[Association between fluid balance trajectory and 28-day mortality and continuous renal replacement therapy in...

To investigate the association between fluid balance trajectories within the first 3 days of intensive care unit (ICU) admission and 28-day mortality as well as the incidence of continuous renal replacement therapy (CRRT) in patients with severe acute pancreatitis (SAP).

Clinical data of SAP patients were extracted from the Medical Information Mart of Intensive Care-IV (MIMIC-IV). Group-based trajectory modeling (GBTM) was used to analyze the daily fluid balance of patients within 3 days of ICU admission, and grouping them accordingly. Univariate and multivariate Logistic regression analyses were performed to assess the association between fluid balance trajectory and 28-day mortality and ICU CRRT in SAP patients.

A total of 251 SAP patients were included, with 33 deaths within 28 days, and a 28-day mortality of 13.15%; 49 patients (19.52%) continued to receive bedside CRRT after 3 days of ICU admission. The fluid balance on the 3rd day, cumulative fluid balance within 3 days of ICU admission, and incidence of CRRT in the death group were significantly higher than those in the survival group. According to GBTM groups, there were 127 cases in the moderate fluid resuscitation with rapid reduction (MF group), 44 cases in the large fluid resuscitation with rapid reduction (LF group), 20 cases in the moderate fluid resuscitation with slow reduction (MS group), and 60 cases in the small fluid resuscitation with slow reduction (SS group). The cumulative fluid balance within 3 days of ICU admission of the MF group, LF group, MS group, and SS group were 8.60% (5.15%, 11.70%), 16.70% (13.00%, 21.02%), 23.40% (19.38%, 25.45%), and 0.65% (-2.35%, 2.20%), respectively, and the incidence of CRRT during ICU hospitalization were 11.02%, 29.55%, 85.00%, and 8.33%, respectively, with statistically significant differences among the groups (both P < 0.05); the 28-day mortality were 11.02%, 18.18%, 20.00%, and 11.67%, respectively, with no statistically significant difference among the groups (P > 0.05). Kaplan-Meier survival curve analysis showed there was no statistically significant difference in 28-day cumulative survival rate among groups with different fluid balance trajectories (Log-rank test: χ ² = 2.31, P = 0.509). Multivariate Logistic regression analysis showed that cumulative fluid balance within 3 days of ICU admission was an independent risk factor for 28-day mortality [odds ratio (OR) = 1.071, 95% confidence interval (95%CI) was 1.005-1.144, P = 0.040] and CRRT requirement (OR = 1.233, 95%CI was 1.125-1.372, P < 0.001); early aggressive fluid resuscitation on day 1 reduced CRRT risk (OR = 0.866, 95%CI was 0.756-0.978, P = 0.030).

Dynamic fluid management is essential in SAP patients. While early aggressive fluid resuscitation may reduce CRRT demand, excessive cumulative fluid balance is associated with increased 28-day mortality and CRRT incidence.