Respiratory changes in subclavian vein diameters predicts fluid responsiveness in intensive care patients: a pilot study

Abstract

The present pilot study investigated whether respiratory variation in subclavian vein (SCV) diameters correlates with fluid responsiveness in mechanically ventilated patients. Monocentric, prospective clinical study on fluid responsiveness in adult sedated, mechanically ventilated ICU patient, monitored with the PiCCO™ system (Pulsion Medical System, Germany), and requiring a fluid challenge (FC). A 10-min fluid bolus of 500 mL of 0.9% saline was administered. Cardiac output (CO) and dynamic parameters [stroke volume variation (SVV) and pulse pressure variation (PPV)] measured by transpulmonary thermodilution and pulse contour analysis (PiCCO™) as well as classical hemodynamic parameters were recorded at baseline and after FC. Fluid responsiveness was described as an increase in CO of ≥ 15%. Ultrasound measurements obtained in the subclavian long-axis view were used to calculate the SCV index. A cut-off value for SCV variation for the prediction of fluid responsiveness was determined using receiver operating curve (ROC) analysis. Nine of 20 FCs (45%) induced an increase in CO of ≥ 15%. At baseline, the SCV index was greater in responders than in non-responders (34.0 ± 21.4 vs. 9.0 ± 5.5; p = 0.0005). Diagnostic performance for the SCV index revealed a cut-off value of 14 with a sensitivity of 100% [Confidence interval (CI) 95% (90; 100)] and a specificity of 82% [CI 95% (48; 98)] for the prediction of fluid responsiveness. Other parameters, such as SVV and PPV, could not predict fluid responsiveness. The correlation coefficient between CO variation and the SCV index was 0.73 (p < 0.001). The SCV index was a reliable, non-invasive parameter for the prediction of fluid responsiveness at the bedside of mechanically ventilated, critically ill patients in this pilot study.

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

“…Techniques to predict relative intravascular volume responsiveness, defined as an increase in cardiac output of 10% to 15% after a volume challenge, can be categorized as static or dynamic. 3 Static parameters include mean values for central venous pressure, right atrial pressure (RAP), pulmonary artery occlusion pressure, maximum inferior vena cava (IVC) diameter, stroke volume, or cardiac output and generally have low sensitivity and specificity to assess relative intravascular volume and volume responsiveness [3][4][5] Dynamic parameters which take into account the respiratory/ventilatory variation of RAP, IVC diameter, stroke volume, systolic blood pressure, or pulse pressure, vary throughout the respiratory and cardiac cycles and tend to have higher sensitivity and specificity to predict volume responsiveness. 3 IVC variability by ultrasound allows a dynamic non-invasive point-of-care estimate of relative intravascular volume.…”

“…SCV respiratory variation has been shown to be predictive of volume responsiveness in mechanically ventilated patients as defined by an increase in cardiac output with volume administration. 5 One small study of subjects undergoing echocardiography for various clinical indications, showed a correlation of IVC variation while supine with SCV variation when semi-recumbent during spontaneous breathing. 16 Another study of surgical intensive care unit patients during spontaneous breathing or on mechanical ventilation (positions not specified), indicated a good correlation of IVC and SCV variations.…”

“…Measurements Ultrasound (US) measurements of the IVC and SCV were performed during bedside rounds using a portable ultrasound machine (LOGIQ e B12, GE Healthcare, Wauwatosa, WI 53226) as previously described. 5,9,13 All patients were imaged in the semi-recumbent position at approximately 30 to 45 degrees during quiet spontaneous breathing or with mechanical ventilation. The SCV and IVC ultrasound studies were both performed during the same patient encounter.…”

Journal of clinical monitoring and computing end of year summary 2018: hemodynamic monitoring and management

“…Another important study was conducted by Giraud and colleagues [24]. These authors rightfully argued that the variability of superior vena cava diameter is impossible to assess with TTE, but that the variability of the subclavian vein (SCV)—given its close proximity of the superior vena cava and the pleural space—could be another way to look at these variations using ultrasound.…”

“…patients where clinicians may rarely be uncertain about the fluid responsiveness state (say, initial phases of hypovolemic or distributive shock), would tend to achieve better prediction characteristics compared with studies including less extreme patients. The simulation might have been more realistic, if SVV had been simulated from a bell-shaped and right skewed distribution rather than a uniform, as evident from the reviewed papers above [24, 25], but the conclusions that classification can be influenced by spectrum bias would hardly change with such a simulation approach. This is an important aspect when assessing individual studies as well as when comparing results across studies because evaluation of spectrum bias should accompany the interpretation of AUC ROC s and grey zones.…”