Drawing labs from CVC locked with heparin

[JollyGreenGiant]

I need to draw a PT/INR from a central venous catheter that is locked with heparin. Per regular lab draw policy we waste 5ml then draw our labs. I have two questions

1. Will this be enough waste to remove the heparin fully from the CVC?

2. If not, will the residual heparin affect my pt/inr results?

Thanks

[MunoRN, RN]

If I meant FLUSH, that is what I would have said. I would not say Blood discard amounts if the research article stipulated that your flush should be 25 mls s/p withdraw of specimen. Why do you assume that I didn't mean what I said? I like you, am well read.

Here is the author:

Mayo DJ, Dimond EP, Kramer W, McDonald KH. Discard volumes necessary for clinically useful coagulation studies from heparinized Hickman catheters. Oncology Nursing Forum.

I was asking if you were referring to a flush volume because that would be about the amount of volume required if for some reason the waste was also used as the flush. The study you cited did actually do just that, the waste was also used as the flush. It takes about 25 ml of combined flush and waste to be able to get a sufficiently 'clean' sample from a lumen. You could either draw off the heparin, then flush with at least 20 mls, then waste another 3-5 ml, or use the patient's own blood to flush the line instead of saline, which means wasting an additional 20 ml or so of the patient's blood for no particular reason.

[Chisca, RN]

All of this discussion begs the question of why more point of care testing, using a drop of blood, isn't used instead of filling a tube and sending it to a different department. If the lab department was more concerned with patients instead of job security we could do away with all this blood letting.

[traumanightsRN, NP]

To make it plain and simple....if you're that worried about a contaminated sample do a peripheral stick and get the blood. Problem solved! 😉

[Asystole RN]

To make it plain and simple....if you're that worried about a contaminated sample do a peripheral stick and get the blood. Problem solved! ������

Sometimes the patients do not like to be poked again and again and again

[traumanightsRN, NP]

If someone is going to be this worried about a contaminated sample then they need to stick the patient regardless of if the patient likes it or not. No one comes to the hospital for spa treatments although the new HCAHP sites would make you think they do lol.

[brdbat416]

I know this is an old Post, but I feel I should clarify for future views. POCT are a screening tool. They do not have the precision and accuracy of a sophisticated lab analyzer. The lab is very concerned about patients.... that's why we work in the hospital lab and make sure test results are accurate.

[Chisca, RN]

I know this is an old Post, but I feel I should clarify for future views. POCT are a screening tool. They do not have the precision and accuracy of a sophisticated lab analyzer. The lab is very concerned about patients.... that's why we work in the hospital lab and make sure test results are accurate.

Your job security should be the least of a patients concern. Point of care is accurate, safe and used daily in the hospital to make clinical decisions.

[brdbat416]

I have been a point of care coordinator, so I know what I'm talking about. I didn't say they were unsafe. I said they were not as accurate. I also said that lab professionals are concerned about patients. That's why we went to college to learn how to give the best quality lab results. Comparing POC analyzers to lab analyzers is like comparing a dollar store walkie talkie to a military grade communication device. I also never said POC testing doesn't have it's place in patient care. It shouldn't be used as the only/primary testing.

[MunoRN, RN]

I know this is an old Post, but I feel I should clarify for future views. POCT are a screening tool. They do not have the precision and accuracy of a sophisticated lab analyzer. The lab is very concerned about patients.... that's why we work in the hospital lab and make sure test results are accurate.

Generally, POCT results are well within the accuracy range needed to guide patient care. Something those whose focus is solely the accuracy of lab results have difficulty understanding is the difference between statistically significant accuracy and clinically significant accuracy, which are two very different things.

While a POCT might read am INR as being 8.3 when it's actually 8.1 it's not a clinically significant difference. The additional amount of time it might take to get that more 'accurate' result is clinically significant however.

I think you'll find some pushback against what you're arguing is not uncommon since these arguments are often just attempts to maintain territory at the expense of patients.

[brdbat416]

I actually do understand the difference between statistically significant and clinically significant accuracy. We are taught that in school. It seems like you're the one who feels threatened. I joined this site to get a nursing perspective on the different roles of hospital staff with the hopes of educating and in return learning something new. Every department in a hospital serves as a check and balance for each other. Nurses have an important role in patient care, but so does the lab and respiratory therapy and radiology, etc. I have close friends and family who are nurses, so I know what your education and work experiences include. On the other hand it seems very few nurses understand the educational requirements for the other staff. You think patient care is solely in your domain and I feel sorry for you. You go ahead and think what you want about the lab though, I know why I became a Medical Laboratory Scientist. It was to help patients. By the way, POCT falls under the lab, so even though you run the test, a MLS still makes sure that everything is done correctly. Quality control, correlation studies, calibration verification, etc is all overseen by lab.

[Chisca, RN]

Point of care is an issue for nursing because we can't charge for our services unlike other departments. When point of care came about to monitor blood sugars nursing did the work but lab billed the patient. Nursing care is included in the room charge. It is one of the reasons bean counters view nursing labor as a cost and lab departments as revenue generators. But please don't pretend this system is somehow a benefit to the patient.

[brdbat416]

Your comments are all over the place. Do you think POCT benefits the patient or not? First, you defend POCT, probably because I'm a "lab tech". Then, after I say it has its place in patient care, you say it isn't what's best for the patient due to how it's billed. I feel it has its place in certain situations, but cannot replace in the lab testing overall. The reason lab bills POCT is because they are lab tests. The lab makes sure all POCT meet regulatory compliance and other "minor" details you may not know about. Just because you stick a patient for blood and put that drop of blood on a very easy to use device doesn't mean you're doing all the work. Please, at least try to see that everyone working as a medical professional has the patient's best interest at heart ( administration not included).