Pneumonia Flashcards
What is pneumonia?
A lower respiratory tract infection of the lung parenchyma, due to proliferation of microbial pathogens in the alveolar level
What are the mechanisms in which bacteria enters the lower respiratory tract?
Aspiration of oropharyngeal secretions, inhalation of aerosols, hematogenous spreading
How is pneumonia diagnosed?
Signs and symptoms (cough, chest pains, SOB, hypoxia, fever, chills, tachypnea, tachycardia, hypotension, leukocytosis, fatigue, anorexia, nausea, changes in mental status)
Physical examination (diminished breath sounds over the affected area, inspiratory crackles during lung expansion)
Radiographic findings (chest XR or CT, looking for new infiltrates or dense consolidations)
Laboratory findings (e.g. CRP, procalcitonin)
Respiratory cultures (sputum, lower respiratory tract samples)
Blood cultures
Urinary antigen tests (Streptococcus pneumonia, Legionella pneumophilia)
What is community-acquired pneumonia?
onset in the community or < 48 hours after hospital admission
What are risk factors for CAP?
Age >=65 years
Previous hospitalisation for CAP
Smoking
COPD, DM, HF, cancer, immunosuppression
Prevention methods for CAP?
Smoking cessation
Immunisations (influenza, pneumococcal)
Outpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, chlamydophilia pneumoniae)
Non-severe inpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, chlamydophilia pneumoniae, Legionella pneuomophilia)
Severe inpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophilia)
Staph aureus
Gram negative bacilli (Klebsiella pneumonia, Burkholderia pseudomallei)
Which microorganism implicated in CAP is endemic in Asia?
Burkholderia pseudomallei
Severity of a CAP patient’s clinical presentation determines _____
Location of treatment (outpatient or inpatient)
Organisms that need to be covered
Empiric antibiotic selection
Route of antibiotic administration
What scoring systems are used for risk stratification for CAP?
Pneumonia severity index
CURB-65 Score
IDSA/ATS Criteria for Severe CAP
IDSA/ATS Criteria for Severe CAP
> = 1 major criteria OR >=3 minor criteria
Major: mechanical ventilation, septic shock requiring vasoactive medications
Minor: RR>= 30 breaths per minute, PaO2 =<250, multilobar infiltrates, confusion/disorientation, uremia (urea >7mmol/L), leukopenia (WBC < 4x10^9/L), hypothermia (core temp < 36degC), hypotension requiring aggressive fluid resuscitation
What antibiotic do you give to an outpatient with osteoporosis?
PO Amoxicillin first line, alternative is PO respiratory fluoroquinolone (levofloxacin or moxifloxacin) if penicillin allergy
Which antibiotic do you give to an outpatient with asplenia?
PO Amoxicillin-clavulanate or cefuroxime PLUS PO macrolide (clarithromycin or azithromycin) or PO doxycycline
OR
PO Respiratory fluoroquinolone (levo and moxi) for those with penicillin allergy
When do you need to cover for atypicals for an outpatient?
Comorbidities (heart, lung, kidney, liver diseases, DM, alcoholism, malignancy, asplenia)
What is the empiric treatment for non-severe inpatient?
B-lactam (amoxicillin-clavulanate OR ceftriaxone) PLUS macrolide (clarithromycin or azithromycin) or doxycycline
OR respiratory FQ (levo, moxi) for severe penicillin allergy
Which beta-lactam has coverage for Burkholderia pseudomallei and is thus used for the standard regimen?
Ceftazidime
What is the empiric treatment for severe inpatient?
Beta-lactam (amoxicillin-clavulanate PLUS ceftazidime) AND macrolide (clarithromycin or azithromycin) or doxycycline
Penicillin allergy: respi FQ AND ceftazidime
What are the indications for anaerobic coverage?
Lung abscess
Empyema
What are the anaerobic microbes that are present?
Bacteriodes fragilis
Prevotella spp
Porphyromonas spp
Fusobacterium spp
What is the antibiotic to add if the current regimen has no anaerobic activity?
Clindamycin IV/PO, metronidazole IV/PO
Which antibiotics from the standard regimen already has anaerobic activity?
Amoxicillin-clavulanate and moxifloxacin
What is the indication for MRSA coverage for CAP?
Prior respiratory isolation of MRSA in last 1 year
Severe CAP only: hospitalisation and received IV antibiotics within last 90 days
What antibiotics to add to standard regimen for those with additional MRSA coverage?
Vancomycin IV or linezolid IV/PO
Why can’t daptomycin be used for MRSA coverage?
It is inactivated by lung surfactant
What is the indication for pseudomonal coverage?
Prior respiratory isolation of Pseudomonas aeruginosa in last 1 year