Hema Flashcards
Tumor Lysis Syndrome
- follows a px with malignancies recently treated with chemotherapy.
- it is considered as a hematology & oncology EMERGENCY as it is life-threatening (Renal, Cardiac and Neurological complications)
Metabolic Abnormalities:
• Hyperuricemia (causes gout & renal colic)
• Hyperkalaemia (causes paraesthesia, muscle weakness & arrhythmias) - often the earliest sign of tumor lysis syndrome
• Hyperphosphataemia (causes acute kidney failure)
• Hypocalcaemia (causes tetany)
Tx: Rehydration with IV fluids
IMPT KEY FEATURES:
- Hx of Leukemia/Burkitt’s Lymphoma
- Chemotherapy
- Acute Renal Failure (d/t Uric Acid nephropathy, acute nephrocalcinosis & precipitation of xanthine)
- Hyperuricemia, Hyperkalemia, Hyperphosphatemia, Hypocalcemia
- IV fluids as part of management
Warfarin
- oral anticoagulant inhibits the reduction of Vitamin K to its active hydroquinone form
What are the indications?
• Venous thromboembolism
> Target INR = 2.5
> If recurrent = 3.5
• Atrial Fibrillation
> Target INR = 2.5
• Mechanical Heart Valves
> Target INR depends on the valve type and
location
> Mitral Valves generally require a higher INR
than aortic valves.
Factors that may potentiate (Inc. effect) of warfarin:
• Liver disease
• P450 enzyme inhibitors (amiodarone and ciprofloxacin)
• Cranberry juice
• Drugs which can displace warfarin from plasma albumin: NSAIDs
• Inhibit platelet function: NSAIDs
Management when INR is high:
• Major bleeding
> stop warfarin
> give IV Vit. K at 5mg
> Prothrombin complex concentrate - if not
available then FFP.
• INR > 8 (Minor bleeding)
> Stop warfarin
> Give IV Vit. K 1-3mg
> Repeat dose of Vit. K if INR still too high after 24h
> Restart warfarin when INR < 5
• INR > 8 (No bleeding)
> Stop warfarin
> Give Vit. K at 1-5mg by mouth (using IV prep)
> Repeat dose of Vit. K if INR still too high after 24h
> Restart when INR < 5
• INR 5-8 (Minor bleeding)
> Stop warfarin
> Give IV Vit. K at 1-3mg
> Restart when INR < 5
• INR 5-8 (No bleeding)
> Withhold 1 or 2 doses of warfarin
*Warfarin can be used when breastfeeding contraindicated when pregnant
*Warfarin is stopped 5 days before planned surgery and when px’s INR is <1.5 then surgery can proceed
Polycythemia Vera
- a myeloproliferative disorder caused by clonal proliferation of a narrow stem cell leading to an increase in Red Cell Volume.
- often accompanied by the overproduction of neutrophils and platelets
- mutation in JAK2 (present in 95% of pxs w/Polycythemia Vera)
FEATURES:
- Pruritus usually after a hot bath
TESTS that should be performed:
> JAK2 mutation
> Serum ferritin
> Renal & Liver Function tests
> Full Blood Count/Film (🔺HCT, (50% of pxs - 🔺Neutrophils, Basophils, Platelets)
Heparin
2 main types:
• Unfractionated, ‘standard’ heparin (Inhibits: Thrombin, Factors: Xa, IXa, XIa and XIIa)
> Monitoring: APTT
> S/E: HIT(typically doesn’t develop until after
5-10 days of Tx)
• Low Molecular Weight Heparin (LMWH) (Increases action of Antithrombin III on factor Xa)
> Monitoring: Anti-Factor Xa
- Both can cause Hyoerkalemia
- Heparin Overdose: reversed by Protamine Sulphate
Direct Coombs Test
- used to test for autoimmune hemolytic anemia
- used to test px’s RBCs
- (+) Coombs test: immune mechanism is attacking own RBCs
> Examples of alloimmune hemolysis:
• Hemolytic disease of the newborn (AKA HDN
or Erythroblastosis fetalis)
• Alloimmune Hemolytic Transfusion reactions
• Rh D Hemolytic disease of the newborn (AKA
Rh Disease)
• ABO hemolytic disease of the newborn
Indirect Coombs Test
- used in prenatal testing of pregnant women
- used in testing blood prior to blood transfusion (Antibody screening, cross-matching)
B12 Deficiency
- found in meat, fish & dairy products
- B12 binds to Intrinsic Factor in the stomach & this complex is absorbed in the terminal ileum
Clinical Presentation:
> Neurological symptoms (Peripheral paresthesia & disturbances of position and vibration sense)
Causes of B12 deficiency:
• Pernicious Anemia (commonest cause)
- d/t autoimmune gastric atrophy
- dietary (vegans)
- after total gastrectomy
- ileal disease (resection of ileum, Crohn’s disease)
Hematological Abnormalities of B12 deficiency:
- Macrocytic anemia and the MCV is typically >110ft (seen in both Folate and B12 deficiency)
- Hypersegmented Neutrophils
Management: Hydroxocobalamin IM
Leukemia
Classification:
• Acute/Chronic:
< 40 yrs old - Acute Leukemia
> 40 yrs old - Chronic Leukemia
• Lymphoid/Myeloid
- look for lymphadenopathy
• Examine the blood
- w/ Neutrophils = Myeloid
- w/ Lymphocytes = Lymphoid
Tx: Chemotherapy
Acute Lymphoid Leukemia (ALL)
Clinical Presentation:
• <40 yrs old
• bleeding, petechiae, purpura/ecchymoses (d/t thrombocytopenia)
• fatigue because of anemia
• recurrent and severe infections
• splenomegaly
How to diagnose?
> FBC (anemia: Hb <5 g/L, WBC: low, normal or elevated, thrombocytopenia)
> Bone Marrow biopsy (shows numerous blasts)
Chronic Myeloid Leukemia (CML)
- Main Feature: 🔺WBC (consisting mainly of neutrophils, blasts are either absent/present in very small amounts)
- The Philadelphia chromosome (>90% of pxs)
Presentation:
- Splenomegaly
Diagnose:
• FBC ( Leukocytosis, differential shows granulocytes at all stages of development - increased #s of neutrophils, myelocytes, basophils, eosinophils)
• Bone Marrow Aspiration & Biopsy
- Ph chromosome (Philadelphia)
Tx:
- Imatinib (1st line)
- Hydroxyurea
- Interferon-alpha
- Allogeneic Bone Marrow Transplant
Chronic Lymphocytic Leukemia (CLL)
• > 65 yrs old
Investigations:
- Normocytic normochromic Anemia
- Blood film: Smudge cells/Smear cells
Hemophilia
- X-linked recessive disorder of coagulation
- males are typically affected
- Hemophilia A (Factor VIII deficiency)
- Hemophilia B/Christmas Disease (Factor IX deficiency)
Features:
- hx of spontaneous bleeding into joints (knees, ankles & elbows) without a hx of significant trauma.
- Spontaneous hemarthrosis (pathognomonic)
Tests:
- Prolonged APTT (can be normal in mild disease)
- Bleeding Time, Thrombin Time and Prothrombin Time = NORMAL
- Factor VIII or IX assay to diagnose
Tx:
• Hemophilia A - Desmopressin (🔺 Factor VIII levels)
• Hemophilia B - Recombinant Factor IX (Tx of choice)
- Avoid NSAIDs and IM Injections
Deep Vein Thrombosis
How to diagnose:
- Two-level DVT wells score (> 2 pts - likely)
• > 2 pts?
- Proximal leg vein ultrasound (within 4hrs), if negative = Do D-dimer test.
* if cannot do within 4hrs, do D-dimer test & interim therapeutic anticoagulation (apixaban/rivaroxaban which are both DOACs) while waiting for Proximal leg vein ultrasound (should be performed within 24hrs)
- Negative scan but D-dimer +?
> stop interim therapeutic anticoagulation (DOAC)
> repeat proximal leg vein ultrasound scan 6-8 days later.
• <1 pt?
- perform D-dimer test (within 4hrs) if not, DOAC should be given until the result is available. If +, do proximal leg vein ultrasound within 4hrs. Should be done within 24hrs.
- DOAC (Direct Oral Anticoagulants) - Apixaban/Rivaroxaban (1st line Tx)
Duration of Anticoagulants:
- at least 3 mos.
• If provoked (with precipitating event): stopped after the initial 3 mos. (If with active cancer upto 6 mos)
• If unprovoked: continued 6 mos total
