Elevated IAP in critically ill patients associated with increased AKI incidence: a cohort study from the MIMIC-IV database

Elevated intra-abdominal pressure can engender a spectrum of adverse physiological repercussions in patients, but further research is needed to ascertain whether elevated intra-abdominal pressure exerts significant effects on renal function. The study used MIMIC-IV database to identify critical patients with IAP monitoring. Patients were categorized into Low-IAP and High-IAP groups based on the results of the restricted cubic splines curve, with HR = 1 set at IAP = 16 mmHg. The primary outcome of the study was the occurrence of AKI within 72 h of ICU admission, and secondary outcomes including the rate of CRRT utilization and 28-day all-cause mortality. Cox proportional hazards regression analysis was employed to clarify the relationship between IAP and AKI. A total of 1746 patients were included in our study. Restricted cubic spline analysis demonstrated an increased risk of AKI with higher IAP. Multivariable Cox proportional hazards analysis uncovered a notable correlation between elevated IAP and AKI incidence (HR: 1.40(1.14-1.71)). After adjusting for confounding factors, patients with elevated IAP remained significantly related with AKI (HR: 1.23(1.01-1.52)). The Kaplan-Meier survival curves indicated a significant superior 28-day survival rate for Low-IAP group (the log-rank test p-value was 0.001) and the cumulative risk curve showed a higher demand for CRRT in the High-IAP group (the log-rank test p-value was 0.0028). Augmented intra-abdominal pressure (above 16 mmHg) is significantly associated with a higher incidence of acute kidney injury (AKI) in critically ill patients, along with an increased need for continuous renal replacement therapy (CRRT) and a higher 28-day mortality rate.