Pneumonia Flashcards
Outpatient pneumonia involving MDR pathogens
HCAP
Pathogen with exclusive risk from home infusion therapy and home wound care
MRSA
Possible pathogens for antibiotic use the preceding 3 months
Pseudomonas
MDR Enterobacteriaceae
MC mode of entry of microbial pathogen
Aspiration from oropharynx
Triggers the clinical syndrome of pneumonia
Host inflammatory response
NOT the proliferation if microorganisms
Caused by inflammatory mediators released by macrophages and newly recruited neutrophils
Capillary leak
4 stages of pneumonia
Edema/Congestion
Red Hepatization
Gray Hepatization
Resolution
Stage with presence of proteinaceous exudates and bacteria in alveoli
Edema/Congestion
Presence of erythrocytes in the cellular intraalveolar exudate with occasional bacteria recognized on collected pathologic specimens
Red hepatization
No new erythrocytes are extravasating; predominant cells are neutrophils; abundant fibrin deposits with disappearance of bacteria; corresponds to the successful containmentof infection and improvement in gas exchange
Gray hepatization
Macrophages predominate
Resolution
Pattern MC in nosocomial pneumonia
Bronchopneumonia
Pattern MC in CAP
Lobar pneumonia
Pattern MC in VAP
Respiratory bronchiolitis
May present as alveolar process in radiography
Viral
Pneumocystis pneumonias
Complications of anaerobic pneumonia
Abscess formation
Empyemas
Parapneumonic effusions
Complicates Influenza infection
S.aureus pneumonia
Serious consequence of MRSA
Necrotizing pneumonia
Adequate sputum specimen fo CS
> 25 neutrophils/hpf
<10 squamous epthelial cells/lpf
Most frequently isolated pathogen in blood culture
S.pneumoniae
Urine antigen test is highly specific and sensitive
Legionella pneumophila
Pneumococcal
Standard of diagnosis of respiratory viral infection
PCR of nasopharyngeal swabs
PCR determination of the pathogen is associated with inc risk of septic shock, need for mech vent and death
Pneumococcal pneumonia
Useful biomarker to identify worsening disease or treatment failure
CRP
Useful biomarker to determine the need for antimicrobial therapy
Procalcitonin
Variables in CURB-65
Confusion Urea >7 mmol/L RR >/= 30 BP = 90 systolic; = 60 diastolic Age >/= 65
Obvious indication for ICU care
Septic shock
Respiratory Failure at ER
Primary organisms with resistance issues
S.pneumoniae
CA-MRSA
Most important risk factor for antibiotic-resistant pneumococcal infection
Use of a specific antibiotic within the previous 3 months
Mechanism of resistance to penicillins
Presence of low-affinity penicillin-binding proteins
MIC penicillin susceptible
= 2 mcg/ml
MDR strains
Isolates resistant to >/= 3 drugs of antimicrobial classes with different mechanisms of action
Resistant to cephalosporins
Enterobacter spp.
Tx: Fluoroquinolones or Carbapenems
(used in ESBL-producing bacteria)
Main risk factors for P.Aeruginosa
Structural lung disease (bronchiectasis)
Recent treatment with antibiotics or glucocorticoids
Longer duration of treatment of pneumonia
Bacteremia Metastatic infection Pseudomonas MRSA Ineffective initial treatment Severe CAP
Causes polymicrobial lung abscess from pneumonia
Typical with aspiration pneumonia, mixed aerobes/anaerobes
Increased risk of MDR in HCAP
Recent hospitalization in 90 days
Highest hazard ratio in developing VAP
First 5 days
Three factors critical in the pathogenesis of VAP
Colonization if oropharynx with pathogenic microorganisms
Aspiration of organisms from the oropharynx into the lower respiratory tract
Compromise of normal host defense mechanisms
Most obvious risk factor which bypass the normal mechanical factors that prevent aspiration
Endotracheal tube
Major risk factor for infection with MRSA and ESBL-positive strains
use of B-lactam drugs (cephalosporins)
Meds added for patients with active influenza or with history of influenza within 2 weeks of CAP
Vanco or Linezolid
Increases the bioavailability of oral ampicillin
Sulbactam
Indication for repeat CXR in CAP
Failure to improve after 72 hours of treatment
De-escalation of antibiotics
(-) fever >24 hours Normal RR and less cough No bacteremia Etiologic agent not high risk No unstable comorbids No organ dysfunction Competent GIT
Duration of treatment for MRSA-CAP
non-bacteremic: 7-21 days
(Pseudomonas: 14-21 days)
bacteremic: up to 28 days
Duration of treatment of MSSA-CAP
non bacteremic: 7-14 days
bacteremic: up to 21 days
Duration of treatment for Mycoplasma and Chlamydophila
10-14 days
Duration of treatment for Legionella pneumonia
14-21 days
During 24 hours prior to discharge
Temp 36-37.5 Pulse <100/min RR 16-24/min SBP >90 mmHg O2 sat >90 % Functioning GIT
