Association between the mean perfusion pressure and the risk of acute kidney injury in critically ill patients with sepsis: a retrospective cohort study.

backgroundMean perfusion pressure (MPP) has recently emerged as a potential biomarker for personalized management of tissue perfusion in critically ill patients. However, its association with the occurrence of acute kidney injury (AKI) in septic patients and the optimal MPP range remain uncertain. Therefore, this study aims to investigate the relationship between MPP and AKI in critically ill patients with sepsis.

methodsWe identified 5867 patients with sepsis from the MIMIC-IV database who met the inclusion and exclusion criteria. The exposure variable was the first set of MPP measured within 24 h after ICU admission with invasive hemodynamic monitoring. The primary outcome was the incidence of AKI at 7 days following ICU admission according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Secondary outcomes included in-hospital mortality, lengths of ICU, and hospital stay. Optimal cut-off point for MPP were determined using the Youden index, and multivariable logistic regression was employed to examine the association between MPP and AKI. Subgroup analyses were conducted to enhance result robustness. Kaplan-Meier survival analysis was utilized to evaluate in-hospital mortality rates categorized by MPP.

resultsA total of 5,867 patients with sepsis were included in this study, and the overall incidence of AKI was 82.3%(4828/5867). Patients were categorized into low MPP (< 63 mmHg) and high MPP (≥ 63 mmHg) groups using the optimal ROC curve-derived cut-off point. The incidence of AKI in the low MPP group was higher than that in the high MPP group (87.6% vs. 78.3%, P < 0.001). Multivariable logistic regression analysis adjusted for confounding factors revealed that each 1 mmHg increase in MPP as a continuous variable was associated with a 2% decrease in AKI incidence within 7 days of ICU admission (OR:0.98, 95%CI:0.97-0.99, P < 0.001). When MPP was used as a categorical variable, patients in the high MPP group had a lower risk of AKI than those in the low MPP group (OR:0.71, 95%CI:0.61-0.83, P = 0.001). Subgroup analyses demonstrated a consistent association between MPP and AKI risk across all variables assessed (P for interaction all > 0.05). Kaplan-Meier curve analysis demonstrated a higher survival rate during hospitalization in the high MPP group compared to the low MPP group (Log-rank test, P < 0.0001).

conclusionsLower levels of MPP are associated with an increased incidence of AKI at 7 days in critically ill patients with sepsis.