CNA Medical Lab and Specimen Collection Skills Flashcards

When collecting a clean-catch midstream urine specimen, what is the correct sequence of steps?

Answer: Void first portion, collect midstream, then finish voiding into toilet

A clean-catch midstream urine specimen requires the patient to void the first portion into the toilet, collect the midstream urine into the cup, and then finish voiding into the toilet. This technique minimizes contamination from skin flora around the urethral opening.

A patient requires a 24-hour urine collection. What should the CNA do at the START of the collection period?

Answer: Discard the patient's first voiding, then begin collecting all subsequent voidings

To begin a 24-hour urine collection, the patient voids and that first specimen is discarded. The collection clock starts at that point, and ALL subsequent urine for the next 24 hours is collected. This ensures a complete 24-hour measurement.

When collecting a urine specimen from a patient with an indwelling Foley catheter, where should the CNA obtain the sample?

Answer: From the drainage port on the catheter tubing using a sterile syringe

Urine specimens from Foley catheters must be obtained from the designated sampling port on the catheter tubing using a sterile syringe and needle or needleless system. The drainage bag contains old, potentially contaminated urine and should never be used for specimens.

A patient needs a stool specimen for occult blood testing. What food should the patient avoid before this test?

Answer: Red meat, raw vegetables, and aspirin

Before a fecal occult blood test (FOBT), patients should avoid red meat (contains blood), certain raw vegetables like radishes and turnips, vitamin C supplements, and aspirin/NSAIDs that can irritate the GI tract and cause false positives or negatives.

When collecting a stool specimen, how much stool is typically required?

Answer: About the size of a walnut (1-2 tablespoons)

For most stool specimens, a walnut-sized amount (approximately 1-2 tablespoons) is sufficient. The exact amount may vary by test type, but this is the general guideline. For FOBT cards, a small smear from two different parts of the stool is used.

A patient needs a sputum specimen for culture. When is the best time to collect this specimen?

Answer: First thing in the morning before eating or drinking

Sputum is best collected early in the morning upon waking, before eating or oral hygiene. Secretions pool in the lungs overnight, making it easier to produce a true sputum sample with the most concentrated bacteria.

A wound culture has been ordered. What is the CNA's role in this procedure?

Answer: Gather supplies, provide privacy, and assist as directed by the nurse

Wound culture collection is typically performed by a nurse or physician. The CNA's role is to gather the necessary supplies, ensure patient privacy and comfort, maintain a clean environment, and assist the nurse as directed during the procedure.

What is the correct action when a urine specimen cannot be sent to the lab immediately after collection?

Answer: Refrigerate the specimen and transport within 2 hours

Urine specimens should be refrigerated (not frozen) if they cannot be immediately transported to the lab. Refrigeration slows bacterial growth and preserves the specimen's integrity. Most urine specimens should reach the lab within 2 hours of collection.

What information is typically included on the laboratory requisition form that accompanies a specimen?

Answer: Patient name, DOB, test ordered, collection date/time, and ordering physician

A complete lab requisition form includes the patient's full name, date of birth, medical record number, the specific test ordered, collection date and time, specimen source/type, and the ordering physician's name. This information ensures the right test is performed on the right patient.

Standard precautions apply to which of the following?

Answer: All patients regardless of their diagnosis or known infection status

Standard precautions apply to EVERY patient in EVERY encounter, regardless of whether they have a known infection. Standard precautions treat all blood, body fluids, secretions, and excretions as potentially infectious. This protects both patients and healthcare workers.

A CNA is collecting a urine specimen and notices the urine is dark brown and has a strong odor. What should the CNA do?

Answer: Collect the specimen, note the observations, and report to the nurse

The CNA should collect the specimen as ordered, note the abnormal characteristics (color, odor, clarity), and immediately report the observations to the nurse. Abnormal urine appearance is clinically significant and must be communicated — it may indicate dehydration, infection, liver disease, or other conditions.

After removing gloves following specimen collection, the CNA notices a small tear in the glove. The CNA's skin was not visibly contaminated. What is the correct action?

Answer: Wash hands thoroughly with soap and water and report to the nurse

Any glove integrity compromise during specimen collection requires thorough handwashing with soap and water and a report to the nurse. Even if the skin appears intact, microscopic exposure may have occurred. The nurse will assess and document the potential exposure per facility protocol.

A patient's blood glucose reading must be documented. Which information is MOST important to record?

Answer: The exact numerical reading, date, time of collection, and the patient's symptoms

Accurate glucometer documentation must include the exact numerical value, the date, the time of collection, and any patient symptoms at the time of testing. This information is essential for trending glucose patterns and recognizing hypoglycemia or hyperglycemia in context with the patient's clinical condition.

A resident needs a clean-catch midstream urine specimen. Which instruction should the CNA give first?

Answer: Clean the urethral area with the provided wipes before urinating

The perineal area must be cleaned with antiseptic wipes before collection to prevent contamination of the specimen.

When collecting a stool specimen for occult blood testing, the CNA should avoid which of the following?

Answer: Collecting the sample after the resident ate red meat recently

Red meat consumption before fecal occult blood testing can cause a false-positive result, so dietary restrictions must be followed.

A urine specimen must be sent to the lab but will not be transported for 30 minutes. The CNA should:

Answer: Refrigerate the specimen until transport

Urine specimens not transported immediately should be refrigerated to prevent bacterial growth and specimen degradation.

While collecting a sputum specimen, the CNA notices the resident has produced only saliva. The CNA should:

Answer: Ask the resident to rinse with water and try again with a deep cough

Sputum must come from the lower airways via a deep cough; saliva is not an acceptable sputum specimen and the collection should be repeated.

A 24-hour urine collection is in progress. The resident voids at 2 PM and the urine is accidentally discarded. What should the CNA do?

Answer: Notify the nurse, as the 24-hour collection may need to restart

A discarded specimen during a 24-hour urine collection compromises accuracy, so the nurse must be notified and the collection typically restarted.

When using a urine dipstick test at the bedside, which action ensures the most accurate result?

Answer: Shake excess urine off the strip and read after exactly the time specified on the bottle

Shaking off excess urine and reading the strip at the manufacturer's specified time interval ensures accurate color comparison and results.

After completing a specimen collection procedure, the CNA's priority action before leaving the room is to:

Answer: Remove gloves and perform hand hygiene

Removing gloves and performing hand hygiene is the priority to prevent transmission of pathogens after any specimen collection.