Chapter 153 Pneumonia Flashcards
(38 cards)
Risk factors for CAP include
alcoholism, asthma, immunosuppression, institutionalization, and an age of ≥70 years.
Risk factors for pneumococcal pneumonia include
Risk factors for pneumococcal pneumonia include dementia, seizure disorders, heart failure, cerebrovascular disease, alcoholism, tobacco smoking, chronic obstructive pulmonary disease, and HIV infection.
is more likely in patients with skin colonization or infection with CA-MRSA.
CA-MRSA pneumonia
tend to infect patients who have recently been hospitalized and/or received antibiotic therapy or who have comorbidities such as alcoholism, heart failure, or renal failure.
Enterobacteriaceae
is a particular problem in patients with severe structural lung disease, such as bronchiectasis, cystic fibrosis, or severe chronic obstructive pulmonary disease.
P. aeruginosa
Risk factors for ____ include diabetes, hematologic malignancy, cancer, severe renal disease, HIV infection, smoking, male gender, and a recent hotel stay or ship cruise.
Legionella infection
Gross hemoptysis is suggestive of
CA-MRSA pneumonia.
the sensitivity and specificity of the findings on physical examination are less than ideal,
averaging 58% and 67%, respectively.
In chest X-ray:
pneumatoceles suggest infection with 1._____
and
an upper-lobe cavitating lesion suggests 2._____
- S. aureus
2. tubercu- losis.
To be adequate for culture, a sputum sample must have
> 25 neutrophils and
<10 squamous epithelial cells per low-power field.
Certain high-risk patients including those with —should have blood cultured.
neutropenia secondary to pneumonia, asplenia, complement deficiencies, chronic liver disease, or severe CAP
Urinary antigen tests
Pneumococcal urine antigen
Legionella urine antigen test
PCR can detect the nucleic acid of
Legionella species,
M. pneumoniae,
C. pneumoniae and mycobacteria.
Biomarkers of severe inflammation. The two currently in use are
C-reactive protein (CRP) and procalcitonin (PCT).
may be of use in the identification of worsening dis- ease or treatment failure
CRP C-reactive protein
____ may play a role in determining the need for antibacterial therapy.
Procalcitonin PCT
For CAP, the main resistance issues currently involve
S. pneumoniae and CA-MRSA.
Risk factors for penicillin-resistant pneumococcal infection include
recent antimicrobial therapy, an age of <2 years or >65 years, attendance at day-care centers, recent hospitalization, and HIV infection.
resistance to macrolides is increasing through several mechanisms:
Target-site modification
Efflux mechanism
___ caused by ribosomal methylation in 23S rRNA encoded by
the ermB gene results in high-level resistance (MICs, ≥64 μg/mL) to macrolides, lincosamides, and streptogramin B–type antibiotics.
Target-site modification
______ encoded by the mef gene (M phenotype) is usually associated with low-level resistance (MICs, 1–32 μg/mL)
efflux mechanism
Changes can occur in one or both target sites (topoisomerases II and IV) from mutations in the gyrA and parC genes, respectively.
Pneumococcal resistance to fluoroquinolones
Methicillin resistance in S. aureus is determined by the ______ gene which encodes for resistance to all β-lactam drugs
mecA gene
If CA-MRSA is suspected, either ______ can be added to the initial empirical regimen;
linezolid or vancomycin