Venipuncture Problems

Question 1

cause: Needle may not be placed at the center of the stopper
causing blockage.

Answer 1

no blood is seen or too little blood flow into the tubes

solution: remove and reposition the tube correctly

Question 2

tourniquet applied to tightly or too long stopping the blood flow

Answer 2

No blood is seen or too little blood flow into the tubes

sol: release pressure slowly

Question 2

needle bevel may be flushed against the wall of the vein causing blockage

Answer 2

no blood is seen or too little blood flow into the tubes

sol: rotate the needle 1/4 turn clockwise

Question 3

*Tube may have been
Prematurely punctured.
*Tube may have been previously opened

Answer 3

No blood is seen or too little blood flow into the tubes

sol: replace the tube

Question 4

the needle has transfixed the vein (going thru the back wall of vein)

Answer 4

No blood is seen or too little blood flow into the tubes

sol: pull back slightly on the needle holder

Question 5

the needle is not completely in the vein or has not reached the vein

Answer 5

No blood is seen or too little blood flow into the tubes

sol: advance the needle forward until you feel the “give” as the needle penetrates the vein

Question 6

cause of underfilling of tubes

Answer 6

• premature removal of tube
• long lines of tubing contain air

Question 7

cause: premature removal of tube

Answer 7

reintroduce tube for collection until vacuum is completely exhausted

Question 8

cause: long lines of tubing contain air

Answer 8

use a dummy tube first to ensure accurate test results

Question 9

Blood stops flowing halfway during blood collection. Causes:

Answer 9

• vein may have collapsed
• needle may have been repositioned or out of the vein during venipuncture

Question 10

cause: vein may have collapsed (blood stops flowing)

Answer 10

Remove the tube holder for a few seconds to allow the vein to fill again. Replace tube to continue collection.

Question 11

needle may have been repositioned or out of the vein during venipuncture (blood stops flowing)

Answer 11

repeat venipuncture at different site when hematoma occurs

Question 12

causes of occurrence of hematoma

Answer 12

• needle not completely in the vein
• needle transfixed in the vein
• excessive probing resulting in enlargment at the site of entry
• tourniquet placed too near the venipuncture site

Question 13

excessive probing leading to hemolyzed specimen

Answer 13

*Release tourniquet and remove
needle. Repeat venipuncture at a
different site.

Question 14

vigorous mixing of tubes leading to hemolyzed specimen

Answer 14

mix additive tubes by gentle invertion

Question 15

under filling of tubes leading to hemolyzed specimen

Answer 15

*Redraw specimen as indicated
with trauma-free venipuncture

Question 16

transferring from syringe and needle to evacuated tube leading to hemolyzed specimen

Answer 16

*Remove needle from syringe and
undo stopper of tube for
transferring.

Question 17

alcohol contamination leading to hemolyzed specimen

Answer 17

*Allow disinfected site to “air-dry”
before venipuncture procedure.

Question 18

prolonged tourniquet application (>2 minutes)

Answer 18

*Release tourniquet, reapply and
the area palpated again.

Question 19

Possible causes leading to hemolyzed specimen.

Answer 19

• excessive probing
• vigorous mixing
• under filling of tubes
• transferring from syringe and needle to evacuated tube
• alcohol contamination
• prolonged tourniquet application (>2 minutes)