Hematology and oncology- Phatology (2) Flashcards
(51 cards)
Lead poisoning
- Clinical features
Microcytic anemia, GI and kidney disease.
Children—exposure to lead paint mental deterioration.
Adults—environmental exposure (eg, batteries, ammunition) headache, memory loss, demyelination
Acute intermittent porphyria
- Etiology
- Accumulate substrates
Porphobilinogen deaminase (uroporphyrinogen I synthase). AD
Porphobilinogen, ALA
Acute intermittent porphyria
- Symptoms
- Treatment
(5 P’s): Painful abdomen Port wine–colored urine Polyneuropathy Psychological disturbances Precipitated by drugs (eg, cytochrome P-450 inducers), alcohol, starvation
Treatment: hemin and glucose, which inhibit ALA synthase.
Porphyria cutanea tarda
- Etiology
- Accumulate substrates
- Symptoms
- Treatment
Uroporphyrinogen decarboxylase. AD
Uroporphyrin (teacolored urine)
Blistering cutaneous photosensitivity and hyperpigmentation.
Most common porphyria. Exacerbated with alcohol consumption. Associated with hepatitis C.
Iron poisoning
- Mechanism
- Symptoms
- Treatment
Cell death due to peroxidation of membrane lipids.
Nausea, vomiting, gastric bleeding, lethargy, scarring leading to GI obstruction.
Chelation (eg, IV deferoxamine, oral deferasirox) and dialysis.
*high mortality rate with accidental ingestion by children.
Coagulation Tests
- PT
- INR
- PTT
Tests function of common and extrinsic pathway (factors I, II, V, VII, and X).
Calculated from PT. 1 = normal, > 1 = prolonged.
Tests function of common and intrinsic pathway (all factors except VII and XIII)
Hemophilia A, B, or C
- Test altered
- Clinical manifestations
- Treatment
Intrinsic pathway coagulation defect (High PTT).
Hemorrhage in hemophilia—hemarthroses easy bruising, bleeding after trauma or surgery.
Desmopressin + factor VIII concentrate (A); factor IX concentrate (B); factor XI concentrate (C).
Platelet disorders
- Test altered
- Clinical manifestations
- Etiologies
Defects in platelet plug formation, increas bleeding time (BT).
Microhemorrhage: mucous membrane bleeding, epistaxis, petechiae, purpura.
Bernard-Soulier, Glanzmann thrombasthenia, HUS, PTT, Immune thrombocytopenia.
Bernard-Soulier syndrome
- Etiology
- Labs
Defect in platelet plug formation. Large platelets. GpIb defect.
Abnormal ristocetin test that does not correct with mixing studies.
Glanzmann thrombasthenia
- Etiology
- Labs
Defect in platelet integrin αIIbβ3 (GpIIb/IIIa).
Labs: blood smear shows no platelet clumping.
HUS
- Labs
- Etiology
- Treatment
thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure.
Typical HUS is seen in children, accompanied by diarrhea. (EHEC) (eg,O157:H7)
Same spectrum as TTP, with a similar clinical presentation and same initial treatment of plasmapheresis
Immune thrombocytopenia
- Etiology
- Labs
- Treatment
Anti-GpIIb/IIIa antibodies, splenic macrophage consumption of platelet-antibody complex.
megakaryocytes on bone marrow biopsy.
Steroids, IVIG; rituximab or splenectomy for refractory ITP.
TTP
- Etiology
- Labs
Inhibition or deficiency of ADAMTS 13 (vWF metalloprotease). large vWF multimers, platelet adhesion, platelet aggregation and thrombosis.
schistocytes, LDH, normal coagulation parameters.
TTP
- Clinical manifestations
- Treatment
(FAT RN): pentad of Fever, microangiopathic hemolytic Anemia, Thrombocytopenia, Renal failure, Neurologic symptoms.
Treatment: plasmapheresis, steroids.
Disseminated intravascular coagulation
- Etiologies
“STOP Making New Thrombi”
Sepsis (gram ⊝), Trauma, Obstetric complications, acute Pancreatitis, Malignancy, Nephrotic syndrome, Transfusion
Disseminated intravascular coagulation
- Labs
schistocytes, fibrin degradation products (d-dimers), fibrinogen, factors V and VIII.
Hereditary thrombosis syndromes leading to hypercoagulability
Antithrombin deficiency, Factor V Leiden, Protein C or S
deficiency, Prothrombin gene mutation
Antithrombin deficiency
- Etiologies
Inherited deficiency of antithrombin: diminishes the increase in PTT following heparin administration.
Can also be acquired: renal failure/nephrotic syndrome.
Factor V Leiden
- Etiology
- Epidemiology
Mutant factor V. Arg506Gln mutation. Resistant to degradation by activated protein C.
Most common cause of inherited hypercoagulability in Caucasians.
Protein C or S deficiency
- Etiology
- Complications
Decrease ability to inactivate factors Va and VIIIa.
risk of thrombotic skin necrosis with hemorrhage after administration of warfarin.
Together, protein C Cancels, and protein S Stops, coagulation.
Blood transfusion (Packed RBCs)
- Effect
- Clinical use
Increase Hb and O2 carrying capacity.
Acute blood loss, severe anemia
Blood transfusion (Platelets)
- Effect
- Clinical use
Increase platelet count.
Stop significant bleeding (thrombocytopenia, qualitative platelet defects)
Blood transfusion (Fresh frozen plasma (FFP)/prothrombin complex concentrate(PCC))
- Effect
- Clinical use
FFP contains all coagulation factors and plasma proteins; PCC contains factors II, VII, IX, and X, as well as protein C and S.
DIC, cirrhosis, immediate anticoagulation reversal
Blood transfusion (Cryoprecipitate)
- Effect
- Clinical use
Contains fibrinogen, factor VIII, factor XIII, vWF, and fibronectin
Coagulation factor deficiencies involving fibrinogen and factor VIII
