Hematologic Disorders Flashcards
Definition of MTP
Replacement of approximately 10 units of pRBCs within 24 hours
Protocols may include early administration of FFP (2-3 units for every 3 units of pRBCs) and platelets (8-10 units or 1 apheretic unit for every 10u pRBCs)
What is the most common infection transmitted in blood transfusion?
Hepatitis B
Which hepatitis viruses are associated with development of HCC?
Hepatitis B and C
Most common presentation of SCD in infants
Dactylitis
Physiologic cause of muscle and cardiac manifestations in hyperkalemia
- Impaired neuromuscular transmission after high extracellular potassium causes persistent depolarization
- Causes inactivation of the sodium channels -> decreased membrane excitability
ECG changes due to hyperkalemia
- Peaked T wave
- Prolonged PR interval and dropped P wave
- Widened QRS complex
- Sine wave
ECG findings consistent with hyperkalemia are seen in the toxic manifestations of what drug?
Digoxin
When does heparin-induced thrombocytopenia usually occur?
Within 5-7 days of initiation of therapy
Tx for HIT
Direct thrombin inhibitor (lepirudin, argatroban)
Factor Xa inhibitor (fondaparinux)
Heparinoids (danaparoid)
4T score of HIT
Thrombocytopenia
Timing of platelet count fall
Thrombosis or other sequelae
Other cause for thrombocytopenia
Q#279895
Pathophysiology of transfusion-related acute lung injury
Acute neutrophilic response that leads to endothelial damage and massive capillary leak in the pulmonary vasculature
S/S of TRALI
- Hypoxemia within 6 hrs of transfusion
- Hypotension, tachycardia
- Fever - not common in transfusion-associated circulatory overload
Medications useful in hemophilia associated bleeding
Severe Disease with deep laceration or muscle compartment bleeding -> factor VIII replacement
Severe Disease with superficial lac or abrasion -> topical thrombin
Mild Disease with minor mucosal or superficial bleeding -> desmopressin, aminocaproic acid or TXA
What agent provides the fastest reversal of warfarin-induced coagulopathy?
Prothrombin complex concentrate
What is the most serious transfusion reaction?
Hemolytic transfusion reaction
Cause of hemolytic transfusion reaction
Most commonly result of ABO incompatibility - alloantibodies formed in response to foreign red blood cell antigens.
Antibody-antigen complex reaction leads to intravascular destruction of transfused red blood cells
Symptoms of hemolytic transfusion reaction
Immediate fever and chills Headache Nausea/Vomiting Myalgias Dark urine Hypotension
Management of hemolytic transfusion reaction
- Stop the transfusion
- Immediate vigorous crystalloid infusion
- Diuretic therapy to maintain urine output 1-2 mL/kg/hr
What is the most common cause of hemolytic transfusion reaction due to ABO incompatibility?
Clerical error
Definition of neutropenic fever
Temperature of 38C for more than 1 hour or temperature of 38.3C once with an absolute neutrophil count less than 500/mm3
Calculating ANC
ANC = WBC count x ((PMNs/100) + (Bands/100)) ANC = Total WBCs x %Total neutrophils (segmented + bands)
After chemotherapy, when is the expected nadir of the patient’s neutrophil count?
6-10 days
How long does it typically take the neutrophil count to recover after nadir?
5 days
Common malignancies that metastasize to bone
- Breast
- Lung
- Thyroid
- Kidney
Clinical features of multiple myeloma
CRAB - hypercalcemia, renal failure, anemia, lytic bone lesions
- Bone pain - back and ribs
- Spinal cord compression
- Hypogammaglobulinemia (leading to sepsis)
- Anemia
- Hyperviscosity syndrome (Rouleaux formation)
- M spike on serum protein electrophoresis
- Bence-Jones proteins on urine analysis
Tumor lysis syndrome is most commonly seen after chemotherapy of what type of malignancies?
Hematologic including acute leukemias and high-grade non-Hodgkin lymphomas, particularly Burkitt lymphoma
Hallmarks of tumor lysis syndrome
- Hyperkalemia from cytosol breakdown
- Hyperphosphatemia from protein breakdown
- Hypocalcemia 2/2 hyperphosphatemia
- Hyperuricemia from DNA breakdown
Neuromuscular irritability, cardiac dysrhythmia, renal failure
Which type of lymphadenopathy in the neck area suggests underlying metastatic disease?
Supraclavicular lymphadenopathy suggests metastatic disease from chest or abdomen
What is the most common location for spontaneous bleeding in children with hemophilia A? What about adults?
Ankle (knee is most common joint in adults followed by elbow and ankle)
What factor is deficient in hemophilia A?
Factor VIII (“A”ight)
What factor is deficient in hemophilia B
Factor IX
Lab values in iron deficiency anemia
Iron <50 mcg/dL Transferrin saturation percent <10% Serum ferritin <15 mcg/L Total Iron Binding Capacity >400 mcg/dL Decreased reticulocyte counts
Causes of acquired sideroblastic anemia?
- Lead toxicity
- Pyridoxine deficiency
- Drug toxicity (chloramphenicol, isoniazid)
- Carcinoma
- Leukemia
- Chronic alcohol use
- Infection
Lab values in DIC
HIGH: PT, aPTT, thrombin clotting time, d-dimer, fibrin complexes
LOW: platelets, fibrinogen
Causes of DIC
- Obstetrical catastrophes such as amniotic fluid embolism or placental abruption
- Metastatic malignancy
- Massive trauma
- Sepsis
- Bacterial endotoxin activation
- Snake envenomation
Tx of DIC
Treat underlying condition
If bleeding complications -> replete clotting factors and platelets with FFP and platelets
Examples of medications that can cause thrombocytopenia
- Heparin
- Certain antibiotics
- Ranitidine
- Phenytoin
What happens to PT/PTT in patients with primary immune thrombocytopenia?
Remains normal
Tx for ITP
IVIG, Steroids, possibly anti-D antibody
Clinical features of polycythemia vera
- Fatigue
- Pruritus (especially following warm bath or shower)
- Facial plethora (ruddy cyanosis)
- Erythromelalgia (burning pain and erythema, pallor, or cyanosis)
- Engorged retinal veins
- Thrombosis
- Gouty arthritis
- Splenomegaly
Tx for polycythemia vera
- Hydroxyurea
- Phlebotomy
- Aspirin
Mutation found in polycythemia vera
JAK2 mutation - chronic myeloproliferative neoplasm with abnormal proliferation in all three cell lines
Which gastric hormone is hypersecreted, resulting in PUD and pruritus, common complications of polycythemia vera?
Histamine
Characteristics of CML (chronic myelogenous leukemia)
- WBC elevated, but differential is fairly normal
- Basophilia on smear
- Hallmark = Philadelphia chromosome - reciprocal translocation of material b/n chromosomes 9 and 22
- Triphasic:
1. Chronic phase - fatigue, weight loss, diaphoresis, abdominal fullness and hepatosplenomegaly
2. Accelerated phase - bleeding and petechiae
3. Blast phase - greater than 20% blasts and resembles acute leukemias
Characteristics of ALL (acute lymphocytic leukemia)
- Most common childhood leukemia
- 75% affects B-cell precursors, 20% affects T-cell precursors
Characteristics of CLL (chronic lymphocytic leukemia)
- Most common adult chronic leukemia
- Smudge cells
Characteristics of AML (acute myelogenous leukemia)
- More common in adults than children
- Auer rods
What is a risk factor for development of CML?
Exposure to ionizing radiation
Tx for CML
Allogenic HSCT
Imatinib
What is a Heinz body?
- Inclusion within RBC composed of denatured hemoglobin
- Formed as a result of oxidative damage
- Macrophages in spleen remove the denatured hemoglobin which results in bite cells
Seen in G6PD deficiency
What type of hereditary pattern for G6PD?
X-linked recessive
A way to tell Systemic (B) symptoms of lymphoma from malaria
Malaria does not have lymphadenopathy
Pathophysiology of TTP
Inhibition of enzyme ADAMTS13 which leads to large multimers of von Willebrand factor
Tx of TTP
Plasmapheresis and consider corticosteroids for inadequate response to plasmapheresis and splenectomy for recurrent cases
What is the most common cause of vitamin B12 deficiency?
Chronic malabsorption, as seen in pernicious anemia
Complications of massive transfusion
- Hypocalcemia
- Metabolic acidosis
- Hyper/hypokalemia
- Hypothermia
- Dilutional coagulopathy
- Thrombocytopenia
- ARDS
When should calcium gluconate be given for hypocalcemia from massive transfusion?
Only if there are ECG changes
Tx for blast crisis in patients with leukemia
Aggressive fluid resuscitation or phlebotomy and replacement with IV fluids
In patients who may not be able to tolerate large volumes of fluid -> leukapheresis
Which tx for hyperkalemia should be avoided in treating tumor lysis syndrome?
Rectal sodium polystyrene sulfonate
What is the most common risk factor for new-onset childhood immune thrombocytopenia?
Viral infection
Tx for polycythemia vera
Low dose aspirin
Phlebotomy to a HCT of 45%
If with hyperviscosity syndrome - require IV fluid hydration and hematology consultation
Other options include hydroxyurea, interferon-alpha, ruxolitinib (JAK1 and JAK2 inhibitor)
Mechanism of action of rivaroxaban, apixaban and edoxaban
Direct factor Xa inhibitor
Intrinsic and extrinsic pathways
Q105929
What bacteria are most commonly implicated in acute chest crisis?
Chlamydia pneumoniae in adults and Mycoplasma pneumoniae in children
What is Waddell triad?
A femur fracture, abdominal or pelvic injury, and head injury in school-age children hit by a car
Hemolysis labs
Decreased haptoglobin
Increased LDH
Increased indirect bilirubin
Symptoms of hemolytic transfusion reaction
Immediate fever and chills
- headache
- n/v
- myalgias
- dark urine
- hypotension
- back pain
- shortness of breath
Management of hemolytic transfusion reaction?
- Stop transfusion
- Immediate vigorous crystalloid infusion
- Diuretic therapy to maintain urine output 1-2mL/kg/hr
Mechanism of hemolytic transfusion reaction
Host antibody attack of donor cells
What blood product is associated with highest risk of febrile nonhemolytic transfusion reaction?
Platelets (approximately 5% incidence)
Labs in von Willebrand Disease
Normal platelets
Normal PT/INR
Normal aPTT (prolonged if very low factor VIII)
Decreased factor VIII and prolonged bleeding time