Chronic Lung Sepsis
Dr. Arun Nair
Includes
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Lung Abscess
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Empyema
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Bronchiectasis
Lung Abscess
Lung Abscess
Definition & overview
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Cavitating, infected, necrotic lesion of lung parenchyma
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Several possible causes
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Single or Multiple
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Small <2cm or large
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Most secondary to aspiration of oropharyngeal secretions
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Mixed growth of organisms, including anaerobes
Causes
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Aspiration
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Bronchial obstruction {Tumour / Foreign Body}
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Pneumonia
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Blood borne infection
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Transdiaphragmatic spread
Differential Diagnosis
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Cavitating tumour
Infected bronchial cyst/bulla
Localised saccular bronchiectasis
Aspergilloma
Wegeners granulomatosis
Hydatid cyst
Gas-fluid level in oesophagus, stomach or bowel
Microbiology
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Anaerobes: Peptostreptococcus, Prevotella, Bacteroides
spp (usually not B. fragilis), and Fusobacterium spp.
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Staph Aureus, Klebsiella, Strep Milleri
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Strep Pneumonia, gram negative bacilli
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M.Tuberculosis
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Fungi
Clinical Features
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Most patients present over several weeks
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Malaise, weight loss, fever
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Cough with copious purulent sputum
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Can be associated with haemoptysis
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Toxic features prominent in patients with pneumonia or blood
borne infection
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Clubbing often seen
Investigations
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CXR: PA & Lateral
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CT Thorax
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Sputum & Blood Cultures
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FBC, CRP, ESR, Serological tests
Treatment
AUGMENTIN
 AMOXIXCILLIN & METRONIDAZOLE
 CLINDAMYCIN
 Physiotherapy & postural drainage
 Trans Thoracic/ endoscopic drainage for large
abscess
Duration of ABx:
3- 4 weeks
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Empyema
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Pus in pleural space
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Sequelae of a complicated parapneumonic
infection, when bacteria invade pleural space
Uncomplicated
Complicated
Frank Empyema
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Pathogenesis
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Uncomplicated parapneumonic effusion —
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occurs when the lung interstitial fluid increases
during pneumonia, and is characterized by
"exudative" pleural fluid chemistries and an
influx of neutrophils into the pleural space.
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resolve with resolution of the pneumonia.
Complicated Parapneumonic
effusion
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occurs when there is persistent bacterial invasion of the
pleural space.
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Results in pleural fluid acidosis (anaerobic utilization).
Lysis of neutrophils increases the LDH concentration
in the pleural fluid to values often in excess of 1000
IU/L.
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Complicated parapneumonic effusions are often sterile
because bacteria can be cleared rapidly from the pleural
space. (Loculation )
Thoracic Empyema

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Formation of empyema is the third stage and is
characterized by bacterial organisms seen on
gram stain or the aspiration of pus on
thoracentesis.
A positive culture is not required for diagnosis.
Bacteriology
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Mixed bacterial flora
Anaerobic bacteria in 36-76%
Streptococcus milleri, Staphylococcus aureus, and
Enterobacteriaceae.
Patients with diabetes mellitus are at increased risk of
empyema secondary to Klebsiella pneumoniae.
S. pneumoniae and S. aureus (including methicillinresistant organisms) are the leading causative bacteria in
children with empyema.
Pleural fluid analysis
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Pus
Ph <7.2
Glucose < 60 mg/dl
LDH>1000 IU/L
WBC>15/nl
Imaging
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CXR
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CT
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USG
Signs favouring empyema
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Evidence of lung compression
Smooth margins
Blunt angle with chest wall
Dissection of thickened visceral and parietal
pleura
Treatment
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Pleural drainage
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Chest Drain
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Thoracoscopy
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Antibiotics
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Fibrinolytics: No convincing benefit
Bronchiectasis
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Abnormal permanent dilatation of one or more
bronchi
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Poor mucous clearance
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Chronic bacterial infection & inflammation
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Long term lung damage
Types
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Saccular /Cystic
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Cylindrical
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Varicose
Saccular Bronchiectasis

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Large baloon like
dilatation from severe
loss of bronchial wall
Assoc with severe lung
infections, large sputum
volumes, finger clubbing
Cylindrical Bronchiectasis
Varicose Bronchiectasis
Causes
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Congenital {defective bronch wall/ sequesteration}
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Post infective {TB, Pertussis, NTM, ABPA}
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Airway obstruction (eg, foreign body aspiration)
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Defective host defenses{ CVID, HIV, phagaocyte dysfn
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Inflammatory pneumonitis {gastric aspiration, toxic gas inhalation}
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Abnormal mucociliary clearance {Primary Ciliary Dyskinesia, cystic fibrosis,
Young's syndrome
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Rheumatic and systemic diseases, cigarette smoking, Chronic Bronchitis.
Symptoms
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Cough (98 percent of patients)
Daily sputum production (78 percent)
Dyspnoea (62 percent),
Rhinosinusitis (73 percent)
Hemoptysis (27 percent)
and recurrent pleurisy (20 percent).
Physical Findings
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Crackles (75 percent)
Wheezing (22 percent) were common,
Digital clubbing occurred in only 2 percent of
patients.
Pathophysiology
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Induction of bronchiectasis requires two factors
An infectious insult
Impaired drainage, airway obstruction, or a
defect in host defense
Recurrent infection leads to further scarring,
obstruction, and distortion of the airways, as
well as temporary or permanent damage to the
lung parenchyma.
Diagnostic workup
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The following LAB studies should be part of the
initial evaluation of a patient with bronchiectasis:
A complete blood count with differential
Immunoglobulin quantitation to measure the
levels of the immunoglobulins IgG, IgM, and
IgA
Sputum culture and smear for bacteria,
mycobacteria, and fungi
Imaging

CXR radiographic
findings include linear
atelectasis, dilated and
thickened airways (ie,
tram or parallel lines,
ring shadows on cross
section) and irregular
peripheral opacities that
may represent
mucopurulent plugs.
High Resolution CT Thorax
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Airway dilatation
Bronchial wall thickening
Lack of tapering
mucopurulent plugs or
debris accompanied by
post-obstructive air
trapping (tree-in-bud)
Distribution
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A central (perihilar) distribution is suggestive of
ABPA.
predominant upper lobe distribution is
characteristic of cystic fibrosis
middle and lower lobe distribution is consistent
with PCD
lower lobe involvement is typical of idiopathic
bronchiectasi
Spirometry
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Obstructive picture common

Frequently isolated pathogens on CULTURE
include Hemophilus influenzae, Pseudomonas
aeruginosa (especially mucoid types), and, less
frequently, Streptococcus pneumoniae
Treatment
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Postural drainage
Based on sputum culture & sensitivity
Non-Pseudomonas organism:
Amoxicillin: 1gm TID 14 days
Augmentin 625 mg TID 14 days
Doxycyline 100mg BD 14 days
Ciprofloxacin 750 mg BD 14 days (Pseudomonas)
Ceftazidime 2gm TID 7-14 days (Pseudomonas)
Nebulised Tobramycin (Pseudomonas)
END
Signs favouring lung abscess
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Spherical shape with irregular and thick wall
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Absence of lung compression
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Sharp angle with chest wall
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Vasculature around abscess