EXAM 5 infection of immunocompromised patients Flashcards
Risk factors for infection: immunocompromised
Neutropenia
Immune system defects
Destruction of protective barriers
Environmental contamination/alteration of microbial flora
neutropenia
ANC < 1000 cells/mm3
Common pathogens
Bacteria: staph aureus/epidermin
Fungi: candida
Viruses: HSV, VZV, CMV
Immune system defects types
Cell-mediated immunity
Humoral immunity
cell mediated immunity
t-lymphocytes against INTRACELLULAR pathogens
defects in t-lymph and macrophage function due to underlying disease and immunosuppressive drugs
Humoral immunity
b-lymphocytes against EXTRACELLULAR pathogens
destruction of protective barriers
Skin: venipuncture, lines/ports
Mucous membranes: chemotherapy, radiation
Surgery: solid organ transplant
Alteration of microbial flora
Oropharyngeal flora rapidly change to primarily gram-negative bacilli in hospitalized patients
Broad spectrum has greatest impact on normal flora
50% of hospital cancer patient infections due to organisms in after admission
epidemiology in neutropenic cancer patients
Febrile episodes attributed to microbiologically documented infection in only 30-40% of cases
Most of bacteremic episodes in cancer patients are due to gram positive cocci
etiology in neutropenic cancer patients
Candida: many patients develop thrush
Aspergillus: heme and HSCT patients – due to prolonged neutropenia
Viruses: HSV
Protozoan:
Clinical presentation and diagnostics
Presence of fever – most important finding, may be only clinical
Labs: blood cultures, CBC, BMP/CMP
Diagnostics:
management of febrile neutropenia
Goals: prevent death, increase QOL, effective treatment
Risk assessment: evaluation at time of fever dictates
Low risk: clinically stable and <7 days
High risk: clinically unstable, ANC < 100 cells/mm AND neutropenia >7 day
low risk of neutropenia
clinically stable
<7 days
inpatient/outpatient
high risk neutropenia
ANC < 100cells/mm AND neutropenia >7 days
clinically unstable
inpatient, IV therapy
Treatment for febrile neutropenia (empiric)
Cefepime
piperacillin/tazobactam
ceftazidime
imipenem
meropenem
Should have activity against most likely pathogens
Should include pseudomonal coverage
Vancomycin use in febrile neutropenia
not recommended for initial therapy
Only indicated if at risk of gram positive: hemo unstable, pneumonia, blood cultures, line/port infection, SSTI, severe mucositis
penicillin allergy for febrile neutropenia
avoid b-lactams and carbapenems
ciprofloxacin + aztreonam + vanc
oral agents for febrile neutropenia
low risk patients:
ciprofloxacin + amoxicillin/clavulanate
levofloxacin
ciprofloxacin + clindamycin
pathogen directed therapy febrile neutropenia
MRSA: vancomycin
VRE: daptomycin/linezolid
ESBL: carbapenem
KPC: meropenem/vaborbactam, imipenem/cilastatin/relebactam, ceftazidime/avibactam
NDM/IMP/VUM: cefiderocol
Antifungal therapy
Initiation: high incidence of fungal infection, persistent fever after 4-7 days of broad-spectrum ABX, <50% positive blood cultures in neutropenic pats with IFI
Treatment options:
* Amphotericin B
* Azoles: fluconazole, voriconazole, posaconazole, isavuconazole
* Echinocandins: micafungin, caspofungin, andulafungin
Antiviral therapy
Initiation: lesions on skin or presumed/confirmed vial infection
Treatment options:
* HSV/VZV: acyclovir, valacyclovir
* CMV: ganciclovir, valganciclovir
Bloodstream infections
Positive cultures –>may remove catheter after 72 hrs of appropriate antimicrobial therapy
Most important determinant of patient outcomes
Resolution of neutropenia
Prophylaxis
Infection control: isolation with strict adherence (laminar air flow rooms)
Patient population
Fluoroquinolones: may decrease risk incidence of infection
Antifungal: azoles, echinocandins
Antiviral: annual inactivated flu vaccine recommended for all patients
