From the Guidelines
For enteral feeds, a free water flush of 30 mL is recommended before, between, and after each drug administration, as well as before starting and after completion of feeds in case of bolus administration or 4-hourly if continuous feeding. This recommendation is based on the strongest and most recent evidence from the ESPEN guideline on home enteral nutrition 1. The purpose of these water flushes is to maintain adequate hydration, prevent tube occlusion, reduce medication interactions with formula, and help maintain electrolyte balance.
When considering the administration of medicines through an enteral feeding tube, it is essential to note that the site of the tube tip and the type of tube material can affect drug efficacy and interactions 1. For example, certain medicines may bind to enteral formula or the tube material, reducing their efficacy. Therefore, flushing the tube with 30 mL of water before, between, and after each drug administration is crucial to ensure proper medication delivery and prevent tube clogging.
In addition to medication administration, regular flushing of the tube with 30 mL of water is necessary to prevent blockages, which can occur due to the chemistry of the protein-rich solutions, the viscosity of the fluid, and the small diameter of the tube lumen 1. This is particularly important for patients with increased fluid requirements or those at risk for fluid overload, as the flush volume may need to be adjusted based on individual patient needs. Sterile water should be used for immunocompromised patients, while tap water is generally acceptable for most others.
Key considerations for free water flushes in enteral feeds include:
- Flushing the tube with 30 mL of water before, between, and after each drug administration
- Flushing the tube with 30 mL of water before starting and after completion of feeds in case of bolus administration or 4-hourly if continuous feeding
- Adjusting the flush volume based on individual patient needs, particularly for those with fluid restrictions or at risk for fluid overload
- Using sterile water for immunocompromised patients and tap water for most others.
From the Research
Enteral Tube Feeding and Free Water Flush
- The amount of free water to flush enteral feeds is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, the studies suggest that the type of water used for flushing enteral tubes can be either tap water or sterile water, with some institutions recommending the use of tap water as a cost-effective alternative 2.
- The frequency of flushing enteral tubes varies among nurses, with some flushing before and after each feeding, and others flushing every 4 hours 3.
- The use of free water flush is important to maintain patency of the enteral tube and prevent complications such as dehydration and malnutrition 4, 5, 6.
- Estimating fluid needs in patients receiving enteral tube feeding can be challenging, and close monitoring is required to prevent fluid imbalance-related complications 5, 6.
- Simplistic equations are often used to determine fluid needs, but these equations have not been validated through evidenced-based science and can overestimate or underestimate fluid needs in older adults 6.