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Flashcards in Haem1 Deck (417)
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241

What are the risk factors for acquired antibodies to Factor VIII?

Elderly
Malignancy
CTD
Postpartum or postsurgical

242

What are the findings in acquired antibodies to Factor VIII?

Soft-tissue ecchymoses, haematomas, mucosal bleeding (as opposed to haemoarthrosis in congenital haemophilia A)

243

What are the lab findings if you have acquired antibodies to factor VIII?

How do you treat it?

- prolonged APTT that does not correct on mixing
- low factor VIII activity
- Bethesda assay will give you titre

Treatment
Low titre - give high doses of factor VIII
High titre - prothromboninex or recombinant activated factor VII
- plus steroids or cyclophosphamide

Refractory:  IVIG, ritux or plasmapheresis

244

What is the red cell distribution width?

Measure of the variation of red blood cell (RBC) volume that is reported as 
part of a standard complete blood count. Usually red blood cells are a standard size of about 6-8 μm in diameter. Certain disorders, however, cause a significant variation in cell size. Higher RDW values indicate greater variation in size.

245

What is the diagnostic criteria for hereditary haemorrhagic telangectasia?

Four criteria, need 3/4 for definite, 2/4 for posible.

1.Spontaneous recurrent epistaxis
2. Multiple telangiectasias in typical locations
3. Proven visceral AVM (lung, liver, brain, spine)
4. First-degree family member with HHT

246

What are the classical manifestations of hereditary haemorrhagic telangectasia?

Spontaneous, recurrent epistaxis - 90%
Skin telangiectases - 75%
Hepatic or pulmonary involvement (arteriovenous malformations [AVMs]) - 30%
Gastrointestinal (GI) bleeding - 15%[31]
CNS lesions inc headache

247

What does GPIIb-IIIa do? 

Expressed on activated platelets
helps platelets adhere to damaged endothelium and to stick to one another

248

Intrinsic - XII XI

IX

249

What clinical phenotype and clotting study would you see in FXII (factor 12) deficiency? Prolonged APTT

but no clinical change on bleeding time

250

Has it normalised? (disclaimer: numbers don't correlate to actual reference ranges; I made it up in my head) NO! The mixed 1 : 1 is in the normal range

but it has not normalised. Need to get within 4-5 seconds of the control (in this example up to 28s) to have 'normalised'; 32 shows there's still some inhibitor at work

251

Name 2 causes of prolonged PT that correct with mixing studies PT = extrinsic pathway

ie Factor 7!

252

Mod

1-5% - minor trauma gives bleed

253

T/F? Getting haemophilia from a de novo mutation is rare - you nearly always inherit it False; 1/3rd of pts don't have a family history

ie haemophilia mutation came on spontaneously

254

Tranexamic acid is particularly useful for stabilising bleeding / clots in which area of the body? GI tract & mouth

good for dental procedures - use as mouthwasy or oral tablets

255

What is the Bethesda assay as it relates haemophilia? Both qualifies (presence / absence) and quantifies (the higher the titre

the stronger) inhibitors against (recombinant) factor

256

What's the most common bleeding disorder in the community? vWF

1%

257

In general

all pts with mild Type 1 vWD and pts with mild haemophilia A should receive what treatment as first-line therapy (prophylaxis/treatment) of low risk ops / slight bleeds? DDAVP

258

What causes HITs? Antibody-mediated platelet activation

antibodies bind to platelet factor 4 (PF4)

259

- thrombocytopenia or >50% fall in plts from baseline

AND

260

- start anticoagulant - danaparoid cover (or direct thrombin inhibitors

eg lepirudin or argatroban or fondaparinux) and start warfarin for 3 months (as HITs is a procoagulant state)

261

What's the management of an INR 2.5 - 4.5 but no bleeding? Withhold or reduce next dose of warfarin

and restart when INR lower

262

What's your warfarin plan for someone with low risk of clots getting a low bleeding risk procedure (eg cataracts

dental work)? Keep on with the warfarin

263

What's the difference between forward grouping & reverse grouping for blood type sorting? Forward - mix pt RCs with anti-A

anti-B and anti-Rh D antibodies. Checks for antigens on pt's RCs. Agglutination = positive.

264

With regards to preparing blood products for transfusion

why do we do leucodepletion? Why do we do irradiation? Leucodepletion - to reduce febrile non-haemolytic transfusion reaction due to HLA sensitisation or release. "CMV safe".

265

Name 2 acquired thrombophilic conditions & two hereditary thrombophilias? Acquired: antiphospholipid syndrome

cancer

266

Why is 'lupus anticoagulant' a misnomer? Because it's not an anticoagulant

it's a prothrombotic agent

267

What is your management for a lady with APLS who is now pregnant

who has had prior clots but no pregnancy complications? Therapeutic anticoagulation

268

T/F? Rivaroxaban can be dialysed off False; highly protein bound

can't HDx off

269

T/F? Dabigatran inhibits free thrombin

but not thrombin that is bound to clots False; inhibits both free & clot-bound thrombin

270

T/F? Dabigatran primarily excreted by liver False

80% renally excreted