Immunocompromised Host Flashcards
True or False: Empiric broad spectrum antibiotics are begun at the first sign of a fever in an immunocompromised host.
True.
Which drug is commonly used for initial antibiotic therapy in an immunocompromised host for its activity against Pseudomomnas aeruginosa?
Ceftazidime.
Immunocompromised hosts with severe mucositis, colonization with resistant Gram-positive organisms (MRSA), and obvious catheter-related infection or hypotension are candidates for the addition of what drug to their therapy?
Vancomycin.
Immunocompromised patients who have defervesced without an underlying etiology are divided into low risk or high risk groups based on expected duration of neutropenia. What is the difference in treatment of the two groups?
Low risk: switch to oral antibiotics. High risk: continue same antibiotics (often Ceftazidime and/or Vancomycin).
A patient has no identified etiology, a persistent fever for 5-7 days, and has an expected prolonged duration of neutropenia (greater than 10 days). What do you do, and why?
This patient is a candidate for the empiric addition of antifungal therapy (such as Amphotericin B or voriconazole). The risk of infection with fungi such as Candida and Aspergillus increases with the duration of neutropenia.
What kinds of infections are asplenic patients especially susceptible to?
Infections with encapsulated organisms, especially Streptococcus pneumoniae. These infections may be fulminant and result in high mortality. Also susceptible to severe infections due to intra-erythrocytic pathogens such as malaria species and Babesia.
We like the spleen. What does the spleen do for us?
Serves as a phagocytic filter for circulating immune complexes, microbes, and parasitized erythrocytes. Also an important site of IgM production and B-cell differentiation during the primary humoral response. Yay spleen!
What does the management of patients with asplenia include?
Antibiotic prophylaxis with penicillin (in childhood) and prompt empiric antibiotic therapy. Immunization against Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae prior to elective splenectomy is recommended.
What kind of recurrent infections are complement deficiencies associated with? How do these infections differ from recurrent infections differ from those of asplenic patients?
Recurrent infections due to encapsulated bacteria, especially Neisseria meningitides. In contrast to splenectomy, these recurrent infections tend to be milder.
How do disorders of B-cell function typically manifest?
Recurrent sino-pulmonary or skin infections.
Absence of the opsonizing effects of antibody results in infections with what kind of bacteria?
Encapsulated bacteria, such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitides.
The management of patients with immunoglobulin deficiencies has been greatly enhanced by the use of what?
Immunoglobulin infusions.
True or False: Pneumocystis jiroveci (formerly carinii) pneumonia (PCP) was rarely seen before the AIDS epidemic.
True.
Defects in cell mediated immunity are associated with what kinds of bacterial agents? What else is included in the differential diagnosis?
Intracellular organisms like Listeria monocytogenes and Mycobacterium sp. Fungi, especially Candida and Cryptococcus are frequently encountered. Viral infections, such as herpesviruses, and protozoal infections, such as Pneumocystis and Toxoplasma are also common.
What determines the net state of immunosuppression?
- The immunosuppressive regiment (doses, duration)
