Association of Serial Intra-Abdominal Pressure Measurements with Renal Outcomes and Mortality in Critically Ill Adults

Background/Objectives: Intra-abdominal hypertension (IAH) is a common but under-recognized condition in critically ill patients and is associated with adverse outcomes, particularly acute kidney injury (AKI) and mortality. However, the prognostic value of intra-abdominal pressure (IAP) remains incompletely defined. This study aimed to evaluate the association between IAP levels and clinical outcomes, and to determine its prognostic significance in intensive care unit (ICU) patients. Methods: This prospective cohort study included adult patients admitted to the ICU between 2024 and 2025. Serial IAP measurements were performed using the transvesical method on days 0, 1, 3, 5, and 7. Demographic, clinical, and laboratory data, along with severity scores (SOFA and APACHE II), were recorded. Patients were followed for 90 days. Primary outcomes were AKI and 90-day mortality. Statistical analyses included regression models, survival analysis, and ROC curve analysis. Results: The prevalence of IAH was 54%. IAH was significantly associated with advanced age, male sex, higher body mass index, increased comorbidity burden, sepsis, positive fluid balance, and higher disease severity scores. Patients with IAH had a significantly higher frequency of AKI occurrence and increased mortality. IAP levels positively correlated with serum urea and creatinine levels. Serial IAP measurements, particularly on days 5 and 7, showed progressively improved predictive performance for mortality. Survival analysis revealed significantly reduced survival in patients with IAH. Conclusions: IAH is highly prevalent in critically ill patients and is strongly associated with renal dysfunction and mortality. Serial IAP measurements may provide useful prognostic information in critically ill patients; however, these findings require validation in larger studies.