Inferior Vena Cava (IVC) Size in Acute Renal Failure

Study Overview
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Brief Summary
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Bedside ultrasonographic assessment of IVC size and IVC collapsibility index can be used to guide the management of patients with acute kidney injury with and without volume overload in the intensive care unit

Detailed Description
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Consecutive patients presenting to the intensive care unit with a diagnosis of acute renal failure (defined as a 1.5 fold increase in plasma Creatinine level compared to baseline ). Baseline characteristics will be recorded and followed for each patient, these include: Demographics Medical history Hemodynamic parameter such as Central Venous Pressure (CVP), Mean Arterial Pressure (MAP) , and measurement of superior vena cava (SVC) size by ultrasound. Laboratory parameter such as chemistry, fractional excretion of sodium , fractional excretion of urea , beta natriuretic peptide , albumin Radiographic parameters Echocardiographic parameters including Left Ventricular Ejection Fraction (LVEF), Right Ventricular (RV) function and IVC size and variations Mechanical ventilation Daily fluid balance Focused bedside ultrasound will be performed for each patient as part of their routine care and initial assessment. The IVC size will be measured at the subcostal window, during inspiration and expiration, using the (Sonosite) Cardiac probe P-21 (5-1 MHZ). The measurement is obtained by applying the M-mode, perpendicular to the IVC axis and 2 cm caudal from its junction with the right atrium. In spontaneously breathing, non-ventilated patients, we will calculate the IVC collapsibility index (IVC-CI) = [IVC max-IVC min]/IVC max. Whereas in patients who are mechanically ventilated we will calculate their IVC variation index (ΔIVC) = IVC max-IVC min/ IVC mean diameter. IVC-CI, ΔIVC, IVC size will be used to classify patient as volume responders or non-responder. Prior studies have suggested Intravascular volume depletion is likely present when the, IVC<1 cm , IVC-CI is > 50% in spontaneously breathing patients and volume responsiveness when the ΔIVC is ≥ 12% in mechanically ventilated patient . The Fractional excretion of sodium as well as the fractional excretion of urea (when diuretics are used) will be calculated to classify the etiology of the renal failure as pre-renal or intrinsic renal failure. Fluid balance as well as the change in plasma Creatinine level at 48 hours post admission will be recorded. Two groups of patients will be identified: Group 1 includes the patients who were managed in concordance with their IVC measurements (Volume responders who had a positive fluid balance at 48 h post admission and volume non responders who had an even or negative fluid balance at 48 hours post admission). Group 2 includes the patients in whom the fluid management was discordant with the IVC measurement. Analyses will be done at 24 as well as 48 hours post admission.

Official Title
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Does the Inferior Vena Cava Size Assessment Help in the Management of Acute Kidney Injury in Critically Ill Patients?

Conditions
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Acute Renal Failure

Intervention / Treatment
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* Other: Ultrasound for measurement of Inferior Vena Cava size.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients presenting to the intensive care unit with a diagnosis of acute renal failure (defined as a 1.5 fold increase in plasma Creatinine level compared to baseline) Exclusion Criteria: Age<18 years Hemodialysis or continuous renal replacement therapy(CRRT) Untreated obstructive uropathy Pulmonary emboli

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acute renal failure in ICU<br>Ultrasound for measurement of Inferior Vena Cava size | Other: Ultrasound for measurement of Inferior Vena Cava size.<br>* Focused bedside ultrasound will be performed for each patient as part of their routine care and initial assessment. The IVC size will be measured at the subcostal window, during inspiration and expiration, using the Sonosite cardiac probe P-21 (5-1 MHZ). The measurement is obtained by applying the M-mode, perpendicular to the IVC axis and 2 cm caudal from its junction with the right atrium.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| percentage of patients with improved Creatinine level in group 1 and 2 | percentage of patients with improved Creatinine level in group 1 and 2 | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| glomerular filtration rate (GFR), changes in hemodynamic parameters (mean arterial blood pressure, urine output, pressors requirement )and Partial oxygen pressure (PO2) /Fio2 in group 1 and group 2 | glomerular filtration rate (GFR), changes in hemodynamic parameters (mean arterial blood pressure, urine output, pressors requirement) and Partial O2 /Fio2 in group 1 and group 2. Different cut off for IVC size measurement and variations will be used to improve the predictive value of the ultrasound in the management of renal failure in hypervolemic patients. | 24 and 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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renal, kidney, creatinine, Inferior Vena Cava (IVC), Acute Renal Failure (ARF), Acute Kidney Injury (AKI)