Association of mean arterial pressure and in-hospital mortality in critically ill patients with acute pancreatitis-associated acute kidney injury: a retrospective cohort study

Acute pancreatitis (AP) is a common gastrointestinal disorder, and acute kidney injury (AKI) is a frequent and severe complication, significantly increasing mortality risk. Mean arterial pressure (MAP) is crucial for maintaining organ perfusion in critically ill patients. However, the optimal MAP target for minimizing mortality in AP patients complicated by AKI (AP-AKI) remains unclear. This retrospective cohort study analyzed data from the MIMIC-IV database, including 934 critically ill adult patients diagnosed with AP-AKI between 2008 and 2019. We investigated the relationship between MAP and in-hospital mortality using logistic regression models, adjusting for demographics, comorbidities, disease severity scores and intensive care interventions. Smooth curve fitting was used to explore potential non-linear associations. Subgroup analyses were performed to assess the impact of MAP across different clinical and demographic groups. Our analysis revealed a non-linear, L-shaped relationship between MAP and in-hospital mortality, with an inflection point at 71.32 mmHg. Below this threshold, increasing MAP was associated with significantly decreased odds of mortality (OR: 0.93, 95% CI: 0.87-0.99, <i>p</i> = 0.026). However, above this threshold, the association was no longer significant (OR: 1.015, 95% CI: 0.98-1.03, <i>p</i> = 0.699). Subgroup analyses showed consistent trends across most subgroups, with the benefit of maintaining MAP above the threshold being most pronounced in AKI stage 1 and 2 patients. This study suggests a potential association between maintaining specific MAP levels, particularly above 71.32 mmHg, and reduced in-hospital mortality in critically ill AP-AKI patients.