Correlation of IVC Diameter and Collapsibility Index With Central Venous Pressure in the Assessment of Intravascular Volume in Critically Ill Patients.

Abid Ilyas,Aftab Akhtar,Salman Mansoor,Salman Assad,Wasib Ishtiaq,Muhammad Haris,Aayesha Qadeer,Haider Ghazanfar

doi:10.7759/cureus.1025

Abstract

ObjectiveThe objective of our study is to assess the correlation between inferior vena cava (IVC) diameters, central venous pressure (CVP) and the IVC collapsibility index for estimating the volume status in critically ill patients.MethodsThis cross-sectional study used the convenient sampling of 100 adult medical intensive care unit (ICU) patients for a period of three months. Patients ≥ 18 years of age with an intrathoracic central venous catheter terminating in the distal superior vena cava connected to the transducer to produce a CVP waveform were included in the study. A Mindray diagnostic ultrasound system model Z6 ultrasound machine (Mindray, NJ, USA) was used for all examinations. An Ultrasonic Transducer model 3C5P (Mindray, NJ, USA) for IVC imaging was utilized. A paired sampled t-test was used to compute the p-values.ResultsA total of 32/100 (32%) females and 68/100 (68%) males were included in the study with a mean age of 50.4 ± 19.3 years. The mean central venous pressure maintained was 10.38 ± 4.14 cmH2O with an inferior vena cava collapsibility index of 30.68 ± 10.93. There was a statistically significant relation among the mean CVP pressure, the IVC collapsibility index, the mean maximum and minimum IVC between groups as determined by one-way analysis of variance (ANOVA) (p < 0.001). There was a strong negative correlation between CVP and IVC collapsibility index (%), which was statistically significant (r = -0.827, n = 100, p < 0.0005). A strong positive correlation between CVP and maximum IVC diameter (r = 0.371, n = 100, p < 0.0005) and minimum IVC diameter (r = 0.572, n = 100, p < 0.0005) was found.ConclusionThere is a positive relationship of CVP with minimum and maximum IVC diameters but an inverse relationship with the IVC collapsibility index.

Highlights

Bedside assessment of intravascular volume status in critically ill patients is challenging
There is a positive relationship of central venous pressure (CVP) with minimum and maximum inferior vena cava (IVC) diameters but an inverse relationship with the IVC collapsibility index
CVP is a good approximation of right atrial pressure (RAP) which in turn is a major determinant to right ventricular filling

Summary

Introduction

Bedside assessment of intravascular volume status in critically ill patients is challenging. Clinicians often use invasive hemodynamic monitoring as an adjunct to information gathered from the physical examination and laboratory evaluation to arrive at a fluid management strategy. Bedside ultrasound is potentially a useful non-invasive adjunct to estimate the intravascular status by measuring IVC diameter [6,7,8]. One technique uses the size and collapsibility of the inferior vena cava (IVC), similar to the method used by echocardiographers to estimate right atrial pressure (RAP) in non-acute care settings. Collapsibility of the inferior vena cava has been found to be useful in monitoring an acute heart failure patient’s response to therapy as well as assisting in ongoing resuscitation by providing means to measure CVP non-invasively [10,11]

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Conclusion