Postoperative Acute Kidney Injury

Coronary artery bypass grafting is a commonly performed heart surgery, but patients may have different risks for postoperative complications even when their preoperative risk scores are similar. EuroSCORE II is widely used to estimate surgical risk before cardiac surgery, but it may not fully reflect how the body responds during the early postoperative period. This retrospective observational study will evaluate adult patients who underwent elective coronary artery bypass grafting with cardiopulmonary bypass between January 1, 2022 and December 31, 2025. The study will use existing hospital records and laboratory data. No additional treatment, test, or intervention will be given to patients as part of this study. The main aim is to examine whether early postoperative changes in inflammatory and renal laboratory markers can identify different patient subgroups, called phenotypes. These markers include neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, triglyceride-glucose index, and serum creatinine. The study will evaluate whether these phenotype groups are associated with postoperative acute kidney injury and prolonged intensive care unit stay. The study will also assess whether this early postoperative phenotype-based classification provides additional risk information beyond EuroSCORE II.

Neurological problems after heart surgery are common and include confusion, memory loss, and difficulty thinking clearly. These issues may appear hours or days after surgery and can negatively affect recovery. During heart surgery, blood flow and oxygen delivery to the brain may decrease, causing changes in blood pressure and cerebral oxygenation. Previous studies suggest that prolonged drops in mean arterial pressure (MAP) or cerebral oxygenation (rSO₂) are linked to worse postoperative outcomes. Continuous monitoring of blood pressure and cerebral oxygenation is standard in cardiac surgery. This study aims to evaluate the duration and severity of intraoperative drops in MAP and cerebral oxygenation. These measures may provide a more accurate assessment of neurological risk than isolated measurements. The primary objective is to determine whether decreases in MAP and cerebral oxygenation, as well as their duration and intensity during surgery, are associated with postoperative neurological complications. This is a prospective, observational study in adult patients undergoing cardiac surgery, with or without cardiopulmonary bypass (CPB). CPB diverts blood through a machine that performs the work of the heart and lungs while the heart is operated on. All patients will receive standard monitoring, including continuous MAP and cerebral oxygenation measurements. No additional interventions will be performed. Neurological status will be assessed using validated clinical scales before and after surgery. Other outcomes include kidney function, ICU and hospital stay length, postoperative complications, and in-hospital mortality. Validating these measures as a predictive tool could enable early identification of patients at higher risk of neurological injury and allow more individualized intraoperative management to reduce morbidity, hospital stay, and healthcare costs.

The primary objectives of study is to compare the difference in the incidence of postoperative AKI between frail and non-frail patients. The secondary objectives of study was to compare the differences in intraoperative blood pressure fluctuations, the incidence and duration of intraoperative hypotension, postoperative extubation time, postoperative complications, length of hospital stay and hospitalization expenses between frail and non-frail patients, and use mediating effect analysis to examine the magnitude of the effect of intraoperative blood pressure on postoperative acute kidney injury caused by frailty.

Postoperative acute kidney injury (AKI) is a serious complication often linked to low blood pressure during surgery. This study aims to better protect patients' kidneys by personalizing how blood pressure is managed during an operation. The project has two main goals: First, researchers will analyze data from over 44,000 past surgeries to identify which specific blood pressure measurements are the most critical warning signs for kidney damage. Second, using this knowledge, they will build a smart tool (a machine learning model) to predict a unique, safe blood pressure target for each individual patient before their surgery begins. This personalized approach is intended to give doctors a specific target to maintain during surgery, helping to prevent kidney injury and improve patient safety.

This study aims to evaluate whether the reduction in the amount of intraoperative norepinephrine required to prevent hypotension, facilitated by processed electroencephalography (pEEG) -guided general anesthesia, will lead to a decrease in postoperative complications, particularly acute kidney injury (AKI).