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RecruitingNCT06386796Updated Mar 10, 2026

Renal Resistive Index as a Predictor of Acute Renal Impairment in High-risk Patients

An observational study in Acute Kidney Injury and Critical Illness, sponsored by Aswan University. Recruiting at 1 site in Egypt. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-03-10.

Sponsored by Aswan University · Observational

From the registry’s dates

  • Started Apr 2024; still recruiting 2 years 7 months later.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
100
Ages
18 Years to 80 Years
Sex
All
01

Study summary

To study the ability of RRI, measured by bedside Doppler ultrasound, in detecting acute kidney injury in high-risk patients admitted to surgical intensive care unit, Aswan university hospital, compared with renal biomarkers and conventional assessment using urine output and serum creatinine levels.

Read the detailed description

Acute kidney injury (AKI) is a common clinical problem encountered in critically ill patients, frequently in the setting of multiple organ failure, and is an independent risk factor for increase hospital stay and mortality risk.

Early-stage acute kidney injury was first assessed based on the risk, injury, failure, loss and end-stage (RIFLE) criteria in 2004, and then by the Acute Kidney Injury Network (AKIN) criteria in 2007. The Kidney Disease: Improving Global Outcomes (KDIGO) classification, based on both the AKIN and RIFLE criteria, was introduced in 2012, offering an assessment based on baseline creatinine and urine output.

The best strategy in clinical practice is to identify AKI as early as possible, reverse its cause, and even improve the sequelae. In the past decades, several serum creatinine (SCr)-based classification systems have been proposed to define AKI.

The limitations of SCr is that the determinants of SCr (rate of production, apparent volume of distribution, and rate of elimination) are variable. Therefore, there is an unmet need for other objective measures to help detect AKI in a timely manner. The role of several biomarkers in the early prediction or risk assessment of AKI has been proposed, including kidney tubular damage markers (e.g., neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM- 1), liver-type fatty acid-binding protein (L-FABP) and cystatin C).

Cystatin C is a protein from the family of cysteine proteinase inhibitors and is of interest as an early marker of decreased renal function. It is a protein that is synthesized at a constant rate by all cells containing nuclei, secreted into biological fluids: plasma, pleural, ascitic, cerebrospinal fluid, freely filtered through the glomerular membrane (due to its low molecular weight), fully metabolized in the kidneys, not secreted by the proximal renal tubules.

Renal resistive index (RRI) is a noninvasive instrument to evaluate kidney hemodynamics, and it is obtained by analysis of intrarenal arterial waves using Doppler ultrasound.

02

Conditions studied

  • Acute Kidney Injury
  • Critical Illness

Keywords

  • renal resisitive index
  • surgical ICU
  • Cystatin C
03

In context

Acute Kidney Injury

1,691 studies on the registry are indexed under Acute Kidney Injury; 395 are open to participants now.

This study's planned enrollment of 100 is below the median of 160 across 814 observational studies indexed under Acute Kidney Injury.

Browse Acute Kidney Injury studies →

Lead sponsor

Aswan University is the lead sponsor of 47 studies on the registry; 21 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Probability sample

Study population

patients who are admitted to SICU, Aswan university hospital, after polytrauma, pre-eclampsia, eclampsia and sepsis

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Patients with severe pre-eclampsia and eclampsia.
  • Polytraumatized patients.
  • Patients admitted to ICU with sepsis.
  • Both genders.
  • Patients above 18 years.

Exclusion criteria

Exclusion Criteria:

  • patients known to have CKD.
  • patients with congenital renal anomalies.
  • patients with renal transplantation.
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
100 participants (estimated)
Patient registry
No
06

What researchers measure

Primary outcomes

  1. Early detection of acute kidney injury.

    Renal artery resistive index will be measured daily.Cystatin C will be measured on admission, after 24 hours and 72 hours.

    Time frame: Day 0,1,2,3,7

  2. Diagnosis of acute kidney injury.

    Renal artery resistive index will be measured daily.Cystatin C will be measured on admission, after 24 hours and 72 hours.

    Time frame: Day 0,1,2,3,7

Secondary outcomes

  1. To grade the severity of AKI.

    Using the KDIGO criteria, AKI is staged as follows: Stage 1: Increase in serum creatinine to 1.5 to 1.9 times baseline, or increase in serum creatinine by ≥0.3 mg/dL, or reduction in urine output to \<0.5 mL/kg/h for 6 to 12 h. Stage 2: Increase in serum creatinine to 2.0 to 2.9 times baseline, or reduction in urine output to \<0.5 mL/kg/h for ≥12 h. Stage 3: Increase in serum creatinine to 3.0 times baseline, or increase in serum creatinine to ≥4.0 mg/dL, or reduction in urine output to \<0.3 mL/kg/h for ≥24 h, or anuria for ≥12 h, or the initiation of renal replacement therapy, or, in patients \<18 years, decrease in estimated glomerular filtration rate (eGFR) to \<35 mL/min/1.73 m2.

    Time frame: day 0,1,2,3,7

  2. To predict clinical outcome (clinical improvement)

    To predict clinical outcome (clinical improvement) at 30 days

    Time frame: Day 0,1,2,3,7,30

  3. To predict clinical outcome (necessity for renal replacement therapy)

    To predict clinical outcome (necessity for renal replacement therapy) at 30 days

    Time frame: Day 0,1,2,3,7,30

  4. To predict clinical outcome (death)

    To predict clinical outcome (death) at 30 days.

    Time frame: Day 0,1,2,3,7,30

07

Study locations

1 of 1 sites recruiting
08

References and documents

Publications

  • Pan HC, Yang SY, Chiou TT, Shiao CC, Wu CH, Huang CT, Wang TJ, Chen JY, Liao HW, Chen SY, Huang TM, Yang YF, Lin HY, Chan MJ, Sun CY, Chen YT, Chen YC, Wu VC. Comparative accuracy of biomarkers for the prediction of hospital-acquired acute kidney injury: a systematic review and meta-analysis. Crit Care. 2022 Nov 12;26(1):349. doi: 10.1186/s13054-022-04223-6. PubMed 36371256 ↗
  • Cruz EG, Broca Garcia BE, Sandoval DM, Gopar-Nieto R, Gonzalez Ruiz FJ, Gallardo LD, Ronco C, Madero M, Vasquez Jimenez E. Renal Resistive Index as a Predictor of Acute Kidney Injury and Mortality in COVID-19 Critically Ill Patients. Blood Purif. 2022;51(4):309-316. doi: 10.1159/000517469. Epub 2021 Jul 19. PubMed 34280921 ↗
  • Provenzano M, Rivoli L, Garofalo C, Faga T, Pelagi E, Perticone M, Serra R, Michael A, Comi N, Andreucci M. Renal resistive index in chronic kidney disease patients: Possible determinants and risk profile. PLoS One. 2020 Apr 1;15(4):e0230020. doi: 10.1371/journal.pone.0230020. eCollection 2020. PubMed 32236125 ↗
  • Fernando S, Polkinghorne KR. Cystatin C: not just a marker of kidney function. J Bras Nefrol. 2020 Mar;42(1):6-7. doi: 10.1590/2175-8239-JBN-2019-0240. Epub 2020 Apr 3. No abstract available. PubMed 32255469 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 10, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06386796
Lead sponsor
Aswan University
Responsible party
Soudy Salah Hammad (Lecturer of anesthesia and surgical intensive care, Aswan University) — Principal investigator
First posted
Apr 26, 2024
Start date
Apr 1, 2024
Primary completion
Oct 1, 2026 (estimated)
Completion
Oct 1, 2026 (estimated)
Last update
Mar 10, 2026

Study contacts

Soudy S Hammad, MD
Contact
soudi.salah@aswu.edu.eg
201014761523
Tarek S Hemaida, MD
Contact
dr.tarek@aswu.edu.eg
01007363190
Mohamed H Abolwafa, MSc
principal investigator · Aswan University
Ahmed E Abd Elrahman, MD
principal investigator · Sohag University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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