- When performing venipuncture using a winged infusion set, the patient care technician observes a flash of blood in the tubing but no blood flow into the collection tube. The needle appears to be in the vein. What should be done next?
Answer: Advance the needle slightly forward to ensure the entire bevel is within the vein lumen
A flash of blood in the butterfly tubing indicates the needle has entered the vein, but if no blood flows into the collection tube, only part of the bevel may be in the vein lumen. Advancing slightly forward ensures the entire bevel is within the vein for proper flow. Choice A suggests going deeper, which could cause the needle to go through the back wall. Choice C is premature since the flash indicates successful vein entry. Choice D is incorrect because you cannot increase vacuum pressure in evacuated tubes.
- A patient care technician is collecting blood using a butterfly needle and notices the patient suddenly becomes pale, diaphoretic, and reports feeling faint. The collection is only half complete. What is the most appropriate sequence of actions?
Answer: Stop the collection, remove the needle, apply pressure to the site, and position the patient supine with legs elevated
The patient is experiencing vasovagal syncope, a medical emergency during phlebotomy. The collection must be stopped immediately, the needle removed, pressure applied to prevent bleeding, and the patient positioned supine with legs elevated to improve cerebral blood flow. Choice A prioritizes collection over patient safety. Choice B applies cold compress incorrectly (cool compress should be to forehead, not neck). Choice D continues collection during a medical emergency, which is dangerous and inappropriate.
- A patient care technician is performing venipuncture on a patient taking warfarin therapy. During the procedure, a large hematoma rapidly develops at the puncture site despite proper technique. What is the most appropriate immediate response?
Answer: Remove the needle immediately and apply firm, continuous pressure for at least 5 minutes
Rapid hematoma development during venipuncture, especially in a patient on anticoagulant therapy, requires immediate discontinuation of the procedure. The needle must be removed and firm, continuous pressure applied for at least 5 minutes (longer than the standard 2-3 minutes due to anticoagulation). Choice A risks worsening the hematoma and patient injury. Choice C ignores the bleeding issue and could cause further trauma. Choice D provides inadequate pressure control for an anticoagulated patient.
- After venipuncture, when should the needle safety device be activated?
Answer: After needle is withdrawn
Activate the safety device immediately after the needle is withdrawn from the vein to prevent needlestick injury. The tempting mistake is recapping the needle first, but recapping exposes you to puncture and is unsafe. The safety feature must engage right after withdrawal, before recapping or labeling.
- During venipuncture with an evacuated tube system, the patient care technician successfully collects the first tube (red top) but when advancing the second tube (lavender top) into the holder, no blood flows into the tube. The needle position appears unchanged. What is the most likely explanation and next step?
Answer: The second tube has lost vacuum; replace with a new lavender top tube and continue
When the first tube fills successfully but the second tube doesn't fill despite unchanged needle position, the most likely cause is loss of vacuum in the second tube. This can occur due to manufacturing defects or micro-cracks in the tube. Replacing with a new tube of the same type should restore collection. Choice B is premature since the first tube filled successfully with the same needle position. Choice C incorrectly suggests vein collapse when the issue is more likely tube-related. Choice D addresses tourniquet pressure, but if the vein was adequate for the first tube, tourniquet adjustment isn't the primary issue.
- A syringe is used for a difficult draw. Which device is used to fill tubes?
Answer: Safety transfer device
After a syringe draw, you attach a safety transfer device to the syringe hub; its shielded needle pierces the tube stopper and lets blood fill the tube without an exposed needle. The most tempting wrong answer is a new hypodermic needle, because it could technically pierce a tube but it creates an avoidable sharps hazard and is not the safe device meant for this task.
- Using a butterfly for aPTT and CBC, which is drawn first?
Answer: Nonadditive discard tube
With a butterfly, the tubing holds air that can underfill the light blue citrate tube and alter aPTT results, so a nonadditive discard tube clears the line first. Then draw the light blue for coagulation, then the lavender EDTA for CBC. The light blue citrate tube is the tempting mistake because coagulation seems urgent, but underfilling ruins the test.
- During venipuncture with a syringe method, the patient care technician successfully enters the vein but notices the syringe plunger is being pulled back by vacuum pressure from the vein. What does this indicate and what should be done?
Answer: Arterial puncture; remove the needle immediately and apply firm pressure for 5-10 minutes
When the syringe plunger is pulled back by pressure from the vessel, this indicates arterial puncture due to the higher pressure in arteries compared to veins. The procedure must be stopped immediately and firm pressure applied for 5-10 minutes. Choice A incorrectly assumes this is normal venous pressure. Choice B suggests tourniquet adjustment but doesn't address the arterial puncture. Choice D misinterprets the high pressure as normal when it actually indicates arterial access.
- When performing venipuncture using a 21-gauge needle with evacuated tubes, the patient care technician notices that the blood appears hemolyzed in the collection tube. The puncture was successful on the first attempt using proper technique. What is the most likely cause of this hemolysis?
Answer: The needle bevel was only partially in the vein, creating turbulent blood flow
Hemolysis during collection with appropriate needle size (21-gauge) most commonly results from turbulent blood flow caused by improper needle positioning, such as the bevel being only partially in the vein lumen. This creates shear forces that damage red blood cells. Choice A is incorrect because 21-gauge is appropriate for evacuated tubes. Choice B describes tourniquet issues but tight application doesn't directly cause hemolysis during flow. Choice C is wrong because overfilling doesn't cause hemolysis during the collection process itself.
- A patient care technician is preparing to perform venipuncture on a 45-year-old patient with a history of difficult venous access. The antecubital veins are not palpable, but a small vein is visible on the dorsal aspect of the hand. Which needle gauge and collection method would be most appropriate for this situation?
Answer: 23-gauge butterfly needle with syringe to minimize trauma to the fragile vein
For small, fragile hand veins, a 23-gauge butterfly needle with syringe is most appropriate. The butterfly provides better control and stability, the smaller gauge reduces trauma to the delicate vein, and the syringe allows controlled suction pressure rather than the stronger vacuum of evacuated tubes. Choice A uses too large a needle for a small vein. Choice C combines an extremely small needle with evacuated tubes, which may cause hemolysis. Choice D uses evacuated tubes which create too much suction pressure for fragile hand veins.
- A venipuncture for a lead level is ordered. Which collection tube is appropriate?
Answer: Royal blue top with EDTA
For lead testing you need a trace-element-free tube, so the royal blue top with EDTA is the right choice. It is certified to avoid lead contamination. A lavender top with EDTA is tempting because it also contains EDTA, but it isn't trace-metal certified and can leach lead into the specimen.
- During venipuncture using an evacuated tube system, the patient care technician observes that blood flow stops after filling only half of the first tube. The needle appears to be properly positioned in the vein. What is the most likely cause and appropriate next action?
Answer: The needle bevel is against the vein wall; gently adjust the needle angle slightly backward
When blood flow stops mid-collection with proper needle positioning, the most common cause is the needle bevel being pressed against the vein wall. Gently adjusting the needle angle backward (pulling slightly) often restores flow. Choice B is incorrect because tourniquet time wouldn't cause sudden flow stoppage. Choice C assumes tube vacuum failure, which is less common than positioning issues. Choice D suggests vein collapse, but removing the tourniquet would make collection more difficult, not easier.
- A frail elderly patient with small veins needs a CBC. Which device is best?
Answer: 23-gauge butterfly needle
For a frail elderly patient with small veins, a 23-gauge butterfly needle is best because it is small enough to minimize trauma while still allowing enough blood flow for a CBC. The 21-gauge straight needle is tempting because it is common for routine draws, but its larger bore can damage fragile veins and cause more pain.
- A patient care technician is collecting multiple tubes of blood using the evacuated tube system. After removing the third tube, blood begins to leak from the hub connection. The needle is still properly positioned in the vein. What is the most appropriate immediate action?
Answer: Discontinue the procedure immediately and apply pressure to prevent further blood loss
Blood leaking from the hub connection indicates equipment failure that poses a safety risk for both patient and technician. The procedure must be discontinued immediately to prevent blood loss and exposure. Pressure should be applied to the venipuncture site. Choice A ignores a serious safety issue. Choice B won't fix equipment failure and wastes time. Choice C creates an unsafe work environment and doesn't address the equipment failure.
- A patient care technician needs to collect blood for a CBC, comprehensive metabolic panel, and PT/INR from a patient with bilateral mastectomies and an arteriovenous fistula in the left forearm. Which venipuncture approach should be used?
Answer: Use the right hand dorsal veins with a 23-gauge butterfly needle and syringe
With bilateral mastectomies, arm restrictions apply to both arms for lymphatic drainage concerns. The AV fistula in the left arm creates an additional contraindication for that entire arm. The right hand dorsal veins with a butterfly and syringe is the safest option, avoiding both mastectomy-related restrictions and the AV fistula. Choice A risks compromising the fistula. Choice C ignores mastectomy precautions. Choice D still uses the contraindicated left arm with the AV fistula.
