Background: AKI is a common and serious complication in critically ill patients, affecting up to 30 % of those admitted to the intensive care unit (ICU). AKI is associated with increased mortality, prolonged ICU stay, and higher healthcare costs. A critically ill patient with AKI refers to an individual who is experiencing a severe medical condition or illness that has resulted in sudden kidney dysfunction or damage. The prognostic nutritional index (PNI) and neutrophil-to-lymphocyte ratio (NLR) are composite biomarkers representing patients’ immunological nutritional status and systemic inflammation and have the advantages of being simple to use and inexpensive and having improved stability. Previous research has posited that PNI or NLR has prognostic value in numerous illnesses, including sepsis, gastric cancer, hepatocellular carcinoma, and pancreatic cancer. So far, no studies have been conducted to evaluate the predictive value of combined PNI and NLR for S-AKI. Consider that inflammation and immune-nutritional status play a vital role in the physiopathology of S-AKI. The association between inflammation and post-operative AKI or mortality after AKI was examined using serum CRP and albumin levels as markers of inflammation. Lower serum albumin was independently associated with post-operative AKI. Post-operative AKI was associated with higher mortality and this association was at least partially mediated by pre-operative serum CRP and albumin levels. These results suggest that those with underlying inflammation are more likely to develop AKI and rather than AKI itself, but underlying inflammation is associated with higher mortality among those with AKI. Hypoalbuminemia was independently associated with the development of post-operative AKI. Associations between higher CRP or lower albumin and AKI have been reported in contrast-induced nephropathy or post-operative AKI in cardiac surgery. In many of these studies, higher CRP was shown to be associated with AKI.