Influence of breathing movements and Valsalva maneuver on vena caval dynamics

Abstract

AIM:To study changes produced within the inferior vena cava (IVC) during respiratory movements and identify their possible clinical implications. METHODS:This study included 100 patients (46 women; 54 men) over 18 years of age who required an abdominal computed tomography (CT) and central venous access. IVC cross-sectional areas were measured on CT scans at three levels, suprarenal (SR), juxtarenal (JR) and infrarenal (IR), during neutral breathing and again during the Valsalva maneuver. All patients were instructed on how to perform a correct Valsalva maneuver. In order to reduce the total radiation dose in our patients, low-dose CT protocols were used in all patients. The venous blood pressure (systolic, diastolic and mean) was invasively measured at the same three levels with neutral breathing and the Valsalva maneuver during venous port implantation. From CT scans, threedimensional models of the IVC were constructed and a collapsibility index was calculated for each patient. These data were then correlated with venous pressures and cross-sectional areas. RESULTS:The mean patient age was 51.64 ± 12.01 years. The areas of the ellipse in neutral breathing were 394.49 ± 85.83 (SR), 380.10 ± 74.55 (JR), and 342.72 ± 49.77 mm 2 (IR), and 87.46 ± 18.35 (SR), 92.64 ± 15.36 (JR) and 70.05 ± 9.64 mm 2 (IR) during the Valsalva (P s < 0.001). There was a correlation between areas in neutral breathing and in the Valsalva maneuver (P < 0.05 in all areas). Large areas decreased more than smaller areas. The collapsibility indices were 0.49 ± 0.06 (SR), 0.50 ± 0.04 (JR) and 0.50 ± 0.04 (IR), with no significant differences in any region. Reconstructed three-dimensional models showed a flattening of the IVC during Valsalva, adopting an ellipsoid cross-sectional shape. The mean pressures with neutral breathing were 9.44 ± 1.78 (SR), 9.40 ± 1.44 (JR) and 8.84 ± 1.03 mmHg (IR), and 81.08 ± 21.82 (SR), 79.88 ± 19.01 (JR) and 74.04 ± 16.56 mmHg (IR) during Valsalva (P s < 0.001). There was a negative correlation between cross-sectional caval area and venous blood pressure, but this was not statistically significant in any of the cases. There was a significant correlation between diastolic and mean pressures measured during neutral breathing and in Valsalva. CONCLUSION:Respiratory movements have a major influence on IVC dynamics. The increase in intracaval pressure during Valsalva results in a significant de-

Vena Cava Responsiveness to Controlled Isovolumetric Respiratory Efforts

“…Because it averaged approximately 80 mmHg, the expiratory effort was presumably close to maximal in the second study. 21 In this study, rather low pressure values (5, 10, and 15 mmHg) were attained at the mouthpiece, as compared with the 40 mmHg commonly used for the Valsalva maneuver, 22 but a progressive and significant decrease in IVC size was observed, again indicating that abdominal pressure prevails on intrathoracic pressure.…”

“…20 Grant et al 20 observed a reduction of the IVC in 100% of males and 50% of females performing a Valsalva maneuver. In a recent study, IVC deformation by the Valsalva maneuver was reinvestigated with computed tomography, 21 and a systematic decrease of IVC size was reported (to 22% of resting CSA, on average). However, in none of these studies was the maneuver controlled or standardized in terms of exerted pressure.…”

Can the inferior vena cava collapsibility index be useful in predicting hypotension during spinal anaesthesia in a spontaneously breathing patient? A mini fluid challenge

“…Furthermore, it is important to note that the inferior vena cava is a large vessel, the diameter of which depends on changes in extrinsic and intrinsic factors. It is known that changes in the intrathoracic pressure and in the breathing manner significantly affect the IVC diameter in a spontaneously breathing patient (18,19). We asked patients to breathe normally while the measurements of IVC were taken.…”

Calibration of interface properties and application to a finite element model for predicting vena cava filter–induced vein wall failure

“…However, there are other physiological situations such as the Valsalva maneuver or the influence of diaphragmatic motion on vena cava shape and size that could cause penetration . Laborda et al demonstrated that filter penetration could be related with IVC cross‐sectional area decrease during Valsalva. We have only analyzed neutral breathing; futures studies should be done in order to check if the radial force produced by Valsalva maneuver could produce a major penetration of the struts.…”

“…Finally, the filter was deployed in the cava by radially removing the previous applied force and allowing the outer surface of the anchor to come into contact with the inner surface of the cava; see Figure . The influence of diaphragmatic motion on vena cava shape and size in the context of neutral breathing and Valsalva has not been considered …”