CRITICAL CARE MEDICINE SECTION
Acute Pancreatitis Fluid Management: Should We Go Chasing WATERFALLs? Emily Straley, MD* and Skyler Lentz, MD FAAEM†
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cute interstitial edematous pancreatitis, defined by the revised Atlanta criteria as inflammation of the pancreatic parenchyma and surrounding tissues, is the third leading gastrointestinal cause of hospital admissions in the United States.1,2 In North America, the occurrence of pancreatitis has been increasing, thought to be secondary to the increasing prevalence of risk factors such as high-fat diets and alcohol use.3 Acute pancreatitis can be further sub-divided into mild, moderately severe, and severe. Moderately severe is defined as transient organ failure (<48 hrs) or systemic complications without persistent organ failure. Severe is defined as persistent organ failure (>48hrs).1 Up to 35% of patients presenting with acute pancreatitis will develop moderate to severe pancreatitis, which is associated with increased morbidity and mortality.4 The current American College of Gastroenterology 2013 guidelines recommend management of pancreatitis with early aggressive fluid resuscitation of 250-500mL/ hour for the first 12 to 24 hours, the goal of which is to decrease the risk of developing ischemia and organ failure by repleting the patient’s intervascular volume.5 Two important questions this recommendation has raised for researchers is what fluid should be used for resuscitation, and how much.
others have shown that mechanical ventilation and renal replacement therapy were more frequent in patients who underwent aggressive fluid resuscitation with no change in mortality.6,7 The other risks of over-resuscitation described include abdominal compartment syndrome, pulmonary edema, and volume overload.5 While several prior studies have speculated on the amount of fluid that should be administered in the early management of acute pancreatitis, there have been few randomized control trials (RCTs) performed on this topic, all of which were single institution studies, until the WATERFALL trial.
In regards to the first question, many studies have investigated which crystalloid is better for resuscitation. The preferred crystalloid for the management of acute pancreatitis is a balanced fluid, such as Lactated Ringers (LR), that has a more physiological pH than normal saline. Studies have demonstrated a potential improvement in outcomes (e.g., reduced ICU admission, reduced hospital length of stay) and less inflammation in acute pancreatitis with LR when compared to normal saline.6 Pertaining to the volume of resuscitative fluids debate, several retrospective studies have suggested that large volume fluid resuscitation is associated with decreased in-hospital mortality, while
The WATERFALL trial is an RCT which aimed to investigate the development of moderately severe or severe pancreatitis during admission in patients who received aggressive or moderate fluid resuscitation.4 The study enrolled 249 patients from 18 centers spanning four countries. Patients with mild or moderate pancreatitis were randomized to receive aggressive or moderate fluid resuscitation. Aggressive resuscitation was defined as a 20mL/kg of body weight bolus followed by 3mL/kg per hour resuscitation and moderate fluid resuscitation was defined as a 10mL/kg bolus only in patients with signs of hypovolemia followed by 1.5mL/kg/hr. The trial was stopped early due
COMMON SENSE SEPTEMBER/OCTOBER 2024
Figure 1. Recommended Fluid Management in Acute Pancreatitis
to significant differences in the primary safety outcome, fluid overload, between groups. Fluid overload was seen in 20.5% of the aggressive group, as compared to 6.3% of the moderate resuscitation group. The median time from randomization to fluid overload was 34 hours, with the highest degree of fluid resuscitation and difference between groups seen over the first 12 hours. The median volumes were 1.5L versus 3.4L (moderate versus aggressive group) in the first 12 hours; the additional volume of fluid after the first 12 hours were similar between the two groups. No significant difference was identified between groups for the primary outcome of the development of moderately severe or severe acute pancreatitis during admission, though the trial was stopped early.4 Importantly, those with heart failure and chronic renal failure were excluded. Based on this landmark study, one can recommend that mild or moderate acute pancreatitis requiring hospital admission should be treated with moderate, rather than aggressive, fluid resuscitation to avoid complications of fluid overload. Though this study did not include severe pancreatitis, less aggressive volume resuscitation may also be warranted in this population. Guidelines lack clear recommendations >>