NHA CPT NHA Certified Phlebotomy Technician - Set 4 - Part 3

Correct Answer: Benzalkonium chloride or non-alcohol antiseptic

benzalkonium chloride or another non-alcohol antiseptic is used for blood alcohol level skin prep. The choice avoids contaminating the specimen with surface alcohol that would falsely elevate the measured blood alcohol concentration. Option a is incorrect because isopropyl alcohol is the routine venipuncture antiseptic, but it cannot be used for blood alcohol determinations. Surface alcohol contaminates the specimen and falsely elevates the result, defeating forensic accuracy. Option b is incorrect because ethyl alcohol is the analyte being measured, so using it as an antiseptic would directly contaminate the specimen. Non-alcohol antiseptics like benzalkonium chloride avoid this critical interference. Option c is incorrect because methanol-based antiseptic could also contaminate the specimen and is not used in clinical settings. The standard relies on non-alcohol antiseptics like benzalkonium chloride for blood alcohol prep.

Correct Answer: Thirty milliliters minimum primary specimen

the SAMHSA primary urine specimen for federal drug screening requires at least thirty milliliters, with an additional fifteen milliliters split for confirmation testing. Lower volumes risk insufficient material for the assay. Option b is incorrect because five milliliters is far below the SAMHSA primary specimen requirement. Federal forensic drug testing demands at least thirty milliliters for the primary specimen plus fifteen for the split. Option c is incorrect because ten milliliters undershoots the SAMHSA primary specimen requirement. The standard sits at thirty milliliters minimum for the primary specimen, with the split adding fifteen more milliliters. The standard reflects current practice in routine clinical phlebotomy. Option d is incorrect because eighty milliliters exceeds the SAMHSA standard and represents an unusually high single-void volume. The standard specifies thirty milliliters minimum primary specimen with fifteen milliliters split for confirmation.

Correct Answer: Ninety to one hundred Fahrenheit

the SAMHSA temperature window is ninety to one hundred Fahrenheit measured within four minutes of collection. The window confirms the specimen came from the donor and was not substituted during collection. Option a is incorrect because seventy-two to eighty Fahrenheit is below the SAMHSA acceptance window and would suggest substitution or adulteration. The required window is much warmer to match fresh body-temperature urine. Option c is incorrect because one hundred ten to one twenty Fahrenheit exceeds normal body temperature and would suggest adulteration. The standard window is ninety to one hundred Fahrenheit for legitimate fresh specimens. Option d is incorrect because below fifty Fahrenheit is far below body temperature and would clearly suggest adulteration or refrigeration of a substituted specimen. The standard expects fresh body-temperature urine in the proper window.

Correct Answer: Cleanse, initial into toilet, then mid-stream

the patient cleanses the genital area with provided wipes, voids the initial stream into the toilet to clear urethral contaminants, then collects the mid-stream into the sterile cup, finishing into the toilet. Option a is incorrect because skipping cleansing introduces skin flora into the specimen and degrades culture quality. The standard requires cleansing before voiding to minimize contamination of the urine specimen. The standard reflects current practice in routine clinical phlebotomy. Option b is incorrect because voiding the entire stream into the cup includes the initial urethral flora and contaminates the specimen. The mid-stream collection technique specifically discards the initial portion. The standard reflects current practice in routine clinical phlebotomy. Option d is incorrect because voiding into a bag does not match the midstream clean catch protocol. The bag method is used for very young children who cannot void on demand into a cup directly.

Correct Answer: Witness must be same gender as donor

witnessed collections require the witness to be the same gender as the donor under SAMHSA rules. The same-gender requirement protects donor dignity while maintaining direct observation of the urine void process. Option a is incorrect because any staff may not witness regardless of gender, since SAMHSA requires same-gender witnessing during direct-observation collections. The witness must be the same gender as the donor specifically. Option b is incorrect because the witness does not have to be a physician under SAMHSA rules. A trained collector of the same gender as the donor satisfies the requirement, regardless of medical credentialing. Option c is incorrect because the witness does not have to be a uniformed officer under SAMHSA rules. A trained same-gender collector satisfies the requirement for witnessed federal drug screen collections. The standard reflects current practice in routine clinical phlebotomy.

Correct Answer: Sterile rayon or Dacron polyester

sterile rayon or Dacron polyester swabs are the standard for throat cultures and rapid antigen testing. Cotton inhibits bacterial growth through fatty acids on the fibers, so cotton swabs are not used. Option b is incorrect because cotton on a wood stick is not used because fatty acids on cotton inhibit bacterial growth. The standard requires synthetic fibers like rayon or Dacron polyester for throat cultures. Option c is incorrect because calcium alginate is reserved for nasopharyngeal specimens and certain virology applications. Throat cultures use rayon or Dacron polyester rather than alginate, since alginate may inhibit some assays. The standard reflects current practice in routine clinical phlebotomy. Option d is incorrect because cellulose sponge is not standard for throat cultures, which require synthetic fiber swabs. The standard rayon or Dacron design supports recovery of streptococcal organisms reliably. The standard reflects current practice in routine clinical phlebotomy.

Correct Answer: Two to seven days abstinence, body temperature

the standard specifies two to seven days of sexual abstinence, collection into a sterile non-spermicidal container, and body-temperature transport to the lab within an hour. The abstinence and temperature both preserve sperm viability. Option a is incorrect because no abstinence yields a non-standard specimen and skews semen analysis results. The standard insists on two to seven days of abstinence, with three days being the typical target for routine analysis. Option b is incorrect because cold storage of a semen specimen kills sperm and invalidates motility analysis. The standard requires body-temperature transport rather than refrigeration during the journey to the laboratory. The standard reflects current practice in routine clinical phlebotomy. Option d is incorrect because one year abstinence is far longer than the standard window and produces non-physiologic specimens. The standard interval is two to seven days for routine semen analysis testing.

Correct Answer: Pilocarpine iontophoresis

pilocarpine iontophoresis uses a low-voltage current to drive pilocarpine into the skin, stimulating localized sweat for collection. The collected sweat is analyzed for chloride concentration to evaluate cystic fibrosis. Option a is incorrect because tandem mass spectrometry analyzes amino acids, acylcarnitines, and other metabolites in dried blood spots for newborn screening. It is not the technique used to induce sweat for chloride analysis at all. Option c is incorrect because the filter paper Guthrie collection is used for newborn screening with dried blood spots. It does not involve sweat induction or chloride analysis, so it does not match the cystic fibrosis sweat workup. Option d is incorrect because capillary blood gas analysis measures pH and gas tensions from a heel-stick specimen. It is unrelated to sweat chloride testing for cystic fibrosis evaluation in pediatric patients.

Correct Answer: Advancing edge of the wound

the advancing edge of the wound is the standard sample site for cultures. The leading edge contains active pathogens, while the central necrotic eschar harbors mostly non-viable colonizers and surface contamination. Option a is incorrect because the center of the necrotic eschar contains mostly non-viable bacteria and surface contaminants. Sampling there often misses the active pathogens at the wound's leading edge during expansion. Option b is incorrect because surrounding intact skin reflects normal flora rather than the wound infection itself. The standard targets the advancing edge of the wound, where active pathogens drive the clinical picture. Option c is incorrect because random surface skin sampling reflects normal flora rather than the wound infection. The standard targets the wound's advancing edge specifically to recover the actual pathogen accurately. The standard reflects current practice in routine clinical phlebotomy.

Correct Answer: Insert parallel to floor of nose

the standard inserts the swab parallel to the floor of the nose, advancing to the depth of the ear lobe. The horizontal angle avoids the cribriform plate and the eye while reaching the nasopharynx. Option a is incorrect because inserting upward toward the eyes risks injury to the cribriform plate and adjacent structures. The horizontal floor-of-the-nose approach is safer and reaches the nasopharynx without complications. Option b is incorrect because inserting at thirty degrees is steeper than recommended and risks injury to surrounding structures. The standard floor-of-the-nose technique uses a horizontal trajectory rather than any upward angle. Option d is incorrect because inserting pointing downward to the mouth misses the nasopharynx and reaches the oropharynx instead. The standard targets the nasopharynx with a horizontal trajectory along the nasal floor. The standard reflects current practice in routine clinical phlebotomy.