Comparison of Respiratory Variations of Subclavian Vein and Inferior Vena Cava in Hospitalized Patients with Kidney Disease

Abnormal characteristics of inferior vena cava and abdominal aorta among neonates with early onset septic shock

BACKGROUND

The variety of shocks in neonates, if not recognized and treated immediately, is a major cause for fatality. The use of echocardiography may improve assessment and treatment, but its reference values across gestational age (GA) and birth weight (BW) are lacking. To address the information gap, this study aimed at correlating GA and BW of newborns with nonhemodynamic abnormalities, and at evaluating the usefulness of such reference values in neonates with early onset septic (EOS) -shock.

METHODS

A total of 200 normal newborns were enrolled as controls and subdivided into groups based on GA, BW, days of age, and patent ductus arteriosus (PDA). Echocardiography was used to document inferior vena cava diameter (IVC), inferior vena cava collapsibility index (IVC-CI), and inferior vena cava to abdominal aorta ratio (IVC/AO). In addition, 18 neonates with EOS shock were recruited and evaluated using echocardiography.

RESULTS

Among the control newborns, IVC and AO were significantly increased with GA and BW (P < 0.05) but IVC-CI and IVC/AO did not correlate with GA, BW, day of age, and PDA. Compared to the control group, the EOS-shock group had significantly decreased IVC and IVC/AO, and increased IVC-CI (P < 0.05). The cut-off values for indicating EOS-shock were > 34.15% for IVC-CI, < 47.58% for IVCmin/AO, and < 66.11% for IVCmax/AO.

CONCLUSIONS

The IVC-CI, IVCmin/AO, and IVCmax/AO indices are applicable to all neonates. Although the number of neonates with EOS-shock in our study is small, the cut-off values showed usefulness for diagnosis. Further research is needed to determine the application of the indices in a larger population and among other populations, especially for clinical application in treatment of shock among neonates.

Ultrasonographic Evaluation of Hypervolemic and Normovolemic Patients: A Comparison of Inferior Vena Cava, Subclavian Vein, Internal Jugular Vein, and Femoral Vein Diameters and Collapsibility Indices

Background and objective We aimed to determine the diameters and respiratory variability of the subclavian vein (SCV), internal jugular vein (IJV), and femoral vein (FV), which are more superficial and easier to visualize with point-of-care ultrasound (PoCUS) in the detection of volume overload, and to investigate whether they can be an alternative to analyzing an inferior vena cava (IVC) to determine volume load. Methodology We prospectively evaluated volume-overloaded and normovolemic patients admitted to the emergency department using PoCUS for six months. Inspiratory-expiratory diameters and collapsibility indices (CI) of IVC and SCV, IJV, and FV were evaluated. The correlation between IVC and SCV, IJV, and FV was analyzed. Results A total of 176 patients were included in the study, including 88 volume-overloaded patients in the study group and 88 normovolemic patients in the control group. The median values of the maximum and minimum diameters of the IVC, SCV, IJV, and FV in the study group were statistically higher compared to the control group. A moderate correlation was found between IVC and SCV, IVC and IJV, and IVC and FV for maximum diameters in all patients (p = 0.447, p = 0.515, and p = 450, respectively). There was a very weak correlation between the IVC-CI and the FV-CI in all patients (p = 0.160), and no correlation was found with the other veins. Conclusion The IVC-CI was not correlated with the SCV-CI, the IJV-CI, or the FV-CI in volume-overloaded patients; therefore, superficial venous vessels cannot be an alternative to the IVC.

Comparison of subclavian vein and inferior vena cava collapsibility index in the intensive care unit

OBJECTIVE

The aim of this study was to evaluate the correlation between changes in the inferior vena cava collapsibility index and subclavian vein collapsibility index in patients undergoing passive leg raising tests in the intensive care unit, considering that respiratory changes affecting the inferior vena cava may similarly affect the subclavian vein.

METHODS

This single-center observational study was conducted on patients aged between 18 and 85 years who underwent passive leg raising in the intensive care unit. When the patient was 45° above the bed, the inferior vena cava and subclavian vein were displayed using ultrasonography; subclavian vein collapsibility index and inferior vena cava collapsibility index values were calculated. After the initial values were recorded, passive leg raising was performed, and the initial measurements were repeated. The CI values measured after passive leg raising were subtracted from those calculated before passive leg raising to determine the changes (Δ) in inferior vena cava and subclavian vein collapsibility indices.

RESULTS

The study was conducted with a total of 64 patients. The mean±standard deviation values for ΔIVC-CI% and ΔSCV-CI% variables were found as 8.97±8.89 and 10.31±10.81, respectively. There were no statistically significant differences in values of ΔIVC-CI% and ΔSCV-CI% (p=0.297). In the Bland-Altman plot, because there were only two values exceeding the +1.96 SD and -1.96 SD limits, it can be said that the agreement between ΔIVC-CI% and ΔSCV-CI% was adequate.

CONCLUSION

ΔSCV-CI% values are compatible and correlated with ΔIVC-CI% values. Inferior vena cava and subclavian vein responded similarly to fluid changes during passive leg raising.

Diagnostic accuracy of subclavian vein versus inferior vena cava collapsibility index for predicting postinduction hypotension: An observational study

Background

Hypotension following induction of general anesthesia (GA) is commonly observed. Ultrasound (US) measurement of collapsibility index (CI) of the inferior vena cava (IVC) for predicting postinduction hypotension has been studied. As there is limited data available comparing the diagnostic accuracy of subclavian vein (SCV) versus IVC-CI, we performed this observational study.

Methods

A total of 132 adult patients scheduled for elective surgery under GA were enrolled. US measurements of three readings of maximum and minimum diameters of SCV and IVC were recorded during both quiet and deep breathing, and the mean of three values was calculated. CI was derived using the formula: (dmax - dmin) × 100/dmax. Subsequently, GA was administered using standard technique, irrespective of the findings of SCV and IVC measurements. The administered drugs and dosage were recorded. Hemodynamic parameters were collected at baseline and then at every minute for the first 20 min. The primary objective was to compare the diagnostic accuracies of SCV-CI and IVC-CI for prediction of postinduction hypotension during quiet breathing. The secondary objectives were to compare the diagnostic accuracies during deep breathing and find the correlation between IVC-CI and SC-CI during quiet and deep breathing, incidence of hypotension, and time required to acquire US images.

Results

Fifty-seven patients developed postinduction hypotension. During quiet breathing, SCV-CI ≥10% had a sensitivity of 68% and specificity of 56% (area under curve [AUC] [95% confidence interval {CI}] of 0.659 [0.56-0.75]; P = 0.002), while IVC-CI ≥34% had a sensitivity of 70% and specificity of 59% (AUC [95% CI] of 0.672 [0.58-0.76]; P = 0.001) for prediction of postinduction hypotension. During deep breathing, both SCV-CI and IVC-CI had moderate accuracy (P = 0.001 for both). Pearson's correlation showed a significant positive correlation between SCV-CI and IVC-CI with a correlation coefficient (r) of 0.313 during quiet breathing and 0.379 during deep breathing (P < 0.001). The time required for acquiring US images was significantly less for SCV compared to IVC during both quiet and deep breathing (P < 0.001 for both).

Conclusion

Both SCV-CI and IVC-CI were found to have good and comparable diagnostic accuracy for the prediction of postinduction hypotension. We also found a significant positive correlation between SCV-CI and IVC-CI. In comparison to IVC, US scanning of SCV took lesser time to acquire the images.

Effect of subclavian vein diameter combined with perioperative fluid therapy on preventing post-induction hypotension in patients with ASA status I or II

BACKGROUND

Perioperative hypotension is frequently observed following the initiation of general anesthesia administration, often associated with adverse outcomes. This study assessed the effect of subclavian vein (SCV) diameter combined with perioperative fluid therapy on preventing post-induction hypotension (PIH) in patients with lower ASA status.

METHODS

This two-part study included patients aged 18 to 65 years, classified as ASA physical status I or II, and scheduled for elective surgery. The first part (Part I) included 146 adult patients, where maximum SCV diameter (dSCVmax), minimum SCV diameter (dSCVmin), SCV collapsibility index (SCVCI) and SCV variability (SCVvariability) assessed using ultrasound. PIH was determined by reduction in mean arterial pressure (MAP) exceeding 30% from baseline measurement or any instance of MAP < falling below 65 mmHg for ≥ a duration of at least 1 min during the period from induction to 10 min after intubation. Receiver Operating Characteristic (ROC) curve analysis was employed to determine the predictive values of subclavian vein diameter and other relevant parameters. The second part comprised 124 adult patients, where patients with SCV diameter above the optimal cutoff value, as determined in Part I study, received 6 ml/kg of colloid solution within 20 min before induction. The study evaluated the impact of subclavian vein diameter combined with perioperative fluid therapy by comparing the observed incidence of PIH after induction of anesthesia.

RESULTS

The areas under the curves (with 95% confidence intervals) for SCVCI and SCVvariability were both 0.819 (0.744-0.893). The optimal cutoff values were determined to be 45.4% and 14.7% (with sensitivity of 76.1% and specificity of 86.7%), respectively. Logistic regression analysis, after adjusting for confounding factors, demonstrated that both SCVCI and SCVvariability were significant predictors of PIH. A threshold of 45.4% for SCVCI was chosen as the grouping criterion. The incidence of PIH in patients receiving fluid therapy was significantly lower in the SCVCI ≥ 45.4% group compared to the SCVCI < 45.4% group.

CONCLUSIONS

Both SCVCI and SCVvariability are noninvasive parameters capable of predicting PIH, and their combination with perioperative fluid therapy can reduce the incidence of PIH.

Inferior vena cava ultrasound and other techniques for assessment of intravascular and extravascular volume: an update

Goals of volume management are to accurately assess intravascular and extravascular volume and predict response to volume administration, vasopressor support or volume removal. Data are reviewed that support the following: (i) Dynamic parameters reliably guide volume administration and may improve clinical outcomes compared with static parameters, but some are invasive or only validated with mechanical ventilation without spontaneous breathing. (ii) Ultrasound visualization of inferior vena cava (IVC) diameter variations with respiration reliably assesses intravascular volume and predicts volume responsiveness. (iii) Although physiology of IVC respiratory variations differs with mechanical ventilation and spontaneous breathing, the IVC collapsibility index (CI) and distensibility index are interconvertible. (iv) Prediction of volume responsiveness by IVC CI is comparable for mechanical ventilation and spontaneous breathing patients. (v) Respiratory variations of subclavian/proximal axillary and internal jugular veins by ultrasound are alternative sites, with comparable reliability. (vi) Data support clinical applicability of IVC CI to predict hypotension with anesthesia, guide ultrafiltration goals, predict dry weight, predict intra-dialytic hypotension and assess acute decompensated heart failure. (vii) IVC ultrasound may complement ultrasound of heart and lungs, and abdominal organs for venous congestion, for assessing and managing volume overload and deresuscitation, renal failure and shock. (viii) IVC ultrasound has limitations including inadequate visualization. Ultrasound data should always be interpreted in clinical context. Additional studies are required to further assess and validate the role of bedside ultrasonography in clinical care.

Prevention of Intradialytic Hypotension in Hemodialysis Patients: Current Challenges and Future Prospects

Intradialytic hypotension, defined as rapid decrease in systolic blood pressure of greater than or equal to 20 mmHg or in mean arterial pressure of greater than or equal to 10 mmHg that results in end-organ ischemia and requires countermeasures such as ultrafiltration reduction or saline infusion to increase blood pressure to improve patient's symptoms, is a known complication of hemodialysis and is associated with several potential adverse outcomes. Its pathogenesis is complex and involves both patient-related factors such as age and comorbidities, as well as factors related to the dialysis prescription itself. Key factors include the need for volume removal during hemodialysis and a suboptimal vascular response which compromises the ability to compensate for acute intravascular volume loss. Inadequate vascular refill, incorrect assessment or unaccounted changes of target weight, acute illnesses and medication interference are further potential contributors. Intradialytic hypotension can lead to compromised tissue perfusion and end-organ damage, both acutely and over time, resulting in repetitive injuries. To address these problems, a careful assessment of subjective symptoms, minimizing interdialytic weight gains, individualizing dialysis prescription and adjusting the dialysis procedure based on patients' risk factors can mitigate negative outcomes.

Comparison of subclavian vein to inferior vena cava collapsibility by ultrasound in acute heart failure: A pilot study

BACKGROUND

Management of acute decompensated heart failure (ADHF) requires accurate assessment of relative intravascular volume, which may be technically challenging. Inferior vena cava (IVC) collapsibility with respiration reflects intravascular volume and right atrial pressure (RAP). Subclavian vein (SCV) collapsibility may provide an alternative.

HYPOTHESIS

The purpose of this study was to examine the relationship between SCV collapsibility index (CI) and IVC CI in ADHF.

METHODS

This was a prospective study of non-ventilated patients with ADHF who had paired IVC and SCV ultrasound assessments. As SCV CI is highly position-dependent, measurements were performed supine at 30-45°.

RESULTS

Thirty-three patients were included with 36 encounters. The sample size was adequately powered for receiver-operator characteristic (ROC) analysis. SCV CI correlated with IVC CI during relaxed breathing (R = .65, n = 36, p < .001) and forced inhalation (R = .47, n = 36, p = .0036). SCV CI < 22% and >33% corresponded to IVC CI < 20% and >50% suggesting hypervolemia (sensitivity/specificity: 72%) and hypovolemia (sensitivity/specificity: 78%), respectively. Moderate to severe tricuspid regurgitation (TR) compared to less than moderate TR was associated with lower SCV CI (medians: 12.4% vs. 25.3%, p = .022) and IVC CI (medians: 9.6% vs. 35.6%, p = .0012). SCV CI and IVC CI were not significantly different among chronic kidney disease stages.

CONCLUSION

In non-ventilated ADHF, SCV CI at 30-45° correlates with paired IVC CI, and may provide an alternative to IVC CI for assessment of relative intravascular volume, which may facilitate clinical management. Moderate to severe TR decreases SCV CI and IVC CI and may result in overestimation of relative intravascular volume.