NHA Patient Care Technician (CPCT) — All Questions

According to the standard order of draw, which specimen is collected first when a blood culture is ordered along with other tests?

• a.Lavender (EDTA) hematology tube
• b.Blood culture (sterile) tubes or bottles✓
• c.Light blue (sodium citrate) tube
• d.Red top (no additive) serum tube

Blood cultures are drawn first so the sterile bottles are filled before the needle and the site have any chance to pick up contamination from another tube's stopper. A single skin organism carried into a culture bottle can produce a false positive that costs the patient days of antibiotics. The CLSI order then runs light blue, serum tubes, green, lavender, and gray, which prevents additive carryover between tubes.

In the CLSI order of draw, which tube is collected immediately after blood culture bottles?

• a.Light blue (sodium citrate) tube✓
• b.Lavender (EDTA) hematology tube
• c.Gray (sodium fluoride) tube
• d.Green (lithium heparin) tube

The light blue sodium citrate tube for coagulation studies is drawn immediately after the blood culture bottles. It comes early because carryover of EDTA or heparin from another stopper would alter clotting results, and citrate results are the most sensitive to contamination of any tube in the sequence. The order then continues with serum tubes, green, lavender, and gray.

A lavender-top (purple) tube is required for a complete blood count (CBC). Which additive does it contain?

• a.EDTA, which chelates calcium✓
• b.Sodium citrate, a reversible chelator
• c.Sodium fluoride, an antiglycolytic
• d.Lithium heparin, a thrombin inhibitor

The lavender-top tube contains EDTA, which binds calcium irreversibly and preserves cell shape and size, which is what a complete blood count depends on. Sodium citrate is the near miss worth knowing: it also works by binding calcium, but it does so reversibly and at a fixed 9-to-1 ratio for coagulation testing, so mechanism alone does not tell the two apart, only the tube and the test do. Fluoride preserves glucose rather than preventing clotting outright, and heparin inhibits thrombin and is used for plasma chemistry. Every additive tube is gently inverted after collection or it clots and the sample is lost.

A green-top tube is used for many chemistry (plasma) tests. Which additive does it contain?

• a.A silica clot activator with gel
• b.EDTA, used for hematology
• c.Sodium citrate, for coagulation
• d.Heparin, lithium or sodium✓

The green-top tube contains heparin, most often as the lithium or sodium salt, which inhibits thrombin and so yields plasma for chemistry testing without waiting for a clot. The cation matters in practice: a lithium level is never drawn into lithium heparin, and a sodium level is never drawn into sodium heparin. A silica clot activator with a separator gel is the serum separator tube, which is the opposite intent, and EDTA and citrate are the hematology and coagulation anticoagulants.

A gray-top tube containing sodium fluoride is most appropriate for which test?

• a.Glucose or lactate levels✓
• b.Coagulation studies (PT/INR)
• c.Blood typing
• d.Complete blood count

The gray-top tube contains sodium fluoride, an antiglycolytic agent that preserves glucose by preventing cells from metabolizing it, making it ideal for glucose and lactate testing. Potassium oxalate is often included as an anticoagulant. It is drawn last in the standard order of draw.

A plain red-top tube (no additive or with clot activator only) is typically used to collect which specimen type?

• a.A sterile blood culture
• b.Plasma requiring immediate anticoagulation
• c.Whole blood with anticoagulant
• d.Serum, after the blood clots✓

A plain red-top tube has no anticoagulant, so the blood is allowed to clot and then centrifuged to yield serum. Serum is used for many chemistry, serology, and blood bank tests. Because it contains no additive, a plain red tube does not require inversion to mix, though clot-activator tubes are inverted.

At what angle should the needle be inserted during a routine venipuncture?

• a.Parallel to the skin at 5 degrees
• b.45 to 60 degrees
• c.Straight down at 90 degrees
• d.15 to 30 degrees, bevel up✓

The needle is inserted at a 15 to 30 degree angle with the bevel facing up during venipuncture. A shallow angle follows the path of the vein and reduces the risk of passing through it. Too steep an angle can puncture the back wall of the vein.

To avoid hemoconcentration and inaccurate results, a tourniquet should not remain in place longer than:

• a.3 minutes
• b.4 minutes
• c.1 minute✓
• d.5 minutes

A tourniquet should be left on for no longer than 1 minute to prevent hemoconcentration, which can falsely elevate certain results such as potassium and protein. If more time is needed to find a vein, the tourniquet is released and reapplied after two minutes. It is loosened as soon as blood flow is established.

Which vein is generally the preferred first choice for routine venipuncture in the antecubital area?

• a.Basilic vein
• b.A vein on the underside of the wrist
• c.Median cubital vein✓
• d.Cephalic vein of the wrist

The median cubital vein is usually the first choice for venipuncture because it is large, well-anchored, and located away from major nerves and arteries. The cephalic vein is a second choice, and the basilic vein is used with caution due to its proximity to the brachial artery and nerves. Veins on the underside of the wrist are avoided due to injury risk.

When performing a capillary (heel) puncture on an infant, which area of the heel should be used?

• a.The very center of the plantar surface
• b.The arch of the foot, behind the toes
• c.The medial or lateral plantar heel✓
• d.The posterior curve of the heel itself

Infant heel sticks are performed on the medial or lateral plantar surface of the heel, at the sides, because the calcaneus lies close to the skin at the center and at the back curve of the heel. Puncturing over bone can cause bruising, injury to the bone, or infection. The arch is avoided because nerves, tendons, and blood vessels run through it. Puncture depth is also limited for the same reason.

The order of draw for capillary (skin puncture) collection differs from venipuncture. Which specimen is generally collected first from a capillary stick?

• a.Coagulation tubes first, then EDTA, then the serum tubes
• b.Blood gases, then EDTA, then additives, then serum✓
• c.Serum tubes first, then EDTA tubes, then the blood gases
• d.Chemistry tubes first, then the EDTA and blood gas tubes

In capillary collection the order is blood gases first, then EDTA hematology tubes, then other additive tubes, and serum last. EDTA comes early so an adequate, well-mixed hematology sample is obtained before platelets begin clumping at the puncture site and the drop starts to clot. This is not the venipuncture order, where the light blue coagulation tube comes near the beginning and serum tubes come before the additive tubes.

Immediately after filling an additive tube, what must the technician do to properly handle the specimen?

• a.Shake it hard so the additive mixes in faster
• b.Place it on ice regardless of the test ordered
• c.Gently invert it the recommended number of times✓
• d.Spin it in a centrifuge immediately at the bedside

An additive tube is inverted gently the number of times the manufacturer specifies, immediately after it is filled, so the blood mixes with the additive before it can clot or clump. Vigorous shaking mixes it too, which is why that answer is tempting, but the shear force ruptures red cells and the resulting hemolysis makes many results unusable. Only certain tests require chilling, and specimens are centrifuged in the laboratory after the required clotting time, not at the bedside.

A technician receives a report that a specimen was hemolyzed. Which action during collection most likely caused the hemolysis?

• a.Gently inverting the tube five times
• b.Filling the tube completely
• c.Vigorously shaking the tube after collection✓
• d.Using an appropriately sized needle

Vigorous shaking of a tube ruptures red blood cells and causes hemolysis, which can falsely elevate results such as potassium. Other causes include using too small a needle, drawing too forcefully, or leaving the tourniquet on too long. Proper gentle mixing and technique prevent hemolysis.

A serum separator tube (SST), often gold or tiger-topped, contains which components?

• a.Sodium fluoride to preserve glucose
• b.An anticoagulant to prevent clotting
• c.EDTA for hematology testing
• d.A clot activator and a gel separator✓

An SST contains a clot activator to speed clotting and a thixotropic gel that forms a barrier between serum and cells after centrifugation. This yields a clean serum sample for many chemistry and serology tests. It is inverted five times after collection and allowed to clot before spinning.

A test requires a fasting specimen. A patient scheduled for a fasting glucose reports eating breakfast an hour ago. What should the technician do?

• a.Tell the patient to fast for one more hour, then draw
• b.Tell the nurse and document that the patient ate✓
• c.Draw the specimen anyway and say nothing to anyone
• d.Cancel the test permanently and remove it from the orders

A fasting specimen typically requires 8 to 12 hours with no food or caloric intake, so a breakfast an hour ago invalidates a fasting glucose. The technician reports the situation to the nurse or provider and documents the non-fasting status so someone with the authority to decide can reschedule the draw or accept a non-fasting result. One more hour does not restore a fasting state. Drawing without comment sends a result that will be read as fasting, and cancelling an order outright is not the technician's decision.

When should specimen tubes be labeled during the blood collection process?

• a.The next day, while charting the previous day's results
• b.At the bedside right after the draw, with patient✓
• c.Only when the specimen looks abnormal inside the tube
• d.Before the patient arrives, to save time during the draw

Tubes are labeled at the bedside immediately after collection, while the technician is still with the patient whose identity was just verified with two identifiers. Pre-labeling before the patient arrives is the dangerous near-miss: it feels efficient and it is how a tube ends up carrying the wrong patient's name, which is one of the most serious errors in the laboratory. The label carries the patient's name and identifiers, the date, the time, and the collector's initials.

A technician draws the lavender-top tube before the green-top tube on a patient whose electrolytes were ordered. Which chemistry result is most likely to be falsely elevated by carryover of the lavender tube's additive?

• a.Calcium, because carryover EDTA releases calcium bound to plasma proteins
• b.Potassium, because the tube's own additive is a potassium salt of EDTA✓
• c.Sodium, because the EDTA in a lavender tube is supplied as a sodium salt
• d.Chloride, because EDTA contributes chloride ions to the plasma

Lavender-top tubes in United States laboratories are filled with dipotassium or tripotassium EDTA, so even a trace of additive dragged from one stopper to the next on the needle adds potassium to the chemistry specimen and can push a normal result into the critical range. EDTA moves calcium and magnesium the other way: it chelates those ions inside the tube, which lowers the measured value, and it does not free calcium that is bound to plasma proteins. Sodium EDTA formulations exist but are not what is packaged in a routine lavender tube, and EDTA contributes no chloride at all. This carryover risk is the reason the EDTA tube sits near the end of the CLSI order of draw, after the heparin tube, rather than near the front.

A technician is using a winged (butterfly) collection set, and the only tube ordered is a light blue sodium citrate tube for a PT/INR. What should the technician do first?

• a.Draw the citrate tube first and then draw a second citrate tube to make up any missing volume
• b.Choose a smaller-volume citrate tube so that the short fill from the tubing still meets the ratio
• c.Draw a discard tube first to fill the air space in the tubing, then draw the citrate tube✓
• d.Draw the citrate tube and reseat it on the holder to finish the fill

The tubing of a winged set holds a column of air, and the first tube on the line loses that much of its vacuum draw, so a citrate tube collected first fills short. Drawing a discard tube first, which does not need to be filled completely, primes the tubing so the citrate tube reaches its fill line and holds the required nine parts blood to one part citrate. Splitting the volume between two citrate tubes does not fix anything, because each tube then holds a full dose of citrate for a partial blood volume. Switching to a smaller tube does not help either, since every citrate tube is calibrated to its own fill line, and pulling a partly filled tube off and reseating it wastes the remaining vacuum instead of restoring it.

A light blue sodium citrate tube collected for a PT and aPTT is filled only about two-thirds of the way to its fill line. Why does the laboratory reject it?

• a.Citrate is in excess for the plasma present, so it binds extra calcium and falsely prolongs clotting✓
• b.The lower fill lets the specimen clot inside the tube, because trapped air dilutes the citrate present
• c.The short draw concentrates the platelets, which falsely shortens the measured clotting times
• d.The reduced volume leaves too little plasma for the analyzer to aspirate at all

A light blue tube is manufactured for a fixed 9:1 ratio of blood to 3.2 percent sodium citrate, and the citrate works by binding the calcium a specimen needs to clot. When the tube is only about two-thirds full, the same dose of citrate is spread across less plasma, so more calcium stays bound when the laboratory adds calcium back to start the test, and the PT and aPTT read longer than the patient's true values. That is a falsely abnormal result that can lead to a real change in anticoagulant dosing, which is why underfilled citrate tubes are rejected rather than run. Air does not dilute citrate, extra citrate lengthens rather than shortens clotting times, and analyzers can usually aspirate the small volume present, so volume alone is not the reason for rejection.

By what mechanism does the additive in a lavender-top tube keep the specimen from clotting?

• a.It neutralizes thrombin directly, in the way an antithrombin agent interrupts the clotting cascade
• b.It coats the cells with a thin film that keeps the platelets from sticking to one another
• c.It chelates calcium, removing the ion that the coagulation cascade needs in order to proceed✓
• d.It blocks the enzymes red cells use to break down glucose, which also stops clotting

EDTA is a chelating agent: it binds free calcium ions in the specimen, and without calcium several steps of the coagulation cascade cannot proceed, so the blood stays liquid. Because EDTA preserves cell size and shape well, it is the additive of choice for a complete blood count and a manual differential. Neutralizing thrombin is how heparin works through antithrombin, not how EDTA works, and no routine additive coats cells in a film to block platelet adhesion. Blocking the enzymes of glycolysis describes sodium fluoride in a gray-top tube, which preserves glucose but is not what keeps an EDTA specimen from clotting.

A chemistry test must be performed on plasma rather than serum. How does plasma differ from serum?

• a.Plasma comes from an anticoagulated tube and still contains fibrinogen and the clotting factors✓
• b.Plasma is the fluid left after a tube has clotted fully and then been spun in a centrifuge
• c.Plasma still contains the red cells and white cells, and serum has had those cells removed
• d.Plasma can be obtained only from arterial blood, while serum is obtained from venous blood

Plasma is the liquid portion of blood collected into an anticoagulant tube and spun before it can clot, so fibrinogen and the other clotting factors remain in it. Serum is what is left after blood in a nonadditive or clot activator tube has clotted, which consumes fibrinogen and leaves it behind in the clot, so serum is the fluid after clotting rather than plasma. Because no volume is lost to a clot, an anticoagulated tube also yields more plasma than an equal draw yields serum, which matters when several tests share one tube. Neither fluid contains red or white cells once the tube is centrifuged, and both plasma and serum are routinely obtained from ordinary venous draws.

A prescriber orders a lithium level on a patient taking lithium carbonate. Which collection tube is unacceptable for this specimen?

• a.A green-top tube containing lithium heparin, because that additive is itself a lithium salt✓
• b.A gold-top serum separator tube, because the gel barrier absorbs lithium during centrifugation
• c.A plain red-top tube with no additive, because serum cannot be used for drug levels
• d.A green-top tube containing sodium heparin, which is not a true anticoagulant

Lithium heparin adds lithium to the specimen, so a level drawn into that tube can read far above the patient's real concentration and prompt a dose change the patient does not need. A lithium level is collected in a plain red-top serum tube or, where the laboratory specifies plasma, in sodium heparin, so both of those choices are acceptable rather than unacceptable. The same logic runs the other way for electrolytes: a sodium level should not be drawn in sodium heparin, and lithium heparin is preferred there. The gel in a serum separator tube does not strip lithium from the sample, and sodium heparin is a genuine anticoagulant that works through antithrombin.

A technician collects a total and direct bilirubin on a newborn who is receiving phototherapy. What should the technician do with the tube immediately after the collection?

• a.Place the capped tube upright in a slurry of ice and water and walk it to the laboratory
• b.Wrap the tube in foil or place it in an amber transport tube, then send it to the laboratory promptly✓
• c.Ask the supervisor to have the tube warmed to 37 degrees Celsius for transport
• d.Leave the tube at the nurses' station for the next scheduled courier pickup round

Bilirubin breaks down when it is exposed to light, and a specimen left under room lighting or a phototherapy lamp can lose a clinically meaningful amount of its measurable bilirubin within an hour. Shielding the tube in foil or an amber transport container and delivering it without delay preserves the value the provider will use to decide whether this newborn needs more aggressive treatment. Chilling in an ice slurry is the handling requirement for specimens such as ammonia and lactic acid, and holding a specimen at 37 degrees Celsius is what cold agglutinin and cryoglobulin testing requires; neither one protects bilirubin from light, and warming offers it no protection at all. Holding the tube for a routine courier run adds exactly the delay that degrades it. Light protection for bilirubin is standard documented handling, with the specific transport container set by facility procedure.

Which specimen must be transported to the laboratory chilled in a slurry of ice and water?

• a.A potassium level, because cooling keeps the cells from releasing their potassium into the plasma
• b.A CBC in a lavender tube, because cooling preserves the cells for the differential
• c.An ammonia level, because cells keep generating ammonia in the tube at room temperature✓
• d.A glucose in a gray tube, because the fluoride works only at refrigerator temperature

Ammonia rises in a collected specimen as blood cells continue to metabolize, so the tube goes into an ice and water slurry and travels to the laboratory immediately; lactic acid and blood gases are handled the same way. Potassium is the trap in this group, because chilling does the opposite of what the tempting answer claims: cold blocks the cell membrane pump, potassium leaks out of the red cells, and the reported value comes back falsely high, so a potassium specimen is kept at room temperature. A CBC is also held at room temperature, since chilling distorts the cells the analyzer is counting and sizing. Sodium fluoride inhibits glycolysis at room temperature and needs no ice to do its job.

A gold-top serum separator tube has just been collected for a chemistry panel. What must happen before that tube is placed in the centrifuge?

• a.The specimen has to clot undisturbed at room temperature for about 30 minutes after mixing✓
• b.The stopper has to come off so that pressure cannot build inside the tube as it spins
• c.The tube has to be chilled so the gel barrier can form completely during the spin
• d.The tube has to be balanced against a second tube ordered for the same test

A serum tube must clot completely before it is spun, which takes roughly 30 minutes at room temperature for a gold-top tube with a clot activator; spinning early leaves fibrin strands that form a latent clot in the serum and can foul the analyzer or force a redraw. Stoppers stay on during centrifugation, because removing them creates an aerosol of blood and lets the specimen evaporate. Chilling is not part of forming the gel barrier and would slow the clotting the tube depends on. Tubes are balanced by matching size and volume across from one another, not by matching the test that was ordered, and a technician never opens a centrifuge lid until the rotor has stopped on its own.

What role does the sodium fluoride in a gray-top tube play in the specimen?

• a.It serves as the anticoagulant, binding calcium so that the specimen stays liquid in the tube
• b.It preserves the sample by killing the bacteria that would otherwise consume the glucose
• c.It inhibits glycolysis, so that the cells in the tube cannot go on consuming the glucose present✓
• d.It separates the plasma from the cells during the spin, the way a gel barrier does

Sodium fluoride is an antiglycolytic agent: it blocks an enzyme step in glycolysis so that the red cells and white cells in the tube stop consuming glucose after the draw, which preserves the value the laboratory reports. Without it, glucose in a collected specimen falls measurably every hour at room temperature, so a delayed sample can read low enough to look like a normal result in a diabetic patient. The anticoagulant work in that tube is done by the potassium oxalate paired with the fluoride, which is what binds the calcium, so crediting the fluoride with keeping the specimen liquid confuses the two additives. Fluoride is not an antibacterial preservative in this setting, and only centrifugation and a gel barrier separate plasma from cells.

The date of birth printed on a requisition does not match the date of birth on the inpatient's armband. What should the technician do?

• a.Correct the requisition at the bedside once the patient has confirmed the right birth date
• b.Draw the specimen and label the tubes with the date of birth printed on the requisition
• c.Draw the specimen and label the tubes using the birth date shown on the armband
• d.Stop and report the discrepancy to the nurse or supervisor before collecting anything✓

Two identifiers must agree across the requisition, the armband, and the label before any tube is filled, and a mismatch means the technician cannot yet prove which patient the order belongs to. Collecting anyway and choosing one source over the other simply moves the error onto the specimen, where it can put one patient's results in another patient's chart, and correcting a requisition from what a patient says is outside the technician's role and does not resolve where the error came from. The right move is to leave the order uncollected, report the discrepancy so nursing or the ordering area can reconcile the record, and draw only after the two identifiers match. Nothing about this delay harms the patient, which is what separates it from a situation that demands immediate action.

Which set of elements must appear on a blood specimen label before the tubes leave the bedside?

• a.The patient's full name and identification number, the room number, and the ordering provider's full name
• b.The patient's full name and date of birth, the name of the test, and the courier's pickup time
• c.The patient's full name and record number, the date and time of collection, and the collector's initials✓
• d.The patient's full name, the diagnosis being investigated, and the tube's expiration date

A specimen label has to carry the patient's full name, a unique identification number such as the medical record number, the date and time the specimen was collected, and the initials or identification of the person who collected it. Those four elements let the laboratory tie the tube to one patient and let anyone reviewing a result know when the sample was taken and who is accountable for it, which is why they are checked at the bedside rather than at the workstation. A room number changes when a patient is moved and identifies a bed rather than a person, so it can never stand in for the identification number. The courier's pickup time, the working diagnosis, and the tube's expiration date belong to other records and have no place on the label.

An inpatient is confused and cannot state a name or a date of birth. How should the technician confirm identity before drawing the specimen?

• a.Ask the patient's roommate to confirm the name and then compare it with the requisition
• b.Use the room and bed assignment on the printed collection label to identify the patient
• c.Match the armband to the requisition and have the nurse confirm the identity✓
• d.Draw the specimen first and have the nurse verify identity when the labels are applied

When a patient cannot participate in identification, the attached armband becomes the primary identifier and it must be compared element by element against the requisition, with a caregiver such as the assigned nurse or a family member at the bedside confirming that this is the right patient. A roommate is not an authorized source of another patient's identity, and a room and bed assignment is not an identifier at all, since patients are moved and beds are reassigned during a stay. Labeling after the fact, away from the bedside, is how specimens get switched, so the tubes are labeled at the bedside once identity is settled. The verification and the draw happen in that order, not the reverse.

A blood specimen is collected for a pre-employment drug screen. Which handling requirement applies here that does not apply to a routine chemistry specimen?

• a.The specimen has to be divided into two tubes so a second laboratory can repeat the test
• b.The specimen has to be centrifuged at the collection site before it leaves the room
• c.A chain-of-custody form has to record every person who handles the specimen and each transfer✓
• d.The specimen has to be labeled with the employer's account name in place of the patient's

Forensic and employment testing is defensible only if the specimen can be tracked from the donor to the analyzer with no unexplained gap, so a chain-of-custody form travels with it and each person who takes possession signs and dates the transfer. The specimen is sealed with tamper-evident tape in the donor's presence and is never left unattended, and the technician's signature on that form is a legal statement about what was collected. Splitting the sample and spinning it at the collection site are not what makes a specimen forensic, and neither one preserves the custody record. The label still carries the donor's own identifiers, since replacing them with an employer's account name would destroy the identification the chain of custody exists to protect.

A requisition lists a test code the technician does not recognize, and the department's collection manual shows no tube for that code. What should the technician do?

• a.Draw a gold-top serum tube, since the large majority of chemistry tests are run on serum
• b.Draw one tube of every stopper color available so the laboratory can pick the right one
• c.Collect nothing and send the requisition back to the unit clerk to be entered again later
• d.Ask the laboratory or the supervisor which tube this test requires before drawing✓

The tube a test requires is a laboratory specification, and when the requisition and the collection manual do not settle it, the technician confirms the requirement before the needle goes in rather than guessing at it. Choosing a serum tube because most chemistry runs on serum sends the patient for a second stick whenever the assay turns out to need plasma or whole blood. Drawing a tube of every color takes blood the patient does not need to give and still may miss a specimen with a special container or handling requirement. Returning the requisition without collecting delays care for an order that is probably valid and simply needs a tube identified, which one telephone call accomplishes.

The laboratory reports that a lavender-top tube sent for a CBC contains a clot. What should the technician do?

• a.Recollect the specimen in a new lavender tube and mix it right after the draw✓
• b.Ask the laboratory to report the platelet count alone, since a clot will not change it
• c.Invert the original tube ten more times to break the clot up and resend the specimen
• d.Send a green-top heparin tube instead so that this specimen cannot clot a second time

A clot in an EDTA tube traps platelets and white cells, so every cell count from that specimen reads falsely low and the laboratory cannot correct for it; the only remedy is a fresh draw into a new lavender tube, mixed by gentle inversion immediately after collection so the additive reaches the blood before clotting starts. The platelet count is in fact the value most damaged by a clot, since platelets are consumed first, so reporting it alone would be worse than reporting nothing. Breaking up a clot after the fact does not return the trapped cells to suspension and adds hemolysis on top of the original problem. Heparin is not an acceptable substitute for a CBC, because it distorts the white cell and platelet appearance on the stained smear.

A technician is sent to collect a CBC. The patient's left arm has an arteriovenous fistula used for dialysis, and an IV is infusing in the right forearm. The requisition gives no site instruction. What should the technician do?

• a.Ask the nurse or the supervisor how to proceed before choosing a site✓
• b.Draw from a hand vein below the running IV after stopping the infusion
• c.Apply the tourniquet above the fistula and use the cephalic vein there
• d.Use the fistula arm, since the vessels there fill quickly and stay firm

Both arms carry a restriction the technician cannot lift alone, so the draw stops until someone with the authority to decide is involved. A dialysis fistula is off limits for venipuncture anywhere in that limb, above or below it, because a puncture can damage the access the patient's dialysis depends on and can bleed heavily. Drawing distal to an infusion after it has been stopped for two minutes is a real technique, but stopping an IV is the nurse's action and not the collector's. Using the fistula because it fills well is exactly the reasoning that destroys an access.

The basilic vein is ranked as the last choice among the antecubital veins for a routine venipuncture. Which anatomy explains that ranking?

• a.It runs directly over the radial artery and a branch of the ulnar nerve
• b.It rolls away from the needle far more readily than the other antecubital veins
• c.The brachial artery and the median nerve lie immediately beneath it✓
• d.It sits deeper than the cephalic vein and can rarely be palpated at all

The basilic vein lies on the medial, little-finger side of the antecubital fossa, and the brachial artery and the median nerve run close underneath it, so a needle that goes too deep or wanders can strike an artery or a nerve. That injury risk, not technical difficulty, is what puts it behind the median cubital and the cephalic. The basilic does tend to roll, but rolling alone would only make it harder to hit, not dangerous. The radial artery runs on the thumb side of the wrist, nowhere near it, and the basilic is often easy to see and palpate, which is precisely why inexperienced collectors reach for it.

A technician inserts the needle and engages the tube, but no blood appears. Palpating above the needle finds the vein lying clearly to the side of the needle shaft. What should the technician do?

• a.Redirect the needle sideways beneath the skin until it enters the vein
• b.Remove the needle and restart at another site with fresh equipment✓
• c.Advance the needle further along its present path to reach the vessel
• d.Seat a fresh tube on the holder, since the first tube may have no vacuum

Palpation has already answered the question: the needle is beside the vein rather than in it, so this attempt is over and the next one begins with a new needle and a new site. Moving the needle laterally under the skin is probing, which is painful and can lacerate the vein or contact a nerve, and it is outside accepted technique. Pushing straight ahead only drives the needle deeper alongside the vessel. A tube that has lost its vacuum is a genuine cause of no flow and changing tubes is worth doing when the needle is seated in a vein, but that is not the situation here.

During a fingerstick the technician wipes away the first drop of blood with clean gauze before beginning to collect. What is the reason for discarding that drop?

• a.It is the richest drop in red cells and would falsely raise the hemoglobin
• b.It is diluted by tissue fluid and by any alcohol left on the skin✓
• c.It carries skin bacteria that would contaminate the microcollection tube
• d.It has begun to clot already and would leave fibrin strands in the sample

The first drop out of a skin puncture is a mixture of blood and interstitial fluid, and it may pick up residual alcohol from the prep, so it is wiped away and collection begins with the second drop. Discarding it is about dilution and contamination by fluid, not about cell concentration; the first drop is not richer in red cells. Skin flora is a concern when blood cultures are collected, which is a venous procedure and not what a microcollection tube is for. Clotting has not had time to occur in the first seconds, although squeezing the finger hard will cause both hemolysis and tissue-fluid contamination and must be avoided.

Veins of the foot and the ankle may be used for venipuncture only after permission is obtained from the patient's physician. What is the main reason for that restriction?

• a.Puncture there carries a raised risk of thrombosis and of poor healing✓
• b.Foot veins are too narrow to accept any standard multisample needle
• c.Blood from the lower extremities cannot be used for coagulation testing
• d.A tourniquet cannot be positioned correctly anywhere above an ankle vein

The lower extremities are the site most prone to clot formation and to slow, complicated healing, and patients with diabetes, peripheral vascular disease, or heart failure are at real risk of thrombophlebitis or a deep vein thrombosis from a foot puncture. That is why facility policy generally requires physician authorization before the site is used. Equipment is not the barrier: a small-gauge or winged needle fits a foot vein and a tourniquet sits above the ankle without difficulty. Blood drawn from the foot is valid for routine testing, including coagulation studies, so the objection is to harming the patient rather than to spoiling the specimen.

Where should the tourniquet be applied for a venipuncture in the antecubital fossa?

• a.Three to four inches above the intended puncture site✓
• b.Directly over the antecubital crease so the vein bulges below it
• c.One inch above the site so that the vein fills as fast as possible
• d.At the wrist, below the site, to trap blood in the forearm veins

A tourniquet placed three to four inches, roughly 7.5 to 10 cm, proximal to the site slows venous return without cutting off arterial inflow, so the veins below it distend and can be felt. Placed on the crease itself it covers the very skin that must be cleaned and punctured and it sits where the needle and holder need to be. One inch above is close enough to interfere with the equipment and with the angle of insertion. At the wrist it is distal to the antecubital veins and cannot fill them, because a tourniquet only distends the vessels downstream of it.

A patient who takes warfarin has just had blood drawn from the antecubital fossa. How should the technician manage the puncture site?

• a.Bandage the site at once and have the patient raise the arm above the head
• b.Hold firm pressure with the arm held straight until the bleeding has stopped✓
• c.Press for about fifteen seconds and then let the patient hold the gauze
• d.Have the patient bend the elbow over the gauze and hold it there five minutes

A patient on an anticoagulant bleeds for longer, so the technician holds direct pressure over the puncture with the arm extended and inspects the site before any bandage goes on; five minutes or more is ordinary and the dressing is applied only once bleeding has stopped. Bandaging immediately traps continued oozing under the dressing and produces a hematoma that nobody sees until later. Fifteen seconds is too short even for a patient on no medication at all. Bending the elbow over the gauze is a habit many patients bring with them, but it reopens the puncture about as often as it seals it and does not replace direct pressure.

A technician cleanses a venipuncture site with 70 percent isopropyl alcohol. What must happen next, before the needle is inserted?

• a.The site is dried with a sterile gauze pad to take up the excess alcohol
• b.The site is wiped a second time with alcohol, working in a circle outward
• c.The alcohol is left to air-dry completely, with no fanning or blowing on it✓
• d.The site is covered with dry gauze for thirty seconds while the alcohol acts

Alcohol has to evaporate on its own before the skin is punctured. A wet site stings sharply on insertion, and alcohol carried into the tube hemolyzes red cells and distorts results. Fanning the area or blowing on it puts organisms from the air and from the technician's breath straight back onto skin that was just disinfected. Wiping the site with gauze drags resident skin flora back across the cleaned area and undoes the antisepsis. A second alcohol pass or a gauze cover changes nothing about the drying time the technique depends on.

An 82-year-old patient needs a CBC. Her antecubital veins cannot be palpated, and the only accessible vessels are small, fragile veins on the back of the hand. Which equipment is the best choice?

• a.A 21-gauge multisample needle and holder used in the antecubital fossa
• b.A 25-gauge needle on a 10 mL syringe, with the plunger drawn back briskly
• c.A 16-gauge needle and holder, so the tube fills before the vein collapses
• d.A 23-gauge winged collection set with a holder and a small-volume tube✓

A winged, or butterfly, set with a 23-gauge needle and short flexible tubing is made for small, fragile vessels such as the dorsal hand veins, and pairing it with a small-volume tube keeps the vacuum from pulling the vein flat. The 21-gauge multisample needle is the routine choice for an antecubital draw, which makes it tempting here, but this patient has no palpable antecubital vein for it to enter. A 25-gauge needle is narrower than blood collection allows and shears red cells, and yanking a syringe plunger hemolyzes the sample as well. A 16-gauge needle is an infusion size that would tear a hand vein rather than preserve it.

During a multiple-tube venipuncture, at what point must the tourniquet be released?

• a.After the needle is out and the gauze is pressed down
• b.Before the needle is withdrawn from the vein✓
• c.Once the bandage has been placed over the puncture
• d.Just before the needle is inserted into the vein

The tourniquet comes off before the needle does. Usual practice is to release it as soon as blood begins to flow into the first tube, and it must be off in every case before withdrawal, because a needle pulled out of a vein still under tourniquet pressure lets blood escape into the surrounding tissue. Releasing it only after the needle is out, or after the bandage is on, is the exact sequence that produces a hematoma and prolonged bleeding at the site. Releasing it just before insertion collapses the vein that was distended for the stick and the attempt fails.

A technician has attempted a venipuncture on the same patient twice and has not obtained blood either time. What should the technician do next?

• a.Attempt a third stick in the opposite arm with a larger-gauge needle
• b.Ask another technician or the supervisor to make the next attempt✓
• c.Reinsert the used needle at the second site and search for the vein
• d.Document that no specimen could be obtained and cancel the order

Two unsuccessful sticks is the customary limit, after which the patient is handed to a second collector who brings fresh eyes and may find a vein the first person could not. A third attempt by the same technician adds pain and bruising without improving the odds, and a wider needle does nothing to locate a vein that has not been found. Reinserting a needle that has already been in the skin is a contamination and injury hazard and has no place in the technique. Cancelling an ordered test is a decision for the provider who ordered it, not for the person collecting.

As the needle enters the arm the patient cries out and describes a sharp, shooting, electric pain running down the forearm into the hand. What should the technician do?

• a.Withdraw the needle slightly and redirect it toward the median cubital vein
• b.Remove the needle immediately and discontinue the draw✓
• c.Loosen the tourniquet and pause until the pain settles, then continue
• d.Finish the collection quickly using the smallest tube available

Shooting, electric pain that radiates toward the hand is the classic sign of needle contact with a nerve, and the only acceptable response is immediate withdrawal; every extra second of contact adds to the risk of lasting injury. Redirecting the needle drags it across the injured nerve again. Waiting for the pain to settle with the needle still in the arm keeps the source of the injury in place. Finishing quickly with a small tube treats the specimen as more important than the patient. After withdrawal the technician holds pressure, records what the patient described in the patient's own words, and reports the incident.

A requisition asks for a basic metabolic panel on a patient who had a right mastectomy with axillary lymph node removal. Why is the right arm avoided for the draw?

• a.Surgical scarring has hardened the veins in that arm so a needle cannot enter cleanly
• b.Blood from the operated side clots faster and would gel inside a chemistry tube
• c.The operated arm carries weaker arterial pressure, so the tubes fill too slowly to use
• d.Lymph node removal impairs drainage, so the arm risks infection and skewed results✓

Taking out the axillary lymph nodes leaves that arm without normal lymphatic drainage, so it swells easily, clears infection poorly, and the fluid changes in the tissue can alter test values; the restriction lasts indefinitely unless the physician specifically authorizes the limb. Scarring is a genuine reason to avoid one patch of skin, but it is local and it is not what makes an entire post-mastectomy arm off limits. A mastectomy does not change how quickly blood clots or how hard the artery pushes, so the tubes would fill and behave normally. With one arm restricted, the unaffected arm is used.

Midway through a venipuncture the technician sees the area around the needle swelling rapidly and the skin starting to discolor. What should the technician do?

• a.Leave the needle in and ask the supervisor to look at the swelling
• b.Stop the draw and hold firm pressure over the site✓
• c.Continue the draw and ice the arm once the tubes are filled
• d.Advance the needle deeper and fill the remaining tubes

Rapid swelling with discoloration at the needle means a hematoma is forming: blood is leaking into the tissue, and the response belongs to the person already at the bedside. The tourniquet is released, the needle is withdrawn, and firm pressure is held over the site for several minutes. Waiting for someone else to come and look leaves a needle in a leaking vessel while the hematoma grows, and this is a situation the technician is trained to manage without delay. Ice may be offered after bleeding is controlled, but collecting more tubes while the tissue fills with blood is not acceptable, and pushing the needle deeper only enlarges the tear.

Before a routine draw, a patient tells the technician that she has fainted at every blood collection she has ever had. What is the best action?

• a.Seat her upright in the drawing chair and talk her through each step of the draw
• b.Have her sip a cup of juice while the tubes are being collected
• c.Hold an ammonia inhalant open near her face throughout the collection
• d.Position her reclined or lying flat for the draw and observe her afterward✓

A patient with a history of syncope at every draw is positioned reclined or supine before the needle goes in, so that losing consciousness cannot become a fall, and she is watched for several minutes after the collection. Talking an anxious patient through the steps is good practice and worth doing, but it does not protect someone who faints regardless of how calm she feels. Anything to eat or drink during the collection becomes a choking hazard the moment she loses consciousness. Ammonia inhalants are no longer recommended, because they can provoke bronchospasm in a patient with asthma and can cause a sudden head jerk that injures the neck.

A technician is performing a capillary puncture on an adult patient. Which site and lancet orientation are correct?

• a.The very center of the fingertip of the index finger, along the fingerprint lines
• b.The pad of the thumb, angled across the print lines toward the nail bed
• c.Slightly off center on the fleshy pad of the middle finger, across the prints✓
• d.The side of the tip of the fifth finger, running along the print lines

An adult skin puncture is taken from the palmar surface of the last segment of the middle or the ring finger, just off the center of the pad, with the lancet placed across the lines of the fingerprint so the blood beads up rather than running down a groove. The center of the fingertip is the most sensitive point and the bone sits closest to the surface there, and the index finger is more calloused and more sensitive than its neighbors. The thumb is calloused and has a palpable pulse. The fifth finger has too little tissue over the bone, which makes bone injury a real risk.