Mean arterial pressure at the initiation of continuous renal replacement therapy as a prognostic indicator in patients with acute kidney injury

Ren Fail. 2025 Dec;47(1):2448582. doi: 10.1080/0886022X.2024.2448582. Epub 2025 Jan 6.

Abstract

Background: Acute kidney injury (AKI) is a common complication in critically ill patients, with approximately 5% requiring continuous renal replacement therapy (CRRT). This study investigated the relationship between mean arterial pressure (MAP) and 28- and 90-day mortality in critically ill AKI patients treated with CRRT.

Methods: This secondary analysis of a bicenter, retrospective, observational study included patients with AKI who were treated with CRRT from January 2009 to September 2016. Mortality at 28 and 90 days post-CRRT initiation was analyzed using multivariate regression, generalized additive models, smooth curve fitting, and sensitivity analyses.

Results: A total of 1,142 patients were included, with 28-day and 90-day mortality rates of 62.1% and 71.8%, respectively. In multivariable-adjusted Cox models, MAP was inversely correlated with the risk of 28-day and 90-day mortality after adjusting for covariates. Hazard ratios (HRs) were calculated per 1 mmHg increment of MAP: adjusted HR for 28-day mortality 0.985 (p < 0.00001) and for 90-day mortality 0.987 (p = 0.00002). The adjusted HRs for 28-day and 90-day mortality in patients in the highest tertile of MAP compared with those in the lowest tertile were 0.682 (95% CI 0.543-0.857) and 0.730 (95% CI 0.592-0.899), respectively. Patients were grouped using MAP thresholds of <65 mmHg, 65-71.85 mmHg, and ≥71.85 mmHg, with similar results observed. Sensitivity analyses confirmed the inverse relationship between higher MAP before CRRT and lower mortality.

Conclusion: The higher the MAP before CRRT is, the lower the 28- and 90-day mortality of critically ill patients with AKI who are treated with CRRT.

Keywords: 28- and 90-day mortality; Mean arterial pressure; acute kidney injury; continuous renal replacement therapy; critically ill patients.

Publication types

  • Observational Study
  • Multicenter Study

MeSH terms

  • Acute Kidney Injury* / etiology
  • Acute Kidney Injury* / mortality
  • Acute Kidney Injury* / physiopathology
  • Acute Kidney Injury* / therapy
  • Aged
  • Arterial Pressure*
  • Continuous Renal Replacement Therapy* / methods
  • Critical Illness* / mortality
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Proportional Hazards Models
  • Retrospective Studies

Grants and funding

This study was supported by the Shenzhen Key Medical Discipline Construction Fund [SZXK009], the Sanming Project of Medicine in Shenzhen [SZSM202211013], the Medicine Engineering Interdisciplinary Research Foundation of Shenzhen University [2023YG033] and the Supply and Demand Matching Employment-Education Integration Project [2024012936000]. However, we maintained independence in the design, execution, data analysis, and interpretation of the study, and were not influenced by any funding sources. All research results were independently analyzed and are the responsibility of the authors.