Collecting a Single-Voided Urine Specimen
A single-voided urine specimen often is ordered. Tests are done to determine the efficiency of the kidneys or to examine the urine for abnormalities. In Practice: Nursing Procedure 52-3 reviews the steps for collecting a singlevoided urine specimen.
Nursing Alert In some cases, such as when doing drug testing, an observed urine specimen must be obtained. In this case, the nurse must actually observe the client voiding into the specimen container Be aware that there are a number of methods used to avoid detection when giving a false urine specimen. If you are expected to obtain accurate urine samples for drug testing, you will require special in-service education.
Collecting a Clean-Catch or Midstream Urine Specimen
By using the clean-catch or midstream method, a specimen is obtained with minimal contamination from external sources without inserting a sterile catheter. Because the genital area and urethral opening are cleansed before the specimen is obtained, and the sample is taken after some urine has already been passed, any bacteria found in the laboratory tests are most likely from urine in the bladder. In Practice: Nursing Care Guidelines 52-3 describes measures for collecting a clean-catch or midstream urine specimen.
Collecting a 24-Hour Urine Specimen
An accumulated quantity of urine gives more detailed information than does a single specimen because the accumulated specimen better shows the type and quantity of wastes being excreted by the kidneys. The urine is usually collected for 24 hours or for some part of that period, depending on the specific order. In Practice: Nursing Procedure 52-4 describes the actions for collecting a 24-hour urine specimen.
Collecting the Fractional Urine Specimen
A 24-hour fractional specimen is collected to determine amounts and characteristics of urine during various periods (“fractions”) of the day. Follow these actions in collecting the 24-hour fractional urine specimen:
• Follow all the steps as when collecting other urine specimens. Be sure to follow Standard Precautions.
• Depending on the order, determine how many bottles you will need. Often fractional specimens are obtained for 6-hour periods of the day: 12 midnight to 6 AM; 6 AM to 12 noon; 12 noon to 6 pm; and 6 pm to 12 midnight. If this is the case, you need four specimen bottles, covers, and labels. Label all bottles before you begin. Indicate times.
• Begin by asking the client to void. Rationale: Each new time
slot begins with an empty bladder.
• Collect all urine from the first fraction of the day in bottle #1. Be sure to ask the client to void at the end of that period. Rationale: Each time slot must contain all the urine from that time slot. Each new time slot begins with an empty bladder. This ensures that all the urine from that specific time slot is in the collection bottle.
• Continue for the other “fractions” of the day. The client should end the total day with an empty bladder.
IN PRACTICE NURSING CARE GUIDELINES 52-3
COLLECTING CLEAN-CATCH MIDSTREAM URINE SPECIMENS
• Label the container before giving it to the client. Rationale: The bottle may become soiled or wet, making it difficult and unsanitary to attach a label. This step also avoids confusion and misidentification.
• Instruct the client to cleanse the urethral area thoroughly Rationale:Thorough cleansing limits external bacteria from entering the specimen. It is important to evaluate only bacteria that appear in the urine and not bacteria from the external genitalia.
• Use prepackaged wipes, if available. Rationale: These wipes are sterile, which avoids introducing added contamination. They are also convenient.
• Instruct the female client to cleanse from front to back and to cleanse each side with a separate wipe or a separate area of the wipe, saving the last for the urethral area itself. Rationale: Cleansing in this manner avoids contaminating the vaginal and urethral areas with bacteria from the anal area. This ensures that the urethral area is as clean as possible.
• Instruct the male client to cleanse the penis using a circular motion and going outward from the urethral meatus. The first wipe or portion of the wipe is used for the urethral meatus. The next wipe cleanses the end of the penis, and the last wipe again cleanses the urethral opening. Rationale: The urethral area should be kept the cleanest.
• Instruct both male and female clients to void a small amount into the toilet and to hold the rest of their urine. Rationale: The voided urine flushes the urethra and urethral meatus of external contaminants.
• Then, instruct the client to void into the sterile container, catching the midstream urine. Rationale: This is the urine that will yield the most accurate information about the condition of the kidneys and bladder.
• Finally instruct the client to void the last of the stream into the toilet. Rationale: The midstream urine is most characteristic of the urine produced by the kidney and is the best indicator of kidney function. The first portion of the voiding is considered contaminated by the urethra and the last part does not yield as much information.
• Clients unable to stop the stream of urine once it has started may be instructed to slip the container into the stream shortly after beginning to urinate and remove the container before the bladder is emptied or when the necessary amount of urine has been collected. Rationale: The nurse can help the client understand why it is important to obtain the specimen from the center of the stream (midstream).
• Take or send the specimen to the laboratory without delay Rationale: Delay could cause a false-positive result, particularly in the case of a urine culture.
• Be sure to wear gloves when handling all specimens. Rationale: Using gloves reduces the risk of infection transmission.
• Store all specimens on ice or in a specimen refrigerator during the 24-hour collection period. Rationale: Urine will begin to decompose faster at room temperature. A specific refrigerator should be available. Be sure to prevent cross-contamination if samples from more than one client are in this refrigerator.
• Take the specimens to the laboratory immediately at the end of the 24-hour collection period. Document the following in the nursing notes: the total volume of urine collected; the time the collection was completed; the time the specimen was sent to the laboratory; characteristics of the urine, such as color or the presence of sediment or a very strong odor; and any other pertinent data. Rationale: The testing is begun immediately, before the urine decomposes. Your observations are very important as part of the testing process.
Nursing Alert If any urine is spilled or accidentally discarded during a 24-hour urine collection period or a specific fractional collection, you must report this error and anticipate that the collection may need to be restarted. If the collection is restarted, urine collected to that point is discarded before the process begins again. New containers are then used. Remember: All 24-hour collections begin with an empty bladder.
Collecting a Specimen From an Indwelling Catheter
Some clients have catheters (tubes) inserted into the urinary bladder that drain urine continuously (an indwelling catheter or retention catheter). Most likely, a catheterized specimen will be obtained only if the person is unconscious or has a retention catheter. (Otherwise, the previously described midstream method is most often used, to prevent the possibility of contaminating the bladder.)
The urinary bladder is considered to be a sterile area. Contamination of any part of any catheter system can cause an infection because microorganisms can travel up the catheter into the bladder. Therefore, when collecting a catheterized specimen, be particularly careful not to endanger the client by contaminating the catheter system. Take care not to allow the collecting bag to be elevated above the level of the bladder. This action could result in urine flowing back into the bladder, carrying microorganisms with it. Also do not allow the collecting bag to touch the floor, which is a highly contaminated area. In Practice: Nursing Procedure 52-5 identifies instructions for collecting a urine specimen from a urinary catheter. In acute healthcare facilities, this is most often done using a blunt-tipped cannula or needleless system. In some cases, a syringe and needle are used. The procedure using both types of equipment is basically the same.
Key Concept The reason for using a blunt-tipped cannula or needleless system is to avoid accidental needle-stick injuries to client or staff.The instructions for using these systems are found on the packaging and should be read before the nurse attempts to access a needleless port.
Obtaining a One-Time Catheterized Urine Specimen
Circumstances may dictate that a urine specimen must be obtained through catheterization. A primary provider’s order is usually required. In this situation, a straight catheter is generally used; it is inserted into the bladder and removed when the specimen is collected. It is unusual for this procedure to be ordered as a stand-alone procedure, because catheterization puts the client at risk for a urinary tract infection (UTI). For this reason, a catheterized urine specimen is usually not done unless there is a specific contraindication for a midstream clean-catch specimen, another catheterized procedure is to be done at the same time, or the catheter is to be left in place after the specimen is obtained. The one-time catheterized specimen procedure may be used for clients in whom a clean-catch specimen cannot be obtained, such as the client who is unconscious, confused, or otherwise unable to obtain a clean-catch specimen.
To obtain a one-time catheterized urine specimen, the client is asked to notify the nurse when he or she feels the urge to void, if he or she is able to do so. The nurse then catheter-izes the client to obtain the necessary specimen or to determine the residual urine volume (see following discussion).
Residual Urine. A one-time catheterized urine specimen may be ordered along with an order to determine residual urine volume. (Residual urine is urine that remains in the bladder after voiding.) In this case, the client is asked to empty the bladder completely and then notify the nurse. The catheterization is done immediately, and the amount of urine obtained is measured and documented. A significant amount of residual urine volume indicates that the client may have a bladder outlet obstruction or deficient contractility in the detrusor muscles (the muscles that push down). The amount of residual urine to be considered significant is determined by the healthcare practitioner. (Generally, residual urine should not exceed 50 mL in the young or middle-aged person or 50-100 mL in the older adult.) A computerized Doppler device is also available to determine residual urine volume.
The written order for catheterization may specify that the catheter is to be left in place if the residual urine volume is significant (e.g., “100 mL or more”). In this case, the initial catheterization will be done with an indwelling type of catheter (e.g., Foley) in anticipation of the possibility that the catheter will be left in place after the procedure. Rationale: This would prevent catheterizing the client twice and further exposing him or her to the risk of infection.
Nursing Alert Strict sterile technique must be followed in doing catheterization to prevent urinary tract infections. The Centers for Disease Control reports that 40% of all nosocomial (hospital acquired) infections are related to infections of the urinary tract.
THE STOOL SPECIMEN
The stool specimen provides information about the functioning of the gastrointestinal (GI) system and its accessory organs. The most common test is for the presence of occult (hidden) blood in stool, which indicates bleeding somewhere in the GI tract. Another common test is for ova and parasites (O&P), which indicates the presence of intestinal parasites or their eggs (ova). In Practice: Nursing Procedure 52-6 gives details for collecting stool specimens.
In the ambulatory care setting, in the home, or on the nursing unit, stools are tested for occult blood using the Hemoccult or Hematest brand methods. Sometimes, these tests are referred to as guaiac tests, named for the substance used to cause the tested occult blood to change color (Fig. 52-3). In these tests, the nurse places a smear of stool on the testing card with a special narrow stick and adds a drop of a reagent (testing solution). After a timed interval, the smear is compared with a color chart to determine the presence of blood. Always check the testing kit for any special instructions. The test is simple enough to conduct in the client’s bathroom or a utility room. As always, be sure to wear gloves when handling stool.
Special Considerations: LIFESPAN
Collecting a Stool Specimen From a Child
When an infant has diarrhea and the stool specimen is to be examined, place the entire diaper in a biohazard bag, label it, and take or send the diaper to the laboratory immediately. In some cases, the entire stool is to be examined, whether it is formed or not. Otherwise, if the stool is formed and a partial stool sample is required, remove a sample of the stool from the diaper with a tongue blade or specimen stick and place in a specimen container, as for an adult.
Nursing Alert Be aware that false-positive results may occur with guaiac tests. "False-positives” can be caused by the client having consumed large amounts of rare red meat or certain foods, such as radishes, tomatoes, beets, horseradish, or some melons. In addition, the client should not take more than 250 mg per day of vitamin C and should not take aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) for 3 days before the test. Be sure to let the client know about the possibility of false-positive results if you perform a test and it seems to be positive. Usually, three separate specimens are collected on 3 separate days before a determination of positive or negative is made. If test results are repeatedly positive, additional examinations, such as colonoscopy are necessary
THE SPUTUM SPECIMEN
For clients with some respiratory disorders, a sputum specimen may be obtained and sent to the laboratory for culture or other examination. This test is often used to determine the presence of the tubercle bacillus, the causative organism for tuberculosis. Often, such specimens are collected 3 days in a row. The best time to obtain a sputum specimen is soon after the client awakens in the morning. (Sputum accumulates in the airways during the night and often is more easily expelled by coughing in the early morning.) The first specimen of the morning is considered to be the most accurate. Obtain the specimen before the client eats, uses mouthwash, or brushes the teeth.
Observe Standard Precautions when collecting sputum. Keep the inside of the specimen container sterile. A sterile container helps to ensure that organisms cultured from the specimen will be contained in the specimen and not be a result of a contaminated container. Keep the cover on the container as much as possible to prevent contamination by particles in the air and the spread of organisms outward from the sputum specimen.
FIGURE 52-3 · Hemoccult testing. (A) While wearing gloves, place a smear of stool on the testing card with a special specimen stick. (B) Add a drop of a reagent. (C) After the prescribed length of time observe the smear for a blue discoloration, indicating the presence of blood. (In this test, the outside of the test kit is kept as clean as possible. The inside is highly contaminated. Dispose of the kit per agency protocol.)
When the cover is removed, place the cover on the counter or table with the inside up. (Only the outside of the cover should touch the table.) You should touch only the outside of the container and its cover. Rationale: The inside of the container is considered to be sterile; the outside is contaminated.
Consuming adequate amounts of fluid and breathing humidified air or aerosolized medications often help to loosen and liquefy secretions, making it easier for the client to expectorate (cough up secretions). If the client has used aerosolized medications, document this in the health record, along with the fact that a specimen has been collected. In Practice: Nursing Procedure 52-7 gives tips for collecting a sputum specimen.
The provider may write an order to measure sputum. If so, do this in one of two ways:
1. If enough sputum is collected in a graduated specimen container, read the amount directly; or
2. Pour an equal amount of water into an identical container and measure the water.
In addition, do the following:
• Weigh the specimen, if ordered. Do so on a balance scale, subtracting the initial weight of the container.
• Take the specimen to the laboratory immediately after collection. Rationale: A delay may alter the result of a culture.
• Label the container appropriately and notify the laboratory personnel that this is a sputum specimen. Make sure the proper requests are in place.
• Document the sputum’s amount (copious, moderate, small), color, and consistency.
NCLEX Alert NCLEX concepts include the principles of Standard Precautions and Transmission-based Precautions. Situations may require knowledge of the principles of prevention of infections and the avoidance of cross contamination.
Nursing Alert
• The sputum specimen is considered highly contaminated. Treat it with caution.
• Paper tissues used by any client also are considered contaminated. Dispose of them properly as per agency protocol.
• Wear gloves when handling tissues and sputum specimens and when providing any nursing care, if the client is coughing up sputum.
• Goggles and a mask or a full face shield may be necessary to protect the nurse from droplet secretions, particularly if the client is coughing or spitting. (A "spit shield” is also available. This is a net-type device that is placed over the client’s head so he or she cannot spit at others.)
KEY POINTS
• Standard Precautions are used when collecting specimens involving any body fluids.
• Careful handwashing limits the transfer of microorganisms from one person to another and retards the spread of disease.
• Fluid intake includes all fluids consumed through the GI system (by mouth or tube feeding) and fluids taken as part of IV therapy or total parenteral nutrition.
• Output includes urine and all other fluids leaving the body by any means. This includes wound drainage, emesis (vomiting), watery diarrhea, bleeding, and nasogastric (NG) or other suction returns.
• Routine specimen collection is usually scheduled for early in the morning.
• Any specimen collected should be transported or sent to the laboratory immediately, to ensure the most accurate results.
• Urine specimens collected include single-voided, clean-catch (or midstream), catheterized, 24-hour, and fractional urine specimens.
• Stool specimens are typically evaluated for occult blood and for ova and parasites.
• Sputum specimen collection requires the client to expectorate or cough up secretions from lower in the respiratory tract. The early-morning specimen is the most accurate.
• All body fluids are considered to be biohazardous materials.
• A vital part of nursing function is to check the results of any test and notify the appropriate person if any abnormalities are noted.
• Collection of blood specimens may be a nursing task, depending on state licensure regulations.
