Specimen Collection - Skills Modules 2.0 - My ATI (Week 2)

Cultures

the type of culture (aerobic or anaerobic), the site from which the specimen was obtained (nose, throat, wound, vein), if a wound culture, a description of the wound and the drainage (color, odor, consistency).

At 0700, a nurse obtains a capillary blood glucose result of 180 mg/dL from a patient who has diabetes mellitus. Which of the following is a correct action for the nurse to take?

Administer insulin according to the patient's sliding scale orders.

Point of care - fecal occult blood testing

An FOBT, or guaiac test, is a widely used screening tool for colorectal cancer. It is routinely recommended for asymptomatic patients over the age of 50 as a prerequisite to colonoscopy. The provider can perform an FOBT during a digital rectal examination (DRE) in the provider's office, or the patient can take the FOBT cards home for serial testing. Studies indicate that home testing with three different samples is more accurate than a one-time office FOBT after a digital rectal examination. FOBT samples should come from fresh stools that are not contaminated with water or urine. You will instruct the patient to collect stool samples and place them on the developing cards with a small wooden stick that comes with the sample kit. There are typically two windows on each card on which to place a smear of the sample. The cards are then developed with a special solution that will react to blood if present in the stool. Often, blood is difficult to identify in the stool, which is why it is called occult blood. If the origin of the bleeding is high in the gastrointestinal (GI) tract, the stool may appear dark or tarry. If the bleeding is from a hemorrhoid somewhere low on the GI tract or from menstrual bleeding, the stool may have bright red streaks of blood and might not yield an accurate result. However, sometimes the stool appears completely normal but still contains blood, which is why an FOBT is so helpful. If a patient has a positive FOBT result, the provider will probably order additional diagnostic tests to identify the location of the bleeding and to help develop a treatment plan. Standard FOBTs should be used only with stool samples. They are not accurate for identifying blood in gastric contents.

My 4-year-old patient is afraid of needles. How can I reduce her anxiety while also obtaining an adequate blood sample for her prescribed tests?

Apply a topical anesthetic cream as directed to the area you select for the venipuncture. Use the smallest size needle available for collecting the required amount of blood. Butterfly needles are quite small; you can use them to access the smaller veins in the hands, for example. Some facilities have pediatric child-life specialists who can provide life-size dolls to use when explaining medical procedures. These specialists can show the child what will be done and allow her to play with some of the equipment (modified, of course, for safety) to ease her anxiety.

Capillary blood samples

Capillary blood sampling is typically done as a point-of-care test. It is used widely for blood glucose determinations, but new rapid testing with fingerstick technology is also being used to determine bleeding times and HIV status. For capillary sampling, you'll use a small lancet or poking device to puncture the skin to obtain a single drop of blood. The usual site is the fingers, but any exposed skin area can be used. Many patients who require repeated fingersticks welcome the use of other sites as fingers do become sore. The palms, forearms, and earlobes are common alternatives. Clean the skin at selected site first; otherwise, any substance the skin contacted previously could alter the test results. Use a facility-approved antiseptic or soap and water to cleanse the skin. Do not use alcohol because it can harden the skin surface, which can be a problem when repeated fingersticks are required. Be sure the selected puncture site is vascular. If the patient's circulation is poor, too little blood might be available when the skin is punctured. Having the patient warm his hands by rubbing them together or dangle them may help with perfusion prior to a fingerstick. Milking the puncture site to get a full blood sample is not recommended as it could lyse (break) the blood cells and alter the test results. Always explain the procedure to the patient first, and allow him to choose or approve the puncture site. To minimize the pain of the puncture when it is a fingerstick, place the lancet on the side of the patient's finger. Avoid the central tip of the finger, which contains a more dense nerve supply. Once you have obtained the sample, place a tissue or a cotton ball at the site, and have the patient apply pressure. Most fingerstick sites do not continue to bleed; therefore, they do not require bandaging. Document the method of sample collection, the patient's tolerance, and any pertinent physical findings in the patient's medical record.

When your patient is a child

Children can obtain clean-catch urine samples, but they might find it easier with a sterile receptacle placed within the toilet for specimen collection. Pour the sample from the receptacle into a sterile collection cup. Then, with the lid in place on the cup, label the sample and send it to the laboratory for analysis. Clear plastic single-use bags can be used for infants or toddlers. The bags have a self-adhesive material which fits around the child's urethral meatus. Do not squeeze samples from a wet diaper or pad, as the results are likely to be inaccurate. Some studies have demonstrated accuracy of some urine tests when urine is collected in a syringe from a disposable diaper. However, the preferred and more reliable collection method for all urine tests is a collection cup or bag.

Specimen collection - throat and gum

Collect throat specimens from the patient's oropharynx or tonsillar region using a sterile swab. A proper collection should include rubbing the sterile swab over the tonsillar area on the right and moving across the right arch, the uvula, and then the left arch and tonsillar area. Use caution not to touch the gums, tongue, or teeth with the sterile swab. Collect gum specimens by lightly scraping the inside of a patient's cheek with a sterile swab. These methods of specimen collection are used both for point-of-care tests and for laboratory analysis. The most commonly performed point-of-care tests for throat specimens are rapid streptococcus (rapid strep) and rapid mononucleosis (monospot). The most commonly performed gum swabbing point-of-care test is rapid human immunodeficiency virus (HIV) testing. Because point-of-care tests are not as accurate as laboratory tests, confirmatory tests are recommended for positive findings. Storage conditions, inadequate specimen collection, and some patient factors can lead to false positive and false negative results. You'll place specimens for laboratory analysis in sterile tubes, label the tubes, and transport them to a laboratory for analysis. Be sure to document the specimen collection technique, the patient's tolerance, and any pertinent data in the patient's medical record.

Laboratory requisition forms

Depending on your facility's policies, you might have to fill out a laboratory form with demographic patient information, the provider's information, the tests ordered, the time the specimen was collected, and the diagnosis supporting the tests ordered. Laboratory requisition forms often require additional information about the patient's insurance carrier, any additional responsible parties, and insurance group numbers. Some laboratory requisition forms require documentation of the exact site from which the specimen was collected, vital signs, and other pertinent information. Typically, the requisition form is transported with the specimen to the laboratory.

Laboratory analysis of sputum cultures

Different methods of laboratory analysis require different transport media. Routine cultures, transported in a sterile container, identify basic bacterial pathology. Sensitivity testing completes the process by determining the correct antibiotic treatment. Acid-fast bacilli (AFB) testing requires a sterile container and is performed on three serial samples to detect tuberculosis. Cytology testing requires a special preservative and identifies which form of lung cancer a patient has (small cell, oat cell, or large cell). For all, you'll complete the appropriate laboratory requisition form with pertinent patient data and send it with the specimen for analysis.

Tips for documentation

Documentation of the site, date, time, and tolerance of the sampling or testing procedure is very important. This documentation also allows the nurse to record any findings that may be helpful to know later about the patient's status. Having consistent parallel documentation on the specimen, in the patient's medical record, and at the laboratory is important for promoting accuracy and the timely delivery of care. Documentation for specimen collection and point-of-care testing should also include any other pertinent data and the following information specific to specimen collection and point-of-care testing.

When your patient is female

Female patients sometimes encounter difficulty because of the potential to contaminate the sample with skin or bacteria from the external genitalia surrounding the urethra. Instruct female patients to wash their hands, hold the collection cup in one hand, and use the other hand to part their external genitalia to help reduce contamination. Clean the area with an antiseptic wipe, moving from front to back. Repeat three times using a fresh wipe each time (left side, right side, and center). Tell them to allow the initial stream of urine to go into the toilet, pause, and then urinate into the collection cup. With the lid in place on the cup, label the sample and send it to the laboratory for analysis.

Blood glucose testing

For blood glucose testing of patients who have diabetes, you'll use a glucometer or a blood sugar meter with small test strips to "read" the blood sample. These systems require proper calibration, storage of supplies, and matching of lot numbers. Poor storage of glucose test strips can lead to falsely high and falsely low readings. Typically, these test strips come in a vial that you'll close and store at room temperature or as directed by the manufacturer. Always check the expiration date on the test strip vial before using to ensure accurate readings. Acceptable fasting blood glucose ranges vary with the source, but are generally in the vicinity of 70 and 105 mg/dL. A reading above the expected range warrants following the provider's orders based on the specific result. Glucometers do have limits on the range of blood glucose they can detect accurately. Blood glucose readings lower than 60 or higher than 400 require retesting and possibly sending a blood sample to the laboratory for analysis. Because bedside glucometers are not as accurate as laboratory testing, it is imperative to repeat any tests with unusually high or low readings to ensure that the patient is not inappropriately treated.

A nursing assistant collected a clean-catch urine specimen from my patient for laboratory urinalysis. By the time I got to the specimen to send it, an hour had passed since it was collected. Can I still send this sample to the laboratory?

Fresh urine samples for laboratory analysis should be placed immediately into a sterile container for transport. They should be kept on ice and transported to the laboratory within 2 hours of collection. Urine that is standing unrefrigerated can become more alkaline, and that can encourage bacterial growth and reduce the validity of the results. This sample was not placed on ice, so you should discard it and start over.

My patient has a nasogastric feeding tube in place. What should the pH be if the tube is placed correctly in the stomach?

Gastric pH should be more acidic than secretions from other areas of the body, which are generally below 5.5. By checking gastric secretions, you can verify both the placement of the nasogastric (NG) tube and the relative rate of gastric emptying (by measuring the residual volume of gastric contents). NG tube placement is initially confirmed by chest x-ray; this is the most reliable method for checking placement. Second only to x-ray, pH testing is considered a reliable method for confirming NG tube placement in the stomach.

A nurse is caring for a female patient who needs to collect a midstream urine specimen. Which of the following actions should the nurse take?

Have the patient urinate a small amount of urine before starting the collection.

My patient performed a home pregnancy test after missing a menstrual period. She said the test was negative, but a subsequent blood test confirmed that she is pregnant. How should I explain the discrepancy?

Home pregnancy tests are commonly misread, either because the test has expired, it was done too soon after a missed period so the hormone levels were not high enough to show a positive finding, or the sample was collected incorrectly. Many women read the test too soon or wait too long to read the test and end up with false results. Most home pregnancy tests have a very specific window of time between collecting the sample and reading the test. Also, some tests are more sensitive than others to the hormone that indicates pregnancy. For all these reasons, following up with a medical provider to confirm the results is always recommended.

Specimen labeling

In addition to documenting the specifics in the patient's medical record, appropriate labeling of the specimen collected is crucial. Include identifying information such as the patient's name, date of birth, and room number on the specimen's label, along with the date and time of collection (as many have a specific time range during which they remain viable). Facilities vary in the data they require on the label, so be sure to follow the appropriate procedure. Specimen label errors can lead to misdiagnosis, delayed diagnosis, and critical medication errors from unnecessary treatment. The most common specimen labeling errors are mislabeling, no labeling, partial or incomplete labeling, and illegible handwriting on the label. Labeling errors have been found to be more common in facilities that do not have an on-site laboratory and do not use laboratory-trained staff to obtain specimens. Studies have demonstrated that facilities with quality control measures for specimen labeling and a greater degree of access to 24/7 testing for patients have lower rates of labeling errors. It is suggested that facilities post documentation and labeling procedures at the bedside or in the area where specimens are prepared for transport.

What indications of urinary tract infection should I check for before I do a urine reagent strip test or request a urinalysis order from the provider?

Key features indicating a urinary tract infection are frequent urination, urgency, hesitancy or difficulty initiating a stream, retention, feeling of incomplete emptying, burning or pain with urination, low-back or flank pain, hematuria (blood in the urine), pyuria, foul-smelling urine, cloudy urine, fever, incontinence, and confusion or behavioral changes. Keep in mind, however, that many urinary tract infections are initially asymptomatic.

Laboratory analysis of stool samples

Laboratory analysis of stool samples is ordered when infection or parasitic contamination is suspected. Typically, leukocytes can be detected in the stool and the causative bacteria can be identified. Clostridium difficile is a common bacterium that causes diarrhea and can be identified by stool sample analysis. If parasitic infection is suspected, a stool sample is sent for a test called ova and parasites. Numerous other tests are available to analyze stool samples. In any case, obtain the sample the same way, without contamination from water or urine. If you are unsure of the appropriate collection method, storage conditions, or transport, be sure to call the laboratory to confirm the protocol for the test ordered.

Laboratory analysis of urine specimens

Laboratory analysis of urine specimens can be done to confirm findings from point-of-care tests or to conduct various other diagnostic tests. The most commonly ordered laboratory test is urinalysis with culture and sensitivity (C & S), used to diagnose urinary tract infection (UTI). If an elevated white blood cell count (above the expected reference range of 0 to 4,000/mm3) is found in the urine reagent test sample, the culture is set up and then sensitivity testing (to identify the appropriate antibiotic treatment) is completed. Sensitivity testing is also helpful in identifying drug-resistant bacteria. Many providers now wait for C & S results to return before treating a patient for a UTI. Laboratory analysis of urine specimens allows for a more accurate analysis and confirmation of findings. Timed urine specimens are usually collected for 24 hours (although 2- and 12-hour collections are sometimes ordered). They are most often done to determine creatinine clearance or to measure protein or hormone levels. The timing begins right after the patient urinates (with that urine discarded). The patient then urinates into a container each time during the prescribed time period, and the collection of urine is kept on ice or in a refrigerator. If the patient urinates and discards the urine, timing the specimen must begin again with the next urination. Never remove urine collected from the 24-hour container for other specimen testing.

My patient's provider ordered a wound culture, but the patient has multiple wounds that are quite large. How do I decide where to collect the specimen from?

Large wounds and multiple wounds call for multiple samples. Never use the same swab on more than one location. Avoid swabbing a wound's edges because they may be contaminated with external skin flora. Swabbing the center of the wound, parts of the wound with different appearances, and individual wounds will help create the clearest clinical picture in the laboratory.

What instructions should I give a patient who is being sent home with fecal occult blood test (FOBT) cards?

Make sure your patient has three FOBT cards. Tell him to collect samples from three separate bowel movements that are not contaminated with urine. Tell him to use the small wooden stick in the test kit to collect fecal samples and place them in the two windows on the card. Once the samples are in place, he can close the window over the card and label each card with the date and time of collection. Remind him to put his name and date of birth on the cards and to return them within 3 to 14 days of obtaining the sample. Suggest that he avoid red meats, poultry, fish, and certain raw fruits and vegetables, including radishes, turnips, and melons, for 3 days prior to testing and during the testing period, as these can lead to false-positive results, and to increase his water and fiber intake for a few days prior to testing. The patient should also avoid NSAIDs or discontinue NSAIDs or warfarin for 1 week prior to testing per the health care provider's prescription. Remind him that the test is meant to look for occult blood, which means that even if he does not see blood in his stool, it might still have blood in it.

When your patient is male

Male anatomy provides a distinct advantage in providing adequate urine samples with the clean-catch method. Instruct the uncircumcised male to retract foreskin before cleaning. Male patients should use an antiseptic wipe moving from the center to the outside in a circular motion to cleanse before beginning stream. Tell male patients to direct the initial stream of urine into the toilet, pause, and then proceed to urinate into the collection cup. With the lid in place on the cup, label the sample and send it to the laboratory for analysis.

My alert and oriented patient's blood glucose reading was 435 after his afternoon snack. What should my next step be?

Monitor the patient continuously. Check agency protocol for laboratory confirmation testing of very high readings, as laboratory testing is considered more accurate. Attain the patient's medical record for a medication prescription related to increased glucose. Administer insulin or a carbohydrate source per provider prescription and notify the health care provider of the patient's response.

A nurse is teaching a patient about home collection of a stool specimen for fecal occult blood testing. Which of the following instructions should the nurse provide?

Obtain specimens from three different stools.

Sampling urine through a catheter

Perform a straight catheterization if prescribed to obtain a sample from a patient who is unable to urinate. Use surgical asepsis when inserting the catheter, and allow a small amount of urine to pass prior to filling a sterile cup for sampling. Use the appropriate port for collecting a urine specimen from a patient who has an indwelling urinary catheter in place. Many catheters have a needleless system that involves cleansing the port and using a syringe to withdraw a sample from the tubing. If too little urine is in the tubing, clamp the catheter below the port to allow some urine to collect in the tubing rather than going into the collection bag. Never take a urine sample from the collection bag as this type of sample is often concentrated or contaminated and can alter the test results. Place the urine sample in a sterile collection cup, label it, and send it to the laboratory for analysis. Perform suprapubic catheter sampling similarly to indwelling catheter sampling. Store the sample on ice or in a refrigerator and transport it as directed by the laboratory.

Peripheral line phlebotomy

Peripheral venous and arterial lines can be used to obtain blood samples. Most of these systems incorporate a sterile needleless method for drawing a blood sample. You'll cleanse the port at the end of the line with the facility-approved antiseptic and attach a sterile syringe. After drawing out the desired amount of blood, remove the syringe and replace it with a syringe containing sterile saline solution. Then flush the external tubing so that the blood in it will not clog the tubing. Transfer the sample using the evacuated collection tube system into appropriate vials. Document the method of sample collection, the patient's tolerance, and any pertinent physical findings in the patient's medical record.

A nurse is instructing the patient regarding collection of stool specimens for fecal occult blood testing. Which of the following should the nurse instruct the patient to avoid a few days before and during the testing period to reduce the risk of false-positive results?

Poultry.

A nurse is caring for a patient who has a stage III pressure ulcer in the sacral area. Which of the following actions should the nurse take when obtaining a wound culture specimen from the pressure ulcer?

Rotate a sterile swab in the area of drainage.

A nurse caring for a group of patients in an ambulatory care clinic is collecting urine for several prescribed diagnostic tests. For which of the following tests is a random sample voided into a clean cup appropriate?

Routine Urinalysis.

A nurse is collecting a blood specimen for culture from a patient hospitalized for pneumonia. During this procedure, the nurse should

Rub the patient's arm at the selected site prior to venipuncture.

I am having difficulty obtaining an adequate fingerstick sample for blood glucose testing for a patient who has diabetes. What should I do?

Since lancets generally come in different sizes for penetrating the skin to different depths, a larger lancet might help. Poor peripheral perfusion can also reduce the availability of blood. Ask the patient to dangle her hands to allow blood to flow into the fingers. Also, ask her to rub her hands together to warm them, as that might promote blood flow. Another option is to wrap the finger in a warm cloth prior to the puncture. Check the skin on her fingers. It might be calloused from repeated fingersticks. If so, try another site, such as the palm of her hand. Do not milk the finger before a fingerstick, though, as this can alter the readings.

Sputum specimens

Sputum specimens are collected to provide a wide variety of diagnostic information. They can be difficult to obtain because they are easily contaminated with saliva. Sputum specimens are most accurate when collected in the morning, before the patient has anything to eat or drink. Patients who can cough and breathe deeply can be coached to produce a sputum specimen and expel it into a collection container. Use chest physiotherapy to mobilize the secretions of patients who cannot produce enough sputum for the sample. For most tests, the sample should contain 1 to 2 teaspoons of sputum. If less invasive methods do not result in an adequate sample, suctioning and transtracheal aspiration (by a physician) are last resorts. (Note: Do not confuse sputum collection with throat or gum swabbing, which is done for different purposes.) Label the sputum specimen and store it as directed until it arrives in the laboratory for analysis. Document the method of collection, the patient's tolerance, and any pertinent physical findings in the patient's medical record.

Collecting a stool sample

Stool specimen collection may differ based on the diagnostic tests ordered. Some tests require partial or full samples of stool for analysis, but most only require a sample the size of a walnut. For some tests, the patient might have to follow a specific diet and fluid regimen in the days prior to the test. Patients should discontinue taking anticoagulants and NSAIDs 7 days prior to testing and not collect during hemorrhoid flares or menstrual cycles. Additionally, patients should be advised to eliminate some raw vegetables, red meat, poultry, and fish. The patient should not undergo any diagnostic tests that require barium and should avoid preparations like mineral oil and laxatives because they can alter test results. If an enema must be performed to obtain a stool specimen, use a normal saline or a tap water enema. Caution must be used with tap water enemas. The tap water enema should never be repeated because it can cause water toxicity if the body absorbs a high amount. Ask the patient to urinate prior to providing a stool sample and to deposit the sample in a dry, clean container for collection so it is not contaminated by water or urine. This process can be embarrassing for patients, so be sure to promote privacy and dignity during specimen collection. Also, be sure to wear gloves and use the proper equipment to collect the samples. Place stool samples in the appropriate specimen collection containers with a tongue blade and replace the lids securely. Some specimens require placing a preservative fluid in the specimen container. The fluid acts like transport media in test tube specimens to keep parasites alive. And some laboratory tests require multiple samples from multiple stools to confirm the results. Label specimen containers with the appropriate patient information. Some samples require immediate analysis at the laboratory while others can be refrigerated and analyzed later. Check with the laboratory for the acceptable time span for appropriate collection, storage, and transport. For infants, avoid urine contamination of stool by applying a urine collection bag. Then collect the urine-free stool from the diaper. If stools are liquid, place a liner in the diaper to keep the sample in place for collection.

Stool specimens

Stool specimens are collected both for screening and for diagnostic tests. The most commonly used point-of-care test for stool is the fecal occult blood test (FOBT). Stool specimens can also be sent to a laboratory for analysis for detection of bacterial infectious agents, such as Clostridium difficile, ova, or parasites or for other diagnostic tests.

My patient is having difficulty generating a sputum sample for analysis. How can I help her produce a sample?

Teaching the patient to deep breathe and cough may help loosen and mobilize her secretions. Chest physiotherapy is also recommended as an intervention that may help loosen secretions deep in the chest. Try to obtain sputum samples early in the morning before the patient eats or drinks anything. If she tires from attempting to produce a sample, let her rest and return in a short time to ask her to try again. If the patient has a pain-control issue with coughing, pre-medicate her for pain as prescribed at least 20 minutes before asking her to cough and deep breathe to produce a sample. Be sure the client is coughing up sputum and not spitting saliva from clearing their throat.

Clean-catch urine samples

The clean-catch method is suitable for patients who are able to understand instructions for depositing a urine sample into a sterile cup or receptacle. Patient education, including written instructions, helps ensure that patients use the proper technique. They must wash their hands prior to providing a sample. Then, with a sterile cup and clear instructions, they produce the sample. You do not need to observe them unless they request assistance. Label urine specimens according to your facility's policy prior to sending them to the laboratory. Refrigerate them or put on ice until they are transported (usually in a cooler to preserve the samples).

Urine for reagent strip testing

The most commonly performed point-of-care urine test is a urine reagent strip or "dipstick" test used for quick screening. It involves placing a chemically treated strip into a random urine sample collected in a clean cup and observing color changes on the strip. Most reagent strips provide information about pH, specific gravity, leukocytes or leukocyte esterase, blood, ketones, bilirubin or urobilinogen, and glucose (depending on the type of reagent strip used). The pH, an indicator of acid-base balance, can range between 4.6 and 8.0. This is pertinent when examining bacterial growth because bacteria grow more easily in an alkaline environment than in an acidic environment. (Samples left unrefrigerated for extended periods will become more alkaline, resulting in higher and inaccurate bacteria counts.) Specific gravity is an indicator of the concentration of the urine. The expected range for urine specific gravity is 1.0053 to 1.030. Higher specific gravity readings indicate concentrated urine and can be an indicator of dehydration. Lower specific gravity readings indicate dilute urine. All other components of the urine reagent test strip should be negative in a normal urine sample. Leukocytes and leukocyte esterase indicate the presence of infection. Blood in the urine can indicate infection, cancer, and other pathology. Ketones are products of fat metabolism; their presence in urine may indicate diabetes mellitus. Bilirubin and urobilinogen in the urine can indicate liver disease or red blood cell destruction. Nitrites in the urine can indicate infection. Glucose in the urine can indicate diabetes mellitus. Urine reagent test strips are used as a screening tool and are not considered diagnostic. Therefore, any unusual findings on a urine reagent test must be confirmed by laboratory analysis.

An assistive personnel (AP) is collecting a 24-hour urine specimen from a patient. Which of the following statements by the AP indicates that the specimen collection will have to be restarted?

The patient just told me that he forgot to put the urine in the container.

Urine for point-of-care testing

Urine pregnancy testing requires a first-voided morning sample to check for levels of human chorionic gonadotropin (hCG). This hormone is produced when the body is preparing for pregnancy. Test kits are available over the counter; results are not necessarily more accurate when completed at the site of care. Most urine pregnancy testing is done by applying a urine sample to a chemically treated system that shows positive results by changes in the color of the paper based on detection of the hCG hormone. These tests can yield both false positive and false negative results. The timing of urine pregnancy tests determines the validity of the test, thus an additional blood test is often recommended. It is important to document the date of the patient's last menstrual period when performing a urine pregnancy test. Urine drug screening is performed in a similar manner and requires analysis to confirm positive findings.

Urine specimens

Urine specimens are collected by either a clean-catch method or from a catheter to obtain diagnostic information and to assess patients' status. Urine can be screened routinely with a clean voided specimen collected during normal voiding for some point-of-care tests, with a routine urinalysis performed in a laboratory as indicated. If a urine specimen is going to be sent for laboratory testing, it must be stored in appropriate conditions and transported properly to ensure the quality of the sample. For all urine sampling, be sure to document the method of collection, the patient's tolerance, and any pertinent physical findings (including a description of the urine specimen, noting the color, clarity, and odor).

Venipuncture

Venipuncture (also called phlebotomy) involves drawing blood from a vein with a needle. Prior to performing venipuncture, explain the procedure and inspect for an appropriate site. Most basic venipuncture is done on the veins of the arms or hands, although many other veins can be accessed. Vein transilluminators are the newest technology used for locating the position of veins beneath the surface by projecting a light pattern on the skin. Place a tourniquet above the selected site to locate a vein. (Veins protrude when below the tourniquet because they are the flow system that returns blood to the heart.) You might want to ask the patient to grasp a ball or pump the hand below the tourniquet to help you find a vein. It can also help to stroke or gently rub the potential site along arm from the distal area to the proximal area to dilate the vein, but avoid vigorous rubbing due to the potential for injury. Remove the tourniquet once you identify the site you'll use, then cleanse the skin with the facility-approved antiseptic and allow it to dry completely. Most needles used for venipuncture can be attached to the tube holder of the evacuated collection tube system (trade name, Vacutainer). Using this system, you can fill multiple tubes from a single puncture; just pull out the filled tube and insert an empty tube. You can use butterfly needles for pediatric patients or for patients who have an aversion to needles as they are a smaller size and typically cause less pain. However, the smaller size needle is inappropriate for some types of phlebotomy as they can lyse blood cells. Needles are available with two size variables, length (in inches) and gauge. Gauge indicates how wide the bore or inside of the needle is. The larger the gauge, the smaller the opening of the needle is. For example, an 18-gauge needle is considerably larger than a 22-gauge needle. The color of the rubber tip of each collection tube indicates which types of blood tests can be performed from that particular tube's environment, which may or may not contain a storage medium. Vials for blood cultures are larger in size and have more specific instructions for placing and transporting specimens. Once you have completed the blood sampling, remove the needle and place a bandage over the site. Document the method of sample collection, the patient's tolerance, and any pertinent physical findings in the patient's medical record.

A nurse is caring for a patient who has a suspected UTI. Which of the following results should indicate to the nurse the presence of a UTI?

WBC count of 8,000/mm3.

Wound specimen laboratory analysis

Wound specimens are most often processed for culture and sensitivity testing. Sensitivity studies assist in the selection of appropriate antibiotic therapy. This two-step testing process determines the type of bacteria present in the wound and the effective antibiotic therapy. It might take a few days to obtain the results. Some wound cultures are contaminated with flora from the surrounding skin; typically, a repeat culture is recommended. Some drainage may appear infected but fail to reveal any bacteria in the laboratory. Keep in mind that most providers recommend obtaining wound cultures prior to initiating broad-spectrum antibiotic therapy. If the patient is already receiving antibiotics, indicate this on the laboratory requisition form as it can alter test results. With increasing problems with drug resistance, many providers have samples collected and then wait for analysis prior to prescribing antibiotic therapy. A Gram stain from drainage collected can be requested by notifying the microbiology laboratory. This test allows the health care provider to prescribe appropriate treatment earlier than when only a culture is assessed.

Wound specimen collection

Wound specimens are obtained to evaluate wounds that are suspected to be infected. Wound cultures and other testing of wound exudate in the laboratory help providers prescribe effective wound treatment.

A nurse caring for a patient who has diabetes mellitus is having difficulty obtaining a capillary fingerstick blood sample for point-of-care blood glucose testing. To help increase blood flow to the finger, the nurse should

Wrap the finger in a warm cloth.

Wound collection methods

You'll collect most wound specimens with either a sterile swab or a syringe. Always perform hand hygiene and wear clean gloves when obtaining a wound sample. If the wound is bandaged, remove the dressing and clean the wound with sterile water or normal saline solution prior to collection. Collect specimens from the center of the wound, not from the wound's edges, as they might be contaminated with outside skin flora. Never collect from pus or pooled exudates. Then use a sterile swab or syringe to obtain a sample of the drainage in the wound. Place the swab into a sterile test tube for transport. Be careful that the swabs do not touch the outside edges of the test tube. Break the ampule near the bottom of the culturette, place the sample in the test tube medium, secure the lid, remove your gloves, and perform hand hygiene. Label the sample and prepare it for transport to the laboratory. Check with the laboratory for the acceptable time span for appropriate collection, storage, and transport. Complete the appropriate requisition form to be sent to the laboratory with the specimen. Document your assessments and any pertinent data, including vital signs, in the patient's medical record, along with the date, time, location, and the patient's tolerance of the specimen collection procedure. Inaccurate collection or mislabeling can lead to repeated collections of specimens and misdiagnosis.

catheter

a flexible tube passed into the body to remove or instill fluids or to keep a passageway open

leukocyte esterase

an enzyme found in some white blood cells, the presence of which in urine is a sign of infection

Sputum specimen

how the specimen was collected (productive cough or sputum trap), the amount, color, and consistency of the sputum.

blood culture

laboratory cultivation of micro-organisms in a blood sample placed in a special growth medium

anaerobic

living only in the absence of oxygen

aerobic

living only in the presence of oxygen

arterial

pertaining to an artery (a blood vessel that carries blood from the heart to the rest of the body)

clean-voided (midstream) specimen

sample of urine collected after beginning to urinate into the toilet, stopping the stream of urine, then urinating into a sterile collection cup

Stool specimen

the color, odor, and consistency of the stool along with any unusual characteristics such as blood or mucus, if testing for occult blood, the results (positive or negative), number of specimens sent to the laboratory if more than one.

blood

the fluid that circulates in the heart and blood vessels carrying nourishment and oxygen to and bringing waste products from all parts of the body

Urine specimen

the method used to obtain the urine specimen (clean-catch, straight catheter, indwelling catheter), the color, odor, and appearance of the urine, if a timed urine specimen, the start time and the finish time.

Blood specimen

the site from which the specimen was obtained (venipuncture, peripheral IV line, central line), for blood cultures, the number of specimens collected, for blood glucose testing, the results recorded in mg/dL and any interventions such as insulin administration.

Gastric specimen

whether the specimen was collected from emesis or from a nasogastric tube, if testing for occult blood, the results (positive or negative), the color and odor of the gastric secretions along with any unusual characteristics such as a coffee-ground appearance.