Pneumonia Flashcards
The constitution of the lung microbiota is determined by three factors: ____
microbial entry into the lungs
microbial elimination,
regional growth conditions for bacteria, such as pH, oxygen tension, and temperature.
Inflammatory mediators that cause fever
IL6
TNF
Inflammatory mediators that increase local neutrophil numbers
IL8
GCSF
Cardiovascular events with pneumonia, particularly in the elderly and usually in association with ____ and ____, are increasingly recognized.
pneumococcal pneumonia
influenza
What stage?
A proteinaceous exudate and often bacteria in the alveoli.
Edema
What stage?
Erythrocytes in the intraalveolar exudate
Red Hepatization
What stage?
Neutrophil dominance.
Gray Hepatization
What stage?
Corresponds to successful infection containment and improved gas exchange.
Gray Hepatization
What stage?
The macrophage reappears as the dominant cell in the alveolar space
Resolution
What pattern of pneumonia is common in nosocomial pneumonias
Bronchopneumonia
Lobar pattern is more common in ___
bacterial CAP
Increasing Incidence of
____ and ____ particularly in young adults.
M. pneumoniae
C. pneumoniae
Most common viral pathogens: ___
Influenza, parainfluenza, respiratory syncytial virus.
Aspiration pneumonia was historically associated with ___
anaerobes
Anaerobes remain relevant in:
Poor dentition.
Lung abscess.
Necrotizing pneumonia.
Empyema.
A primary etiologic agent of CAP
MRSA
Risk Factors for CAP
Alcoholism.
Asthma.
Immunosuppression.
Institutionalization.
Age >70 years.
Elderly-Specific Risk Factors
Decreased cough and gag reflexes.
Reduced antibody and Toll-like receptor responses.
Risk factors for Pneumococcal Pneumonia:
Dementia.
Seizure disorders.
Heart failure.
Cerebrovascular disease.
Alcoholism.
Tobacco smoking.
Chronic obstructive pulmonary disease (COPD).
HIV infection.
Risk factors for Enterobacteriaceae Infections:
Recent hospitalization.
Recent antibiotic use.
Comorbidities:
Alcoholism.
Heart failure.
Renal failure.
Risk factors for Pseudomonas aeruginosa Infections:
Severe structural lung disease:
Bronchiectasis.
Cystic fibrosis.
Severe COPD.
Risk factors for Legionalla Pneumonoa
Diabetes.
Hematologic malignancy.
Cancer.
Severe renal disease.
HIV infection.
Smoking.
Male gender.
Recent hotel stay or cruise ship travel.
CXR pneumotoceles
S Aureus
CXR Upper lobe cavitating lesion
TB
To be suitable, a sputum sample must have ___ neutrophils and ___ squamous epithelial cells per low-power field.
> 25
<10
Can detect antigen even after the initiation of a priate antibiotic therapy.
Urinary Antigen Test
PCR of nasopharyngeal swabs has become the standard for diagnosis of _____
respiratory viral infection.
Two of the most commonly used markers are ___
C-reactive protein (CRP) and procalcitonin (PCT).
A prognostic model that identifies patients at low risk of dying,
PSI
____ yield a severity-of-illness score
CURB-65 Criteri
PSI Class: Outpatient management
Class 1 and 2
PSI Class: Observation unit or outpatient management with close follow-up.
Class 3
PSI Class: Inpatient admission required.
Class 4 and 5
CURB-65 Criteria
C: Confusion.
U: Urea >7 mmol/L.
R: Respiratory rate ≥30/min.
B: Blood pressure (systolic ≤90 mmHg or diastolic ≤60 mmHg).
65: Age ≥65 years.
CURB 65 Score 0
Outpatient
CURB 65 Score 1-2
Hospitalization unless score is due solely to age ≥65 years
CURB 65 Score ≥3
Mortality rate 22% → Consider ICU admission.
Necessary to admit patients with Oxygen saturation of ___ on room air.
<92%
The S. pneumoniae minimal inhibitory concentration (MIC) breakpoint cutoffs for penicillin in pneumonia are:
____ for susceptible
_____ for intermediate
____ for resistant
≤2 μg/mL
>2–4 μg/mL
≥8 μg/mL
Target-site modification caused by ribosomal methylation in 23S rRNA encoded by the ___ gene results in high-level resistance (MIC, ≥64 μg/mL
ermB
The efflux mechanism encoded by the ___ gene (M phenotype) is usually associated with low-level resistance (MIC, 1–32 μg/mL).
mef
The most important risk factor for antibiotic-resistant pneumococcal infection is _____
use of a specific antibiotic within the previous 3 months.
Risk factors for penicillin-resistant pneumococcal infection include ______
recent antimicrobial therapy
an age of <2 or >65 years
attendance at a day-care center recent hospitalization
HIV infection.
Methicillin resistance in S. aureus is determined by the ___ gene, which encodes for resistance to all β-lactam drugs.
mecA
The typical hospital-acquired strain usually has a type II or III SCCmec element, whereas CA-MRSA has type ___.
IV
Mycoplasma resistance to ____ is increasing as a result of binding-site mutation in domain V of 23S rRNA.
macrolides