From George’s Birmingham colleague, Vicki Cardone: We are trying to discontinue bleeding times! I have spoken to Helena PlateletWorks about their method and they said it will not pick up VWD or Glanzmann thrombasthenia. Do you know of anything to replace BT? We don’t want to use PFA. Thank you, Vicki.
Hi, Vicki. I encourage you to discontinue bleeding times as pre-surgical screens, as they offer no predictive value for intraoperative bleeding and because they leave scars. I have many scars from the days when I invited students to practice on me. There are several pubications from the 1990s that are critical of the bleeding time, here is one example, authored by respected Cleveland Clinic researchers: Gewirtz AS, Kottke-Marchant K, Miller ML. The preoperative bleeding time test: assessing its clinical usefulness. Cleve Clin J Med. 1995;62:379–82.
Most bleeding time publications assert that a thorough history that includes questions about first-degree relatives’ bleeding episodes, is the best predictor of intraoperative bleeding. None encourage the use of laboratory screens. The Siemens PFA-100 may offer slightly better predictive values and has been used by many, but it requires an 800 uL sample and is affected by thrombocytopenia and anemia. Accriva’s VerifyNow and the Multiplate offer assays to monitor antiplatelet drug efficacy, not for screening.
If your surgeons insist on a pre-operative screen, you may want to investigate the Thromboelastograph (TEG) or rotational thromboelastometry using the ROTEM. Anesthetists and cardiac surgeons love them and you are likely to find them in your operating suites. Both instruments now offer cartridge-based updates that use smaller samples and improved stability, and they offer a speedy turn-around when testing whole blood. However, there exist little data that supports using either as screens for VWD, and I can find none for Glanzmann. Here is a reference about the TEG and VWD: Topf HG, Weiss D, Lischetzki G, et al. Evaluation of a modified thromboelastography assay for the screening of von Willebrand disease. Thromb Haemost. 2011;105:109–9. I hope this helps.
Joyce Low’s message: In our
Joyce Low’s message: In our lab we stopped doing the bleeding time some time soon after the publication of the following article in Blood -Lind SE: The bleeding time does not predict surgical bleeding. Blood 77:2547, 1991. As far as discontinuing the test, it was relatively easy because once we ran out of bleeding time devices we could not do any more tests and it is a test that cannot be physically sent to another laboratory – only the patient.
We purchased a PFA-100 in 1998 and found it and its successor (PFA-200) one of the most frustrating pieces of equipment we have ever used. It’s repeatability is awful. An allowable cv of <15% for duplicates is mentioned in the package insert. The calculation for this cv by the instrument is (difference/sum x 100%) which is about a cv of 20% as calculated by the usual method. What other tests do we have that perform with a cv of 20%. Surely duplicate testing for this test is essential - not mentioned in the package insert. Our lab procedure is to repeat any EPI closure time that is outside the reference interval and if the duplicate is not within 15% (manufacturer cv) then we do the test a third time and take the mean of the closest 2. We would then proceed to test with the ADP cartridge. In other words we might use up to 6 cartridges for the one patient – very expensive and time consuming.
All in all, my opinion is that the PFA may be useful for screening for VW disease which as Emmanuel states requires VWF assays anyway and for monitoring DDAVP administration and that is about all. Emmanuel will attest to that fact that I have been critical of the PFA performance from the time we first acquired one. Also, our 2 PFAs (100 and 200) have had an extensive breakdowns and the software would hang at the smallest provocation.
From Joyce Low: Hi George,
From Joyce Low: Hi George,
A couple of weeks ago I posted a comment regarding the efficacy of the bleeding time test, more specifically some comments regarding the PFA instrument. It did not appear under comments for that post. Did that comment get through or was it filtered out because of my less than complementary thoughts regarding the PFA? Our uninspiring experience with the PFA goes back many years (at least 1998). Either way I am not particularly fussed–just wanted to know.
Hi, Joyce, I’m sorry your comment didn’t appear. I can’t find it on the “admin” side of the blog, so I just pasted in your email message here.
I’ve been hosting Fritsma Factor since 2007, and can think of only two or three instances where I had to filter out a comment (except for spams that pop up once or twice a week) . Our participants are both polite and well-informed. If a comment is critical of a specific product, it gets posted as long as it is documented and not a “flame.” Please send your comment again, and I will insure it gets entered into the comment trail. The full message appears below.
More from Donna: I would go
More from Donna: I would go with factor XIII and platelet function. The factor IX is really high, I’ve not really ever seen that. Any idea about CRP, that can impact and prolong the PTT. Maybe looks like a prolongation—steering you away from platelets.
From Donna Castellone, So my
From Donna Castellone, So my 2 cents–first hi everyone. CLSI discontinued the bleeding time document–and think about this– if this test was introduced today, we could never validate it. How would you do precision and accuracy? And method correlation- -to what, and what about a control? I donate enough blood for platelet aggregation studies, but I pass on being a bleeding time control–how do you proficiency test it? what does it prove? Nothing; no advantage. Would you like me to write you a note to stop doing it? That is my comment. Have a good weekend. Donna.
The bleeding time is an
The bleeding time is an outdated screening test that was used to measure platelet function and vascular integrity. Under controlled conditions an incision is made in the skin and the duration of bleeding measured using a modified template device.
The bleeding time is a highly operator–dependent test, plagued by a lack of clinical reproducibility, and affected by numerous technical factors such as location of the incision, pressure applied, operator experience, and patient factors such as age, gender, diet, hematocrit, skin laxity and medications. Over the past decade, abundant evidence has accumulated that the bleeding time is not reliable as a screening test for perioperative bleeding or as a diagnostic test for bleeding disorders. Arch Path Lab Med, 1996;120:353–6; Arch Surg, 1998;133:134–9; Clin Chem 2001; 47: 1204–11.
This is information from Clin Lab Navigator. I wholeheartedly agree with this information. At my institution we stopped doing the Ivy bleeding time in 1999. As to what can replace the test the arguments are many but the first thing is a good patient personal and family history to predict bleeding occurring in a surgical setting. One assay is the PFA-100 or the PFA-200. In a publication by Cariappa R. et al J Pediatr Hematol Oncol 2003. the authors found the following:
PATIENTS AND METHODS
Between February 2000 and August 2001 patients aged more than 6 months and less than 18 years of age who were referred to the authors’ institution for a hemostatic evaluation were included in the study if residual blood was available for testing on the PFA-100 instrument. Fifty-two children had platelet count, prothrombin time, partial thromboplastin time, bleeding time, and PFA-100 testing performed as well as an evaluation by a hematologist. For PFA-100 testing, 52 patients had Col/Epi measurements; adequate sample remained for Col/ADP testing on 32. Additional testing for diagnostic purposes was at the discretion of the treating physician.
Use of the Col/Epi cartridge in the PFA-100 instrument offered 100% sensitivity and 97% specificity for detection of qualitative platelet abnormalities, compared with 37% and 88%, respectively, for bleeding time testing. For pediatric patients with von Willebrand disease, the sensitivity was 100% using the Col/Epi cartridge, compared with 17% for the bleeding time test. The sensitivities for combined qualitative platelet defects and von Willebrand disease using the Col/Epi or Col/ADP cartridges were 100% and 87%, respectively, compared with 37% for the bleeding time test.
The PFA-100 is a more efficient test; it can replace the bleeding time test as a component of the laboratory evaluation of children with a potential bleeding problem.
As recently as March 2016 the following was stated by Charbek E: Special Note: The bleeding time is a historical footnote in the archives of laboratory medicine. At the current time, it has been largely discredited and, in part, replaced by other testing. It is included in this collection of other laboratory tests for the convenience of our readers, who may see a reference to the bleeding time from older medical literature. This was in Medscape.
Arguments can be made for a number of assays to replace the bleeding time which include screening with the PFA systems, Platelet aggregation testing hopefully by whole blood aggregometry, the Multiplate and VerifyNow system. The bleeding time is a dinosaur that is so operator dependent you may as well flip a coin and you will get a 50/50 prediction on the possible bleeding outcomes. Its time has come and should be gone.
At a recent presentation I gave at the TACLS meeting in San Antonio, TX in April 2016 on testing for the DOACs, I asked a room of about 65 people if anyone still performed the bleeding time. Thankfully the answer was none. It’s time has come and gone.
From Bob Gosselin:
From Bob Gosselin:
Definitely NOT recommending TEG for any kinda platelet function testing…it really blows.
The bleeding time is no
The bleeding time is no longer used in most developed countries. We gave it up at least a decade ago. It may have a place in developing countries with limited resources but still retaining experienced operators, but yes, you need to convince your clinicians/surgeons that the bleeding time has had its day in the USA. A good clinical history is better value. If you want a lab test to identify or discount VWD, then I would recommend the PFA as a screen, although really you need to do the VWF assays to truly know. The TEG/ROTEM/Platelet works will not pick up/exclude VWD. The TEG/ROTEM have limited utility for identifying/excluding platelet disorders in their classical presentation. Not sure I understand why clinicians/surgeons no longer want to be clinicians and take clinical histories; sure, time is money, but it can be done quickly with one of the condensed bleeding score systems should they want a structured approach and to do it quickly.