Catheters are flexible, hollow tubes used in various medical procedures. They are inserted into body cavities, ducts, or vessels for drainage, fluid administration, or to provide access for instruments. Catheters are manufactured from medical-grade materials and come in different levels of stiffness to suit their intended use. The process of inserting a catheter is known as catheterization.
Urinary Catheter Placement
Urinary catheters manage urine flow when an individual cannot empty their bladder naturally. They are used for conditions such as urinary retention, incontinence, or to facilitate drainage during and after surgery. Two primary sites for urinary catheter insertion are urethral and suprapubic.
Urethral Catheters
Urethral catheters, such as the Foley catheter, are inserted into the bladder through the urethra, the tube that carries urine out of the body. This method is used for short-term or long-term bladder drainage, collecting urine samples, or delivering medications directly into the bladder. A small balloon at the tip of the Foley catheter is inflated with sterile water once inside the bladder to hold it in place.
Suprapubic Catheters
Suprapubic catheters are an alternative for urinary drainage. This catheter is inserted into the bladder through a small incision in the lower abdomen, above the pubic bone. Suprapubic placement is chosen for long-term drainage or when urethral insertion is not feasible due to obstructions. Both urethral and suprapubic catheters connect to a drainage bag that collects the urine.
Intravenous Catheter Placement
Intravenous (IV) catheters are inserted into veins to administer fluids, medications, or blood products directly into the bloodstream. They are categorized into peripheral IVs and central venous catheters, differing in placement and duration of use.
Peripheral IVs
Peripheral IVs are inserted into smaller veins in the arms or hands. Common sites include the dorsal arch veins on the back of the hand, or veins in the forearm and upper arm. They are used for short-term access, such as for hydration, short courses of antibiotics, or during surgical procedures. Peripheral IVs are not suitable for all types of medications or long-term therapy.
Central Venous Catheters (CVCs)
Central venous catheters (CVCs) are placed into larger veins closer to the heart. Examples include the internal jugular vein in the neck, the subclavian vein under the collarbone, or the femoral vein in the groin. Types of CVCs include peripherally inserted central catheters (PICCs) or tunneled catheters. CVCs are used for longer-term treatments, such as chemotherapy, prolonged antibiotic therapy, or nutritional support. Their placement in larger veins allows for higher flow rates and less irritation from certain medications compared to peripheral IVs.
Specialized Catheter Placement
Beyond urinary and intravenous applications, catheters serve specialized roles in various medical fields. They access distinct body areas for specific diagnostic or therapeutic purposes. Each specialized catheter type is designed for its unique function and insertion site.
Cardiac Catheters
Cardiac catheters access the heart and its vessels for diagnostic procedures or interventional treatments. They are inserted into an artery or vein in the groin (femoral artery/vein), wrist (radial artery), or sometimes the arm or neck. Once inserted, they are guided through blood vessels to the heart, allowing for procedures like angiograms to visualize coronary arteries, measure pressures within heart chambers, or angioplasty to open blocked vessels.
Dialysis Catheters
Dialysis catheters provide access to the bloodstream for individuals undergoing hemodialysis, a treatment for kidney failure. They are inserted into large central veins, most commonly the internal jugular vein in the neck, or sometimes the subclavian or femoral veins. They feature a larger diameter to accommodate the high blood flow rates required for filtering waste products from the blood outside the body. Dialysis catheters can be temporary or tunneled for longer-term use.
Epidural Catheters
Epidural catheters are placed into the epidural space, an area surrounding the spinal cord. This space in the spine contains nerve roots that branch off the spinal cord. Insertion occurs in the lower back, allowing for the administration of pain-relieving medications, such as local anesthetics or narcotics, directly to the nerves. Epidural catheters are used for pain management during childbirth, after surgery, or for chronic pain conditions.
Peritoneal Dialysis Catheters
Peritoneal dialysis catheters are used for peritoneal dialysis, another method for treating kidney failure. They are surgically inserted into the abdominal wall to access the peritoneal cavity, the space within the abdomen that contains the digestive organs. The peritoneum, a thin membrane lining this cavity, acts as a natural filter. Dialysis fluid is introduced into this cavity through the catheter, dwells to absorb waste products from the blood, and is then drained out, allowing patients to perform dialysis treatments at home.