Community Acquired Pneumonia Flashcards
1
Q
Etiopathogenesis of Community-acquired-Pneumonia
A
- Lower respiratory tract infetion acquired in the community within 24 hours or less than 2 weeks
- Results from the proliferration of microbial pathogens at the alveolar level and the host’s response to those pathogens
- Classic pneumonia (lobar pneumococcal pneumonia) evolves through a series of changes
2
Q
Most common access of microorganisms to the LRT
A
aspiration from the oropharynx
3
Q
Phases of CAP
A
- Edema
- Red Hepatization
- gray Heaptization
- Resolution (final phase)
4
Q
Edema Phase of CAP
A
- Initial phase with the presenc eof a proteinaceous exudtae, and often a bacteria in the alveoli
5
Q
Red Hepatization
A
- Presence of erythrocytes in the cellular intraalveolar exudate
- Neutrophil influx is more important from the standpoimt of host defense
- Bacteria are occasionally seen in pathologic specimens
6
Q
Gray Hepatization
A
- No new erythrocytes are extravasating and those already have been lysed and degraded
- The neutrophil is the predominant cell, fibrin deposition is abundant, and bacteria have disappeared
- Corresponds with successful containment of the infection and improvement of gas exchange
7
Q
Resolution
A
- macrophage reappears as the dominant cell type in the alveolar space, and the debris of neutrophils, bacteria, and fibrin has been cleared, as has the inflammatory response
8
Q
Manifrstations of CAP
A
- commonly presents with acute cough, abnormal vital signs of tachypnea, tachycardia, and fever with at least one abnormal chest finding f diminished breath sounds, ronhi, crackles, or wheeze
9
Q
Classification and Disposition of CAP
A
10
Q
Chest Xray for CAP
A
- Essential in diagnosis of CAP, assessing severity, differentiating pneumonia from other conditions and in prognostication
- Best radiologic evaluation cosists of standing posteroanterior and lateral views
- Does not predict the likely etiologic agents
11
Q
Sputum Gram Stain and Culture
A
- Strongly indluenced by the quality of collection, transport, and processing
- Main purpose of gram stain is to ensure that a sample is suitable for culture
12
Q
Adequate sputum sample
A
- >25 neutrophils/LPF
- <10 squamous epithelial cells/LPF
13
Q
Blood culture for CAP
A
- Yield is relatively low, therfore it is optional for hospitalized patients
- Most common isolate: S. pneumoniae
- Strongest indication for blood cultures: severe CAP (more likely be infected with S. aureus, P. aeruginosa, other gram negative bacilli)
14
Q
Invasive procedures
A
- transtracheal
- Transthoracic biopsy
- Bronchoalveolar lavage
- Proteted brush specimen
- Options for non-resolving pneumonia, immunocopmpromised patients, and in patients in whom no adequate respiratory specimens can be sent despite sputum induction androutine diagnostic testing
- Most clear cut indication for extensive diagnostic testing is in the critically-ill CAP patient
15
Q
Pneumonia Risk Score
A
- CURB-65
- Predicts mortality in CAP
16
Q
Empiric Microbial Therapy for Low risk CAP
A
17
Q
Empiric Management Therapy for Moderate Risk CAP
A
19
Q
Common Antibiotics Used in CAP
A
