Which fluid resuscitation strategy is associated with shorter length of stay in mild acute pancreatitis? Interaction between crystalloid type and administration rate.

BACKGROUND

While fluid resuscitation is the cornerstone of acute pancreatitis (AP) management, uncertainty remains regarding the optimal crystalloid selection and administration rate. This study assessed the independent and interactive associations of crystalloid type and resuscitation rate with clinical outcomes in mild AP.

METHODS

This single-center, retrospective cohort study (2018-2024) included 204 patients hospitalized with mild AP. Patients were categorized by crystalloid type (Lactated Ringer's (LR), normal saline (NS), Isolyte S, or dextrose-containing solutions) and resuscitation rate (aggressive, moderate, minimal, or low). The primary endpoint was length of stay (LOS). Multivariable linear regression and analyses stratified by Bedside Index for Severity in Acute Pancreatitis (BISAP) score were performed to assess main associations and interactions.

RESULTS

LR and NS were associated with comparable hospital stays, with no significant difference in LOS (P = 0.24). Both were associated with significantly shorter LOS than Isolyte S and dextrose (p < 0.001). A significant interaction occurred between fluid type and resuscitation rate: LR and NS at moderate-to-aggressive rates yielded the shortest stays, whereas Isolyte S and dextrose at low rates yielded the longest. In multivariable analysis, fluid type, resuscitation rate, BISAP score, age, and hypertension were independent predictors of LOS (R² = 0.739). These associations remained consistent across severity subgroups.

CONCLUSIONS

In mild AP, LR and NS showed comparable outcomes, both of which were associated with shorter hospital stays than Isolyte S and dextrose. The significant interaction between fluid type and rate suggests that crystalloid composition and infusion rate may need to be considered jointly when optimizing resuscitation. NS appears to be a reasonable alternative when LR availability is limited.