5. Pneumonia pathogens according to
location
• Lobar pneumonia
• Most common: S. pneumoniae
• Less common
• Legionella
• Klebsiella
• H. influenzae
• Bronchopneumonia
• S. pneumoniae
• S. aureus
• H. influenzae
• Klebsiella
• Interstitial pneumonia
• Atypical pathogens
• Mycoplasma pneumoniae
• Chlamydophila pneumoniae
• Chlamydophila psittaci
(primarily transmitted by
parrots)
• Legionella
• Viruses (e.g., RSV, CMV,
influenza, adenovirus)
• Coxiella burnetii
6. Risk factors
• Old age and immobility of any
cause
• Chronic diseases
• Preexisting cardiopulmonary
conditions (e.g., bronchial asthma,
COPD, heart failure)
• Acquired or congenital
abnormalities of the airways (e.g.,
bronchiectasis, space-occupying
lesions, cystic fibrosis)
• Immunosuppression
• Impaired airway protection
• Alteration in consciousness (e.g.,
due to stroke, seizure, anesthesia,
drugs, alcohol)
• Dysphagia
• Smoking
• Environmental factors
• Crowded living conditions (e.g.,
prisons, homeless shelters)
• Toxins (e.g., solvents, gasoline)
• Endemic exposures (e.g., areas of
high Coccidioides and Histoplasma
endemicity)
• Contaminated water systems (e.g.,
in hotels, on cruise ships)
• Zoonotic exposures (e.g., birds,
farm animals)
• Specific medications (e.g.,
amiodarone, bleomycin)
• Chronic inflammatory disorders
(e.g., rheumatoid arthritis)
• Surgical procedures
• Upper abdominal surgery
• Chest surgery
7. Classification :
• Location acquired
• Community-acquired pneumonia (CAP): pneumonia that is
acquired outside of a healthcare establishment
• Hospital-acquired pneumonia (HAP): nosocomial
pneumonia, with onset > 48 hours after admission
• Ventilator-associated pneumonia (VAP): pneumonia
occurring in patients who are on mechanical ventilation
breathing machines in hospitals (typically in the intensive
care unit)
• Healthcare-associated pneumonia (HCAP): pneumonia that is
acquired in healthcare facilities (e.g., hospital, nursing homes,
hemodialysis centers, and outpatient clinics); this
terminology is no longer recommended but is included for
historical purposes.
8. Pathophysiology :
• Routes of infection
• Most common: microaspiration (droplet
infection) of airborne pathogens or
oropharyngeal secretions
• Aspiration of gastric acid (aspiration
pneumonitis) , food, or liquids
• Hematogenous dissemination (rare)
9. Clinical features :
• Typical pneumonia is characterized by a sudden onset of
symptoms caused by lobar infiltration.
• Severe malaise
• High fever and chills
• Productive cough with purulent sputum (yellow-greenish)
• Crackles and bronchial breath sounds on auscultation
• Decreased breath sounds
• Enhanced bronchophony, egophony, and tactile fremitus
• Dullness on percussion
• Tachypnea and dyspnea (nasal flaring, thoracic retractions)
• Pleuritic chest pain when breathing, often accompanying
pleural effusion
• Pain that radiates to the abdomen and epigastric region
(particularly in children; see also “Pneumonia in children”)
10. Clinical features :
• Suspect bacterial pneumonia in
immunocompromised patients with acute high fever
and pleural effusion.
• Atypical pneumonia
• Atypical pneumonia typically has an indolent course
(slow onset) and commonly manifests with
extrapulmonary symptoms.
• Nonproductive, dry cough
• Dyspnea
• Auscultation often unremarkable
• Common extrapulmonary features include fatigue,
headaches, sore throat, myalgias, and malaise.
11. Diagnostics :
• CBC, inflammatory markers: ↑ CRP, ↑ ESR, leukocytosis
• ↑ Serum procalcitonin (PCT): Procalcitonin is an acute
phase reactant that can help to diagnose bacterial lower
respiratory tract infections.
• PCT can be used to guide antibiotic treatment but should
not be used to decide if antibiotic therapy is necessary on
its own. PCT levels ≥ 0.25 mcg/L correlate with an
increased probability of a bacterial infection.
• Low PCT level after 2–3 days of antibiotic therapy can
help facilitate the decision to discontinue antibiotics.
• Decrease of PCT to ≤ 80% of peak level
• ABG: ↓ PaO2
• BMP, LFTs
12. Microbiological studies:
• Indication Microbiological studies to consider
• Any admitted patient MRSA nares swab (PCR and/or
culture)
• Any patient being treated empirically for MRSA or P. aeruginosa
• Blood cultures (2 sets)
• Sputum culture and Gram stain
• Severe CAP
• Blood cultures (2 sets)
• Sputum culture and Gram stain
• Pneumococcal urinary antigen
• Legionella pneumophila urinary antigen
• Consider Chlamydia pneumoniae respiratory PCR.
• Influenza season
• Influenza nasal swab (NAAT)
• Consider respiratory virus panel nasal swab (NAAT).
13. Imaging:
• Chest x-ray (posteroanterior
and lateral)
• Indications: all patients
suspected of having
pneumonia
• X-ray findings in pneumonia
• Lobar pneumonia
• Opacity of one or more
pulmonary lobes
• Presence of air bronchograms:
appearance of translucent
bronchi inside opaque areas of
alveolar consolidation
14.
15. Bronchopneumonia on imaging :
• Poorly defined patchy
infiltrates scattered
throughout the lungs
• Presence of air
bronchograms
21. • Bronchoscopy
• Indications
• Suspected mass (e.g., recurrent pneumonia)
• Need for pathohistological diagnosis
• Inconclusive results on CT
• Poor response to treatment
22. Criteria for hospitalization :
• CURB-65 score
• Confusion (disorientation, impaired consciousness)
• Serum Urea > 7 mmol/L (42 mg/dL)
• Respiratory rate ≥ 30/min
• Blood pressure: systolic BP ≤ 90 mm Hg or diastolic
BP ≤ 60 mm Hg
• Age ≥ 65 years
• Interpretation
• CURB-65 score 0 or 1: The patient may be treated as
an outpatient.
• CURB-65 score ≥ 2: Hospitalization is indicated.
23.
24. Empiric antibiotic therapy for
community-acquired pneumonia in an
outpatient setting
• Previously healthy patients without comorbidities or
risk factors for resistant pathogens
• Monotherapy with one of the following:
• Amoxicillin 1 g PO every 8 hours
• Doxycycline 100 mg PO every 12 hours
• A macrolide (only in areas with a pneumococcal
macrolide resistance < 25%)
• Azithromycin 500 mg PO on the first day, then 250
mg daily
• Clarithromycin 500 mg PO every 12 hours OR
clarithromycin extended release 1,000 mg PO daily
25. Patients with comorbidities or risk
factors for resistant pathogens
• Combination therapy
• An antipneumococcal β-lactam:
• Amoxicillin-clavulanate 500 mg/125 mg PO every 8 hours OR 875
mg/125 mg PO every 12 hours
• Cefuroxime 500 mg PO every 12 hours
• Cefpodoxime 200 mg PO every 12 hours
• PLUS one of the following:
• A macrolide
• Azithromycin
• Clarithromycin
• Doxycycline
• Monotherapy: with a respiratory fluoroquinolone
• Gemifloxacin 320 mg PO daily
• Moxifloxacin 400 mg PO daily
• Levofloxacin 700 mg PO daily
26. Empiric antibiotic therapy for
ventilator-associated pneumonia
• Recommended combination therapy
• An antipneumococcal, antipseudomonal β-lactam
• PLUS one of the following antibiotics with MRSA
activity:
• Vancomycin
• Linezolid
• PLUS one of the following:
• A fluoroquinolone
• An aminoglycoside
• A polymyxin
27. Aspiration pneumonia
• Aspiration pneumonia: a type of pneumonia that
occurs as a result of oropharyngeal secretions
and/or gastric contents aspiration
• Aspiration pneumonitis
• Aspiration of gastric acid that initially causes
tracheobronchitis, with rapid progression to
chemical pneumonitis
• May cause ARDS
28. Aspiration pneumonia :
• Risk factors for aspiration
(predispose individuals to
reduced epiglottic gag reflex
and dysphagia)
• Altered consciousness:
alcohol, sedation, general
anesthesia, stroke
• Gastroesophageal reflux
disease
• tracheoesophageal fistula
• Use of a nasogastric feeding
tube
• Clinical features
• Aspiration pneumonitis
• Immediate symptoms:
bronchospasms
• Late symptoms: fever,
shortness of breath, cough
• Aspiration pneumonia
• Late symptoms: fever,
shortness of breath, cough
with foul-smelling sputum
• Complications
• Abscess
29. • Prevention :
• Treatment of underlying causes to reduce the
risk of aspiration
• Aspiration precautions for patients with risk
factors for aspiration
• Elevation of the head of the bed
• Dysphagia-modified diet
• One-on-one observation with meals
• Suctioning equipment at bedside
