What is the recommended protocol for a free water flush via Percutaneous Endoscopic Gastrostomy (PEG) tube?

Free Water Flush Protocol via PEG Tube

Flush the PEG tube with 30-40 mL of plain water before and after each medication, after each feed, and at least once daily even when not actively using the tube. 1, 2

Standard Flushing Volume and Technique

• Use 30-40 mL of water for each flush to ensure complete tube clearance and prevent occlusion. 1, 2
• The water can be drinking water, still mineral water, fresh tap water, cooled boiled water, or sterile water. 2
• Draw up the appropriate volume into a syringe, connect to the PEG tube port, flush using gentle steady pressure, then disconnect and cap the tube. 2

The ESPEN guidelines from 2020 and 2022 recommend a minimum of 30 mL, particularly emphasizing this volume for small diameter tubes to reduce occlusion risk. 1 The American Gastroenterological Association recommends approximately 40 mL, which provides an additional margin of safety. 2 When in doubt, use 40 mL to ensure complete clearance, as insufficient water volume is the primary cause of tube occlusion. 2

Timing of Flushes

Flush the tube at these specific intervals:

• Before administering any medication 1, 2
• Between each individual medication (never mix medications together) 1
• After all medications are given 1, 2
• After each feed administration 1, 2
• At least once daily, even if the tube is not being actively used for feeds or medications 2

Medication Administration Protocol

• Administer each drug individually through the tube, never mix medications together before administration. 1
• Flush with 30-40 mL water before the first medication, between each medication, and after the last medication. 1, 2
• Use liquid formulations (elixirs or suspensions) rather than syrups when possible. 2
• Avoid hyperosmolar drugs, crushed tablets, potassium, iron supplements, and sucralfate through the tube. 2

The rationale for individual administration is to prevent drug-drug interactions and ensure each medication clears the tube completely. 1 While some practitioners mix medications to save time, this practice increases the risk of interactions and tube occlusion. 1

Managing Tube Occlusion

If the tube becomes clogged despite proper flushing:

• First attempt: Flush with warm water using gentle pressure 2, 3
• Second attempt: Use an alkaline solution of pancreatic enzymes if warm water fails 2
• Expert intervention: A soft guidewire or commercially available tube declogger may be used by an experienced provider 2, 3

Never use carbonated drinks, pineapple juice, or sodium bicarbonate solution, as these can degrade the tube material or promote bacterial growth. 2, 3 The sugar content in sodas enhances bacterial contamination risk. 3

Critical Pitfalls to Avoid

• Insufficient water volume: Always use the full 30-40 mL; partial flushes leave residue that accumulates and causes occlusion. 2, 3
• Using inappropriate fluids: Stick to plain water only—no juices, sodas, or other beverages for routine flushing. 2, 3
• Mixing medications: This creates drug-drug interactions and increases occlusion risk despite time pressures. 1
• Neglecting daily flushes: Even when not actively using the tube, flush at least once daily to maintain patency. 2
• Small-caliber tubes: These require especially diligent flushing as they are more prone to occlusion. 2, 3

Special Considerations

• Polyurethane PEG tubes are preferable to silicone tubes for medication administration due to better retention of patency. 1
• Patients with neurological diseases have higher rates of tube occlusion, likely related to increased medication use. 3
• The site of drug delivery (gastric vs. duodenal) affects drug efficacy, so confirm tube tip location when drug effectiveness is questioned. 1
• Regularly inspect the tube for signs of degradation, breakage, or occlusion, and address issues promptly before they become severe. 2, 3