If your Paradigm pump has been not been exposed to powerful magnetic fields, such as those found near MRI machines, you have nothing to worry about. Go about your merry way and keep up the good work. In the unlikely event that such exposure has occurred, however, you need to be aware that it may cause the pump’s motor to malfunction and significantly over-deliver insulin, causing severe hypoglycemia.
As a result of this potential, the FDA has, based upon Medtronic’s voluntary report, identified certain Paradigm pumps as subject to a Class II recall. (The action is described by Medtronic as a Class II field correction rather than a recall because no pump need be returned unless it has been actually damaged by magnetic exposure.)
Medtronic reports that on April 24, 2007, the company sent a warning letter, enclosed in a red envelope, to 200,000 Paradigm pump purchasers, as well to 30,000 healthcare practitioners, including every prescriber of their pumps, and every one of the over 14,000 MRI facilities in the United States. The patient letter read as follows:
Recently, we have become aware of cases where exposure to Magnetic Resonance Imaging (MRI) has resulted in damage to the component that monitors and controls the movement of the motor used in Medtronic MiniMed Paradigm insulin infusion pumps. Although the insulin pumps exhibited alarms as a result of this damage, in some cases, users have cleared these alarms and continued to use the pump. Under these conditions, the insulin pump will exhibit significant over-delivery of insulin, potentially causing severe hypoglycemia.
Medtronic MiniMed (along with other insulin infusion pump manufacturers) has always cautioned users to avoid exposing their infusion pump to strong magnetic fields, such as those associated with MRI machines. Until recently, all testing has indicated this exposure would cause significant pump damage and prevent MiniMed Paradigm insulin pumps from delivering any insulin following this exposure. However, we now know that significant over-delivery of insulin can occur following this exposure.
In light of this new information, we are reminding insulin pump users not to expose your insulin pump to strong magnetic fields such as those generated by MRI equipment. YOUR INSULIN PUMP MUST BE REMOVED AND KEPT OUTSIDE THE PROCEDURE ROOM IF YOU ARE UNDERGOING MRI.
If the insulin pump is damaged by exposure to a high strength magnetic field, the insulin pump will typically provide multiple and frequent alarms such as “motor error” alarms (especially after rewind), A35 alarms and A43 alarms. In addition, the pump will no longer provide a “low reservoir” alert prior to an empty reservoir and the actual volume in the reservoir will be less than the amount displayed on the pump’s status screen. IF YOU SUSPECT THE PUMP MAY HAVE BEEN EXPOSED TO MRI OR OTHER VERY STRONG MAGNETIC FIELD, DISCONTINUE USE OF THE PUMP AND CONTACT THE MEDTRONIC MINIMED 24-HOUR HELP LINE AT 800-826-2099 FOR FURTHER ASSISTANCE.
Please note that MiniMed Paradigm insulin infusion pumps have undergone extensive testing with devices such as airport metal detectors, electronic article surveillance equipment and cellular phones and we have confirmed that exposure to these devices will not adversely affect pump operation.
If you have any additional questions regarding this letter or any other questions regarding our products, please feel free to contact the Medtronic MiniMed 24-Hour Help Line at 800-826-2099.
Nearly three months later, in its July 11, 2007, weekly Enforcement Report, the FDA announced that Medtronic had initiated action regarding Paradigm pumps that the FDA categorized as a Class II recall.
The FDA report read as follows:
PRODUCT: Medtronic MiniMed Paradigm Insulin Infusion Pumps for the following Paradigm models: MMT-511, MMT-512, MMT-712, MMT-515, MMT-715, MMT-522 and MMT-722, Recall # Z-1007-2007
CODE: All serial numbers for the following Paradigm models: MMT-51 1, MMT-512, MMT-712, MMT-515, MMT-715, MMT-522 and MMT-722
RECALLING FIRM/MANUFACTURER: Medtronic MiniMed, Northridge, CA, by letters on April 24, 2007. Firm initiated recall is ongoing.
REASON: Exposure to Magnetic Resonance Imaging (MRI) has resulted in damage to the component that monitors and controls movement of the motor in the MiniMed Paradigm insulin infusion pump. Although there were alarms as a result of the damage, some users cleared these alarms and continued using the pump. Under such conditions, the pump will significantly over-deliver; potentially causing severe hypoglycemia.
VOLUME OF PRODUCT IN COMMERCE: 334,000 pumps
DISTRIBUTION: Nationwide and Internationally
On July 14, Medtronic posted an announcement on the website Insulin-Pumpers.org, stating the following:
“Recently, Medtronic became aware of cases where exposure to strong magnetic fields like Magnetic Resonance Imaging (MRI) resulted in damage to Medtronic Paradigm insulin infusion pumps. Medtronic has taken this situation very seriously, and we have voluntarily notified our patients, physicians and the FDA about these incidences, reinforcing the need for caution when using our insulin infusion pumps while in close proximity to strong magnetic fields like MRIs.
The FDA has agreed with our assessment of the situation, and categorized this announcement as a Class II Field Correction, requiring us only to notify patients of the potential risk MRIs pose to their insulin pumps. Patients should not be concerned or take any further action unless they believe their Paradigm insulin pump has been exposed to an MRI machine. Patients should not return their Paradigm insulin pump to Medtronic unless they believe this exposure has taken place.
Extensive testing with other magnetized devices such as airport metal detectors, electronic article surveillance equipment and cellular phones will not adversely affect pump operation.”
Medtronic asserts that it has handled the situation more than aggressively by intensifying its already strong warnings against exposing pumps to magnetic fields. We did have a few concerns, however. For one, why is there no fail-safe mechanism that automatically shuts down the pump in the event of magnetic damage that might cause insulin over-delivery? As the Medtronic letter states, the pump does sound an alarm, but it is a generic alarm that pump users may be inclined to simply ignore.
To address our concerns, we spoke with Medtronic and contacted the FDA. Steve Sabicer of Medtronic notes that since May, when Medtronic discovered the potential for over-delivery of insulin, the company has not only voluntarily notified all its customers and distributors (as well as the FDA), but has also included a symbol on each pump that warns of exposure to magnetic fields. With regard to the absence of a fail-safe feature, Mr. Sabicer states that Medtronic will work to design future insulin pump models to ensure they cannot over-deliver insulin in the event of magnetic exposure. In the meantime, he emphasizes, exposure to strong magnetic fields is forbidden for insulin pumps, and patients should contact Medtronic if they suspect such exposure.
We were also concerned by the fact that according to the FDA’s records, five adverse events related to the MRI issue were recorded after Medtronic’s letters were sent. In that regard, Mr. Sabicer reports that three of the five pumps in question passed all in-house inspections and were returned to their owners. In the other two cases, both patients exhibited hypoglycemia with no long-term adverse effects. Although the hypoglycemic events could not be definitively attributed to MRI exposure or even to the insulin pumps, the pumps were repaired or replaced.
Based upon information from the FDA, the word “recall” is rather misleading in this case because it seems to imply that all pumps must be returned. In truth, however, the word “recall” is used by the FDA to announce a variety of far less drastic actions. As the FDA website states, “A medical device recall does not always mean that you must stop using the product or return it to the company. A recall sometimes means that the medical device needs to be checked, adjusted, or fixed….A recall is either a correction or a removal depending on where the action takes place. A correction addresses a problem with a medical device in the place where it is used or sold.” Actions that may be considered recalls include: inspecting the device for problems; repairing the device; re-labeling the device; or notifying patients of a problem.
With regard to the steps Medtronic took to notify its clients, the FDA states, “In a Class II recall, the company notifies their customers (i.e. distributors or vendors) and sometimes asks them to notify the intended recipients of the device. The FDA generally does not issue a press release or expect the company to issue a press release for Class II recalls.”
According to Medtronic, no action is required from any customer who has not exposed a pump to strong magnetic fields. If you have done so, however, you should stop using your pump immediately and contact Medtronic. Their customer service representatives can guide you through a simple test that will discern if your pump has been affected. If it has, the company will replace your pump if it still under warranty.