1/ Antidote news! There has been promise recently regarding antidotes being developed for DOACs. Before we get onto that, a quick summary of what we have so far...
2/ In the case of bleeding while on warfarin, this should be stratified by severity. Usual rule is if life/limb/sight threatening bleeding, prothrombin complex concentrate + vit K is used. If not, vitamin K +- pause/cessation of warfarin is advised.
3/ Warfarin works by inhibiting vitamin K-dependent clotting factor production. These factors are II, VII, IX and X. The 'antidote' is prothrombin complex concentrate (e.g beriplex) which is a concentrated 'soup' of factors II, VII, IX and X (and some protein C and S)
4/ So a fairly straightforward replacement of 'missing' factors. The effect lasts ~6 hours, hence the need for vit K as well so the liver can start making clotting factors again. Without it, the bleeding risk will return. There is a small risk of thrombosis associated with PCC
5/ Dabigatran is a direct thrombin inhibitor, not used as commonly as anti-Xa agents (rivaroxaban etc). Idarucizumab is the 'antidote' and is a small molecule which binds dabigatran, with no prothrombotic activity itself. V effective. See NEJM ref nejm.org/doi/full/10.10…
6/ Andexanet is an 'antidote' for the anti-Xa agents (specifically rivaroxaban and apixaban in the FDA approval 2018). It was sped through approval due to the huge demand. It is available in the US, but was not recommended by NICE due to limited evidence of efficacy over...
7/ .. PCC which is often used in the context of bleeding on anti-Xa agents, even though it is not a formal antidote, rather an infusion of activated clotting factors. At a cost of £15k per dose at list price, cost effectiveness could not be assured. nice.org.uk/guidance/gid-t…
8/ *Note the Scottish medicines consortium has recently approved andexanet for uncontrolled/life-threatening bleeding on rivaroxaban or apixaban.* A paper released last month has shown significant concern about the efficacy of andexanet in a retrospective observational report...
9/ Numbers were small (n=21) but anticoagulation reversal was deemed 'effective' in only 47.6%, and poor in 52.8%. 8 patients died, and a further 6 patients had ischaemic complications, both arterial and venous.
Coagulation studies can sometimes be hard to interpret, so here are a few tips 👇
First (and perhaps most important!) tip – does your patient REALLY need a coag screen? Remember, they are not a “screen” for abnormal bleeding and are meaningless without a positive bleeding history!
Second tip – if your patient is already on an anticoagulant and you want to check its effect, request the correct tests (INR, anti-Xa, DOAC level, etc) rather than a coag screen - saves lab time and 💰!
1. An isolated prolonged APTT is less common than an isolated prolonged PT, and often requires further investigation... 🔎
2. As with any test - if unexpected/unexplained, repeat in the first instance! Spurious results are frequently seen with coagulation testing
3. If truly prolonged, the most important thing to check is the patient's bleeding history 🩸 This is the most sensitive test (much more than blood tests!) in predicting risk of abnormal bleeding
Bone marrow biopsy (BMB) FAQs! Ever wondered what it's all about? Keep reading... 👀
What makes up a BMB? Usually it includes 2 samples - the aspirate (liquid marrow 🩸) and the trephine (bone core 🦴)
Why do we need 2 samples? The aspirate allows us to individually look at each BM cell under the microscope 🔬 (e.g. WBCs, RBCs) and classify them via flow cytometry (a method of identifying and measuring pathological cells using their surface markers e.g. CD19 for B-cells)
Quick tip; A prolonged APTT is more likely to indicate an underlying factor deficiency than a prolonged PT
BUT factor deficiency is not the most common cause for a prolonged APTT
2/ The most common causes include
- Heparin (either circulating in blood or in the line the sample was taken from)
- Lupus anticoagulant
- Liver disease (expect prolonged PT also)
- DIC (expect prolonged PT and low fibrinogen also)
- Factor deficiencies
3/ The coagulation factors associated with the APTT test are;
Is supported by data from the PLADO study + others (see refs) which show that giving more than a standard dose of platelets (1 pool/unit* in an adult) did not ⬇️ bleeding incidence
2/ Each platelet exposure has (uncommon but significant) risks of allergic reaction, virus transmission and...
Each exposure to platelets is also another potential exposure to HLA antigens which the recipient does not have
3/ This may not have a big impact for many patients but for those awaiting transplants (haem or solid organ @BukuRenal) it increases the chance of graft rejection.
Febrile neutropenia is a common and serious complication of chemotherapy treatment and can rapidly progress to life-threatening severe sepsis. Patients with bone marrow failure conditions (e.g. AML, Myelodysplastic syndrome) are also at risk.
2/ Outcomes have improved with increased recognition of the importance of prompt treatment and better supportive care, driven by initiatives such as the Surviving Sepsis Campaign.
🔥IV antibiotics must be given within one hour in all suspected neutropenic sepsis 🔥
3/ Patient education is crucial, as is a failsafe, 24/7 contact line for prompt assessment and treatment in secondary care: once there, antimicrobials should be given within the hour.
🔬History, examination, imaging and cultures are then used to pinpoint the source.