Effects of Red Blood Cells Transfusion on Renal Blood Flow

Study Overview
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Brief Summary
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The renal Doppler resistive index (RRI) is a noninvasive tool that has been used to assess renal perfusion in the intensive care unit (ICU) setting. It is associated with the occurrence of acute kidney injury (AKI). Many parameters have been described as influential on the values of renal RI. Red blood cell (RBC) transfusion were shown to be able to increase renal oxygenation in animal model, whereas crystalloid resuscitation did not. We sought to describe the different effect of crystalloids infusion and RBC transfusion on renal blood flow, as evaluated with doppler ultrasound

Official Title
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Effects of Red Blood Cells Transfusion on Renal Resistivity Index and Renal Venous Stasis Index

Conditions
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Acute Kidney Injury, Transfusion-Associated Circulatory Overload, Anemia, Fluid Overload

Intervention / Treatment
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* Other: Transfusion
* Other: Crystalloids infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 18 and < 90 Hemoglobin ≥7 and ≤ 10 g/dl Exclusion Criteria: Ultrasound RRI evaluation non available Patients with arrhythmia Pregnancy Refusal to give consent History of renal transplantation Central venous access in superior vena cava not available Critical active bleeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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 |
| --- | --- |
| RBC group<br>Patients who received RBC transfusion | Other: Transfusion<br>* RBC transfusion (1 unit)<br>|
| crystalloids group<br>Patients who received fluid resuscitation with crystalloids | Other: Crystalloids infusion<br>* Infusion of 500 ml of balanced crystalloids<br>|
| control group<br>Patients not receiving RBC nor crystalloids | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in renal resistivity index (RRI) after intervention | To compare change in RRI after intervention between groups. Values over>0.70 are considered pathological. Higher values means worse outcome. | after 60 minute from intervention | 
| Change Renal Venous Stasis Index (RSVI) after intervention | To compare change in RSVI after intervention between groups. Under physiological conditions, the index is zero. Higher values means worse outcome. | after 60 minute from intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurence of AKI | Occurence of AKI as defined by Kidney Disease: Improving Global Outcomes (KDIGO) | Once a day for 7 days | 
| Variation in renal resistivity index (RRI) | To compare change in RRI after intervention between groupsValues over>0.70 are considered pathological. Higher values means worse outcome. | after 24 hours from intervention | 
| Variation in Renal Venous Stasis Index (RSVI) | To compare change in RSVI after intervention between groups. Under physiological conditions, the index is zero. Higher values means worse outcome. | after 24 hours from intervention |