Dynamic behavior of venous collapsibility and central venous pressure during standardized crystalloid bolus: A prospective, observational, pilot study

Abstract

Introduction:Measurement of intravascular volume status is an ongoing challenge for physicians in the surgical intensive care unit (SICU). Most surrogates for volume status, including central venous pressure (CVP) and pulmonary artery wedge pressure, require invasive lines associated with a number of potential complications. Sonographic assessment of the collapsibility of the inferior vena cava (IVC) has been described as a noninvasive method for determining volume status. The purpose of this study was to analyze the dynamic response in IVC collapsibility index (IVC-CI) to changes in CVP in SICU patients receiving fluid boluses for volume resuscitation.Materials and Methods:A prospective pilot study was conducted on a sample of SICU patients who met clinical indications for intravenous (IV) fluid bolus and who had preexisting central venous access. Boluses were standardized to crystalloid administration of either 500 mL over 30 min or 1,000 mL over 60 min, as clinically indicated. Concurrent measurements of venous CI (VCI) and CVP were conducted right before initiation of IV bolus (i.e. time 0) and then at 30 and 60 min (as applicable) after bolus initiation. Patient demographics, ventilatory parameters, and vital sign assessments were recorded, with descriptive outcomes reported due to the limited sample size.Results:Twenty patients received a total of 24 IV fluid boluses. There were five recorded 500 mL boluses given over 30 min and 19 recorded 1,000 mL boluses given over 60 min. Mean (median) CVP measured at 0, 30, and 60 minutes post-bolus were 6.04 ± 3.32 (6.5), 9.00 ± 3.41 (8.0), and 11.1 ± 3.91 (12.0) mmHg, respectively. Mean (median) IVC-CI values at 0, 30, and 60 min were 44.4 ± 25.2 (36.5), 26.5 ± 22.8 (15.6), and 25.2 ± 21.2 (14.8), respectively.Conclusions:Observable changes in both VCI and CVP are apparent during an infusion of a standardized fluid bolus. Dynamic changes in VCI as a measurement of responsiveness to fluid bolus are inversely related to changes seen in CVP. Moreover, an IV bolus tends to produce an early response in VCI, while the CVP response is more gradual. Given the noninvasive nature of the measurement technique, VCI shows promise as a method of dynamically measuring patient response to fluid resuscitation. Further studies with larger sample sizes are warranted.

Correlations between pulmonary artery pressures and inferior vena cava collapsibility in critically ill surgical patients: An exploratory study

“…[22] Intensivist–performed focused bedside sonographic assessment of intravascular volume status is increasing in popularity due to its relative simplicity, skill standardization, and mounting evidence of clinical utility. [910121322232425] Given these parallel developments, as well as the need for more evidence–based comparative research, we set out to examine the relationship between IVC-CI and PAPs in a modest sample of patients.…”

“…[3] With declining the use of indwelling intravascular monitoring devices, including the pulmonary artery catheter (PAC),[45] search continues for reliable, accessible, and easy-to-use minimally invasive hemodynamic monitoring alternatives. [678] Although the correlation between inferior vena cava collapsibility index (IVC-CI) and central venous pressures (CVP) has been well described,[9101112] little information exists regarding the relationship between central vein collapsibility (including pertinent subcomponent measurements) and pulmonary artery pressures (PAPs). [1314] The aim of this study is to answer important questions regarding correlations between information traditionally provided by the PAC and the corresponding IVC-CI findings.…”

Cardiac Ultrasonography in the critical care setting: a practical approach to asses cardiac function and preload for the “non-cardiologist”

“…They also found that an IV bolus tends to produce an early response in IVC, while the CVP response is more gradual [47]. However, other studies have shown that bedside ultrasonographic measurement of the inferior vena cava fails to predict fluid responsiveness in the first 6 hours after cardiac surgery [48] and hemodynamic response to early hemorrhage [49].…”

Advancing clinician-performed sonography in the twenty-first century: building on the rich legacy of the twentieth century pioneers

“…Within 20 years of its initial clinical use, scientists had advanced the technology to a point where ultrasound machines were much more compact and offered image quality sufficient to evaluate the fetus in obstetrics care [4]. Since then, diagnostic applications of sonography have incrementally increased to encompass literally every field of health care, from physical medicine and rehabilitation to obstetrics and gynecology, emergency medicine to pulmonology, critical care to disaster management, oncology to trauma and emergency surgery, and pediatrics to gastroenterology [5][6][7][8][9][10].As clinical applications of ultrasound have expanded and image resolution has improved, the actual sizes of machines and probes have progressively become smaller [11][12][13]. This portability has allowed ultrasound studies to occur at a patient's bedside, largely eliminating the need for * S. P. Stawicki…”

“…Within 20 years of its initial clinical use, scientists had advanced the technology to a point where ultrasound machines were much more compact and offered image quality sufficient to evaluate the fetus in obstetrics care [4]. Since then, diagnostic applications of sonography have incrementally increased to encompass literally every field of health care, from physical medicine and rehabilitation to obstetrics and gynecology, emergency medicine to pulmonology, critical care to disaster management, oncology to trauma and emergency surgery, and pediatrics to gastroenterology [5][6][7][8][9][10].…”