Intro to ID pt1 Flashcards
hallmark of infection
fever
non-infectious causes (false-positives) (4 but one main one)
- DRUG-INDUCED FEVERS
- malignancies
- blood transfusions
- auto-immune disorders
1 class/3 drugs that can mask poor therapeutic response -> meaning use is discouraged during tx
antipyretics
acetaminophen, NSAIDs, aspirin
number for fever in C and F
> 38C or 100.4F
5 systemic signs for establishing presence of infection
- BP
- HR
- RR
- Fever
- Inc/dec WBC count
for the systemic vital signs (minus BP) how many criteria out of 4 are needed for systemic inflammatory response syndrome (SIRS)
at least 2
systemic symptoms (not vital signs) for presence of infection (4)
- chills
- rigors
- malaise
- mental status changes
example of sx referable to specific body system
flank pain in pyelonephritis
some non-infectious things that can cause elevated WBC (5)
steroids, leukemia, stress, rheumatoid arthritis, pregnancy
associated with bacterial infections:
A. Leukocytosis
B. Lymphocytosis
A
increased neutrophils+bands:
A. Leukocytosis
B. Lymphocytosis
A
presence of bands indicates (inc/dec) bone marrow response to infection
increased
leukocytosis may be elevated to 2 non-infectious diseases (kinda) or drugs. what diseases and what drugs
leukemia, stress
steroids
Proliferate into plasma cells to produce antibodies & memory B-cells
A. B-lymphocytes
B. T-lypmocytes
A
CD4
A. T-helper
B. T-suppressor
A
CD8
A. T-helper
B. T-suppressor
B
bind to and directly kill tumor cells
A. T-helper
B. T-suppressor
B
help with antibody production and secrete lymphokines
A. T-helper
B. T-suppressor
A
help with regulation of humoral and cell-mediated immunity
A. T-helper
B. T-suppressor
B
risk of infection dramatically (increases/decreases) as ANC decreases
increases
ANC <___ associated with substantial risk of infection
<500
(start to worry when ANC is <1000)
Neutropenia:
- ANC < ___
- ANC expected to _______ to <500 cells in next 48 hours
- ANC < ___ is termed profound neutropenia
500, decrease, 100
T or F:
ESR (erythrocyte sedimentation rate) & CRP (C-reactive protein) are elevated in the presence of an inflammatory process and confirm infection
False, they do NOT confirm infection
Normal ESR
0-15 mm/hr (males)
0-20 mm/hr (females)
normal CRP
0-0.5 mg/dL
if you see acute phase reactant what should you think of
Procalcitonin (PCT)
wtf is procalcitonin
precursor to calcitonin, this is also more specific for bacterial infections than ESR and CRP
normal procalcitonin (PCT)
< 0.05 mcg/L
PCT increases _-__ hours after stimulation then declines over 24-__ hours
3-12, 72
mature neutrophils description
(2)
most common WBC
fight infections
Immature neutrophil (bands) description
elevated during infection (we call it the left shift)
eosinophil description
involved in allergic reactions and immune response to parasites
basophil description
associated with hypersensitivity reactions
lymphocyte description
B-cell and T-Cell immunity
monocytes description
(2)
mature into macrophages
serve as scavengers for foreign substances
types of cultures collected: bone biopsy
A. Osteomyelitis
B. Meningitis
C. Endocarditis
A
types of cultures collected:
CSF
A. Osteomyelitis
B. Meningitis
C. Endocarditis
B
types of cultures collected:
Blood cultures, heart valve tissues
A. Osteomyelitis
B. Meningitis
C. Endocarditis
C
what does 1 set of blood cultures typically contain
1 aerobic and 1 anaerobic bottle
minimum inhibitory concentration (MIC) definition
lowest antimicrobial concentration that prevents visible growth
MIC or zone diameter value used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, resistant, or non-susceptible
breakpoint
Isolates with an MIC at or below or a zone diameter at or below the (S) breakpoint are inhibited by the usually achievable concentrations of antimicrobial agent when normal dosing regimens are used, resulting in likely clinical efficacy
Susceptible (S)
Implies susceptibility is dependent on the dosing regimen used
Susceptible-dose dependent (S-DD)
Isolates with MICs approach achievable blood or tissue concentrations and response rates may be lower than for susceptible isolates
Intermediate (I)
Isolates not inhibited by usually achievable concentrations of agent with normal dosage schedules; clinical efficacy has not been reliably demonstrated
Resistant (R)
Used for isolates for which only susceptible breakpoint is designed; if MIC is above or zone diameter is below the susceptible breakpoint, isolate is categorized as ____
Non-susceptible (NS) -> he said something about picking the option that has the “s” in it on the exam *
what is the “gold standard” method for identifying a pathogen?
broth dilution
what does “semi-quantitative” mean in the context of broth dilution
no ability to determine exact inhibitory concentration
alternate option for identifying a pathogen that isnt broth dilution
disk diffusion assay
there are 3 results for disk diffusion assay, what are they?
susceptible, intermediate, resistant
T or F:
you can derive an MIC from the zone of inhibition
false, you cannot (although i have no idea what this means)
there is another susceptibility test, what is it called and whats special about it?
Gradient strip tests (also called epsilometer or e-test)
it is more precise than “standard” methods
T or F:
When given the option to choose a drug, you want to pick the ones that say intermediate
false, you want susceptible
what is empiric therapy? (4)
- typically first regimen we pick
- initiation of drugs before we know identification and susceptibility results
- drugs that should cover MOST COMMON pathogens
- broad ass coverage
what is directed (targeted) therapy (1)
therapy selected after organism identification and/or susceptibility is known
what is de-escalation? (2)
- selecting a drug with the narrowest spectrum of activity
- can be stepwise or all at once
what is spectrum of activity? (1)
what anti-microbials does the drug cover (easy as shit)
primary goal of antimicrobial stewardship
optimize clinical outcomes while minimizing unintended consequences
unintended consequences of AMS (3)
- toxicity
- selection of pathogenic organism such as C.Diff
- emergence of resistant pathogens
secondary goal of AMS
reduce healthcare cost without impacting quality of care
Which of the following is an example of an antimicrobial stewardship strategy?
a) Switch to broad spectrum antimicrobials to better treat infections
b) Require ID pharmacist approval before ordering broad spectrum antibiotic
c) Continuing empiric antibiotics for 96 hours prior to reassessment
d) Developing polices aimed at increasing antimicrobial resistance
B lmao
