infants at a cut-off point of less than 0.75. In contrast, physician clinical diagnosis showed a sensitivity of 70%, a specificity of 63%, and an accuracy of 73%.

CONCLUSIONS

The IVC/Ao diameter ratio can be used as a reliable predictor for diagnosing significant dehydration in infants.

Comparison of sonographic inferior vena cava and aorta indexes during fluid administered in children

OBJECTIVES

This prospective, observational study evaluated changes in ultrasound measurements of the inferior vena caval index (IVCI), the aorta diameter/IVC diameter index (Ao/IVCD), and the aorta area/IVC area index (Ao/IVCA) during fluid administration in children requiring intravenous fluid administration.

METHODS

Children who presented to the pediatric emergency department with symptoms of dehydration were enrolled between May 2015 and February 2016. The maximum diameter of the aorta, from inner wall to inner wall, and the long and short axis diameters of IVC were measured using a convex array transducer in the transverse view. Subsequently, we measured the diameter of the IVC at the subxiphoid area during inspiration and expiration in longitudinal view. We calculated IVCI, Ao/IVCD, and Ao/IVCA during administration of 10ml/kg and 20ml/kg normal saline boluses.

RESULTS

IVCI and Ao/IVCA significantly changed immediately after administration of initial 10ml/kg of NS. Ao/IVCA showed significant change during the additional administration of 10ml/kg (total 20ml/kg) normal saline boluses (1.43, IQR 1.12-1.86 vs. 1.08, IQR 0.87-1.45, p value<0.001). No significant changes were observed for IVCI and Ao/IVCD. Ao/IVCA was significantly correlated with the volume of fluid administered. The coefficient between initial and administration of the 10ml/kg normal saline bolus was -0.396 (p value=0.010), and that between the 10ml/kg and 20ml/kg normal saline boluses was -0.316 (p value=0.038).

CONCLUSIONS

Ao/IVCA showed better correlations with the volume of fluid administered than IVCI and Ao/IVCA. Ao/IVCA might be a promising index for assessing the effects of fluid administration.

Sonographic assessment of volaemia: development and validation of a new method in dogs

OBJECTIVES

The aims of this study were to describe a method for the sonographic assessment of volaemia, to determinate inter- and intra-operator variability and to assess the ability to detect blood loss after blood donation in healthy dogs.

MATERIALS AND METHODS

The left kidney was identified in a spleno-renal view, and transverse views of the caudal vena cava and aorta were obtained in 12 dogs. Vessel diameters were measured in B-mode, in duplicate by two operators, and the caudal vena cava:aorta ratio was calculated. Intra- and inter-operator variabilities were assessed using a Bland-Altman method by plotting the differences between the repeated measurements obtained from the same subject by the same operator and by the two operators against their means. Before and after blood donation measurements were compared using paired t-tests or one-sample t-tests, if appropriate.

RESULTS

Intra- and inter-operator variability was within the limit of agreement for the vast majority of measurements. After a blood donation of 9·8 ±2·2 mL/kg, the mean aorta measurements were not significantly different from those obtained before blood donation (1·11 versus 1·10, P=0·28), whereas the mean caudal vena cava measurements and caudal vena cava:aorta ratios were significantly lower (1·28 versus 1·01, P<0·0001; 1·17 versus 1·01, P=0·0001, respectively).

CLINICAL SIGNIFICANCE

The low intra- and inter-operator variabilities in the caudal vena cava, aorta and caudal vena cava:aorta ratio measurements support their reliability and operator independency. The sonographic assessment of volaemia appears to be a promising non-invasive, repeatable point-of-care ultrasound protocol for assessment and monitoring of blood loss. Further studies are needed to assess the sonographic assessment of volaemia protocol in spontaneously bleeding dogs.

Sonographic Evaluation of Internal Jugular Vein Diameter and Cross-sectional Area Measurements in Correlation with Left Ventricular End Diastolic Area as a Tool for Perioperative Assessment of Volume Status in Pediatric Patients Undergoing Cardiac Surgery

Aim:

The aim of this study is to compare the ultrasound estimation of the cross-sectional area (CSA) and diameter of internal jugular vein (IJV) with left ventricular end diastolic area (LVEDA) for the assessment of intravascular volume in pediatric patients during cardiac surgery.

Patients and Methods:

The CSA and diameter of the left IJV were defined, using ultrasound machine, and compared with LVEDA, estimated by transesophageal echo, in four times intervals (immediately after induction [T1], before the start of cardiopulmonary bypass [CPB] [T2], immediately after weaning of CPB [T3], and at the end of surgery before transfer to the Intensive Care Unit [T4]) as a tool for intravascular volume assessment in 16 pediatric patients undergoing cardiac surgery.

Results:

There was a poor correlation between IJV CSA and diameter with LVEDA. r values were 0.158, 0.265, 0.449, and 0.201 at the four time intervals (T1, T2, T3, and T4), respectively.

Conclusion:

Estimation of the CSA and diameter of the left IJV using ultrasound is not reliable and cannot be used alone to decide further management.

Internal jugular vein/common carotid artery cross-sectional area ratio and central venous pressure

PURPOSE

To investigate the accuracy of the sonographic assessment of internal jugular vein/common carotid artery (IJV/CCA) cross-sectional area ratio in predicting central venous pressure (CVP) in critically ill patients.

METHODS

In adult patients who underwent central venous catheterization for monitoring of hemodynamic status, we used bedside sonography for diameter and cross-sectional area measurement of IJV and CCA. The IJV/CCA ratio was then calculated, and its correlation with CVP as well as its sensitivity, specificity, and positive and negative predictive values were analyzed.

RESULTS

We enrolled 52 patients with a mean age of 58.8 ± 10.7 years. The mean IJV/CCA ratio was 1.89 ± 0.83 and 1.90 ± 0.83, respectively, at inspiration and expiration. A significant correlation was observed between IJV/CCA ratio and CVP (r = 0.728, p < 0.0001 at inspiration, and r = 0.736, p < 0.0001 at expiration). Sensitivity was 90%, specificity 86.36%, positive predictive values 90%, and negative predictive values 86.36% for the prediction of CVP <10 cm H2 O.

CONCLUSIONS

Assessing the IJV/CCA ratio with a portable sonographic device could be a noninvasive alternative for central venous catheterization in order to evaluate the hemodynamic status of critically ill patients. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:312-318, 2016.

Accuracy of Inferior Vena Cava Ultrasound for Predicting Dehydration in Children with Acute Diarrhea in Resource-Limited Settings

Introduction

Although dehydration from diarrhea is a leading cause of morbidity and mortality in children under five, existing methods of assessing dehydration status in children have limited accuracy.

Objective

To assess the accuracy of point-of-care ultrasound measurement of the aorta-to-IVC ratio as a predictor of dehydration in children.

Methods

A prospective cohort study of children under five years with acute diarrhea was conducted in the rehydration unit of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). Ultrasound measurements of aorta-to-IVC ratio and dehydrated weight were obtained on patient arrival. Percent weight change was monitored during rehydration to classify children as having “some dehydration” with weight change 3–9% or “severe dehydration” with weight change > 9%. Logistic regression analysis and Receiver-Operator Characteristic (ROC) curves were used to evaluate the accuracy of aorta-to-IVC ratio as a predictor of dehydration severity.

Results

850 children were enrolled, of which 771 were included in the final analysis. Aorta to IVC ratio was a significant predictor of the percent dehydration in children with acute diarrhea, with each 1-point increase in the aorta to IVC ratio predicting a 1.1% increase in the percent dehydration of the child. However, the area under the ROC curve (0.60), sensitivity (67%), and specificity (49%), for predicting severe dehydration were all poor.

Conclusions

Point-of-care ultrasound of the aorta-to-IVC ratio was statistically associated with volume status, but was not accurate enough to be used as an independent screening tool for dehydration in children under five years presenting with acute diarrhea in a resource-limited setting.

Inferior vena cava collapsibility loses correlation with internal jugular vein collapsibility during increased thoracic or intra-abdominal pressure

PURPOSE

Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJV) measurements to estimate intravascular volume status. The reliability of the IVC and IJV collapsibility index during increased thoracic or intra-abdominal pressure remains unclear.

METHODS

Three phases of sonographic scanning were performed: spontaneous breathing phase, increased thoracic pressure phase via positive pressure ventilation (PPV) phase, and increased intra-abdominal pressure (IAP) phase via laparoscopic insufflation to 15 mmHg. IVC measurements were done at 1-2 cm below the diaphragm and IJV measurements were done at the level of the cricoid cartilage during a complete respiratory cycle. Collapsibility index was calculated by (max diameter - min diameter)/max diameter × 100 %. Chi square, t test, correlation procedure (CORR) and Fisher's exact analyses were completed.

RESULTS

A total of 144 scans of the IVC and IJV were completed in 16 patients who underwent laparoscopic surgery. Mean age was 46 ± 15 years, with 75 % female and 69 % African-American. IVC and IJV collapsibility correlated in the setting of spontaneous breathing (r (2) = 0.86, p < 0.01). IVC collapsibility had no correlation with the IJV in the setting of PPV (r (2) = 0.21, p = 0.52) or IAP (r (2) = 0.26, p = 0.42). Maximal IVC diameter was significantly smaller during increased IAP (16.5 mm ± 4.9) compared to spontaneous breathing (20.6 mm ± 4.8, p = 0.04) and PPV (21.8 mm ± 5.6, p = 0.01).

CONCLUSION

IJV and IVC collapsibility correlated during spontaneous breathing but there was no statistically significant correlation during increased thoracic or intra-abdominal pressure. Increased intra-abdominal pressure was associated with a significant smaller maximal IVC diameter and cautions the reliability of IVC diameter in clinical settings that are associated with intra-abdominal hypertension or abdominal compartment syndrome.

Is there a relationship between the diameter of the inferior vena cava and hemodynamic parameters in critically ill patients?

INTRODUCTION

The early detection of critically ill patients together with the rapid initiation of effective treatment in emergency departments(ED) increase the survival rates.

AIM

This study investigated whether a correlation exists between haemodynamic parameters of critically ill patients and the diameter of the inferior vena cava (IVC).

MATERIALS AND METHODS

A cross-sectional study was performed included patients aged ≥18 years with an unstable haemodynamic and/or respiratory status who were referred to the ED for non-traumatic issues. IVC diameters were measured by ultrasound (US) and then central venous pressures (CVP) were measured. Anteroposterior (AP) and mediolateral (ML) diameters of the IVC, both in the inspirium (IAP, IML) and expirium (EAP, EML), were measured by US.

RESULTS

102 patients were evaluated with a median age of 59. The relationship between the diameters of IVC and CVP was evaluated and significant correlation was found in IAP, EAP according to CVP values (p<0.001). ROC analyses were performed and significant relationship was found between the EAP diameter with haemoglobin (Hmg), haemotocrit (Hct), and central venous oxygen saturation (ScvO2) and also significant correlation was detected between the IAP diameter and white blood cell (WBC).

DISCUSSION

We detected significant correlation between the CVP and the IVC diameter in our study compatible with recent studies besides, significant correlation was found between the diameter of the IVC and CVP values as well as between the EAP diameter and Hmg, Hct, ScvO2 levels.

CONCLUSION

Measurement of IVC diameters, especially EAP may be useful at the monitoring of critically ill patients in ED.

The baseline diameter of the inferior vena cava measured by sonography increases with age in normovolemic children

OBJECTIVES

To evaluate normative sonographic measurements of the inferior vena cava (IVC) diameter in healthy pediatric patients.

METHODS

We performed a prospective observational study of a convenience sample of healthy patients between the ages of 0 and 22 years presenting to a pediatric emergency department. Exclusion criteria included abnormal vital signs, pregnancy, or illnesses thought to influence volume status. During quiet respiration, the maximum and minimum IVC diameters were measured in the sagittal plane distal to the hepatic vein-IVC junction. As second measurements, the maximum diameters of the IVC and aorta were measured in the transverse plane distal to the insertion of the left renal vein into the IVC.

RESULTS

From February 2013 through April 2014, 63 children (51% female; mean age, 11 years) were enrolled. There were 20 children in each age group of 2 to 7, 7 to 12, and 12 to 22 years. The correlations between IVC and aortic diameters as a function of age were calculated using the Spearman rank correlation coefficient. The correlation coefficients were all statistically significant (P < .001): sagittal maximum IVC diameter (0.81), sagittal minimum IVC diameter (0.79), transverse maximum IVC diameter (0.79), and transverse maximum aortic diameter (0.81).

CONCLUSIONS

This pilot study of sonographic measurements of the IVC diameter in normovolemic children suggests a statistically significant positive correlation between age and IVC diameter. Future studies should focus on multicenter enrollment, children in the youngest age group, and the development of normative growth curves for the IVC by age, sex, and body mass index.

Diagnosing clinically significant dehydration in children with acute gastroenteritis using noninvasive methods: a meta-analysis

OBJECTIVE

To determine the most accurate, noninvasive method of assessing dehydration.

STUDY DESIGN

The following data sources were searched: electronic databases, gray literature, scientific meetings, reference lists, and authors of unpublished studies. Eligible studies were comparative outpatient evaluations that used an accepted reference standard and were conducted in developed countries in children aged <18 years with gastroenteritis. Data extraction was completed independently by multiple reviewers before a consensus was made.

RESULTS

Nine studies that included 1039 participants were identified. The 4-item Clinical Dehydration Scale (CDS), the "Gorelick" score, and unstructured physician assessment were evaluated in 3, 2, and 5 studies, respectively. Bedside ultrasound, capillary digital videography, and urinary measurements were each evaluated in one study. The CDS had a positive likelihood ratio (LR) range of 1.87-11.79 and a negative LR range of 0.30-0.71 to predict 6% dehydration. When combined with the 4-item Gorelick Score, the positive LR was 1.93 (95% CI 1.07-3.49) and negative LR was of 0.40 (95% CI 0.24-0.68). Unstructured dehydration assessment had a pooled positive LR of 2.13 (95% CI 1.33-3.44) and negative LR of 0.48 (95% CI 0.28-0.82) to detect ≥ 5% dehydration.

CONCLUSIONS

Overall, the clinical scales evaluated provide some improved diagnostic accuracy. However, test characteristics indicate that their ability to identify children both with and without dehydration is suboptimal. Current evidence does not support the routine use of ultrasound or urinalysis to determine dehydration severity.

Sonographic inferior vena cava measurements to assess hydration status in college football players during preseason camp

OBJECTIVES

The purpose of this study was to determine whether sonographic measurement of the inferior vena cava (IVC) in college football players during preseason camp is a reliable way to detect and monitor dehydration. Our primary hypothesis was that IVC diameter measurements, the postpractice caval index, and expiratory diameter were significantly related to percent weight loss after a preseason football practice.

METHODS

A prospective cohort sample of Division I intercollegiate football players in preseason training camp was recruited before practice. All football players on the active roster who were at least 18 years of age were eligible to participate in the study. Sonographic IVC measurements were obtained in the long axis using either the subcostal or subxiphoid approach during inspiration and expiration both before and after an approximately 3-hour practice with moderate to high levels of exertion at high ambient temperatures. Player weights were recorded in the locker room before and after practice.

RESULTS

A total of 27 prepractice and postpractice sonographic measurements were obtained. The postpractice expiratory IVC diameter was significantly related to percent weight loss after practice (R(2) = 0.153; P = .042), with the IVC diameter being significantly inversely correlated with percent weight loss; the regression coefficient was -1.07 (95% confidence interval, -2.09 to -0.04). There was no statistically significant relationship between percent weight loss and the postpractice caval index; the regression coefficient was 0.245 (95% confidence interval, -0.10 to 0.59; R(2) = 0.078; P = .16).

CONCLUSIONS

The postpractice expiratory IVC diameter was significantly related to percent weight loss after practice, whereas the caval index was not found to correlate with weight loss.

Pulmonary embolism in the pediatric emergency department: a case demonstrating the application of point-of-care cardiac ultrasound in a pediatric patient with pulmonary embolism

Although pulmonary embolism in children is rare, it is important for the pediatric emergency medicine provider to be aware of its presentation and emergent management. We present a case of bilateral pulmonary embolisms in an adolescent patient to illustrate the benefits from the timely diagnosis of right ventricular dysfunction by point-of-care echocardiography performed by emergency medicine physicians. Ultrasonographic techniques and the emergent management of pulmonary embolism are reviewed.

The BUDDY (Bedside Ultrasound to Detect Dehydration in Youth) study

Background

Prior research suggests that the ratio of the ultrasound-measured diameter of the inferior vena cava to the aorta correlates with the level of dehydration in children. This study was designed to externally validate this and to access the accuracy of the ultrasound measured inspiratory IVC collapse and physician gestalt to predict significant dehydration in children in the emergency department.

Methods

We prospectively enrolled a non-consecutive cohort of children ≤18 years old. Patient weight, ultrasound measurements of the IVC and Ao, and physician gestalt were recorded. The percent weight change from presentation to discharge was used to calculate the degree of dehydration. A weight change of ≥5% was considered clinically significant dehydration. Receiver operating characteristic (ROC) curves were constructed for each of the ultrasound measurements and physician gestalt. Sensitivity (SN) and specificity (SP) were calculated based on previously established cutoff points of the IVC/Ao ratio (0.8), the IVC collapsibility index of 50%, and a new cut off point of IVC collapsibility index of 80% or greater. Intra-class correlation coefficients were calculated to assess the degree of inter-rater reliability between ultrasound observers.

Results

Of 113 patients, 10.6% had significant dehydration. The IVC/Ao ratio had an area under the ROC curve (AUC) of 0.72 (95% CI 0.53 to 0.91) and, with a cutoff of 0.8, produced a SN of 67% and a SP of 71% for the diagnosis of significant dehydration. The IVC collapsibility index of 50% had an AUC of 0.58 (95% CI 0.44 to 0.72) and, with a cutoff of 80% collapsibility, produced a SN of 83% and a SP of 42%. The intra-class correlation coefficient was 0.83 for the IVC/Ao ratio and 0.70 for the IVC collapsibility. Physician gestalt had an AUC of 0.61 (95% CI 0.44 to 0.78) and, with a cutoff point of 5, produced a SN of 42% and a SP of 65%.

Conclusions

The ultrasound-measured IVC/Ao ratio is a modest predictor of significant dehydration in children. The inspiratory IVC collapse and physician gestalt were poor predictors of the actual level of dehydration in this study.