Healthcare practitioners are the primary users of medical devices for direct patient care. As such, they are in the best position to recognize problems (such as in the example above) that result from the use of medical devices. 82% of all device‐related incidents are discovered by nurses or physicians. The outcome of a device‐related adverse event or product problem, as with any other medical product (i.e., drug, biologic, or special nutritional product), can be serious and result in illness, injury, or even death

The active monitoring and reporting of medical device problems by health professionals and the facilities in which they work leads to improved patient care and increased safety, both for the patient and for the operator of the device. The reporting of device problems to the manufacturer and/or the Food and Drug Administration (FDA), the federal agency which regulates medical devices, is a critical communication link to ensure the safety and effectiveness of medical devices marketed in the United States.

The sooner that FDA learns about a problem, the sooner the agency can take action to protect patient and user safety. Sometimes a single report can initiate this action. Several case examples, based on actual reports received by FDA, are found throughout this article.

DEFINITION OF A MEDICAL DEVICE

“There probably are not many terms in the English language that cover as much ground as ‘medical devices.’ Those words encompass a great diversity of products from bandages to heart valves, from thermometers to the most advanced therapeutic and diagnostic machinery”    David A. Kessler, MD ,

Former Commissioner Food and Drugs

The Federal Food, Drug, and Cosmetic Act) defines a medical device a "an instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article,...which is...intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease...,or intended to affect the structure or any function of the body..., and which does not achieve any of its principal intended purposes through chemical action within or on the body...and which is not dependent upon being metabolized for the achievement of any of its principal intended purposes." Therefore, medical devices are different from drugs, which work by chemical or metabolic reactions within or on the body to achieve their principal intended effects.

There are over 1800 categories of medical devices, and they vary in both complexity and risk potential.  Some of the more common medical devices include ventilators , heart valves , pacemakers, X‐ray machines, infusion pumps, implants, biopsy equipment, and ultrasound. Accessories to devices such as hoses, tubing, or software controlling a device are also regulated as devices.

Less complicated devices include sutures, bedpans, thermometers, sharps containers, and medical gloves.

Examples of lesser known products that are also regulated as devices are laboratory diagnostic tests; sterilants and disinfectants used for medical devices; water treatment used for dialysis; cementing agents; sunglasses; topical wound dressings; home diagnostic kits; and even leeches.

CASE EXAMPLE: An 81 year old female was undergoing surgery for a left hip implant. The surgery was proceeding routinely until the surgeon placed bone cement into the acetabular area in preparation to fit the hip implant. The patient went into anaphylactic shock and died.

Q ­ Is bone cement a medical device? A ­ Yes.

Simply, if a product is not a medication (drug or biologic) and is used for diagnosis or treatment, it is probably a medical device.

An understanding of the routes by which medical devices come to be marketed, and the limitations of what is known about a device before it is marketed, offers valuable insight into why it is so important that health professionals closely monitor medical devices which they use in their clinical practice.

THE PREMARKET REVIEW

Before medical devices can be made available for use by the healthcare community, the manufacturer must first gain approval or permission for marketing by F DA. Part of the premarket review requires that device manufacturers develop good testing and manufacturing practices (which are inspected by FDA). The desired outcome of this process is the production of a consistently well‐made, reliable, safe, and effective medical device which the user can depend upon to function for the specified life of the product.

In 1976, Congress amended the Food, Drug, and Cosmetic Act, and the FDA received the authority to require that new medical devices be proven safe and effective before being marketed.

Prior to that time, FDA could only take action against hazardous or misrepresented devices after they were in the marketplace. The 1976 law created two primary routes to market medical devices, based on risk potential and product complexity:

1)      The 510(k) or premarket notification is the simplest and most common route. For a device to be cleared via this route, the manufacturer must demonstrate t h at the new product is "substantially equivalent" to a device that is already on the market (the assumption is that the new product is safe and effective for the intended use, performs consistently, and is as good as what is currently available on the market). FDA then reviews the device by assessing the similarities to a device(s) already on the market. Examples include infusion pumps, foley catheters, and endotracheal tubes.

2)      The PMA or premarket approval application route must be used if the new medical device is not similar to a device already on the market. In this case, the manufacturer must conduct clinical and pre clinical scientific studies to demonstrate that the device is safe and effective for its intended uses. Examples of devices in which a PMA was filed include stentless heart valves, coated vascular grafts, and implantable devices that combine cardiac pacing with defibrillation.

Note: Medical devices which were on the market prior to 1976 were "grandfathered," which means they were allowed to remain in general use, but are subject to an FDA request for safety and effectiveness data from studies.

In spite of a rigorous premarket review process, medical devices (or any other medical products) are only as safe as the information known at that moment in time. For example, clinical trials for a medical device may involve only a few hundred patients; medical devices are typically "bench‐tested" (rather than tested in real‐life clinical situations); and unlike drugs, most durable medical devices have no established end‐of‐life (i.e. it is unknown how long a device can be used and how frequently it can be used). Therefore, healthcare professionals cannot assume that FDA has determined definitively that a device cleared for marketing is absolutely safe for human use.

The accumulation, review, and evaluation of information that is gained about a product once it is cleared and available for marketing is called Postmarket Surveillance.

THE IMPORTANCE OF POSTMARKET SURVEILLANCE

Once the premarket process is completed and a device goes into widespread use, unforeseen problems can still arise. For example, adverse effects that occur relatively rarely or relate to product labeling (including instructions) or user technique and skill, cannot always be detected during the premarket review. Furthermore, questions related to durability, biocompatibility, and toxicology in humans may not be answered with certainty until a device has been on the market for a number of years.

Hospitals and other clinical settings monitor for problems with devices and other products within their facilities .

These internal surveillance systems help to track and trend problems within the facility to improve the delivery of patient care.

FDA and manufacturers utilize a variety of postmarket surveillance tools to signal important events or trends in order to help identify the cause of device failures and to take appropriate action. In addition, medical devices continue to be tested by the manufacturer even after approval. FDA also performs in‐house laboratory research to further analyze problems related to device safety.

To optimize postmarket surveillance in the detection of medical device problems, FDA and manufacturers are dependent upon individual healthcare professionals and the facilities in which they work to report problems with medical devices.