Overview

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.

Eligibility

Inclusion Criteria:

• Patient is 18 years or older
• Diagnosis of acute pancreatitis according to the revision of the Atlanta classification (Banks et al, Gut 2013), which requires at least two of the following three criteria: A) typical abdominal pain, B) increase in serum amylase or lipase levels higher than three times the upper limit of normality, and C) signs of acute pancreatitis in imaging
• Signature of informed consent

Exclusion Criteria:

• New York Heart Association class II heart failure (slight limitation of physical activity; fatigue, palpitations, or dyspnea with ordinal physical activity) or worse, or ejection fraction <50% in the last echocardiography
• Decompensated cirrhosis (Child's class B or C)
• Hyper or hyponatremia (<135 or >145 mEq/L)
• Hyperkalemia (>5 mEq/L)
• Hypercalcemia (albumin or protein-corrected calcium >10.5 mg/dL or 2.62 mmol/L)
• Criteria for moderately severe or severe acute pancreatitis (revision of the Atlanta classification, Banks et al, Gut 2013) at recruitment: any of the following: A) presence of creatinine ≥1.9 mg/dL or ≥170 mmol/l, B) PaO2/FiO2≤300, C) systolic blood pressure <90 mmHg despite initial fluid resuscitation, D) presence of local complications (acute peripancreatic fluid collections, acute necrotic collection, pseudocyst, walled-off necrosis, gastric outlet dysfunction, splenic or portal vein thrombosis, or colonic necrosis), E) exacerbation of previous comorbidity such as coronary artery disease or chronic lung disease, precipitated by the acute pancreatitis
• Signs of volume overload or heart failure at recruitment (peripheral edema, pulmonary rales, or increased jugular ingurgitation at 45º)
• Time from pain onset to arrival to emergency room >12 h
• Time from confirmation of pancreatitis to randomization >8 h
• Chronic pancreatitis defined by a Wirsung duct ≥4mm and/or pancreatic calcifications
• More than 1 previous episode of acute pancreatitis (only 2 episodes of acute pancreatitis are allowed, one of them the present episode)