Effect of first-day fluid intake after transferring to ICU on 7-day risk for death in patients with chronic liver disease after surgery: a retrospective cohort study based on MIMIC-Ⅳ database

Patients with chronic liver diseases often exhibit unique hemodynamic abnormalities and metabolic disorders. Postoperative fluid management presents numerous challenges, especially for critically ill patients admitted to the intensive care unit (ICU) after surgery. This study aimed at exploring the relationship between postoperative fluid therapy and prognosis.

Based on 2414 patients with chronic liver diseases who underwent surgical treatment and were subsequently transferred to the ICU in the MIMIC-Ⅳ database, a retrospective cohort study was conducted on the final 2143 patients after our inclusion and exclusion criteria. Multivariate adjusted logistic regression model was used to analyze the association between fluid therapeutic regimens on the first day after ICU admission and the risk of 7-day death after surgery. Restricted cubic spline (RCS) was applied to analyze the dose-response relationship.

Multivariate analysis indicated that restrictive fluid resuscitation was an independent protective factor. Compared with the non-restrictive fluid resuscitation group, restrictive fluid resuscitation significantly reduced the 7-day postoperative mortality rate (6.4% vs 12.4%, OR=0.44, 95%CI: 0.22~0.88, P=0.021), decreased the use of mechanical ventilation (42.9% vs 72.3%, OR=0.29, 95%CI: 0.24~0.35, P<0.001), and shortened the ICU stay (1.86 vs 3.47 d, OR=0.81, 95%CI: 0.78~0.84, P<0.001). RCS curve showed that the fluid intake on the first postoperative day and the 7-day postoperative mortality risk presented a J-shaped curve relationship, with an inflection point at 1850 mL. Beyond this threshold, the 7-day postoperative mortality risk was increased. Subgroup analysis results indicated that the protective effect of restrictive fluid resuscitation was consistent across different age and comorbidity groups.

For patients with chronic liver diseases, adopting a restrictive fluid therapy on the first day after surgery can effectively reduce the risk of short-term death. Moreover, there is a non-linear dose-effect relationship between the fluid intake and the 7-day mortality risk. When the fluid intake exceeds 1850 mL, the risk of death significantly increases.