Haem Flashcards

Question

List some diseases that can cause autoimmune hemolytic anemia

Answer 1

Neoplasms (CLL, CML, lymphoma, myeloma, thyoma, ovrain teratoma) Collagen vascular disease (SLE, RA, periarteritis nodosa) Infections (Mycoplasma, syphilis, malaria, CMV, EBV, coxsackie, Bartonella) Miscellaneous (thyroid, UC, drug immune reactions)

Answer 2

DIC TTP HUS Pre-eclampsia Malignant hypertension Prosthesthetic heart valves Vasculitis (Wegners) Malignancy

Answer 3

X-linked deficiency of glucose-6-phophate dehydrogenase Needed in early steps of glycolysis and therefore unable to maintain glutathione Leads to hemolysis from oxidative stress Triggers - Aspirin - Sulpha drugs - Methylene blue - Vit K - Antimalarials - Fava beans - Nitrofuratoin

Answer 4

Abnormal allele at gene loci for Hb beta chain relates to single amino acid change within the beta chain and results in anbormal tertiary structure

Answer 5

- any prior intracranial hemorrhage - known structural intracranial cerebrovascular disease (eg, arteriovenous malformation) - known malignant intracranial neoplasm - ischemic stroke within 3 months - suspected aortic dissection - active bleeding or bleeding diathesis - recent surgery encroaching on the spinal canal or brain - recent significant closed-head or facial trauma with radiographic evidence of bony fracture or brain injury

Answer 6

- age >75 years - current use of anticoagulation - pregnancy - noncompressible vascular punctures - traumatic or prolonged cardiopulmonary resuscitation (>10 minutes) - recent internal bleeding (within 2 to 4 weeks) - history of chronic, severe, and poorly controlled hypertension - severe uncontrolled hypertension on presentation (systolic blood pressure >180 mm Hg or diastolic blood pressure >110 mm Hg) - dementia - remote (>3 months) ischemic stroke - major surgery within 3 weeks

Answer 7

>65kg 100mg alteplase <65kg ~1.5mg/kg total dose alteplase Regiment depends on cause (stroke, STEMI, PE) eg Can consider half dose in high risk bleeding pts with PE Tenecteplase <60 kg: 30 mg (6000 units) 60 to 69 kg: 35 mg (7000 units) 70 to 79 kg: 40 mg (8000 units) 80 to 89 kg: 45 mg (9000 units) 90 kg or more: 50 mg (10 000 units)

Answer 8

STOP IT ALL Don’t forget to reverse any other agents given (antiplatelets, anticoagulants) FBC, Coags, Fibrinogen level 10 units cyropercipitate. Aim Fibrinogen 150-200mg/dL 2 units FFP if bleeding ongoing Tranexamic acid 10 milligrams/kg IV every 6–8 h

Answer 9

Vit K inhibitor (Factor 2,7,9,10) Protein C and S inhibition first - transient prothrombotic effect for first 24-36hrs Metabolized by CYP450 Reversal depends on INR and bleeding INR < 4.5 and no bleeding - Lower or omit next dose of warfarin and recommence at lower dose INR 4.5-10 and no bleeding - Cease warfarin, Vitamin K 1-2mg orally if bleeding risk high, recheck INR and resume warfarin at lower dose INR > 10 and no bleeding - Cease warfarin, Vitamin K 3-5 mg IV/PO, daily INR and resume at lower dose - If bleeding risk high, prothrombinex 15-30 units/kg INR > 1.5 and major bleeding - Cease warfarin, Vitamin K 50mg IV, prothrombinex 50units/kg IV, FFP 150-300ml Any INR and minor bleeding - Omit warfarin dose, consider Vitamin K 1-2mg PO IV Vit K can cause anaphylactoid reaction when given quickly

Answer 10

Prothrombinex preferred over FFP as - Lower volumes - Faster and more consistent reversal - No need for it to be thawed or crossmatched - No risk of immune reactions (TRALI, fever) However significantly higher cost

Answer 11

CYP inhibitors INCREASE warfarin levels (INR) - Azoles: ketoconazole, fluconazole - Antibiotics: sulfonamides, metronidazole, ciprofloxacin, chloramphenicol, macrolides, isoniazid - Amiodarone - Cimetidine - Omeprazole - Sodium valproate - Grapefruit CYP inducers DECREASE warfarin levels (INR) - Anticonvulsants: phenytoin, carbamazepine, barbituates (NOT Valproate) - Steroids: dexamethasone, prednisolone, glucocorticoids - Antibiotics: rifampicin, griseofulvin - Others: nicotine, alcohol, cigarette smoke, St John’s Wort

Answer 12

Direct thrombin inhibitor (factor IIa) Renally excreted Short half like (12-14hrs) and peak effect in 2hrs A normal thrombin time excludes a significant coagulopathy due to dabigatran while a diluted thrombin time is even more specific. Reversal - Oral activated charcoal if recent or excessive ingestion - Maintain urine output - Consider 50 units/kg IV (maximum dose 5000 units) Prothrombinex - TxA 1g over 10minutes and then 1g over 8hrs - For severe bleeding or urgent reversal, idarucizumab (PRAXBIND) 5 grams IV infusion given as two consecutive doses of 2.5 g over 5 to 10 minutes each. - Consider hemodialysis for pts with kidney impairment, life-threatening bleeding or a high risk of life-threatening bleeding in the immediate future or idarucizumab administration has failed to reverse coagulopathy.

Answer 13

Direct Xa inhibitor Reversal - Oral activated charcoal if recent or excessive ingestion - Consider 50 units/kg IV (maximum dose 5000 units) Prothrombinex - TxA 1g over 10minutes and then 1g over 8hrs - Very protein bound so can’t dialyse - Andexanet is experimental drug that binds to Factor Xa inhibitors but may not be available

Answer 14

Heparin - Binds and potentiates antithrombin (inactivates thrombin and Xa) LMWH Inhibits factor Xa (less effective) Therapeutic dosing of clexane is 1mg/kg BD or 1.5mg/kg daily In obese pts use 1mg/kg BD (actual body weight) up to 150kg or BMI>40 HITS, alopecia and osteoporosis all potential side effects Reversal with protamine (rapid administration may cause hypotension, bradycardia, and anaphylactoid reaction) - 1mg/100units heparin or 1mg/1unit of clexane < 8 hours (half dose if between 8-12 hours sine last dose) Protamine lasts for ~2 hours, so multiple doses may be required Follow Xa level after giving protamine and then q2hr. aPTT at 10 minutes and then 2-8hrs for heparin Protamine neutralizes at most ~60-75% of enoxaparin

Answer 15

Replacement of >1blood volume in 24hrs or >50% blood volume in 4hrs Goals to the management MTP - Early recognition of blood loss - Maintenace of tissue perfusion and oxygenation by restoration of the blood volume and Hb - Arrest of bleeding with early surgical or radiological intervention - Appropriate use of blood component therapy to manage coagulopathy A transfusion ratio of 1:1:1 would equate to 4 units of red blood cells, 4 units of FFP and 1 adult unit of platelets. Need to remember Fibrinogen replacement: 3-4 g of fibrinogen (10 units of whole blood cryoprecipitate, or 4-5 units of apheresis cryoprecipitate)

Answer 16

1) Major hemorrhage that is life-threatening and is likely to result in the need for massive transfusion (greater than or equal to 5 units of red blood cells in 4 hours) 2) Hemorrhage of a smaller volume in a critical area or organ (e.g., intracranial, intraspinal or intraocular), resulting in patient morbidity or mortality.

Answer 17

Temp >35 pH>7.2 BE<-6 Lactate<4 Ca>1.1 Plt>50 PT/APTT<1.5 x ULN INR<1.5 Fibrinogen>1 Check every 30 minutes or every 4 units of blood