Association Between Liver Function Tests and Acute Kidney Injury in Cardiac Surgery Patients

In this study data will be retrospectively collected from the intensive care patient management system for patients admitted postoperatively to the cardiac intensive care unit (ICU) following cardiac surgery. The inclusion period spans from 2012 to 2017 (5 years) and includes about 3,500 patients. For all included patients, retrospective data collection will include variables related to renal function, fluid balance, hemodynamics, and transaminase levels. Additionally, demographic information, surgical procedure details, comorbidities, and laboratory values will be gathered. Cardiac surgery-associated acute kidney injury (CSA-AKI) has a multifactorial etiology influenced by non-modifiable factors such as age, comorbidities (e.g., heart failure/ejection fraction, chronic kidney disease, hypertension, diabetes), medication use (NSAIDs, ACE inhibitors/ARBs), type of surgery, duration of surgery/cardiopulmonary bypass time. Central venous pressure (CVP) can serve as a marker of venous congestion, which may contribute to the development of AKI. Venous congestion may also result in elevated transaminase levels. The primary aim of this study is to investigate the association between postoperative transaminase elevation in the ICU and the development of AKI during the intensive care stay. Data about transaminases will be collected in the first 24 hours after ICU admission. The occurrence of AKI and its severity will be investigated within 72 hours after cardiac surgery. Furthermore, the relationship between the transaminase elevation and the severity of acute kidney injury will be examined, as well as the association between central venous presure (CVP) and transaminase levels postoperatively in the ICU. Acute kidney injury will be defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, with severity classified based on the KDIGO staging system.