Renal Resistive Index in Early Detection of Postoperative Acute Kidney Injury

Effectiveness of Doppler Renal Resistive Index in Early Detection of Postoperative Acute Kidney Injury in Prolonged Cardiopulmonary Bypass Cardiac Surgeries

The primary aim of our study was to investigate the role of renal doppler ultrasonography (USG) and preoperative/postoperative renal resistive index (RRI) in the early prediction of AKI. Our secondary aim is to evaluate perioperative parameters that may cause AKI, to determine the duration of intensive care unit (ICU)/hospitalization and 30-day mortality.

Our prospective, observational, cross-sectional study included patients with elective cardiac surgery under general anesthesia with prolonged CRP (>70 min) and aortic cross-clamp (ACC) (>60 min), >18 years of age, without preoperative acute/chronic renal failure, and with preoperative/postoperative RRI measurements. Demographic data, comorbidities, medications, preoperative ejection fraction, admission hematocrit (HCT) and baseline serum creatinine (sCr), type of operation, and preoperative RRI were recorded. Intraoperative operation and CPB/ACC duration, blood product transfusion, urine output, amount of bleeding, fluid balance, use of vasopressor/inotropic agents and diuretics, and complications were recorded. RRI was measured by the same radiologist in the first postoperative hour. Urine output and fluid balance, vasopressor/inotropic agent requirement, diuretic use, sKr, HCT level and blood product transfusion were recorded for 3 days postoperatively. According to KDIGO guidelines, patients who did not develop CCI-AKI were divided into 2 groups as Group 1 (n:64) and patients who developed CCI-AKI were divided into Group 2 (n:26). In Group 2, renal failure stage, duration (acute/chronic) and RRT were recorded. ICU and hospital length of stay, postoperative complications and 30-day mortality were recorded.

Inclusion Criteria:

• Elective cardiac surgeries under general anesthesia with prolonged CPB (>70 min) and aortic cross clemp (>60 min) time
• >18 years of age, without preoperative acute or chronic renal failure
• with preoperative and postoperative RRI measurements

Exclusion Criteria:

• Patients with known renal insufficiency,
• Patients with acute renal failure in the last 3 months
• Emergency surgeries,
• Patients with arrhythmia end-stage renal disease and renal transplant
• Patients Patients with short duration of CPB (<70 min) and ACK (<60 min)
• Failed Doppler ultrasonography imaging