Case Study: When silent changes in a device cause incompatibility with another

Note: this article is a summary of the original article published on the Let's Talk Risk! newsletter on Substack, a reader-supported publication. Read the full article here.

Summary

This case study is based on a recent safety communication from the FDA which advised healthcare providers to not use Cardinal Health Monoject(TM) syringes with certain syringe pumps and patient controlled analgesia (PCA) pumps due to an incompatibility issue. These devices are used to deliver controlled amounts of potent, life-saving or life-sustaining medications to patients in a healthcare facility. This may result in pump issues leading to delay or interruption of treatment.

This issue also led to a Class I recall of certain infusion pumps that were validated with an older version of these syringes.

The main issue

According to the FDA safety communication:

In June 2023, Cardinal Health began distributing Monoject syringes branded as “Cardinal Health” Monoject syringes. These new syringes differ from the previously branded “Covidien” Monoject syringes as they have different dimensions (example shown in image below) and are made by a different contract manufacturer. The dimensional changes made to the Cardinal Health Monoject syringes, when used with syringe pumps or PCA pumps, may result in recognition, compatibility, and pump performance issues such as overdose, underdose, delay in therapy, and delays in occlusion alarms.

Dimensional changes noted in the Cardinal Health Monoject syringes are likely to result in the following issues in the affected infusion pumps:

1. Syringe module: user selects the correct volume Monoject syringe, but the pump calculates incorrect volume, which will affect the delivery rate.
2. PCA module: the system does not recognize the installed syringe, which will lead to delay in therapy.

The main issue here is that both the infusion pump manufacturer and the healthcare provider are unaware of changes in the syringe dimensions under new branding. The syringe is an important part of the overall system, but the infusion pump manufacturer has no control over changes in its design. This leads to the use of a non-validated syringe in this system.

Who is responsible?

This is a tricky question!

The short answer is that no single party has the sole responsibility and we all have a role to play in this complex system of healthcare delivery to ensure patient safety.

1. Infusion pump manufacturers are ultimately responsible for the safety and effectiveness of their devices. Although, the syringe is a safety-critical component of their system, they are regulated as a separate medical device. These types of syringes are becoming increasingly commoditized and syringe manufacturers may change their designs due to cost or competitive pressures. However, the infusion pump manufacturers need to ensure their pump systems always remain validated when their customers begin to use another off-the-shelf syringe model.
2. Users at a healthcare facility do not have any control over changes in the system and its components. They are trained on the system as designed, and expect it to be safe and effective when operated according to the manufacturer’s instructions. Procurement function at these facility is likely to treat syringes used in the system as a disposable commodity. They may not realize that the syringe model/brand has changed and that it may affect pump performance.
3. Syringe manufacturer may not fully understand the impact of seemingly small changes in dimensions. These syringes are used in many different applications not only in infusion pumps. It may not be practicable for them to inform users of potential safety issues due to incompatibility in a broad range of use cases.
4. ISO 7886-2:2020 applies to syringes for use with power-driven syringe pumps, but it also recognizes significant limitations in standardization of features that enable automatic syringe identification by an infusion pump. The standard recognizes the combination of a power-driven syringe pump and a syringe as a complete system. It advises manufacturers of different components to communicate with each other all relevant design changes that can affect the overall system performance. However, it is not practical in light of the fragmented nature of the syringe manufacturing industry.
5. The US FDA has the primary responsibility for public safety in the United States, but its regulatory framework lacks a systems-approach to medical devices. Each medical device is regulated on an individual basis. Unless a manufacturer owns every single component in their device, FDA cannot hold them directly responsible for issues related to components from other registered manufacturers.

If you manufacture infusion pump systems, consider these best practices:

1. Consider a systems approach to safety and performance
2. Optimize the extent of risk control but adapt to a changing environment through active post-market surveillance
3. Improve cross-functional collaboration, especially among Marketing, Medical Safety, Quality Assurance and Engineering

Consider this simple governance structure in your post-market surveillance program:

In conclusion

This case study illustrates the challenge in maintaining safety and effectiveness of complex medical devices, especially when they utilize safety-critical components from different manufacturers.

Patient safety is inadvertently compromised when design changes are made in a safety-critical component, such as a syringe used in an infusion pump, and the users and manufacturers have no information about these changes. In a complex healthcare delivery environment with multiple stakeholders, no single party has the sole responsibility for patient safety. However, since the infusion pump is used to directly control the delivery of life-saving or life-sustaining medication, the manufacturer of these infusion systems bears a higher degree of responsibility.

It is a good practice to consider principles of systems safety engineering in the design of these devices. Understandably, risk control decisions involve making trade-offs to balance the needs of different stakeholders. But it is also important to actively monitor and adapt to changes in the post-market phase. Finally, creating and nurturing a collaborative environment, especially among Quality, Medical Safety, Engineering and Marketing, can help achieve business results through a robust post-market surveillance process.

References

1. FDA safety communication: Do Not Use Cardinal Health Monoject Syringes with Syringe Pumps and PCA Pumps, November 20, 2023.
2. FDA Class I recall announcement: Becton Dickinson (BD)/Carefusion 303 Recalls Alaris Infusion Pumps Due to Compatibility Issues with Cardinal Health Monoject Syringes.
3. ISO 7886-2:2020: Sterile hypodermic syringes for single use - Part 2: Syringes for use with power-driven syringe pumps.
4. Case study: When silent changes in one device cause incompatibility in another.
5. Let's Talk Risk! newsletter