The blood return should look like whole blood with the same color and consistency, however there are no requirements that you be able to aspirate a specific amount of blood before using the catheter.
Many times, it seems impossible to obtain a blood return, leaving you to think that the catheter may not be functioning properly. Frequently the technique used for aspiration is the cause of the problem. Here are a few technique tips to ensure a blood return.
- Always use a slow and gentle technique to aspirate from any catheter. Pulling to rapid and with a lot of force applied to the plunger rod could be the issue. Excessive force could cause a flexible PICC to temporarily collapse and occlude the backflow of blood. On a peripheral vein, you could be pulling the vein wall over the catheter lumen as in this drawing.
- If slow and gentle does not produce a blood return, change to a smaller syringe. Using a 5 mL or 3 mL syringe on aspiration will generate less force and could produce a blood return when a 10 mL syringe will not.
- For a central VAD, changing the patient’s position could help if the catheter is against the vein wall. Just remember that when changing the arm and shoulder position on a subclavian inserted catheter yields a blood return, pinch off syndrome could be the problem. The catheter is compressed between the clavicle and first rib. Over time this could easily produce a hole in the catheter and could cause catheter embolism to the heart.
- For a peripheral catheter, place a tourniquet on the arm well above the catheter and try again to aspirate.
- Take the fluid container off the infusion pump and lower the bag or bottle below the insertion site.
Failure of these step to produce a blood return means that the catheter is not functioning properly. Other steps in assessment include looking at the site to check for color changes (redness or blanching), fluid leakage from the puncture site, or swelling. Sometimes you will have to compare both extremities to see that swelling is present with a peripheral catheter. This is because fluid is accumulating in compartments of the arm and it is not appearing as a raised swollen area at the catheter tip.
Flush the catheter with normal saline to check for resistance. Palpate the site before and during the flush. Did the patient complain of any discomfort when palpated? Did you feel any temperature change at the site? Did you feel the flush solution moving through the vein or feel fluid accumulating at the catheter tip?
Finally, listen to everything the patient tells you about how the entire area feels. Flushing a central venous catheter whose tip has migrated to the jugular vein will cause the patient to hear a gurgling sound or running stream. Complaints of pain or discomfort in strange locations of the chest, neck, or upper abdomen could be related to the catheter.
Before any medication is given through the catheter, you need to ensure that the site is free from all signs and symptoms of complications, that the patient has no complaints about the site, and that a blood return can be easily obtained. Many may think that a blood return will not provide useful information from a short peripheral catheter, but it is an important part of your assessment. A peripheral vein may have an additional puncture that allows fluid to leak into the tissue but you still get a blood return. That is why it is important to perform a complete assessment looking for all signs and symptoms.
To download a poster that might be useful in teaching other nurses about this process, go to our website – hadawayassociates.com and scroll down to the Free Poster download.