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Drainage and collection systems

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Several types of drainage systems are available to use for collecting urine from urinary catheters. The only type of catheter that does not warrant a drainage system is a straight catheter because you’ll drain the urine from this type of catheter directly into a basin or other container.

Drainage systems vary by manufacturer and by clinical site, but most share the same fundamental characteristics. Most drainage systems come in either a standard or a leg-bag style. There are different rationales for and advantages and disadvantages of each type of system.

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 6 hours. Overfull bags and bags that drag on the floor are more prone to leaking and becoming contaminated.

Always fit collection bags to either an appropriate, non-movable part of the patient’s bed or to the patient’s wheelchair. If you attach a standard bag to a patient’s wheelchair, though, it is important to consider the patient’s dignity and privacy. If possible, use a cloth covering so that the patient’s urine is not readily visible to others around them. With the drainage bag uncovered, patients 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 patient’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 patient’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. Some facilities promote cleansing collection bags with a diluted bleach solution. Studies have shown that this is an effective method of reducing infection as well as the cost of replacing equipment. However, some facilities elect to replace collection bags on a routine basis. Of course if a collection bag leaks, replace it.

Leg-bag drainage systems are another option for collecting the urine of patients with urinary catheters. Leg bags have the benefit of being smaller in size and attaching directly to the patient. The plastic collection bag is simply a smaller version of the standard bag and is attached using small elastic bands that wrap around the patient’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 patient’s autonomy and dignity. They are an excellent choice for patients who are able to participate in their own care. Many patients 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 patients who are confused or are not ambulatory.

Specimen collection

Urinary specimens are collected for a number of reasons, including ruling out infection and monitoring hydration status. The tests available and the methods for obtaining samples vary. Some yield immediate results while others require laboratory analysis.

Urinary samples obtained from a catheterization system are typically collected in the same manner no matter which tests the provider orders. Always collect specimens from the catheter’s tubing between the bladder and the collection bag. Never take a urine sample from the collection bag. After urine passes through the tubing into the collection bag, it sits in an unclean environment. Bacteria can develop in the collection bag, resulting in unreliable test results.

Most catheters have a small port located on the catheter’s tubing near the end of the catheter that is attached to the collection bag. To obtain a sample, cleanse the port using an alcohol swab. Then, using a sterile syringe, withdraw a sample of urine directly from the tubing of the catheter. Use surgical asepsis when obtaining the sample, transferring it to a sterile cup and affixing the lid, and transporting the sample. Label urine samples with the patient’s name, birth date, and the date/time the sample was obtained, along with any other information the facility’s policies require. Refrigerate them or place them on ice to preserve them until they are transported to a laboratory. The length of time between obtaining a sample and the laboratory analysis varies, so it is important to communicate clearly with the laboratory staff once you obtain a specimen.

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.

Although dipsticks provide immediate feedback, they are not considered diagnostic. A common temptation is to assume that a patient has a urinary tract infection based on a urine dipstick result. However, it has been found that most patients with catheters have positive findings on a urine dipstick because of chronic low levels of bacteria from catheterization.

In most settings, you do not need a provider’s order to perform a urine dipstick on a sample. But, if there are several positive findings, it may be helpful to keep the sample sterile and put it on ice while attempting to obtain an order for further testing (thus avoiding having to obtain two samples).

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 patients with an ineffective antibiotic. For this reason, many providers wait until the sensitivity results are available before prescribing antibiotic therapy.


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