What are the treatment recommendations for the Waterfall trial?

Recommendations from the WATERFALL Trial for Acute Pancreatitis Fluid Resuscitation

Moderate fluid resuscitation is superior to aggressive fluid resuscitation in acute pancreatitis, as it results in fewer complications without compromising clinical outcomes. 1

Key Findings of the WATERFALL Trial

The WATERFALL trial was a multicenter, open-label, randomized controlled trial comparing aggressive fluid resuscitation (AFR) versus moderate fluid resuscitation (MFR) in patients with acute pancreatitis. This trial provides the most recent and highest quality evidence for fluid management in acute pancreatitis.

Key results from the WATERFALL trial 1:

• The trial was stopped early after interim analysis of 249 patients due to safety concerns
• No significant difference in the primary outcome (development of moderately severe or severe pancreatitis): 22.1% in AFR vs. 17.3% in MFR
• Fluid overload was significantly higher in the aggressive resuscitation group (20.5% vs. 6.3%)
• Median hospital stay was longer with aggressive resuscitation (6 days vs. 5 days)

Recommended Fluid Resuscitation Protocol

Based on the WATERFALL trial results 1, the following moderate fluid resuscitation protocol is recommended:

1. Initial Assessment:

   • Evaluate for hypovolemia
   • If hypovolemic: Administer lactated Ringer's solution 10 mL/kg bolus
   • If normovolemic: No bolus required

2. Maintenance Fluid Rate:

   • Administer lactated Ringer's solution at 1.5 mL/kg/hour

3. Reassessment Schedule:

   • Reassess at 12,24,48, and 72 hours
   • Adjust fluid resuscitation based on clinical status

Rationale for Moderate Fluid Resuscitation

The WATERFALL trial 1 challenged the previously widespread recommendation for aggressive fluid resuscitation in acute pancreatitis. The theoretical benefit of aggressive fluid resuscitation was to improve end-organ perfusion, particularly to the pancreas and gut, potentially reducing pancreatic necrosis and bacterial translocation 2. However, the trial demonstrated that:

1. Aggressive fluid resuscitation did not reduce the incidence of moderately severe or severe pancreatitis
2. Aggressive fluid resuscitation significantly increased the risk of fluid overload (adjusted relative risk, 2.85)
3. Aggressive fluid resuscitation was associated with longer hospital stays

Monitoring Parameters During Fluid Resuscitation

When implementing moderate fluid resuscitation, monitor:

• Vital signs (heart rate, blood pressure, respiratory rate)
• Urine output
• Clinical signs of fluid overload (peripheral edema, pulmonary crackles)
• Laboratory values (BUN, creatinine, hematocrit)

Common Pitfalls to Avoid

1. Overaggressive fluid resuscitation: The WATERFALL trial clearly demonstrated increased complications with aggressive fluid resuscitation without clinical benefit 1

2. Inadequate monitoring: Even with moderate fluid resuscitation, patients require regular reassessment to ensure adequate hydration without fluid overload

3. One-size-fits-all approach: While moderate fluid resuscitation is generally recommended, patients with severe dehydration or shock may require more aggressive initial resuscitation before transitioning to moderate rates

4. Failure to reassess: Fluid requirements may change during the course of illness, requiring regular reassessment and adjustment

Special Considerations

• Cardiac or renal dysfunction: Patients with pre-existing cardiac or renal disease may require even more cautious fluid administration and closer monitoring
• Severe hypovolemia: Patients presenting with severe hypovolemia may require additional initial fluid boluses before transitioning to maintenance rates
• Persistent SIRS: Patients with persistent systemic inflammatory response syndrome may have increased fluid requirements

The WATERFALL trial 1 provides the most current and highest quality evidence for fluid management in acute pancreatitis, and its findings should guide clinical practice by promoting moderate rather than aggressive fluid resuscitation strategies.