Renal complications are frequently encountered in cardiac surgery and constitute significant causes of morbidity and mortality. They most commonly present in the form of acute kidney injury (AKI). The etiological factors of AKI include hemodynamic alterations, hemolysis and pigment nephropathy, inflammatory response and cytokine storm, ischemia-reperfusion injury, use of nephrotoxic agents, patient-related risk factors (advanced age, diabetes mellitus, preoperative renal insufficiency, congestive heart failure, hypertension, anemia), duration of surgery, and postoperative complications such as low cardiac output syndrome, sepsis, bleeding and reoperation, hypoalbuminemia, and fluid imbalance.
Previous studies have demonstrated several mechanisms through which elevated HbA1c levels may contribute to acute renal injury, including glomerular damage and hyperfiltration, endothelial dysfunction and microvascular injury, tubular damage, accumulation of glycation products and advanced glycation end products (AGEs), structural changes in blood vessels, and metabolic and systemic factors.
The evaluation of acute renal failure relies on fundamental scoring systems, biomarkers, and imaging modalities. Among the scoring systems, the most current and widely used is the KDIGO (Kidney Disease: Improving Global Outcomes) classification. According to the KDIGO definition, the diagnosis of AKI can be established when at least one of the following three criteria is met: an increase in serum creatinine of ≥0.3 mg/dL within 48 hours, an increase in serum creatinine to ≥1.5 times baseline within 7 days, or a urine output of \<0.5 mL/kg/hour for more than 6 hours. AKI staging is performed based on these parameters.
Imaging modalities used in the assessment of renal function include renal ultrasonography (US), Doppler ultrasonography with measurement of the renal resistive index (RRI), renal MRI/MR angiography, and renal computed tomography (particularly CT angiography). RRI is a non-invasive, bedside-applicable method that provides direct information about renal vascular resistance by evaluating renal arterial flow patterns.
In our clinic, the rationale of the present study is to measure preoperative HbA1c and Doppler-derived RRI values in patients undergoing isolated coronary artery bypass surgery, and to evaluate their relationship with postoperative KDIGO classification and Doppler RRI values in order to gain insight into the development of AKI.
Patients undergoing isolated elective CABG surgery
Patients with available preoperative and postoperative Doppler RRI measurements
Patients with available HbA1c data
Patients with chronic kidney disease
Emergency surgeries
Redo/revision surgeries
Patients undergoing concomitant valve surgery
isolated coronary bypass graft surgery patients
Cohort
Prospective
Not listed
To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and development of acute kidney injury (KDIGO Criteria) after isolated coronary artery bypass grafting
Preoperative HbA1c Level; Glycated hemoglobin level will be measured from blood samples preoperatively. Unit of Measure: Percentage (%) Measurement Tool:Standard laboratory high-performance liquid chromatography (HPLC) assay Preoperative and Postoperative Renal Resistive Index(RRI) RRI will be measured using Doppler ultrasonography from segmental or interlobar renal arteries. Unit of Measure: Dimensionless ratio (RRI value) Measurement Tool: Doppler ultrasonography Normal Value Reference: RRI \< 0.70 Outcome Measure Title: Incidence of Acute Kidney Injury (KDIGO Criteria) Acute kidney injury will be assessed according to KDIGO criteria. Unit of Measure: Incidence of AKI (% of patients meeting KDIGO criteria) AKI Stage (Stage 1-3 classification) Measurement Tool: Serum creatinine measurement (mg/dL) Urine output monitoring Definition: Increase in serum creatinine ≥0.3 mg/dL within 48 hours OR increase to ≥1.5 times baseline within 7 days OR urine output \<0.5 mL/kg/hour for ≥6 hours
To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and intensive care unit length of stay after isolated coronary artery bypass grafting
Length of Stay in the Intensive Care Unit Description:Duration of postoperative stay in the intensive care unit. Unit of Measure: Days Measurement Tool: Hospital electronic medical records
To evaluate the correlation between preoperative HbA1c Level, Doppler-Derived Renal Resistive Index (RRI), and hospital length of stay after isolated coronary artery bypass grafting
Total Hospital Length of Stay Description: Total duration of hospitalization following surgery. Unit of Measure: Days Measurement Tool: Hospital electronic medical records
To evaluate the correlation between preoperative HbA1c level, Doppler-Derived Renal Resistive Index (RRI), and duration of mechanical ventilation after Isolated coronary artery bypass grafting
Duration of Postoperative Mechanical Ventilation Description: Total duration of invasive mechanical ventilation following surgery. Unit of Measure: Hours Measurement Tool: Ventilator records and hospital electronic medical records
Click on the lead sponsor to view all of their trials.
Osman Sila Aydin
Lead sponsor
Bursa Sevket Yilmaz Training and Research Hospital
Sponsor institution
