Flashcards in Chapter 11: The management of hematological malignancy Deck (52):
Why are central venous catheters used for general supportive therapy for hematologic malignancies?
Central catheters give ease of access for administration of chemotherapy, and other therapeutics while also allowing blood to be easily drawn for tests.
What is used to support the anemia caused by malignancy and its treatment?
Red blood cell and platelet transfusions.
What is the usual threshold for red cell support?
Hgb lower than 8g/dL. If platelets are also needed the platelets are given first
What is the threshold for platelet therapy?
Platelet count of 10 x 10^9 /L
What is used to reverse coagulation defects?
Fresh frozen plasma
What is a potential hazard with large transfusions of 3 units or more?
They may cause pulmonary edema in older patients. transfusions should be given slowly and monitored very closely.
What can be used to prevent febrile reactions during transfusion?
Antihistamine, pethidine, or hydrocortisone can be given to reduce febrile reactions.
Why should blood given to immunocompromised patients be irradiated before it is given?
To eliminate leukocytes and reduce the risk of GVHD.
What growth factor can be used therapeutically to reduce the anemia associated with chemotherapy?
Why should coagulation screens be performed regularly during chemotherapy?
Because clotting deficiency is associated with chemotherapy. (low platelet counts)
What is given to pre-menopausal women to prevent bleeding?
progesterone is given to stop mentruation.
How can nausea and vomitting associated with chemotherapy be treated?
(1) 5-HT3 serotonin inhibitors (ondansetron, granisetron) (60%)
(2) Dexamthasone (20%)
What is tumor lysis syndrome?
The rapid lysis of tumor cells by chemotherapy may release uric acid, potassium, and phosphate leading to hypocalcemia. Allopurinol, Rasburicase, and electrolyte therapy are used prophylactially to treat tumor lysis syndrome.
Why should men starting chemotherapy be encouraged to store their sperm?
Because sterility is a possible adverse effect of chemotherapy for men and women. However, it is not as practical to store ova as it is for sperm.
Under what conditions should total nutritional support be given?
If the patient loses 10% or more of their body weight total nutritional support is warranted via an NG tube or central catheter.
Is pain a significant feature of hematologic malignancies?
Not usually. although multiple myeloma is associated with significant pain which can be managed with analgesia. Sometimes bone pain can be a presenting symptom of malignancy.
What is the major cause of morbidity and mortality associated with hematological malignancies?
Infections because of neutropenia and hypogammaglobulnemia often cause morbidity associated with malignancy or its treatment. G-CSF may sometimes be used to limit periods of neutropenia.
From where do infections often come from during treatment of hematological malignancy?
Normal flora often become the source of infection during hematological malignancies and treatment.
What bacteria commonly colonize venous catheter lines?
Gram positive skin microbes Staph and Strep
What bacteria commonly cause septicemia during malignancy?
Gram negative gut bacteria Pseudomonas, E. coli, Proteus, Kelbsiella..
How can bacterial infections be prevented during hematological malignancy?
Prophylactic antibiotics, topical antiseptics and mouthwashes, clean diet, and non absorbable GI antibiotics are used to prevent infection.
What is the main indication of infection during hematological malignancy?
How should infection be treated during hematological malignancy?
Immediate therapy with broad spectrum antibiotics is the usual strategy. If fever does not subside change antibiotic or consider antiviral/fungal therapy.
What is the most common source of viral infections in individuals undergoing treatment for malignancy?
reactivation of latent viral infections (Herpes, vericells, EBV, CMV)
How can viral infection be treated in patients with hematological malignancies?
Aciclovir is most commonly used to control viral infections. Immunoglobulin therapy may be used to treat severe primary infections particularly in children.
What unique condition is associated with EBV and stem cell transplants?
Post transplant lymphoproliferative disorder (PTLD)?
What two major subtypes of fungus represent a major cause of morbidity and mortality in patients with hematological malignancies?
Candida yeasts and Aspergillus molds.
What is the most common cause of death in intensively immunocompromised patients?
How are fungal infections diagnosed?
(1) fever that fails to resolve after 3-4 days
(2) biopsy specimen with invasive gowth (definitive)
How are Aspergillosis infections treated?
How are Candida infections treated?
(3) Can be treated locally if blood or urine is not infected.
How is pneumocystic carnii treated?
An important cause of peumonitis
(1) Treated with co-trimoxazole
Why are alkylating agents used to treat Hematological malignancies?
The alkylating agents crosslink Purines within DNA. This impairs DNA function and results in a cell cycle block at G2 causing apoptosis.
What is the fundamental mechanism of the antimetabolite antineoplastic drugs?
They block metabolic pathways required for DNA synthesis
What are the three major groups of antimetabolites?
(1) Folate antagonists
(2) Pyrimidine analogs
(3) Purine analogs.
What is the most common folate angtagonist and what is it used for?
Methotrexate is used for ALL, AML, or high grade non-hodgkin's lymphomas. It can penetrate the CNS at higher concentrations or can be used intrathecally
How to the pyrimidine analogs work?
Pyrimidine analogs such as cytarabine are incorporated into DNA and block DNA polymerase during replication.
How do the Purine analogs work?
Purine analogs work the sam way as pyrimidine analogs. They are incorporated into DNA where they inhibit replication.
How do the anthracyclines work?
The anthracyclines (including the -rubicins and mitozantrone) intercalate into DNA and bind tightly with topoisomerases.
How does the antineoplastic Bleomycin function?
Bleomycin is a metal chelating agent that produces superoxide radicals within cells degrade DNA. Bleomycin can function on non-cycling cells
What is the mechanism of the vinca alkaloids?
They bind to tubulin and prevent the polymerization of microtubules. (M phase inhibitors)
What is the mechanism of Etopioside?
Etoposide inhibits topoisomerase action.
How does hydroxyurea function?
Hydroxyurea functions by inhibiting ribonucleotide reductase. It is used widely for hematologic disorders.
How does Imatinib function?
Imatinib binds to the bcr-abl fusion protein and inhibits its binding to ATP. Without ATP bcr-abl cannot perform its phosphorylation function. Used in CML
Why are corticosteroids useful for some lymphoid malignancies and myelomas?
Because corticosteroids have a lymphotoxic effect.
How is all-trans retinoic acid used to treat hematologic malignancies?
ATRA acts as a differentiating agent in acute premyelocytic leukmeia (APML)
Why is INF-alpha useful in treating some malignancies?
INF-alpha is an anti-viral and anti-mitotic substance.
What is the mechanism of the antineoplastic azacytidine?
Azacytidine is a demethylating agent.
Against what sort of malignancies are MABs particularly useful?
MABs are effective against B cell malignancies
For what malignancy is asparaginase particularly useful?
Acute lymphoblastic leukemia (ALL)
What are the platinum agents used to treat?