NHA CPT Special Collections: Blood Cultures, Tolerance Tests, Blood Alcohol, Drug Screens and Newborn Screening

Special Collections has only 12 of the 100 scored items on the NHA CPT, but NHA's test plan gives it ten tasks (4A to 4J) that have little in common: a blood culture, a newborn heelstick, a donor unit, a glucose tolerance test, a blood alcohol draw and a urine drug screen each follow their own rules. Three of the ten are new with the January 2026 exam (point-of-care testing, tolerance tests and blood alcohol site preparation), and drug screening moved over from Processing.

Blood cultures on the NHA CPT (task 4A)

Blood cultures carry five knowledge statements (k75 to k79), more than any other Special Collections task: skin preparation and site, equipment, volume, order of draw and bottle preparation. The steps guard against two errors. MedlinePlus explains that skin bacteria can contaminate a blood culture and produce a positive result without a true infection, and CDC's blood culture quality tool adds that too little blood can produce false negatives.

The volume numbers differ only slightly. BD's 8 to 10 mL per adult bottle is the range marked for its bottles, and CDC's 10 mL per bottle sits at the top of it. For an exam question, an answer of 8 to 10 mL per adult bottle, filled to the mark, fits both; the error both sources warn against is underfilling, which CDC links to false negatives.

Two cautions. BD says chlorhexidine should be used with caution in babies under two months and that repeated 70% isopropyl alcohol applications are an acceptable alternative for them. And CDC says well-run collection should keep contamination rates "substantially below 3%." For short recall of these numbers, 54 Special Collections flashcards are planned for NHA CPT prep.

Assisting with pediatric, geriatric and line draws (tasks 4B and 4E)

Task 4B asks you to assist other professionals with pediatric, geriatric and tunneled or non-tunneled line collections, and k80 covers the equipment and transfer procedures. The WHO guidelines on drawing blood say that nursing staff and physicians may access central venous lines following their protocols, and warn that line specimens carry a risk of contamination or erroneous results. In WHO's description the line itself is accessed by nursing staff or physicians, so assisting typically means having the right tubes, labels and order of draw ready under your facility's procedure.

Task 4E asks you to calculate or look up volume limits for higher-risk patients to avoid illness caused by the collection. NHA doesn't give a formula, and limits are set by facility policy. One published example: BD's 1% of total blood volume limit for pediatric blood cultures, above.

Newborn and metabolic screening (task 4C)

The test plan names PKU and galactosemia (4C) and filter-paper technique (k81). MedlinePlus says newborn screening takes a few drops of blood from the baby's heel, that the panel varies by state, and that the test is usually done before the baby leaves the hospital, between 24 hours and 7 days old. PKU was the first disorder screened, which is why some people still call it "the PKU test"; galactosemia is on MedlinePlus's list too. CDC's dried blood spot page says the blood is placed on an NBS filter paper card and the dried sample goes to the state's newborn screening laboratory.

Heel site and depth follow WHO's capillary rules, covered in the venipuncture and dermal puncture guide. MedlinePlus adds that holding the baby skin-to-skin or breastfeeding during the heelstick reduces distress.

Blood donation phlebotomy (task 4D)

Knowledge statement k82 lists hemoglobin and hematocrit checks, weight and donor screening. In the United States, FDA's donor eligibility rule (21 CFR 630.10) sets them:

• Weight: at least 50 kg (110 pounds)
• Hemoglobin or hematocrit: measured from a fingerstick or venipuncture sample; earlobe blood is not acceptable. Minimums for allogeneic donors are 12.5 g/dL or 38% for women and 13.0 g/dL or 39% for men, with a narrow alternative standard for women
• Temperature: no higher than 37.5 °C (99.5 °F) orally
• Pulse: regular, between 50 and 100 beats per minute, unless the responsible physician documents otherwise

WHO's donation chapter adds the collection side: donation should be voluntary, the donor's history should include a mastectomy (blood is taken from the opposite arm), consent should be informed and written as national rules require, and the donor should be offered fluids to reduce the risk of fainting. WHO also says to choose a large, firm vein, preferably in the antecubital fossa, and to mix the collected blood with the anticoagulant about every 30 seconds.

Point-of-care testing (task 4G)

Task 4G lists hemoglobin and hematocrit, blood glucose screening, urine pregnancy tests and urinalysis. Many such tests are CLIA-waived. Under 42 CFR 493.15, the waived list includes non-automated dipstick urinalysis, visual urine pregnancy tests, blood glucose by devices FDA cleared for home use, spun microhematocrit and hemoglobin by single-analyte instruments, and a lab with a certificate of waiver must follow the manufacturer's instructions. WHO adds a safety point: shared devices such as glucometers must be visibly clean before each patient, because blood-contaminated reusable fingerstick and point-of-care devices have been linked to hepatitis B outbreaks. Quality control for these tests is in Safety and Compliance (1F), and reporting critical values in Processing (5G).

Tolerance tests (task 4H)

The test plan's examples are gestational glucose, lactose and 2-hour postprandial glucose. The phlebotomist's job is timing and labeling; the patient's preparation and the drink are set by the ordering provider. MedlinePlus describes the procedures:

MedlinePlus also notes that some people feel nauseated, sweaty or lightheaded, or even faint, after the glucose drink, so a patient's history of fainting matters here. Passy doesn't give drink amounts; they're set by the ordering provider and the lab.

Blood alcohol: site preparation (task 4I)

Knowledge statement k85 is about skin preparation, and the rule is simple: don't clean the site with alcohol. WakeMed's ethyl alcohol test entry says not to use alcohol or other volatile disinfectants, suggests soap and water, benzalkonium chloride wipes, iodine or other aqueous disinfectants instead, and notes that alcohol pads are acceptable only for non-legal, non-chain-of-custody collections. Children's Minnesota's medical ethanol entry is stricter: it lists collection with alcohol skin cleansing as a reason to reject the sample, and asks that the tube be completely filled and kept sealed until analysis.

Labs differ on the details, so the safe exam answer is a non-alcohol antiseptic for every blood alcohol draw. When the result may be used legally, the specimen also needs chain-of-custody documentation; that's in the NHA CPT specimen processing guide.

Drug screen collections (task 4J)

Coverage note: the rules below are the U.S. Department of Transportation's, in 49 CFR Part 40, which apply to DOT-regulated workplace tests. Other employers and programs may follow their own procedures, but NHA's knowledge statement k86 ("specimen collection requirements for drug screening") is most easily learned from this rule.

MedlinePlus's general advice is to tell the tester about medicines you take, but in a DOT collection the collector must tell the employee not to list them on the form. The custody and control form is the chain-of-custody record, explained in the processing guide. When rules like these blur together, planned Redemption challenges bring back the NHA CPT questions you missed.

Throat, nasal and wound specimens (task 4F)

MedlinePlus's throat swab culture page gives the throat procedure: the patient tilts the head back, the swab is rubbed along the back of the throat near the tonsils, sometimes several times, and the patient shouldn't use antiseptic mouthwash beforehand. For nasal and wound swabs, follow the collection kit and your lab's instructions. Patient instructions for urine, stool, semen and sputum belong to Patient Preparation (2P) and are in the patient preparation guide.

Three Passy examples on special collections

These are original Passy practice items, not NHA questions.

Example 1: culture bottles through a winged set

A phlebotomist is drawing one blood culture set and a lavender tube with a push-button winged set and holder. In what order does she fill them?

• A. Aerobic bottle, anaerobic bottle, then the lavender tube
• B. Anaerobic bottle, aerobic bottle, then the lavender tube
• C. Lavender tube, then the aerobic and anaerobic bottles
• D. Aerobic bottle, lavender tube, then the anaerobic bottle

Answer: A. Blood cultures come first in the order of draw, and BD's instructions for this set say to select the aerobic vial first. B reverses the bottles, C puts a tube before the cultures, and D splits the set.

Example 2: a legal blood alcohol draw

Police bring a driver for a blood alcohol test that may be used in court. Which skin preparation is appropriate?

• A. An aqueous antiseptic such as benzalkonium chloride
• B. A 70% isopropyl alcohol pad, allowed to dry fully
• C. An alcohol-based chlorhexidine applicator and drying
• D. No antiseptic, so the site isn't touched before the draw

Answer: A. WakeMed lists benzalkonium chloride wipes among the suggested alternatives and says alcohol pads are acceptable only for non-legal collections, which rules out B and C. D skips skin antisepsis altogether.

Example 3: a DOT urine temperature

A DOT urine specimen is handed to the collector. When must she read its temperature, and what range is acceptable?

• A. Within 4 minutes, 32–38 °C (90–100 °F)
• B. Within 10 minutes, 30–40 °C (86–104 °F)
• C. Within 4 minutes, 35–37 °C (95–99 °F)
• D. Before sealing, any time; 32–38 °C (90–100 °F)

Answer: A. 49 CFR 40.65 sets both numbers: no later than four minutes after the employee hands over the specimen, and 32–38 °C (90–100 °F).

Small domains are easy to under-practice, and planned NHA CPT practice saves the special-collection items you miss so you can rework them.

Your next step for NHA CPT special collections

Make one card per task, 4A to 4J, with the single rule a question is most likely to test: alcohol plus a second disinfectant and 8 to 10 mL per bottle for cultures, no alcohol for blood alcohol, 45 mL and 4 minutes for DOT urine. Then check where blood cultures sit in the order of draw guide and try the 20 free NHA phlebotomy practice questions.