Evaluation of intraoperative kidney tissue oxygenation in liver transplant recipient patients

Background: Liver transplantation (LT) is an accepted treatment for many end-stage liver diseases. Significant advances have been made in liver transplantation recently. The role of the anesthesiologist is to provide safe general anesthesia and maintain an acceptable hemodynamic performance by ensuring adequate perfusion of the patient's vital organs. An adequate renal hemodynamic status, especially renal blood flow, is an important issue for the preservation of renal function. Acute kidney injury (AKI) has a significant impact on short- and long-term survival in liver transplant (LT) patients. Aim: Our aim in this study is to use the NIRS method to evaluate renal tissue oxygenation through a sterile sheath over Gerota's fascia intraoperatively, and to determine whether this method is clinically useful in evaluating kidney damage in the liver transplantation procedure. Similar studies have been conducted before, but no study has been conducted to evaluate renal tissue oxygenation through the renal parenchyma (1,2). Material and Method: 41 patients aged 18–65 years, who were planned for elective liver transplantation and had normal kidney functions before, were included in the study. Patients who did not want to participate in the study, patients who will be transplanted due to fulminant hepatic failure, patients with hepatic encephalopathy, patients with hepatorenal or hepatopulmonary syndrome, patients with previous lung and heart disease were not included in the study. Following ethical approval, preanesthetic examination of the cases was performed, and after being taken to the operating room, routine monitoring methods such as ECG, blood pressure, SpO2, temperature, and BIS were performed and measurements were taken. Anesthesia was induced with thiopental 3-5 mg/kg, fentanyl 1-2 mcg/kg, lidocaine 1 mg/kg, vecuronium 0.1 mg/kg, end-induction data were recorded, and an endotracheal tube of appropriate size was inserted after sufficient anesthesia depth was achieved. After the location of the intubation tube was confirmed (auscultation and etCO2 detection), a masimo non-invasive measurement probe was attached to the patient for near-infrared spectroscopy (NIRS) and pleth variable index (PVI), perfusion index (PI), oxygen reserve index (ORI), SpHb measurement. ,input data has been saved. After routine invasive arterial monitoring, cardiac output, stroke volume, stroke volume variation, dPmax were monitored using the pulse contour analysis method and added to the follow-up. Kidney NIRS values were recorded after parenchymal dissection was completed but before vascular connections were clamped (T0). After the hepatic vein and portal vein connections of the graft were clamped, NIRS values (T1) were recorded in the anhepatic phase. Kidney NIRS values (T2) were recorded after the clamps were opened after the portal vein and hepatic vein anastomosis of the graft and the hepatic artery anastomosis of the graft was made and perfused. After the graft blood supply was ensured, liver Doppler USG was performed. Hemodynamic, respiratory, routine laboratory data and hourly urine output of the patients were recorded throughout the surgery. At the end of the surgery, the total operation time, cold ischemia time, warm ischemia time and artery perfusion time were recorded. Postoperative intensive care unit stay, mechanical ventilation duration, KDIGO score and complications were recorded. Patient follow-up was terminated after the postoperative intensive care period was completed. Footnote: There are no conflicts of personal and financial interest within the scope of the study Keywords: Kidney oxygenation, Acute kidney injury, Liver transplant anesthesia, Post Reperfusion syndrome