Pump design flaws demonstrate need for practitioner involvement in FMEA
From the May 4, 2006 issue
Problem: On April 28, 2006, FDA issued a Preliminary* Public Health Notification to healthcare providers regarding safety issues with Baxter’s COLLEAGUE infusion pumps (www.fda.gov/cdrh/safety/042806-baxter.html). Within the past year, Baxter has issued four urgent safety notices and recalls of these pumps (which can be accessed from the link above). Most of the cited problems are design flaws that cause a stoppage of the pump or under-infusion of the solution. Some of the problems include:
Before the recent FDA notification about these problems, ISMP learned of yet another error-prone condition when programming the Colleague Guardian infusion pump. The pharmacist who reported the problem described an error with a heparin infusion (25,000 units/250 mL) running at 1,300 units/hour (13 mL/ hour). When replacing the heparin bag, the nurse correctly entered 250 mL in the volume to be infused field and pressed the confirm settings key. She accidentally pressed this button twice, which changed the programming mode from “primary” to “piggyback.” The pump then defaulted to a rate of infusion previously used for a piggyback solution administered to this patient, 125 mL/hour. The nurse did not notice the change in infusion rate, even though the pump prompted her to enter the volume to be infused again. After entering 250 mL in the volume field, a note appeared on the screen saying:
- A false air detection alarm
- Worn gearbox that leads to failure codes
- External communication port failures
- Misaligned head components during IV set loading in the presence of an obstruction
- Upstream occlusions that may not be detected with certain BURETROL sets
- Depleted batteries (leading to interruption of therapy and unrecognized loss of GUARDIAN memory)
- Disruptions in internal pump communications leading to failure codes
- Pressing the power off key when intending to press the start key directly above it.
will run at 13.0 mL/hr
when piggyback is complete
The nurse read the note and saw that the heparin infusion was to run at 13 mL/hour. However, she missed the third line that stated, “when piggyback is complete.” She again pressed the same key she had used before to confirm settings, but this time, it changed the programming mode back to the primary solution. After the nurse pressed the start button, the patient received the heparin infusion at 125 mL/hour until the bag was empty 2 hours later. (See www.ismp.org/sc?k=baxterpump for screen shots of the pump.) Luckily, the 10-fold overdose did not lead to harm. Shortly after reporting this error, the same pharmacist reported a 10-fold overdose of an insulin infusion had occurred in the same manner.
There are several design flaws that contributed to these errors, most notably:
- The key used to confirm settings can also be used to change from a primary to secondary mode of infusion. Since a change mode key already exists on the pump, not allowing the confirm settings key to be used to change the mode may be a better design.
- While in the piggyback mode, the pump defaults to the infusion rate used for a prior piggyback. A better design may require the user to enter the rate of infusion each time.
- Informational notes about piggyback solutions list the primary solution first, followed by a message that this solution will infuse after the piggyback is complete. Making it clear that the piggyback will infuse first would be a better screen display.
Safe Practice Recommendations: To reduce the risk of patient harm, FDA has urged Colleague pump users to take important safety steps as recommended by the manufacturer in its safety notices. FDA stressed the need to:
- Avoid using the pumps if delaying or interrupting therapy may be life threatening
- Have a contingency plan for any disruption of infusion therapy (e.g., back-up pumps)
- Monitor patients/pump settings frequently
- Report any problems to Baxter and FDA
- If relying on Colleague pumps, consider evaluating other pumps for use.
FDA is working with Baxter to correct the problems with the Colleague pump as quickly as possible. Replacement units will be cleared for marketing as soon as the company is able to provide reasonable assurance that they will function reliably.
These pump design flaws and others we have reported in the newsletter present a compelling argument for pump manufacturers and users to perform a thorough failure mode and effects analysis (FMEA) before marketing or using infusion pumps. Many manufacturers already conduct this analysis, but they may not include practitioners who would use the pumps and safety specialists. Potential or current users of pumps also need to conduct an FMEA. An example of questions to ask during the analysis is provided below and on page 4 of the PDF version of the newsletter. A literature search of published problems with the particular infusion pump model should be undertaken, and additional questions should be added to the list as needed. Vendor input should be sought whenever necessary to answer the questions. Once the FMEA is completed, implement safety measures to reduce the risk of the failures uncovered during the analysis. Also, pumps should be introduced slowly. Test them in a small, controlled setting first to ensure that all safety features are operational and to correct any unanticipated problems.
*Understanding of the issues is evolving.