What is the Difference Between an Open and Closed Enteral Feeding System?

November 19, 2025 •

3 min read

According to studies, closed enteral feeding systems have a significantly lower bacterial contamination rate compared to open systems, highlighting a key difference between an open and closed enteral feeding system. The choice between these two systems is critical for patient safety, infection control, and optimizing nutrition delivery in various healthcare settings.

Quick Summary

Closed enteral feeding systems are pre-filled and sterile, reducing contamination risk. In contrast, open systems use a manual preparation process, leading to increased potential exposure and shorter hang times.

Key Points

Contamination Risk: Open systems have a higher risk of bacterial contamination due to manual preparation, while closed systems are sealed and sterile.
Hang Time: Open systems typically allow for an 8-hour hang time, whereas sterile closed systems can hang safely for 24-48 hours.
Preparation Time: Closed systems are ready-to-hang, saving significant nursing time compared to the manual pouring required for open systems.
Cost Implications: While the initial unit cost of a closed system may be higher, overall costs can be lower due to reduced labor and formula waste.
Flexibility: Open systems offer more flexibility for adding modular nutrients, but closed systems are safer for standard, uninterrupted nutrition.
Nutrient Delivery: Longer hang times and reduced interruptions in closed systems generally lead to more consistent and complete nutrient delivery to the patient.
Patient Setting: Patient condition and location (e.g., hospital vs. home) influence the best choice, with closed systems often favored for high-risk, acute care patients.

Understanding Enteral Feeding Systems

Enteral feeding, or tube feeding, is a method of delivering nutrients directly to the stomach or small intestine for patients who are unable to consume enough food by mouth. The system used to administer this nutrition is a fundamental aspect of the process. The two primary types are open and closed systems, each with distinct characteristics that impact safety, cost, and workflow.

What is an Open Enteral Feeding System?

An open enteral feeding system requires manually pouring formula into a feeding bag from a can or container, increasing the potential for contamination during preparation and administration. This manual process adds labor and typically limits the 'hang time' to 8 hours in medical settings to minimize bacterial growth. However, open systems do offer flexibility for mixing formulas or adding nutrients.

What is a Closed Enteral Feeding System?

A closed enteral feeding system uses a sterile, pre-filled container that connects directly to the feeding tube set, maintaining a sealed environment. This significantly reduces the risk of contamination and allows for longer hang times, often 24 to 48 hours. Preparation is minimal, saving nursing time and labor costs.

Open vs. Closed Enteral Feeding System: A Direct Comparison


Characteristic	Open System	Closed System
Preparation	Manual pouring of formula from a container into a feeding bag.	Pre-filled, ready-to-use bag spiked directly to the feeding set.
Contamination Risk	Higher risk due to multiple points of environmental exposure.	Significantly lower risk due to sterile, sealed packaging.
Hang Time	Maximum 8 hours in clinical settings.	Maximum 24 to 48 hours, as per manufacturer guidelines.
Labor Costs	Higher due to manual preparation, labeling, and frequent changes.	Lower due to minimal preparation and less frequent system changes.
Formula Waste	Often higher due to 8-hour hang time and unused formula disposal.	Lower due to longer hang time, reducing the need to discard unused formula.
Flexibility	Allows for mixing, adding modules, or specialized adjustments.	Less flexible; additives require breaking the sterile seal, increasing contamination risk.
Nutrient Delivery	Can be less consistent due to manual refilling and hang time constraints.	Can provide more consistent and reliable nutrient delivery over 24-48 hours.
Initial Cost	Potentially lower initial formula cost per unit, but higher overall due to waste and labor.	Potentially higher initial formula cost, but lower total cost when factoring in labor and waste.

Advantages of Closed Enteral Feeding Systems

Closed systems are increasingly preferred in acute care due to reduced infection risk, improved patient safety, and efficiency. They offer enhanced efficiency by saving nursing time with less preparation and fewer bag changes. The longer hang times of 24-48 hours ensure more consistent nutrient delivery and less formula waste.

Disadvantages and Risks of Open Enteral Feeding Systems

Open systems, while flexible, carry a higher risk of bacterial contamination from environmental exposure and handling. The shorter 8-hour hang time can lead to suboptimal nutrient delivery and increased formula waste. The manual process also increases labor costs and the potential for errors.

Deciding Between Open and Closed Systems

The choice depends on clinical, logistical, and economic factors. Patient acuity, especially for those immunocompromised, favors closed systems due to reduced infection risk. Formula type is also a factor; specialized or powdered formulas may necessitate an open system. The care setting matters, with hospitals often preferring closed systems for infection control, while home care might consider other factors. A cost-benefit analysis should consider not just initial formula cost but also labor, waste, and infection-related expenses. For patients needing frequent formula adjustments, a hybrid approach or careful open system use might be needed.

Conclusion: Choosing the Right Enteral Feeding System

The core difference between open and closed enteral feeding systems lies in administration and infection control. Closed systems prioritize safety through sterility and reduced contamination, offering longer hang times and less labor. Open systems provide flexibility but increase contamination risk and waste. While open systems have specific uses, guidelines often favor closed systems for their safety and efficiency. The decision should be a comprehensive assessment of patient needs to ensure optimal nutritional care.

Learn more about safe enteral feeding practices from reputable sources like the American Society for Parenteral and Enteral Nutrition (ASPEN).

Frequently Asked Questions

The primary safety advantage is the significantly reduced risk of bacterial contamination. Since the formula is pre-filled in a sterile bag and never exposed to the outside environment, it prevents environmental microbes from entering the feeding system.

The hang time is shorter because the formula is manually transferred to an open bag, which exposes it to air and increases the risk of bacterial growth. To minimize this risk, any formula hanging for more than 8 hours in a clinical setting must be discarded.

The initial cost per unit of a closed system formula may be higher, but they can be more cost-effective in the long run. This is due to reduced nursing labor time, less formula waste, and a lower risk of infection-related costs.

An open system might be preferred when a patient requires a specialized formula not available in a closed-system bag. It also offers more flexibility for clinicians to add modular nutrients or use reconstituted powdered formulas.

Adding supplements to a closed system requires breaking the sterile seal, which introduces a risk of contamination. If additives are necessary, the system essentially becomes an 'open' one, and strict hang time limits must be followed.

If an open-system bag hangs for longer than the recommended time (typically 8 hours), the formula inside is at a higher risk of bacterial growth. This could lead to a gastrointestinal infection or other complications for the patient.

The closed enteral feeding system requires significantly less nursing labor. The pre-filled bags eliminate the manual steps of pouring, labeling, and frequent bag changes, freeing up more time for patient care.

No, the type of feeding tube itself does not generally dictate whether an open or closed system is used. The choice is primarily based on factors related to formula preparation, patient safety, and clinical needs.

Closed systems can potentially lead to less formula waste due to longer hang times. However, they may generate more plastic waste from the pre-filled bags compared to the reusable bags sometimes used with open systems. This is a factor that can be considered in a comprehensive evaluation.

Modular nutrients are individual components like protein, carbohydrates, or fats that can be added to a base formula to meet specific patient needs. Open systems allow for easier addition of these modules compared to closed systems, where adding them breaks the sterile seal.

Yes, open systems may still be used in hospitals in specific situations, such as when a patient requires a unique formula not available in a closed system, or when frequent modular additions are necessary. However, strict adherence to hang time protocols and aseptic technique is critical to minimize risks.

ASPEN stands for the American Society for Parenteral and Enteral Nutrition. They provide evidence-based guidelines for nutrition support practices, including recommendations for enteral feeding systems that often highlight the safety benefits of closed systems.

No, open and closed systems use different types of bags and administration sets. Closed systems use pre-filled, sterile bags that connect directly to a dedicated set, while open systems use bags designed for manual filling from other containers.