An invasive device is any medical device introduced into the body. They enter either through a break in the skin or an opening in the body. Examples of common invasive devices include:

• Urinary catheters: Urinary catheters are rubber or silicone tubes inserted through your urethra to your bladder. A small balloon at the tip of the catheter is inflated once the catheter is in your bladder. This is to keep the catheter from sliding back out. The urine drains through the catheter into a bag attached to the other end. Sometimes, someone only needs a one-time catheterization. The catheter is inserted only long enough to allow the urine to flow from the bladder and is then removed. This one-time catheter use is less likely to cause an infection but is more inconvenient for patients if their doctors need to make sure that all the urine has been collected and measured. Every time the catheter is inserted, there is a chance that bacteria may enter the urinary tract.
• Intravenous lines: IVs provide fluids, medications, and blood products directly into your bloodstream. A small narrow catheter is inserted into a vein, most often in your hand or lower arm. This catheter attaches to plastic tubing, which in turn attaches to a bag of fluid. In some cases, the catheter has a cap instead to close it off. If you need IV fluid or medication later, the cap is removed and the tubing is attached.
• PICC lines: Similar to an IV, a PICC line is a special catheter inserted into a vein in your upper arm. It stays in place for a longer period than a regular IV. A PICC line is very long and reaches nearly to your heart, to veins that are called central veins. A PICC line allows you to receive medications, such as an extended course of antibiotics or chemotherapy without having to restart IVs throughout the treatment. Patients can sometimes go home with a PICC line to continue their treatment at home. The line is removed when the antibiotics or other medicines are finished. A PICC line can also allow ICU patients to receive drugs that help keep their blood pressure stable.
• Central lines: Central lines or central venous catheters are similar to PICC lines but are usually inserted into a large vein in the chest or neck. They also stay in place for longer periods. These lines are also long enough to reach the central veins. They can do the same things as a PICC line while a patient is in the hospital, but they can’t be left in when a patient goes home. Central lines are the IV catheters most likely to become infected, so doctors only use them when they are clearly necessary.
• Colonoscopes and endoscopes: Scopes are used to perform colonoscopies and endoscopies (to view the upper part of the gastrointestinal system). If the equipment is not thoroughly cleaned or sterilized, it can introduce bacteria into the GI system, causing an infection.

Less frequently used devices include:

• Endotracheal tubes: An endotracheal tube is a semi-rigid tube inserted into your trachea (windpipe), most often through the mouth. The tube connects to a ventilator, a machine that helps you breathe. A surgeon may perform a tracheotomy if someone needs to be on a ventilator for an extended period. This provides an opening in the throat for the endotracheal tube.
• Nephrostomy tubes: A nephrostomy tube is a narrow flexible catheter inserted directly into your kidney through an incision in your skin. It’s attached to a bag that collects urine.
• Gastrostomy tubes: A gastrostomy tube is a large catheter that provides liquid food and medications directly into your stomach. The tube enters through an incision in your abdomen and hooks up to a special bag or a syringe.
• Traction pins: Traction pins are inserted through the skin into the bone to stabilize it as it heals. Usually, these pins are used for accidental breaks in bones.
• Defibrillators: Inserted in the chest and wired to the heart to ensure the heart beats effectively at the appropriate rate.
• Joint implants: Knees, hips, and other joints can be implanted to replace diseased or injured joints.

There are many more devices. These are just a few examples.

Invasive devices themselves don’t cause infections, but they can provide a route for bacteria and fungi to enter the body. This can happen in different ways.

During insertion

Healthcare professionals must maintain a sterile field when inserting devices. The equipment must be sterilized and sterility must be maintained during the insertion procedure. If the device is contaminated or becomes contaminated during the procedure, there is the risk of infection.

After insertion

The site or area must be kept as clean as possible after insertion. There is now an unnatural opening into the body that can allow bacteria and fungi to enter. Here are a few examples of how to reduce the risk of infection with some invasive medical devices.

Intravenous lines:

Most facilities have guidelines regarding how frequently to change IV lines and IV sites (where the catheter enters the skin). The most common recommendations are to change IV tubing every three to seven days, unless the patient is receiving blood products or fat emulsions. Tubing for these products need changes within 24 hours. Certain types of medications given by IV also require more frequent changes. While it can be painful to have an IV inserted, the catheter (“needle”) should be removed and the IV restarted in another area every 72 to 96 hours.

Signs of an infected IV site include redness around the catheter insertion site, pain, and skin that is warm to the touch.

PICC lines and central lines are not replaced at the same rate as IVs. Inserting these devices requires special care with surgical masks, gowns, and sterile gloves. This allows the devices to remain in place for longer, as long as they do not look infected.

Urinary catheters:

People with urinary catheters are at risk for developing urinary tract infections (UTIs). The catheter provides an opening into the bladder for bacteria to enter. Urinary catheters should never be left open to air. They should be attached to a closed-bag system, with the bag positioned lower than the body for urine flow. These should never be placed on the floor though. Bacteria may collect on the bag and then enter the system. The bag should be emptied at least every 8 hours or when it is full, whichever comes first. It is also important that good hygiene be given to the genital area on a regular basis.

Urinary catheters are inserted for a variety of reasons, but are not usually meant to be left in for long periods of time. A person may have a catheter after surgery or if they aren’t urinating. Occasionally, urinary catheters stay in longer than they should. If you have a urinary catheter, you can ask your healthcare professional each day if you still need the catheter.

Signs of a UTI include cloudy and/or foul-smelling urine, pain on urination and fever. Seniors may develop confusion and not show any of the typical signs.

Traction pins:

Traction pins go directly into the bone, so infections could delay bone healing if they develope in the bone itself. Pins are cleaned regularly as per your healthcare professional’s instructions, usually twice a day.

Signs of an infection in the pin area include redness and warmth around the area, swelling, increasing pain at the site, drainage or pus from the site, and fever.

If you have any invasive devices, watch for any signs and symptoms of infection and sepsis.