Acute Kidney Injury Secondary to Abdominal Compartment Syndrome: Biomarkers, Pressure Variability, and Clinical Outcomes

<i>Background and Objectives</i>: Abdominal compartment syndrome (ACS) is a severe clinical condition caused by intra-abdominal hypertension (IAH), often observed in surgical and trauma patients. However, ACS can also develop in non-surgical patients with massive ascites, leading to acute kidney injury (AKI) due to renal hypoperfusion. This study investigates the association between intra-abdominal pressure (IAP) changes, renal biomarkers, and mortality in patients with ACS-related AKI. <i>Materials and Methods:</i> A prospective cohort study was conducted on 24 hospitalized patients with ascites due to malignancy, cirrhosis, or heart failure. IAP was measured via the trans-vesical method on the first and seventh days of hospitalization. Serum and urinary biomarkers, including kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and interleukin-6 (IL-6), were assessed for their correlation with IAP changes. The primary outcome was in-hospital mortality, and the secondary outcomes included AKI progression and the effect of paracentesis on IAP reduction. <i>Results:</i> The overall in-hospital mortality rate was 50%. Patients who survived had significantly lower IAP on the seventh day compared to those who died (14.9 ± 3.5 mmHg vs. 20.2 ± 5.6 mmHg, <i>p</i> = 0.01). A 25% reduction in IAP was associated with improved kidney function and increased survival (<i>p</i> < 0.001). Urinary KIM-1 and serum NGAL levels showed a moderate correlation with IAP (r = 0.55, <i>p</i> = 0.02 and r = 0.61, <i>p</i> = 0.018, respectively), while IL-6 levels were significantly higher in non-survivors (<i>p</i> = 0.03). Paracentesis was associated with improved survival outcomes (<i>p</i> = 0.04). <i>Conclusions:</i> ACS is a critical but often overlooked cause of AKI in non-surgical patients with massive ascites. Lowering IAP significantly improves renal function and reduces mortality. Urinary KIM-1 and serum NGAL may serve as useful biomarkers for monitoring IAP changes. The early identification and management of IAH through timely interventions such as paracentesis and volume control strategies could improve patient outcomes.