The Predictive Value of Doppler Based Renal Ultrasound and Urinary Oxygen Tension for Prediction of Acute Kidney Injury After Open Heart Surgery

This study aims to investigate the predictive value of Doppler-based renal ultrasound and urinary oxygen tension in the development of acute kidney injury after cardiac surgery.

Study Overview

• Status: Recruiting
• Conditions: Acute Kidney Injury; Open Heart Surgery; Doppler-Based Renal Ultrasound; Urinary Oxygen Tension
• Intervention / Treatment: Other: Renal resistive index; Other: Renal Artery Pulsatility Index; Other: Urinary oxygen tension (PUO2)

Detailed Description

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a complication following cardiac surgery occurring in 15-30% of patients. It is associated with increased morbidity and mortality as well as prolonged hospital stay and higher medical costs.

The renal artery pulsatility index (RAPI), which is determined using Doppler measurements, has been reported to detect patients with a high risk of AKI. Additionally, the renal resistance index (RRI), measured by Doppler ultrasound, can accurately predict the occurrence of AKI.

Urinary oxygen partial pressure in the bladder has been shown to decrease in the setting of sepsis, reduced renal blood flow, and decreased cardiac output.

• Study Type: Observational
• Enrollment (Estimated): 50

Contacts and Locations

• Study Contact: Name: Amany M Badr, Master; Phone Number: 00201018038038; Email: amany.badr@med.tanta.edu.eg

Study Locations

• Egypt
  • El-Gharbia
    • Tanta, El-Gharbia, Egypt, 31527
      • Recruiting
      • Tanta University
      • Sub-Investigator: Ayman A Yousef, MD
      • Sub-Investigator: Aliaa M Belal, MD
      • Sub-Investigator: Sabry M Amin, MD
      • Contact: Amany M Badr, Master; Phone Number: 00201018038038; Email: amany.badr@med.tanta.edu.eg
      • Sub-Investigator: Rabab M Mohammed, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This prospective cohort observational study will be conducted at Tanta University Hospitals for a period of at least two years, from October 2024 to September 2026, pending approval from the institutional ethics committee.

Description

Inclusion Criteria:

• Age above 21 years.
• Both sexes.
• Undergoing elective on-pump cardiac surgery.

Exclusion Criteria:

• Patients with chronic kidney disease.
• Patients with any renal pathology or anatomic kidney abnormalities.
• Patients on renal replacement therapy.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Study group; Patients undergoing elective on-pump cardiac surgery

Other: Renal resistive index; It will be measured with ultrasound-Doppler using an abdominal curvilinear probe ultrasonography by two independent, trained sonographers (who will not be involved in patient care). After visualizing the kidney in ultrasound mode and checking for renal abnormalities, an arcuate or inter-lobar artery will be localized, and three successive Doppler measurements at different positions in the kidney (high, middle, and low) will be performed. The average value for each kidney will be taken. The renal resistive index will be calculated as follows: (systolic peak flow velocity - diastolic minimum flow velocity)/systolic peak flow velocity; Other: Renal Artery Pulsatility Index; It will be measured using an abdominal curvilinear probe ultrasonography by two independent, trained sonographers (who will not be involved in patient care). After visualizing the kidney, the interlobular artery will be located using color Doppler mode, and the velocity of the interlobular arteries will be assessed in one or two kidneys. The Renal Artery Pulsatility Index (RAPI) will be calculated as follows: RAPI = [(peak systolic velocity) - (end diastolic velocity)] /average velocity; Other: Urinary oxygen tension (PUO2); Urinary oxygen tension (PUO2) will be measured preoperatively (baseline), postoperatively just after intensive care unit admission, 12 hours after surgery, and then once daily for 7 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of cases developed acute kidney injury	Number of cases developed acute kidney injury as defined by KIDGO guidelines (serum creatinine ≥ 0.3 mg/dL from base line within 48 hours, or ≥1.5 fold within 7 days, or urine output <0.5 mL/kg/hour for six hours) in patients undergoing open heart surgery.	7 days after the procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Length of intensive care unit stay	The length of stay in an Intensive Care Unit (ICU) is defined as the duration a patient spends in the ICU, typically measured from the time of admission to the ICU until the time of discharge.	7 days after the procedure
Length of hospital stay	Length of hospital stay will be measured from admission till discharge from hospital.	7 days after the procedure
Need for renal replacement therapy	Need for renal replacement therapy will be recorded.	7 days after the procedure
Number of patients developed chronic kidney disease	Number of patients developed chronic kidney disease will be recorded.	7 days after the procedure
Mortality rate	Mortality rate will be recorded.	7 days after the procedure

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2024
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: June 17, 2025
• First Submitted That Met QC Criteria: June 17, 2025
• First Posted (Estimated): June 25, 2025

Study Record Updates

• Last Update Posted (Estimated): June 25, 2025
• Last Update Submitted That Met QC Criteria: June 17, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Renal Insufficiency; Acute Kidney Injury; Wounds and Injuries
• Other Study ID Numbers: 36265MD279/9/24

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be available upon a reasonable request from the corresponding author after the end of study for one year.
• IPD Sharing Time Frame: After the end of study for one year.
• IPD Sharing Access Criteria: The data will be available upon a reasonable request from the corresponding author.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No