An infusion pump is a medical device that delivers fluids, such as nutrients and medications, into a patient’s body in controlled amounts. Infusion pumps are in widespread use in clinical settings such as hospitals, nursing homes, and in the home.
In general, an infusion pump is operated by a trained user, who programs the rate and duration of fluid delivery through a built-in software interface. Infusion pumps offer significant advantages over manual administration of fluids, including the ability to deliver fluids in very small volumes, and the ability to deliver fluids at precisely programmed rates or automated intervals. They can deliver nutrients or medications, such as insulin or other hormones, antibiotics, chemotherapy drugs, and pain relievers.
There are many types of infusion pumps, including large volume, patient-controlled analgesia (PCA), elastomeric, syringe, enteral, and insulin pumps,. Some are designed mainly for stationary use at a patient’s bedside. Others, called ambulatory infusion pumps, are designed to be portable or wearable.
Because infusion pumps are frequently used to administer critical fluids, including high-risk medications, pump failures can have significant implications for patient safety. Many infusion pumps are equipped with safety features, such as alarms or other operator alerts that are intended to activate in the event of a problem. For example, some pumps are designed to alert users when air or another blockage is detected in the tubing that delivers fluid to the patient. Some newer infusion pumps, often called smart pumps, are designed to alert the user when there is a risk of an adverse drug interaction, or when the user sets the pump’s parameters outside of specified safety limits.
Over the past several years, significant safety issues related to infusion pumps have come to FDA’s attention. These issues can compromise the safe use of external infusion pumps and lead to over- or under-infusion, missed treatments, or delayed therapy.
- Certified to have no single point of failure. That is, no single cause of failure should cause the pump to silently fail to operate correctly. It should at least stop pumping and make at least an audible error indication. This is a minimum requirement on all human-rated infusion pumps of whatever age. It is not required for veterinary infusion pumps.
- Batteries, so the pump can operate if the power fails or is unplugged.
- Anti-free-flow devices prevent blood from draining from the patient, or infusate from freely entering the patient, when the infusion pump is being set up.
- A “down pressure” sensor will detect when the patient’s vein is blocked, or the line to the patient is kinked. This may be configurable for high (subcutaneous and epidural) or low (venous) applications.
- An “air-in-line” detector. A typical detector will use an ultrasonic transmitter and receiver to detect when air is being pumped. Some pumps actually measure the volume, and may even have configurable volumes, from 0.1 to 2 ml of air. None of these amounts can cause harm, but sometimes the air can interfere with the infusion of a low-dose medicine.
- An “up pressure” sensor can detect when the bag or syringe is empty, or even if the bag or syringe is being squeezed.
- A drug library with customizable programmable limits for individual drugs that helps to avoid medication errors.
- Mechanisms to avoid uncontrolled flow of drugs in large volume pumps (often in combination with a giving st based free flow clamp) and increasingly also in syringe pumps (piston-brake)
- Many pumps include an internal electronic log of the last several thousand therapy events. These are usually tagged with the time and date from the pump’s clock. Usually, erasing the log is a feature protected by a security code, specifically to detect staff abuse of the pump or patient.
- Many makes of infusion pump can be configured to display only a small subset of features while they are operating, in order to prevent tampering by patients, untrained staff and visitors.