Normal Saline Versus Lactated Ringer's Solution for Acute Pancreatitis Resuscitation

Background: Acute pancreatitis (AP) is an acute inflammatory disease of variable severity. Mild cases have an uncomplicated clinical course, but local and systemic complications occur in one-third of patients and are associated with a longer hospital stay, increased morbidity, increased hospital costs, and increased risk of death. Some evidence suggests that fluid resuscitation with lactated Ringer\'s solution (LR) may have an anti-inflammatory effect on AP when compared to normal saline (NS), and may be associated with a decrease in severity, but randomized controlled trials showed conflicting results. The WATERLAND trial has been designed to investigate the efficacy and safety of fluid resuscitation using LR as compared with NS in patients with AP. Methods: The WATERLAND trial is an international multicenter, open-label, parallel-group, randomized, controlled, superiority trial. Patients will be randomly assigned in a 1:1 ratio to receive LR versus NS-based moderate fluid resuscitation. The primary outcome will be moderately severe to severe AP, according to the revision of the Atlanta classification. The primary safety outcome will be a composite variable involving any of the following: fluid overload, acute kidney injury, hyperkalemia, hypercalcemia, or acidosis. A total sample of 720 patients, 360 in the LR group and 360 in the NS group will achieve 90% power to detect a difference between the group proportions of 10%, assuming that the frequency of moderately severe to severe AP in LR group will be 17%. The frequency in the NS group is assumed to be 27% under the null hypothesis and 17% under the alternative hypothesis. The test statistic used is the two-sided Z test with pooled variance set at a 0.05 significance level.