Maximum Inferior Vena Cava Diameter Research Articles

Ultrasound Does Not Detect Early Blood Loss in Healthy Volunteers Donating Blood

Ultrasound has been suggested as a useful non-invasive tool for the detection of early blood loss. Two possible sonographic markers for hypovolemia are the diameter of the inferior vena cava (IVC) and the thickness of the left ventricle (LV). The goal of the study was to evaluate the utility of ultrasound to detect signs of early hemorrhagic shock in healthy volunteers, compared with changes in vital signs. In the current study, healthy volunteers from blood donation drives were used as models for early hemorrhage. Changes in vital signs, IVC diameter, and LV wall thickness were recorded after approximately 500 cc of blood loss. Thirty-eight subjects were enrolled and completed the study. After blood donation, there was a 7-mm Hg (8%) decrease in mean arterial pressure without a significant change in heart rate. There was a decrease in maximum IVC diameter (IVCmax) (12% decrease [95% confidence interval (CI) -6 to -19] in short axis and 20% decrease [95% CI -12 to -27] in long axis), but no change was seen in the respiratory caval index ((IVCmax - IVCmin)/IVCmax) × 100). There was no change in LV wall thickness. In this study, serial changes in vital signs, IVC diameter, and LV wall thickness were clinically insignificant after approximately 500 cc of blood loss in healthy volunteers.

Age-Related Decrease in Inferior Vena Cava Diameter Measured with Echocardiography

The diameter of the inferior vena cava (IVC) measured with echocardiography is clinically used as a parameter to estimate right atrial pressure, which reflects dehydration or overhydration. Because elderly patients fall easily into dehydration, normal values for IVC diameters in elderly patients may be helpful for geriatric medicine. However, normal values of IVC diameter in relation to age have not been investigated. The purpose of this study was to elucidate age-related changes in IVC diameter using echocardiography. Enrolled in the study were 200 patients (67 ± 15 yrs: range 17-94 yrs) with cardiovascular risk factors but no overt cardiac diseases. IVC diameters throughout the respiratory cycle were measured as maximum and minimum IVC diameters (IVC(max), IVC(min)) using M-mode echocardiography. To assess IVC collapsibility, the respirophasic variation of IVC diameter was calculated as (IVC(max) - IVC(min))/(IVC(max)) ×100. Maximum IVC diameter was decreased with advancing age (r = -0.221, p = 0.002). The respirophasic variation of the IVC diameter was increased with advancing age (r = 0.244, p = 0.001). Stepwise multiple regression analysis showed that age was an independent determinant for both maximum IVC diameter (ß coefficient = -0.249, p < 0.001) and respirophasic variation of the IVC diameter (ß coefficient = 0.268, p < 0.001). Age-related decrease in maximum IVC diameter and increase in the respirophasic IVC collapsibility may indicate the decrease in right atrial pressure in some elderly patients. Therefore, elderly patients with decreased maximum IVC and increased respirophasic IVC collapsibility may need prevention for dehydration.

Use of Hand Carried Ultrasound, B-type Natriuretic Peptide, and Clinical Assessment in Identifying Abnormal Left Ventricular Filling Pressures in Patients Referred for Right Heart Catheterization

Background The estimation of left ventricular filling pressure (LVFP) remains a critical component in the management of patients with known or suspected acute heart failure syndromes. Although right heart catheterization (RHC) remains the gold standard, several noninvasive parameters, including clinical assessment, B-type natriuretic peptides (BNP), and echocardiography can approximate LVFP. We sought to use a combination of these measures to noninvasively predict high or low LVFP in a population referred for RHC. Methods and Results The study consisted of validation of hand-carried ultrasound (HCU)-derived measurement of mitral E/E′ against standard echocardiograms in 50 patients, as well as direct comparison of jugular venous pressure (JVP), a clinical congestion score, HCU-derived E/E′ and maximum inferior vena cava diameter (IVCmax), and BNP with pulmonary capillary wedge pressure (PCWP) in another 50 patients. The mean age was 61 years, ejection fraction 40%, JVP 9 cm, BNP 948 pg/mL, IVCmax 2.1 cm, E/E′ 13, and PCWP 21. All parameters performed well in determining PCWP ≥15 mm Hg, with clinical score performing the worst (area under the receiver-operator characteristic curve [AUC] 0.74), and IVCmax performing the best (AUC 0.89). JVP, in combination with HCU-derived parameters and BNP performed better than any of the individual tests alone (AUC 0.97 for combination of all 3). Conclusions Clinical score, JVP, HCU indices, and BNP perform well at identifying patients with a PCWP ≥15 mm Hg. Use of these indices alone or in combination can be used to identify and potentially monitor patients with high LVFP in the inpatient and outpatient settings.

The Use of Inferior Vena Cava Filters in Young Children

The present report describes the authors' experience with the placement and retrieval of inferior vena cava (IVC) filters in children with a maximum IVC diameter of 1 cm. Over a 14-month period, three filters were placed in three children. Two filters were placed via the right internal jugular vein, with one placed via the right femoral vein. The filters were deployed successfully in all three children and retrieved in two. In one case, the child was receiving palliative care and removal was not attempted. No complications were encountered during placement, the period of implantation, or retrieval.

Common bile duct anteroposterior movement synchronized with inferior vena cava pulsation observed by cine magnetic resonance imaging

To reveal the phenomenon of common bile duct (CBD) anteroposterior movement caused by inferior vena cava (IVC) pulsation depending on the cardiac cycle using cine magnetic resonance imaging. A breath-hold trans-axial cine segmented true fast imaging with steady-state precession (trueFISP) sequence was prospectively performed on 11 healthy volunteers to observe CBD anteroposterior movement and IVC pulsation during the cardiac cycle. Changes in IVC anterior-posterior diameter and CBD location were compared using Pearson rank correlation analysis. Nine (81.8%) of 11 CBDs moved back and forth in synchronicity with IVC anterior wall motion depending on the cardiac cycle; the mean maximum and minimum IVC diameters were 16.2+/-2.7 and 12.9+/-3.1 mm, respectively. Two (18.2%) of 11 CBDs and IVC walls did not move; the mean unchanged IVC diameter was 5.3+/-2.1 mm. There were significant correlations between the mean change in IVC diameter and distance of CBD anteroposterior movement (2.7+/-2.1 and 1.8+/-1.4 mm, respectively, r=0.911, P<.05). Many CBDs move back and forth in synchronicity with IVC pulsation depending on the cardiac cycle.

Sonographic measurement of the inferior vena cava as a predictor of shock in trauma patients

Detecting and monitoring blood loss is always a challenging dilemma in emergency settings. The diameter of the inferior vena cava (IVC) in trauma patients may be useful in this way. This has been classically done with computed tomography (CT); however, doing it with ultrasound as a bedside easily available modality is a relatively novel approach. Between January 2006 and March 2006, 88 injured patients referred to our center were investigated. The patients were divided in to two groups: a shock group (n = 11, 12.5%) and a control group (n = 77, 87.5%) who were trauma patients with normal blood pressure. The maximum anteroposteroir diameter of IVC was measured ultrasonographically both in inspiration (i) and expiration (e) by M-mode in the subxyphoid area. The difference between the diameters of IVCe and IVCi was regarded as collapsibility, and collapsibility index was defined as IVCe - IVCi/IVCe. Statistical analysis included Mann-Whitney U test and correlation analysis. The average diameters of IVCe and IVCi in the shock group at arrival were significantly smaller than in the control group (5.6 +/- 0.8 mm, 4.0 +/- 0.7 mm versus 11.9 +/- 2.2 mm, 9.6 +/- 2.0 mm; P < 0.0001). The maximum diameter of IVC in the shock group was in a 30-year-old male patient with an IVCe and IVCi of 7.0 and 5.3 mm, respectively. Correlation analysis revealed a negative correlation between the diameter of IVCe (r = 0.72) and IVCi (r = 0.73) and the presence of shock. Regarding the collapsibility index, the mean collapsibility index of IVC was significantly higher in the shock group compared to patients in the control group (27% versus 20%; P < 0.001). The diameter of IVC was found to correlate with shock in trauma patients. The measurement of the IVC may be an important addition to the ultrasonographic evaluation of trauma and other potentially volume-depleted patients and can be added to the focused assessment with sonography for trauma (FAST) of the trauma patient with minimum additional time.

Improvement of cardiac function by dry weight optimization based on interdialysis inferior vena caval diameter.

In hemodialysis (HD) patients, the diameter of the inferior vena cava (IVC) serves for evaluation of the amount of body fluid. IVC measurement is usually performed immediately before and/or after an HD session. In the present study, we examined the validity of IVC diameter in the interdialysis period (interdialytic IVC) for dry weight (DW) optimization. In 100 HD patients, interdialytic IVC was measured ultrasonographically. The average maximum IVC diameter during quiet expiration (IVCe) was 14.2+/-3.8 mm. In 32 patients with volume dependent hypertension, the interdialytic IVCe was > 16 mm in 29 of 32. Thus, we defined an interdialytic IVCe > 16 mm as a hypervolemic state. Next, by screening 306 HD patients ultrasonographically, 31 patients with left ventricular volume overload were chosen based on criteria of an interdialytic IVCe > 16 mm, together with a left ventricular ejection fraction (EF) < 55%. After the DW was lowered to obtain an interdialytic IVCe < 16 mm, 25 of the 31 patients had a significant increase in EF, decrease in diastolic left ventricular dimension, and amelioration of hypertension. In conclusion, interdialytic IVCe is considered to be a useful parameter for DW optimization. In hypervolemic patients with IVCe > 16 mm, reduction in DW is expected to improve volume overload and cardiac function.

Measurement of anterior-posterior diameter of inferior vena cava by ultrasonography: a new non-invasive method to assess acute changes in vascular filling state.

The aim was to determine whether measurement of the anterior-posterior diameter of the inferior vena cava (IVC) by ultrasonography, before and during deep inspiration, allows indirect information on baseline blood volume and changes in vascular filling state to be obtained in healthy subjects. Blood volume was measured in 12 volunteers by a standard radioactive isotope method. The IVC dimensions were measured by ultrasound in various positions. In addition, in 10 male subjects the effect on the IVC dimensions of volume loading was evaluated by rapid infusion of plasma expander. During and immediately following volume loading, the IVC dimensions and blood volume were remeasured. Neither the baseline IVC diameters nor any combination of these variables correlated with the concomitant blood volume. Volume loading increased the anterior-posterior IVC dimensions linearly, the largest increase being observed with the maximum IVC diameter and the subject in supine position. It follows that ultrasonic IVC indices cannot be used as accurate indirect estimate of baseline blood volume, but provide reliable information on acute changes of the subjects' vascular filling state.

Sonospirometry: A new method for noninvasive estimation of mean right atrial pressure based on two-dimensional echographic measurements of the inferior vena cava during measured inspiration

A noninvasive method of estimating mean right atrial pressure would be useful in evaluating hemodynamics and calculating pulmonary pressures by Deppler echocardiography. An electronic pressure gauge was built and tested for measurement of inspiratory pressures during two-dimensional echocardiography to quantitate the diameter of the inferior vena cava. Thirty-one studies were made in 27 alert, informed, consenting patients with an in-place pulmonary artery catheter having right atrial ports. Inferior vena cava diameter was measured in successive 10 mm segments distal to the right atrial-inferior vena cava junction on images obtained while the patient suspended breathing at full inspiration and during each 4 mm Hg increment of a calibrated inspiratory maneuver.Results show that the segment between 5 and 30 mm distal to the right atrial-inferior vena cava junction was the region most responsive to increasing inspiratory pressure. In this segment, the inspiratory pressure required to decrease the inferior vena cava diameter to ≥85% of the difference between its maximal (suspended full inspiration) and minimal (over the entire inspiratory maneuver) values was similar or equal to the mean right atrial pressure (measured from the pulmonary artery catheter) (r = 0.87, SEE = 2.9 mm Hg). Minimal inferior vena cava diameter was directly related to mean right atrial pressure (r = 0.56); the minimal to maximal inferior vena cava diameter ratio was inversely related to mean right atrial pressure (r = −0.57). Maximal inferior vena cava diameter and the absolute (measured) amount of inferior vena cava diameter decrease correlated weakly with mean right atrial pressure. This method appears to be useful for noninvasive estimation of mean right atrial pressure.