Flushing Nasogastric Tubes with Water
Yes, you should routinely flush nasogastric tubes with water—specifically, at least 30 mL of drinking quality water before and after each feeding or medication administration, and every 4 hours during continuous feeding to prevent tube obstruction. 1
Standard Flushing Protocol
Routine water flushing is essential for maintaining NGT patency and should be a core component of patient and caregiver education. 1 The evidence strongly supports this practice:
- Flush with at least 30 mL of water before starting and after completion of feeds for bolus administration 1
- Flush every 4 hours during continuous feeding 1
- Flush before, between, and after each medication when administering drugs through the tube, using 30 mL of water for each flush 1
The rationale is straightforward: NGTs are prone to blockages due to protein-rich formula chemistry, fluid viscosity, and small tube diameter—problems that worsen with longer tubes and medication administration. 1
Water Quality Considerations
In immunocompromised patients, water quality becomes critical. For hematopoietic stem cell transplant (HSCT) patients or solid-organ transplant recipients:
- Use sterile water for flushing NGTs if the facility's water supply is contaminated with Legionella 1
- Standard drinking quality water is acceptable for immunocompetent patients 1
This distinction matters because Legionella-contaminated water poses serious infection risks to severely immunocompromised patients. 1
Medication Administration Context
When using the NGT for drug delivery, the flushing protocol becomes even more important:
- Never mix medications before administration through the tube 1
- Administer drugs individually with 30 mL water flushes between each medication 1
- Adequate flushing technique is more critical than adding agents like heparin to prevent occlusion 1
Using at least 30 mL of water for irrigation when giving medicines through small diameter nasogastric tubes significantly reduces tube occlusions. 1
Common Pitfalls to Avoid
Do not use inadequate flush volumes—less than 30 mL increases occlusion risk, particularly in small-bore tubes. 1
Avoid acidic beverages like cranberry juice or carbonated drinks for flushing, as these can degrade the tube material and promote blockages. 2
Do not use excessive force when flushing; resistance may indicate obstruction or malposition requiring further evaluation rather than forceful irrigation. 3
Troubleshooting Occluded Tubes
If an NGT becomes blocked despite proper flushing:
- First attempt: 40-60 mL of warm water with gentle pressure, which clears approximately one-third of obstructions 2
- Second-line: alkaline pancreatic enzyme solution if warm water fails, showing 96% success rate for formula-related clogs 2
- Last resort: mechanical devices or tube replacement only after enzymatic treatment fails 2
Position the patient upright during flushing attempts to minimize aspiration risk. 2