Draft - First Aid - Hem/Onc - Pharmacology

TTP - Treatment

Plasma exchange<br>Glucocorticoids<br>Rituximab

HUS - Treatment

Supportive care

von Willebrand disease - Treatment

vWF concentrates<br>Desmopressin

How does desmopressin help in von Willebrand disease?

Desmopressin causes release of vWF stored in endothelium

Why does antithrombin deficiency blunt the PTT response to heparin?

Heparin works by potentiating antithrombin activity → if antithrombin is deficient, heparin has less anticoagulant effect → less prolongation of PTT than expected after standard heparin dosing

Why does protein C or S deficiency increase the risk of warfarin-induced skin necrosis?

Warfarin decreases protein C and S rapidly because they have relatively short half-lives → transient hypercoagulable state before procoagulant factors fall sufficiently<br><br>If protein C or S is already deficient, this transient hypercoagulability is exaggerated → microvascular thrombosis → skin necrosis

Packed RBCs - Main effect

↑ Hb and O₂-binding/carrying capacity

How much does 1 unit of packed RBCs typically increase hemoglobin and hematocrit?

1 unit packed RBCs → ↑ hemoglobin ~1 g/dL + ↑ hematocrit ~3%

Packed RBCs - Clinical uses

Acute blood loss<br>Severe anemia

Platelet transfusion - Expected effect

↑ Platelet count by ~30,000/μL per unit (~5000/mm³/unit)

Platelet transfusion - Clinical uses

Used to stop significant bleeding due to:<br>Thrombocytopenia<br>Qualitative platelet defects

Fresh frozen plasma (FFP) - Contents + Effect

Contains all coagulation factors + plasma proteins → ↑ coagulation factor levels

Fresh frozen plasma (FFP) - Clinical uses

Cirrhosis<br>Immediate anticoagulation reversal

Prothrombin complex concentrate (PCC) - Contents

Generally contains factors II, VII, IX, and X<br>+ proteins C and S

Cryoprecipitate - Contents

Fibrinogen<br>Factor VIII<br>Factor XIII<br>vWF<br>Fibronectin

Cryoprecipitate - Clinical use

Coagulation factor deficiencies involving fibrinogen and factor VIII

Albumin transfusion - Effect

↑ Intravascular volume + ↑ oncotic pressure

Albumin transfusion - Clinical uses

Post-paracentesis<br>Therapeutic plasmapheresis

Major risks of blood transfusion

Infection transmission (low)<br>Transfusion reactions<br>TACO<br>TRALI<br>Iron overload → may cause 2° hemochromatosis<br>Hypocalcemia<br>Hyperkalemia

What is TACO?

Transfusion-associated circulatory overload<br><br>Volume overload → pulmonary edema + hypertension

What is TRALI?

Transfusion-related acute lung injury<br><br>Hypoxia + inflammation → noncardiogenic pulmonary edema + hypotension

TACO vs TRALI

TACO: Volume overload → pulmonary edema + hypertension<br><br>TRALI: Inflammatory lung injury → noncardiogenic pulmonary edema + hypotension

Why can blood transfusions cause hypocalcemia?

Transfused blood contains citrate, which chelates Ca²⁺ → ↓ free Ca²⁺ → hypocalcemia

Why can blood transfusions cause hyperkalemia?

RBCs may lyse in old blood units → release intracellular K⁺ → hyperkalemia

Why can repeated blood transfusions cause secondary hemochromatosis?

Repeated transfusions deliver large amounts of iron → progressive iron accumulation → iron overload / 2° hemochromatosis

Hairy cell leukemia - Treatment

Purine analogs such as cladribine or pentostatin

Acute promyelocytic leukemia (APL) - Treatment

All-trans retinoic acid (ATRA, vitamin A derivative) + arsenic trioxide

How does ATRA treat APL?

Induces differentiation of abnormal promyelocytes

CML - Treatment

Tyrosine kinase inhibitors such as imatinib

Why do tyrosine kinase inhibitors work in CML?

They inhibit the constitutively active BCR-ABL tyrosine kinase created by t(9;22)

Polycythemia vera - Treatment

Phlebotomy<br>Hydroxyurea<br>Ruxolitinib (JAK1/2 inhibitor)

Tumor lysis syndrome - Prevention + Treatment

Aggressive hydration<br>Allopurinol<br>Rasburicase

What does rasburicase do in tumor lysis syndrome?

Helps rapidly reduce uric acid burden