c3-NONBLOOD SPECIMEN COLLECTION.docx

NONBLOOD SPECIMEN COLLECTION ============================ Patient instructions -------------------- You might collect specimens other than blood or instruct patients how to collect them at home. Common nonblood specimens are urine, stool, sputum, and semen. In general, physicians are responsible f...

NONBLOOD SPECIMEN COLLECTION ============================ Patient instructions -------------------- You might collect specimens other than blood or instruct patients how to collect them at home. Common nonblood specimens are urine, stool, sputum, and semen. In general, physicians are responsible for collecting other types of specimens (cerebrospinal fluid, amniotic fluid, material from a wound). Nurses are also responsible for collecting urine specimens for urinalysis through a urinary catheter. Urine ----- One of the most common of all laboratory tests is a routine urinalysis, which is an examination of a patient\'s urine for a variety of factors, including its appearance, color, odor, pH, specific gravity, and the presence or absence of many other components (protein, glucose, hemoglobin). A urinalysis can be requested as random or at a specific time. If the urine specimen is to be collected upon waking in the morning, which could be another time of day if the patient is a night-shift worker, it must be done at this time. In addition, if the urine specimen is to be collected after fasting for a designated period of time (usually 6 to 12 hr.), the patient should be given clear instructions on this collection detail. Another common urine test is a culture, which consists of the laboratory technician preparing the urine for the growth and identification of micro-organisms. Often, a sensitivity test follows to determine which antibiotics effectively kill that specific pathogen. The urine specimen for these tests needs to be a clean-catch (midstream) specimen or obtained from a catheter. The clean-catch method is suitable for patients who are able to understand instructions for depositing a urine sample into a sterile container. Patient education-including written instructions-ensures that patients use the proper technique for urine cultures. Various tests, including some for assessing the function of the renal system, require a timed urine specimen. This involves collecting urine excreted over a specific period of time (such as 2, 4, or­ most commonly-24 hr.). Random urine specimen --------------------- When instructing a patient to collect a random urine specimen, give the patient a clean, disposable urine collection container and a label with the patient\'s information. The label must go on the container and not on the lid because a technician might process multiple urine cups with the lids removed. It is preferable to put the label on the specimen after collection in case urine or water accumulate on the outside of the container. There is no preparation for this type of specimen. The patient only has to urinate into the container. Generally, 30 to 60 mL is enough to evaluate the specimen. For testing accuracy, specimens collected at home should be stored in the refrigerator and brought to the laboratory as soon as possible after collection. The date and time of the collection should be noted on the label. Fasting (first morning) urine specimen -------------------------------------- When instructing a patient to collect the first urine of the morning or a fasting urine specimen, give the patient the same supplies and instructions as for a random specimen. Instruct the patient to urinate before going to sleep and then collect a specimen immediately after waking in the morning. Because this type of specimen is more concentrated than a random urine specimen, it is likely to be used for specific testing (pregnancy, glucose). The patient should refrigerate the specimen and get it to the laboratory as soon as possible. Urine begins to deteriorate within 30 min of collection. Refrigeration slows this deterioration. Clean-catch (midstream) urine specimen -------------------------------------- When instructing patients to collect a clean-catch or midstream urine specimen, give them a sterile urine container and make sure they understand not to allow anything other than urine to come in contact with the inside surface of the container and lid. This test is mainly used to detect bacteria. Instruct patients to wash their hands prior to and after specimen collection, and then use soapy water or antiseptic wipes to cleanse the urinary meatus. **Male patients.** Instruct patients to clean from the meatus outward in a circular fashion. If uncircumcised, the foreskin should be retracted and then the same cleansing technique is used. The patient should start to urinate in the toilet, then collect urine in the container until it is one-fourth to half full, being careful not to allow the penis to touch the container. The final part of the stream should be deposited in the toilet. **Female patients.** Instruct the patient to separate the labia around the urinary meatus and clean the area with a mild antiseptic soap and water (or antiseptic towelettes) using a front-to-back technique. Then the patient should separate the labia with one hand, begin to urinate in the toilet, urinate into the container until it is one-fourth to half full, and finish urinating into the toilet. Without touching the inner surface of the container and the lid, the patient should close the container, wash and dry it if needed, and give it to the phlebotomist. Immediately affix the completed label after receiving the urine sample. The same procedure for storage applies until the specimen can be delivered to the laboratory. Timed urine specimen -------------------- When instructing a patient to collect a timed urine specimen, provide a container of the appropriate size, with a preservative in it if the facility requires it. These are usually rigid, light-resistant containers with about a 3,000 mL capacity, wide mouth, and leakproof screw-on cap. For a 24-hour collection, the patient should begin at a specific time, urinate into the toilet, and then record the start time. The patient should then collect all urine passed until the same time the following morning. If the patient urinates into the toilet at any time during that 24-hour period, the entire collection is invalid and must be discarded. The process will begin again. During the collection period, the specimen must be kept in the container on ice or in the refrigerator. Be sure the patient understands that nothing other than urine should go into the container. The final specimen should be collected as close as possible to the end of the 24-hour period. Urine reagent testing --------------------- In some settings, phlebotomists perform point-of-care urine testing using reagent strips. Urine reagent testing is a CUA-waived test. This involves placing a chemically treated strip into a urine sample. You will conduct a visual or physical observation of the specimen, noting color, clarity, and odor. Observation of the chemical components of urine involves viewing color changes on the strip at designated intervals and documenting the results. This procedure requires you to wear clean gloves, dip the reagent strip into the urine, observe the squares on the strip for color changes, and compare the strip to the key on the reagent container. Follow the manufacturer\'s directions. For example, with some reagent strips, the colors can change misleadingly if there is an excessive amount of urine on the strip or if you don\'t adhere to the time period that must elapse prior to reading the results. Most reagent strips provide information about pH, specific gravity, white blood cells, hemoglobin, ketones, bilirubin, protein, nitrites, and glucose (depending on the type of strip used). - **pH** can range from 4.6 to 8.o and the normal range for a urine specimen is between 5-5 and 8.o. This is important when examining urine for 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 1.003 to 1.030, but it is usually 1.010 to 1.025. A specific gravity below 1.010 indicates diluted urine. A specific gravity above 1.010 indicates concentrated urine. Highly concentrated urine can be an indicator of dehydration. - **White blood cells** and nitrites indicate infection. - **Hemoglobin** can indicate bleeding, infection, cancer, kidney disease, chemical poisoning, and other pathology. - **Ketones** are products of fat metabolism. Their presence in urine can result from diabetes mellitus, starvation, or vomiting. - **Bilirubin** can indicate liver disease or red blood cell destruction. - **Protein** can indicate inflammation, infection, kidney disease, or chemical poisoning. - **Glucose** can indicate diabetes mellitus. - All other components of the urine reagent test strip should be negative in a random urine sample. Urine reagent test strips are screening tools. Further laboratory analysis is usually necessary to confirm any unusual findings on a urine reagent test. Stool ----- The most common point-of-care test on stool is the fecal occult blood test (FOBT), which identifies the presence of blood in the stool that is not visible. It helps providers diagnose gastrointestinal lesions (such as ulcers) and colorectal cancer. Laboratory technicians also test stool specimens to detect bacteria, viruses, fungi, and parasites. If a patient is collecting stool for laboratory testing, you will provide a sterile container, usually a wide-mouth plastic container with a tight-fitting lid. This type of collection device allows the patient to defecate directly into the specimen container. Patients can also collect a specimen into a clean container and then transfer it to a smaller specimen container using a tongue depressor or a spoon-like component of some containers. Instruct the patient to avoid getting urine in the container. Urine can prevent further growth of the micro-organisms being tested. The sample also should not contain water from the toilet. Stool tests do not require a large amount of stool. Instruct the patient to secure the lid tightly on the specimen container, wash the outside of the container if necessary, and wash their hands thoroughly after the collection. Stool specimens should not be refrigerated if undergoing testing for parasites but should be returned to the laboratory immediately. Some samples require immediate analysis at the laboratory, while others can be refrigerated and analyzed later. For an FOBT, the patient will collect small stool specimens on specific cards. You will give the patient a kit that contains the cards, instructions for preparing them, and a mailing envelope to return the samples to the testing laboratory. There are some pretesting requirements. For example, patients should not eat some foods (red meat, citrus fruits, raw vegetables) or take some medications (vitamin C, aspirin) for 3 days before specimen collection. The patient needs to follow the manufacturer\'s instructions, which usually includes collecting three separate stool samples and placing them on the cards with the applicators in the kit. Samples should not be collected from toilet water. Using a collection container or obtaining a smear from toilet tissue is acceptable. Discussing stool collection can be embarrassing for some patients. Maintain a professional, matter-of-fact demeanor while encouraging the patient to ask questions. Sputum ------ Sputum is material coughed from the lungs. Providers typically order sputum testing for patients who have a respiratory infection (tuberculosis, pneumonia) to confirm which micro-organisms are causing the infection. Providers also request sputum samples to determine if a treatment being used is effective. As a result, the sputum is likely to contain infectious material. Testing of sputum specimens is most accurate when the patient collects the sputum in the morning, before having anything to eat or drink, because the sputum is more concentrated. It is not yet diluted with food or fluid it would come in contact with as the patient expectorates. Provide a sterile sputum container. Make sure the patient understands to collect sputum first thing in the morning before using mouthwash (because it could kill some micro-organisms), eating, or drinking. Instruct the patient to take a deep breath, cough forcefully and deeply, and expectorate into the container. The patient should not spit saliva into the container. For testing, a sufficient amount of sputum is generally 1 or 2 teaspoons. The patient should then close the lid, clean the outside of the container, affix the label, and deliver the specimen to the lab as soon as possible. Semen ----- Laboratory technicians analyze semen as part of fertility testing, assessing effectiveness of a sterilization procedure (vasectomy), or as part of a criminal investigation. Depending on the purpose of the test, there can be pretesting instructions (such as abstaining from sexual activity or alcohol for several days before collection). Provide a collection container that is clean and free of chemicals (detergents, spermicides). The patient must ejaculate, deposit semen into the container, secure the lid and label, and write the date and time of the collection. The patient must protect the specimen from extreme heat and cold. It must reach the laboratory within 2 hr. after collection (within 1 hr. is preferred).