Delivering nutrition through a bolus feed is an important part of caring for patients who are unable to eat normally. A bolus feed provides nutrition quickly through a tube into the stomach or small intestine. There are three main methods used to deliver a bolus feed: gravity bolus, pump-assisted bolus, and syringe bolus.
Gravity Bolus
A gravity bolus utilizes gravity to deliver formula or blended food into the stomach or small intestine. To deliver a gravity bolus, the feed container is held upright above the level of the feeding tube. Then the clamp on the feeding tube is opened to allow the formula to flow in by gravity. Once the desired volume has infused, the clamp is closed. The steps are:
- Check for residual volume and reflux if needed as per facility policy
- Wash hands and gather supplies – feed, water, tube feeding pump/pole/hook if using, gloves, tissues, pitcher for water flushes
- Ensure patient is in an upright sitting position (at least 30-45 degrees)
- Attach feed container 3-4 feet above patient’s stomach level
- Prime the tubing and close the clamp
- Connect tube to patient’s feeding tube
- Open clamp and allow formula to flow in by gravity
- When desired volume infused, close clamp
- Flush with 30-60mL water
- Clamp tube and disconnect feed tubing
- Wipe mouth and record procedure
Advantages of a gravity bolus include simplicity and low cost. No feeding pump is required. It also allows the patient more mobility. However, flow rate can vary based on formula thickness and elevation of container. The residual volume should be checked before feeding to prevent overfilling the stomach.
Pump-Assisted Bolus
A pump-assisted bolus uses an enteral feeding pump to deliver the feed. This provides more consistent flow control compared to a gravity bolus. The pump is set to deliver a certain feed volume over a specified time period. Typical feed durations are 10-20 minutes. The steps are:
- Check for residual volume and reflux if needed
- Wash hands and gather supplies
- Ensure patient is upright at 30-45 degrees
- Prime the pump tubing with feed
- Connect to patient’s feeding tube
- Program the pump with feed amount and duration
- Start the pump
- When completed, flush with 30-60mL water
- Clamp tube and disconnect
- Wipe mouth and record procedure
The advantages of a pump assisted bolus include better flow control and consistent volumes. It prevents too rapid infusions. The disadvantages are it requires a feeding pump, prevents patient mobility during feeding, and may be more time consuming to set up.
Syringe Bolus
With a syringe bolus method, a large syringe (35-60mL) is used to deliver the feed. The plunger is depressed by hand to administer the feed. The steps are:
- Check for residual volume and reflux if needed
- Draw up feeding formula into syringe
- Position patient upright at least 30-45 degrees
- Attach syringe to feeding tube
- Give feeding slowly over 3-5 minutes
- When complete, flush with water and disconnect
- Wipe mouth and record procedure
The advantages of a syringe bolus include simplicity and low cost. No feeding pump is required. It gives the nurse good control over the flow rate. However, it may take more time and several refills of the syringe to administer large volumes. The flow rate can also vary each time the plunger is pushed.
Conclusion
In summary, the three main methods for delivering a bolus enteral feeding are:
Gravity Bolus
– Formula flows in by gravity from an upright container
– Simple, inexpensive, promotes patient mobility
– Flow rate can vary
Pump-Assisted Bolus
– Formula delivered by an enteral feeding pump
– Consistent flow rates and volumes
– Requires a feeding pump
Syringe Bolus
– Formula delivered by a large syringe
– Nurse controls flow rate
– Time consuming for large volumes
The best method depends on the patient’s condition, feed tolerance, mobility needs, and care setting resources. Proper training and monitoring are essential for safe bolus feeding by any method. Following evidence-based facility protocols helps ensure appropriate feed delivery to meet patient nutrition needs.