Urinary Catheter Skills

• The primary organs involved in urinary elimination are the kidneys. The kidneys are located in the retro peritoneal space just below the rib-cage on the back. The external landmark for the kidneys is known as the costovertebral angle. The left kidney is slightly higher in position than the right kidney because the right kidney lies beneath the liver.

• The primary sections of the kidneys are the pelvis, the medulla, and the cortex. Most of the blood supply to the kidneys arrives via the renal arteries, which branch from the abdominal aorta.

  • The kidneys are innervated by the sympathetic component of the autonomic nervous system. It is the nephrons that perform most of the bodily functions of filtering, reabsorbing, and excreting.

• Each nephron contains a glomerulus, proximal convoluted tubule, descending loop of Henle, ascending loop of Henle, and collecting tubule. Each component serves different functions in the filtration, re-absorption, and excretion processes. Ultimately, the kidneys filter 7 liters of fluid per hour, 99% of which is reabsorbed. Most adults produce between 1 to 3 liters of urine per day. The kidneys also play a role in the production of erythropoietin, which contributes to red blood cell production, and in the activation of vitamin D.

• Several hormones are created in the kidneys. The kidneys produce an enzyme

  called renin.

  • Renin regulates blood flow, glomerular filtration, and blood pressure.

• Blood pressure is closely related to proper filtration. Renin also activates angiotensinogen called angiotensin I. Angiotensin I is then converted by angiotensin-converting enzyme (ACE) into its most active form, angiotensin II. Angiotensin II increases blood volume and blood pressure.

• Antidiuretic hormone (ADH) plays a major role in the volume of urine that is actually produced. High levels of ADH limit urine production, while low levels of ADH generate large amounts of urine. ADH is produced in the posterior pituitary gland.

• Once filtered in the kidneys, urine passes through the ureters into the bladder, the storage reservoir for urine. Once an adequate amount of urine collects in the bladder (250 to 400 mL), a signal is sent to the brain to indicate the need to urinate. The person then relaxes the internal and external sphincters located at the bottom of the bladder and the urethra. Urine passes from the bladder through the urethra where it exits the body. The act of urinating is sometimes called micturition.

Equipment

• Urinary catheters come in several varieties, including straight catheters, indwelling (Foley) catheters, urinary retention (multiple-lumen) catheters, Coude catheters, condom catheters, and suprapubic catheters.

• Straight, indwelling, retention, Coude, and suprapubic catheters all involve a narrow tube that provides a passageway for urine from the bladder to a collection bag outside the body.

  • Straight catheters are for one-time use and are

    removed immediately after the insertion and

    drainage of urine.

  • Indwelling catheters are used short-term and

    provide a closed drainage system for urine.

  • Retention catheters are most commonly used

    post-operatively because they have multiple

    lumens to allow for the drainage of urine,

    irrigation of the bladder, and instillation of

    medications into the bladder.

• Coude catheters are used for clients who have prostatic hyperplasia (enlargement). This type of catheter has a curved tip to allow for easier insertion.

• Suprapubic catheters are similar to indwelling

  catheters except that they are placed through a

  surgical opening in the abdomen rather than through the urethra.

• Condom catheters have a latex or silicone sheath to place over the penis.

• Catheters come in many different sizes and materials (latex, silicone). A client's size, age, pathology, and potential allergies to materials are all considerations when selecting a catheter. Indwelling, retention, Coude, and suprapubic catheters have a small balloon at their tip to keep them in place.

  • Balloon and catheter sizes also vary and are chosen based on the client's age and size and the clinical indications for catheterization.

• Always use sterile water to inflate catheter balloons. Whether or not to pretest balloon

  inflation varies with the manufacturers' recommendations. Evidence suggests that testing the balloon may lead to integrity

  compromise and failure.

Standard collection bag

• A standard collection bag is the most commonly used drainage system. The primary benefit of using a standard collection bag is its size; it has a large capacity (much greater than the human bladder) for holding urine. Despite its capacity, however, do not wait until it is completely full to empty a standard collection bag. Most facilities' policies require emptying bags a minimum of every 8 hours.

  • Overfull bags and bags that drag on the floor are more prone to leaking and becoming contaminated. Always fit collection bags to a non-movable part of the client's bed or to the client's wheelchair. If you attach a standard bag to a client's wheelchair, it is important to consider the client's dignity and privacy.

• If possible, use a cloth covering so that the client's urine is not readily visible to others around them. With the drainage bag uncovered, clients might feel embarrassed or uncomfortable and thus avoid social or public situations.

• Most standard collection bags have either free-flowing drainage or a one-way valve at the top of the bag that attaches to the end of the catheter away from the client's body. Collection bags with one-way valves may help prevent the reflux of urine from the collection bag back up into the bladder.

• Nevertheless, most collection bags allow free-flowing drainage from the catheter into the bag. It is always important to place collection bags at a level below the client's bladder to avoid reflux. On the opposite end of the collection bag near the bottom is a port for emptying the bag.

  • Most bags have some type of drain valve in place to prevent leaks. To drain urine from the collection bag, open the drain valve and allow the urine to flow into a urinal, a basin, or a measuring container. Then, flush the urine down a toilet.

Leg-bag drainage systems

• These are another option for collecting the urine of clients with urinary catheters. Leg

  bags have the benefit of being smaller in size and attaching directly to the client. The plastic collection bag is simply a smaller version of the standard bag and is attached using small elastic bands that wrap around the client's leg.

  • Leg bags typically hold much smaller amounts of urine than standard bags hold, but they are easily concealed beneath clothing, which helps to promote the client's autonomy and dignity. They are an excellent choice for clients who are able to participate in their own care. Many clients are able to empty leg bags on their own with adequate training.

• The valve systems in leg bags are very similar to those in standard bags. There is a one-way valve that allows urine to flow from the catheter into the bag and a drain valve at the bottom of the bag for draining the bag's contents. A disadvantage of leg bags is that they must be emptied more often. Leg bags can also be difficult to use with clients who are confused or are not ambulatory.

• Collection bags vary in size and location on the body. Most clients prefer either a standard collection bag or a smaller leg bag. Most catheterizations require sterile insertion except for condom catheters (which require medical asepsis). Nurses can insert or place all but one type of catheter; a physician must insert a suprapubic catheter surgically.

Insertion

• Assessment of the client before and after catheterization is critical. Allergies, mental status, urine quality, voiding patterns, vital signs, skin assessment, and abdominal assessment are all essential.

  • Urine assessment includes color, odor, presence of sediment or blood, and amount. Assess voiding patterns both for increased and for decreased urination.

• Check vital signs to monitor for fever, alterations in blood pressure, and any other changes.

  • Skin assessment includes hydration status and potential areas for skin breakdown.

• Abdominal assessment provides information about bladder distention in clients unable to sense the need to urinate. Always be sure to

  document all pertinent findings in the client's chart.

Basic laboratory studies performed on urine

• A urine dipstick is a mainstay for nurses who need the immediate information this method can provide. Dipsticks are small pieces of paper with squares of chemically treated areas that identify pH, specific gravity (an indicator of hydration status), white blood cell content, the presence of blood, and other factors. A urinalysis is a formal laboratory study of a urine sample. It requires a provider's order.

• Urinalysis provides in-depth information about a urine sample from blood to protein to white blood cells. Although a urinalysis can confirm that there are bacteria present in the urine, it cannot determine the type of bacteria.

• Therefore, urinalysis is often ordered along with culture and sensitivity. Urine culture and sensitivity are components of a laboratory evaluation of a urine sample that provide valuable information for treating infection. Essentially, if bacteria are identified, the culture grows samples of the bacteria for determination of their type.

• Then, this grown sample is used to determine which antibiotics kill the bacteria. This test helps prevent treating clients with an ineffective antibiotic. For this reason, many providers wait until the sensitivity results are available before prescribing antibiotic therapy.