Acute Kidney InjuryNCT07837037
Kidney Oxygen Saturation and Neutrophil Gelatinase-associated Lipocalin (NGAL) for Detecting Acute Kidney Injury (AKI) After Cardiac Surgery
An observational study of Acute Kidney Injury and Cardiac Surgery, run by Haseki Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
Acute kidney injury (AKI) is an important complication following cardiac surgery with cardiopulmonary bypass (CPB). Early identification of patients at risk of AKI may facilitate timely clinical management. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Kidney Injury, Cardiac Surgery, Cardiopulmonary Bypass
- What is being tested?
- Renal Near-Infrared Spectroscopy Monitoring and Neutrophil Gelatinase-Associated Lipocalin (NGAL) Measurement
- How many people
- 85 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Mar 2025to 20 Feb 2026
- 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: Adult patients undergoing elective cardiac surgery with cardiopulmonary bypass at a tertiary care hospital in Istanbul, Türkiye, who were expected to remain in the coronary intensive care unit for at least 48 hours.
Who may be able to join
- Age ≥18 years.
- Scheduled for elective cardiac surgery with cardiopulmonary bypass.
- Expected postoperative coronary intensive care unit stay of at least 48 hours.
- Written informed consent provided.
Who cannot join
- Previously diagnosed renal disease, including acute tubular necrosis, chronic kidney disease, or nephropathy.
- Use of medications known to affect renal function, including nonsteroidal anti-inflammatory drugs (NSAIDs).
- History of renal surgery or kidney transplantation.
- Skin-to-kidney depth ≥4 cm.
- Emergency cardiac surgery.
- Off-pump cardiac surgery.
- Preoperative estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m².
- Intraoperative conditions requiring a reduction in cardiopulmonary bypass pump flow with mean arterial pressure below 50 mmHg.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Sultangazi Haseki Training and Research Hospital
Istanbul, Istanbul, 34265
About this study
Official title: Association of Renal Oxygen Saturation and Neutrophil Gelatinase-Associated Lipocalin With Acute Kidney Injury After Cardiac Surgery With Cardiopulmonary Bypass: A Prospective Observational Study
Acute kidney injury (AKI) is an important complication following cardiac surgery with cardiopulmonary bypass (CPB). Early identification of patients at risk of AKI may facilitate timely clinical management.
This prospective observational study investigated the association of perioperative renal regional oxygen saturation (rSO₂), measured using near-infrared spectroscopy (NIRS), and neutrophil gelatinase-associated lipocalin (NGAL) levels with postoperative AKI.
Read more
A total of 85 adult patients undergoing elective cardiac surgery with CPB were enrolled. Bilateral renal rSO₂ was measured during four predefined perioperative phases. NGAL levels were evaluated preoperatively and at 24 and 48 hours postoperatively.
The primary objective was to assess the discriminatory performance of renal rSO₂ and NGAL, individually and in combination, for identifying postoperative AKI.
AKI was defined and staged according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria during the first seven postoperative days. Secondary objectives included determining the incidence and severity of AKI and investigating associated patient-related and perioperative factors.
Read the detailed description
This prospective, single-center observational study was conducted at Haseki Training and Research Hospital, Istanbul, Türkiye, between March 20, 2025, and February 20, 2026. The study received ethics committee approval on March 19, 2025 (approval number: 34-2025), and written informed consent was obtained from all participants.
Among 95 adult patients assessed for eligibility, 85 patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB) were enrolled.
Renal regional oxygen saturation (rSO₂) was monitored using bilateral near-infrared spectroscopy (NIRS) probes placed over the renal regions. Perioperative measurements were collected during four predefined phases:
A0: Before induction of anesthesia.
A1: From induction of anesthesia to initiation of CPB.
A2: From initiation of CPB to separation from CPB.
A3: From separation from CPB to the end of surgery.
During A1, A2, and A3, right and left renal rSO₂ values and other perioperative parameters were recorded every 15 minutes. Mean values were calculated separately for each phase. Bilateral mean renal rSO₂ was calculated as the arithmetic mean of the corresponding right- and left-sided values and was used as the primary renal oxygenation parameter.
Urine output was recorded for each perioperative phase and expressed as mL/kg/h.
NGAL levels were measured preoperatively (T0) and at 24 (T24) and 48 (T48) hours postoperatively.
Postoperative AKI was assessed during the first seven postoperative days according to KDIGO criteria using serum creatinine changes and/or urine output.
Participants were classified into AKI and non-AKI groups according to postoperative AKI development.
The diagnostic performance of renal rSO₂ and NGAL was assessed using receiver operating characteristic (ROC) curve analysis. The primary combined biomarker model incorporated bilateral mean renal rSO₂ during CPB (A2) and NGAL measured at 24 hours postoperatively (T24).
Additional analyses investigated temporal changes in biomarkers and potential patient-related and perioperative factors associated with postoperative AKI.
- Conditions
- Acute Kidney Injury, Cardiac Surgery, Cardiopulmonary Bypass
- Being tested
- Renal Near-Infrared Spectroscopy Monitoring, Neutrophil Gelatinase-Associated Lipocalin (NGAL) Measurement
- Keywords
- Renal regional oxygen saturation, Near-infrared spectroscopy, Neutrophil gelatinase-associated lipocalin, Cardiac surgery-associated acute kidney injury, KDIGO, Biomarkers
- Medical subject headings
- Acute Kidney Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Renal Near-Infrared Spectroscopy MonitoringDiagnostic test
Bilateral renal regional oxygen saturation (rSO₂) was monitored using near-infrared spectroscopy (NIRS). Measurements were obtained before anesthesia induction (A0) and recorded at 15-minute intervals during three perioperative phases (A1, A2, and A3). The mean rSO₂ values were calculated separately for each kidney, and the bilateral mean was used as the primary renal oxygenation parameter.
Neutrophil Gelatinase-Associated Lipocalin (NGAL) MeasurementDiagnostic test
Blood samples were collected to measure neutrophil gelatinase-associated lipocalin (NGAL) levels at three predefined time points: preoperatively (T0), and at 24 (T24) and 48 (T48) hours postoperatively. NGAL levels were evaluated for their association with postoperative acute kidney injury.
| Study group | Role | What they receive |
|---|---|---|
| Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass | Adult patients undergoing elective cardiac surgery with CPB. Perioperative renal oxygen saturation and NGAL levels were evaluated, and patients were followed for postoperative AKI. Receives: Diagnostic Test: Renal Near-Infrared Spectroscopy Monitoring; Diagnostic Test: Neutrophil Gelatinase-Associated Lipocalin (NGAL) Measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Discriminatory Performance of Perioperative Renal Oxygen Saturation for Postoperative AKI
The discriminatory performance of bilateral mean renal rSO₂ for identifying postoperative AKI will be evaluated separately for each perioperative phase (A0, A1, A2, and A3) using ROC curve analysis. The area under the curve (AUC) and its 95% confidence interval will be calculated.
Measured: Perioperatively (A0-A3), with postoperative AKI assessed through day 7.
Discriminatory Performance of NGAL for Postoperative AKI
The discriminatory performance of NGAL levels measured preoperatively (T0), at 24 hours (T24), and at 48 hours (T48) postoperatively will be evaluated separately using ROC curve analysis. AUC values and corresponding 95% confidence intervals will be calculated.
Measured: Preoperatively and at 24 and 48 hours postoperatively, with AKI assessed through postoperative day 7.
Combined Discriminatory Performance of Renal Oxygen Saturation and NGAL for Postoperative AKI
The primary combined biomarker model will incorporate bilateral mean renal rSO₂ during CPB (A2) and NGAL measured at 24 hours postoperatively (T24). Binary logistic regression will be used to derive predicted probabilities, and ROC analysis will be performed to calculate the AUC and its 95% confidence interval. Incremental discrimination will be assessed by comparing AUCs with those of the individual biomarker models.
Measured: During CPB and at 24 hours postoperatively, with AKI assessed through postoperative day 7.
Secondary outcomes (3)
Incidence of Postoperative Acute Kidney Injury
The proportion of patients developing postoperative AKI, defined according to KDIGO criteria using serum creatinine changes and/or urine output.
Measured: Within 7 days after surgery.
Severity of Postoperative Acute Kidney Injury
Postoperative AKI severity will be classified according to KDIGO stages 1, 2, and 3, based on serum creatinine changes and/or urine output.
Measured: Within 7 days after surgery.
Patient-Related and Perioperative Factors Associated With Postoperative AKI
Associations of demographic characteristics, comorbidities, preoperative renal function, CPB duration, aortic cross-clamp duration, and relevant intraoperative clinical and hemodynamic variables with postoperative AKI will be evaluated using logistic regression. Odds ratios and 95% confidence intervals will be reported.
Measured: From the preoperative period through postoperative day 7.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Sep 2026
- Study start20 Mar 2025
- Primary completion20 Feb 2026
- Study completion20 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Acute Kidney InjuryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 85 participants (actual)
Sponsor and investigators
- Lead sponsor
- Haseki Training and Research Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sinan Uzman, Haseki Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07837037
- Sponsor's protocol ID
- HASEKI-AKI-034-2025
- Status last verified
- Sep 2026
- First submitted
- 17 Sep 2026
- Last updated
- 28 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: A final decision regarding the sharing of de-identified individual participant data has not yet been made. Any future data sharing will be subject to institutional policies, ethics committee requirements, and applicable data protection regulations.
Publications
Wang Y, Bellomo R. Cardiac surgery-associated acute kidney injury: risk factors, pathophysiology and treatment. Nat Rev Nephrol. 2017 Nov;13(11):697-711. doi: 10.1038/nrneph.2017.119. Epub 2017 Sep 4.
PubMed 28869251
Study at a glance
From the registry record, last updated by the sponsor on 28 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Association of Renal Oxygen Saturation and Neutrophil Gelatinase-Associated Lipocalin With Acute Kidney Injury After Cardiac Surgery With Cardiopulmonary Bypass: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07837037
- Acronym / sponsor ID
- HASEKI-AKI-034-2025
- Conditions
- Acute Kidney Injury, Cardiac Surgery, Cardiopulmonary Bypass
- Keywords
- Renal regional oxygen saturation, Near-infrared spectroscopy, Neutrophil gelatinase-associated lipocalin, Cardiac surgery-associated acute kidney injury, KDIGO, Biomarkers
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 85 participants (actual)
- Lead sponsor
- Haseki Training and Research HospitalUniversity, hospital or other
- Study start
- 20 Mar 2025 (actual)
- Primary completion
- 20 Feb 2026 (actual)
- Study completion
- 20 Feb 2026 (actual)
- First posted
- 23 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Acute kidney injury (AKI) is an important complication following cardiac surgery with cardiopulmonary bypass (CPB). Early identification of patients at risk of AKI may facilitate timely clinical management.
This prospective observational study investigated the association of perioperative renal regional oxygen saturation (rSO₂), measured using near-infrared spectroscopy (NIRS), and neutrophil gelatinase-associated lipocalin (NGAL) levels with postoperative AKI.
A total of 85 adult patients undergoing elective cardiac surgery with CPB were enrolled. Bilateral renal rSO₂ was measured during four predefined perioperative phases. NGAL levels were evaluated preoperatively and at 24 and 48 hours postoperatively.
The primary objective was to assess the discriminatory performance of renal rSO₂ and NGAL, individually and in combination, for identifying postoperative AKI.
AKI was defined and staged according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria during the first seven postoperative days. Secondary objectives included determining the incidence and severity of AKI and investigating associated patient-related and perioperative factors.
Detailed description
This prospective, single-center observational study was conducted at Haseki Training and Research Hospital, Istanbul, Türkiye, between March 20, 2025, and February 20, 2026. The study received ethics committee approval on March 19, 2025 (approval number: 34-2025), and written informed consent was obtained from all participants.
Among 95 adult patients assessed for eligibility, 85 patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB) were enrolled.
Renal regional oxygen saturation (rSO₂) was monitored using bilateral near-infrared spectroscopy (NIRS) probes placed over the renal regions. Perioperative measurements were collected during four predefined phases:
A0: Before induction of anesthesia.
A1: From induction of anesthesia to initiation of CPB.
A2: From initiation of CPB to separation from CPB.
A3: From separation from CPB to the end of surgery.
During A1, A2, and A3, right and left renal rSO₂ values and other perioperative parameters were recorded every 15 minutes. Mean values were calculated separately for each phase. Bilateral mean renal rSO₂ was calculated as the arithmetic mean of the corresponding right- and left-sided values and was used as the primary renal oxygenation parameter.
Urine output was recorded for each perioperative phase and expressed as mL/kg/h.
NGAL levels were measured preoperatively (T0) and at 24 (T24) and 48 (T48) hours postoperatively.
Postoperative AKI was assessed during the first seven postoperative days according to KDIGO criteria using serum creatinine changes and/or urine output.
Participants were classified into AKI and non-AKI groups according to postoperative AKI development.
The diagnostic performance of renal rSO₂ and NGAL was assessed using receiver operating characteristic (ROC) curve analysis. The primary combined biomarker model incorporated bilateral mean renal rSO₂ during CPB (A2) and NGAL measured at 24 hours postoperatively (T24).
Additional analyses investigated temporal changes in biomarkers and potential patient-related and perioperative factors associated with postoperative AKI.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass | – | Diagnostic Test: Renal Near-Infrared Spectroscopy Monitoring, Diagnostic Test: Neutrophil Gelatinase-Associated Lipocalin (NGAL) MeasurementAdult patients undergoing elective cardiac surgery with CPB. Perioperative renal oxygen saturation and NGAL levels were evaluated, and patients were followed for postoperative AKI. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients undergoing elective cardiac surgery with cardiopulmonary bypass at a tertiary care hospital in Istanbul, Türkiye, who were expected to remain in the coronary intensive care unit for at least 48 hours.
Key inclusion criteria (4 listed)
- Age ≥18 years.
- Scheduled for elective cardiac surgery with cardiopulmonary bypass.
- Expected postoperative coronary intensive care unit stay of at least 48 hours.
- Written informed consent provided.
Key exclusion criteria (8 listed)
- Previously diagnosed renal disease, including acute tubular necrosis, chronic kidney disease, or nephropathy.
- Use of medications known to affect renal function, including nonsteroidal anti-inflammatory drugs (NSAIDs).
- History of renal surgery or kidney transplantation.
- Skin-to-kidney depth ≥4 cm.
- Emergency cardiac surgery.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Renal Near-Infrared Spectroscopy MonitoringBilateral renal regional oxygen saturation (rSO₂) was monitored using near-infrared spectroscopy (NIRS). Measurements were obtained before anesthesia induction (A0) and recorded at 15-minute intervals during three perioperative phases (A1, A2, and A3). The mean rSO₂ values were calculated separately for each kidney, and the bilateral mean was used as the primary renal oxygenation parameter. | Diagnostic test | Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass |
| Neutrophil Gelatinase-Associated Lipocalin (NGAL) MeasurementBlood samples were collected to measure neutrophil gelatinase-associated lipocalin (NGAL) levels at three predefined time points: preoperatively (T0), and at 24 (T24) and 48 (T48) hours postoperatively. NGAL levels were evaluated for their association with postoperative acute kidney injury. | Diagnostic test | Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass |
Primary outcome
Discriminatory Performance of Perioperative Renal Oxygen Saturation for Postoperative AKI
Time frame: Perioperatively (A0-A3), with postoperative AKI assessed through day 7.
The discriminatory performance of bilateral mean renal rSO₂ for identifying postoperative AKI will be evaluated separately for each perioperative phase (A0, A1, A2, and A3) using ROC curve analysis. The area under the curve (AUC) and its 95% confidence interval will be calculated.
Discriminatory Performance of NGAL for Postoperative AKI
Time frame: Preoperatively and at 24 and 48 hours postoperatively, with AKI assessed through postoperative day 7.
The discriminatory performance of NGAL levels measured preoperatively (T0), at 24 hours (T24), and at 48 hours (T48) postoperatively will be evaluated separately using ROC curve analysis. AUC values and corresponding 95% confidence intervals will be calculated.
Combined Discriminatory Performance of Renal Oxygen Saturation and NGAL for Postoperative AKI
Time frame: During CPB and at 24 hours postoperatively, with AKI assessed through postoperative day 7.
The primary combined biomarker model will incorporate bilateral mean renal rSO₂ during CPB (A2) and NGAL measured at 24 hours postoperatively (T24). Binary logistic regression will be used to derive predicted probabilities, and ROC analysis will be performed to calculate the AUC and its 95% confidence interval. Incremental discrimination will be assessed by comparing AUCs with those of the individual biomarker models.
3 secondary outcomes
Incidence of Postoperative Acute Kidney Injury
Time frame: Within 7 days after surgery.
Severity of Postoperative Acute Kidney Injury
Time frame: Within 7 days after surgery.
Patient-Related and Perioperative Factors Associated With Postoperative AKI
Time frame: From the preoperative period through postoperative day 7.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Sep 2026.
- Background: PubMed 28869251Wang Y, Bellomo R. Cardiac surgery-associated acute kidney injury: risk factors, pathophysiology and treatment. Nat Rev Nephrol. 2017 Nov;13(11):697-711. doi: 10.1038/nrneph.2017.119. Epub 2017 Sep 4.
- Individual participant dataSharing planned: Undecided. A final decision regarding the sharing of de-identified individual participant data has not yet been made. Any future data sharing will be subject to institutional policies, ethics committee requirements, and applicable data protection regulations.
Related trials for Acute Kidney Injury
Not yet recruiting
Vitamin C for Acute Kidney Injury in ACLF With Septic Shock: A Randomized Controlled Trial
Acute-on-Chronic Liver Failure (ACLF)
Not yet recruiting
Early Biomarker Kidney Injury Assessment After Acumen Directed Fluid Management in Cardiac Surgery
Renal Injury, Acute Kidney Injury
Recruiting
Acute Kidney Injury and Ultra-endurance Running
AKI (Acute Kidney Injury) Due to Trauma
Recruiting
WIN Ratio Analysis to Determine a Strategy of Non- Invasive SUpport for Respiratory Failure in the EmeRgency Department
Acute Hypoxic Respiratory Failure, Acute Respiratory Distress Syndrome (ARDS)
Not yet recruitingObservational study
Diastolic Shock Index for Predicting Hemodynamic Instability During Continuous Renal Replacement Therapy
Acute Kidney Injury, Hypotension (MeSH: D007022)
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Acute Kidney Injury and Cardiac Surgery, run by Haseki 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 4 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 28 Sep 2026. 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?
Discriminatory Performance of Perioperative Renal Oxygen Saturation for Postoperative AKI (time frame: Perioperatively (A0-A3), with postoperative AKI assessed through day 7.). 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 NCT07837037, which also lists 1 linked publication.
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 28 Sep 2026.