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Acute Kidney InjuryNCT05945706

Evaluation of Renal Resistive Index in Patients with Controlled Hypotension

An observational study of Acute Kidney Injury and Hypotension, Controlled, run by Ankara Diskapi Training and Research Hospital at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

In recent studies, it has been reported that the renal resistive index is effective in detecting postoperative acute kidney injury in the early period. This study aims to evaluate the preoperative and postoperative renal resistive index variation with intraoperative controlled hypotension and research the renal… Read more about this study

Who is it for?
Ages 18 years and older
How many people
65 participants
Where
1 siteTurkey (Türkiye)
Study dates
1 Jul 2023to 31 Dec 2023
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: All ASA I-II-III patients who are scheduled to undergo elective arthroscopic shoulder surgery older than 18 years old

Who may be able to join

  • >18 years old
  • will undergo elective arthroscopic shoulder surgery
  • ASA (American Society of Anesthesiologist Classification) I-II or III

Who cannot join

  • Cardiac arrhythmia
  • Asymmetric kidney disease
  • Poor echogenicity (for imaging)
  • Chronic renal dysfunction (GFR<30)
  • Renal artery stenosis
  • Endocarditis
  • Postoperative agitation or confusion
  • Postoperative polypnea >35/min or respiratory failure

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site

  • Dıskapı Training and Research Hospital

    Ankara, Altındağ, 06110

Other trials in Turkey (Türkiye)

About this study

Official title: Evaluation of Renal Resistance Index by Doppler Ultrasonography in Patients Undergoing Arthroscopic Shoulder Surgery with Controlled Hypotension

In recent studies, it has been reported that the renal resistive index is effective in detecting postoperative acute kidney injury in the early period. This study aims to evaluate the preoperative and postoperative renal resistive index variation with intraoperative controlled hypotension and research the renal resistive index's utility in the early detection of renal dysfunction that may develop after surgery.

Read the detailed description

Controlled hypotension could be defined as a reduction of the systolic blood pressure to 80-90 mmHg, a reduction of mean arterial pressure (MAP) to 50-65 mmHg, or a 30% reduction of baseline MAP (1). It is frequently applied in orthopedics, neurosurgery, and ear-nose-throat surgeries to reduce blood loss and provide a good field of view to the surgeon. However, the combination of hypotension with hypovolemia may result in postoperative acute kidney injury (AKI), especially in the elderly and in patients with hypoperfusion-sensitive disease. The situation may worsen with nephrotoxic drugs.

In patients with AKI, the length of hospital stay is prolonged, and the risk of morbidity and mortality increases, so early detection of AKI is significant. Perioperative AKI diagnosis is difficult and often delayed. Although there are various tests (cystatin-c, urea, serum creatinine, creatinine clearance, etc.), there is still no early, accurate, easy-to-use AKI marker in clinical practice.

The most commonly used guidelines for AKI classification are 2004-RIFLE (Risk, Injury, Failure, Loss of kidney function, End stage renal disease), 2007-AKIN (Acute Kidney Injury Network), and 2012-KDIGO (Kidney Disease Improving Global Outcomes). Based on the validity of the RIFLE and AKIN criteria, the KDIGO guideline was developed to diagnose AKI with a straightforward definition for clinical practice.

Doppler ultrasonography is widely used in the evaluation of chronic kidney diseases. Renal resistive index (RRI), one of the Doopler-derived indices, is calculated by imaging the intrarenal (arcuate or interlobar) artery and measuring the highest systolic and lowest end-diastolic blood flow velocity using a colored Doppler. It is generally accepted that the normal value of the RRI is 0.60 ± 0.01 (mean±SD), and there is a general opinion that the upper limit of the RRI is 0.7 (2). The renal resistive index has been used for years to diagnose and follow up on various kidney diseases (evaluation of chronic renal allograft rejection, detection and management of renal artery stenosis, and chronic differential diagnosis) (3). Recent studies have reported that RRI effectively detects postoperative AKI in the early period before the criteria for AKIN are formed (4-5).

This study aims to evaluate the preoperative and postoperative renal resistive index variation with intraoperative controlled hypotension and research the renal resistive index's utility in the early detection of renal dysfunction that may develop after surgery.

Keywords
acute kidney injury, blood flow velocity, Renal Doppler ultrasound, Renal Resistive Index, Controlled hypotension
Medical subject headings
Acute Kidney Injury, Hypotension, Renal Insufficiency

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Renal resistive index

    Renal resistive index measurement by Doppler ultrasonography before anesthesia induction

    Measured: baseline, pre-surgery

  2. Renal resistive index

    Renal resistive index measurement by Doppler ultrasonography at the end of surgery under anesthesia

    Measured: immediately after the surgery under anesthesia

  3. Renal resistive index

    Renal resistive index measurement by Doppler ultrasonography in the postanesthetic care unit

    Measured: within 30 minutes after surgery

Secondary outcomes (4)

  1. serum creatinine

    blood serum creatinine level at admission to the hospital

    Measured: preoperative (baseline)

  2. serum creatinine

    blood serum creatinine level on postoperative day one

    Measured: postoperative day 1

  3. serum creatinine

    blood serum creatinine level on postoperative day two

    Measured: postoperative day 2

  4. postoperative urine output

    postoperative urine output measurement

    Measured: every 6 hours for 48 hours

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 Jul 2023
  2. Study start1 Jul 2023
  3. Primary completion1 Oct 2023
  4. Study completion31 Dec 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case crossover
Time perspective
Prospective
Enrolment
65 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05945706
Sponsor's protocol ID
Renal Rezistif Index
Status last verified
Mar 2025
First submitted
5 Jul 2023
Last updated
14 Mar 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Xu N, Chen L, Liu L, Rong W. Dexmedetomidine versus remifentanil for controlled hypotension under general anesthesia: A systematic review and meta-analysis. PLoS One. 2023 Jan 17;18(1):e0278846. doi: 10.1371/journal.pone.0278846. eCollection 2023.

    PubMed 36649357

  • Tublin ME, Bude RO, Platt JF. Review. The resistive index in renal Doppler sonography: where do we stand? AJR Am J Roentgenol. 2003 Apr;180(4):885-92. doi: 10.2214/ajr.180.4.1800885. No abstract available.

    PubMed 12646425

  • Marty P, Ferre F, Labaste F, Jacques L, Luzi A, Conil JM, Silva S, Minville V. The Doppler renal resistive index for early detection of acute kidney injury after hip fracture. Anaesth Crit Care Pain Med. 2016 Dec;35(6):377-382. doi: 10.1016/j.accpm.2015.12.013. Epub 2016 Apr 28.

    PubMed 27133237

  • Bossard G, Bourgoin P, Corbeau JJ, Huntzinger J, Beydon L. Early detection of postoperative acute kidney injury by Doppler renal resistive index in cardiac surgery with cardiopulmonary bypass. Br J Anaesth. 2011 Dec;107(6):891-8. doi: 10.1093/bja/aer289. Epub 2011 Sep 22.

    PubMed 21940396

  • Viazzi F, Leoncini G, Derchi LE, Pontremoli R. Ultrasound Doppler renal resistive index: a useful tool for the management of the hypertensive patient. J Hypertens. 2014 Jan;32(1):149-53. doi: 10.1097/HJH.0b013e328365b29c.

    PubMed 24172238

  • Ozkan Sipahioglu F, Atar F, Bayraktaroglu M, Karaca Akaslan F, Ozkan D. Evaluation of renal resistive index in patients undergoing arthroscopic shoulder surgery with controlled hypotension. BMC Anesthesiol. 2026 Aug 28;26(1):653. doi: 10.1186/s12871-026-04196-x.

    PubMed 42972515

Questions about this trial

What is this clinical trial studying?

An observational study of Acute Kidney Injury and Hypotension, Controlled, run by Ankara Diskapi Training and Research Hospital at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 14 Mar 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Renal resistive index (time frame: baseline, pre-surgery). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05945706, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Mar 2025.

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