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

Abstract

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 positiondependent, 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.

The Role of Ultrasonographic Inferior Vena Cava Measurement in the Volume‐Based Classification of Patients With Hyponatremia

“…19,20 Although there is a growing need of a noninvasive tool to accomplish correct fluid management, the available methods are still nonoptimal, expensive and require long procedures and highly specialized personnel, so less invasive techniques such as respiratory CI of IVC with its' prompt identification of intravascular volume in critically ill patient especially in ED has been implemented in clinical use. 10,[21][22][23][24][25][26] Although our study supports previous studies, it primarily investigated an unstudied topic, that is, the relationship between IVC CI measurement and volume status in patients with hyponatremia. Thus, unlike its predecessors, the present study may provide guidance in hyponatremia management (Figure 4).…”

“…The absence of methods that directly measure body volume status, with the paramount importance to accurately assess volume status in patients presenting to ED, necessitated the development of indirect measurement methods; such as the dilution techniques for the body fluids assessment, energy X‐ray absorptiometry, underwater weighing, air displacement plethysmography, bioelectrical impedance analysis, magnetic resonance, and computed tomography 19,20 . Although there is a growing need of a noninvasive tool to accomplish correct fluid management, the available methods are still nonoptimal, expensive and require long procedures and highly specialized personnel, so less invasive techniques such as respiratory CI of IVC with its' prompt identification of intravascular volume in critically ill patient especially in ED has been implemented in clinical use 10,21–26 …”

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

“…Respiratory variations of the subclavian/proximal axillary vein (SCV) and internal jugular vein (IJV) are highly position dependent, as is jugular venous distension, and should be performed at a 30–45 degree upper body incline [ 45 ]. SCV CI and IJV CI do not appear to be affected by intra-abdominal hypertension or positive end-expiratory pressure [ 46 , 47 ].…”

“…In 120 patients undergoing general anesthesia, a cut-off of 36% for SCV CI with deep breathing (presumably without head elevation) predicted post-induction hypotension in 42% of patients (sensitivity 90%, specificity 87%), similar to performance of IVC CI using a cut-off of 37% (sensitivity 94%, specificity 84%) [ 43 ]. Comparison of cut-off values for the SCV CI to predict IVC CI cut-off at 30–45 degrees supine without deep breathing from four studies are shown in Table 5 [ 45 , 48 , 50 , 51 ].…”

“…IVC diameters and IVC CI may be altered by a number of factors, resulting in over-estimation or under-estimation of intravascular volume, which are summarized in Table 10 [ 5 , 45 , 93 ]. If the patient has factors that tend to cause IVC distention and yet the IVC is small or collapsing, intravascular hypervolemia is unlikely, and vice versa.…”