Lung abscess&Bronchiectasis

1. CMT05210:INTERNAL
MEDICINE
Session 14: Lung abscess
and Bronchiectasis

2. Learning objectives
At the end of this session each participant should be able to
• Define Lung abscess, Bronchiectasis
• Explain epidemiology of Lung abscess, Bronchiectasis
• Describe pathogenesis of Lung abscess, Bronchiectasis
• Explain clinical features of Lung abscess, Bronchiectasis
• Describe management of Lung abscess, Bronchiectasis
• Provide measures to prevent and control of Lung abscess,
Bronchiectasis

3. Lung abscess
• Lung abscess is suppurative lesion, collection of puss in the
lung parenchyma due to infected lung tissue necrosis.
• The formed cavities contain necrotic debris or puss of
serosanguinous fluid. An abscess is formed by one or more
cavities, each >2 cm in diameter.
• Failure to recognize and treat lung abscess is associated with
poor clinical outcome
• The following are patients with high risk of Lung abscesses:
• Periodontal disease
• Risk of Aspiration (Dysphagia, Alcohol abuse, Seizure disorder,
encephalopathy, drug addition, Cerebral vascular accident, endotracheal
tube, Poor technique in inserting nasogastric)
• Diminished gag or cough reflex ( Comatose or under general anesthesia)
• Acute necrotizing pneumonia ( gram-negative bacteria).
• Hematogenous spread of infection from distant site.
• Direct inoculation with contiguous spread.

4. Pathophysiology of Lung abscess
• Most frequently, the lung abscess arises as a
complication of aspiration pneumonia caused by oral
anaerobes.
• A bacterial inoculum from the oral cavity reaches the
lower airways, and infection is initiated if the bacteria
are not cleared by the patient's host defense
mechanism (which is most common in immunodeficient
and chronically ill patients).
• Aspiration pneumonitis and progression to tissue
necrosis 7-14 days later, then formation of lung abscess
• Other mechanisms for lung abscess formation include
bacteremia or tricuspid valve endocarditis, causing
septic emboli (usually multiple) to the lung.
• The oral anaerobe fusobacterium necrophorum is the
most common pathogen..

5. Clinical Features
• Depending on acuteness and severity Signs and symptoms,
include;
• Cough, productive foul smelling sputum
• Chest tightness, chest pain, Dyspnea, Shortness of breath.
• Fever, chills, night sweat.
• Constitutional symptoms: fatigue, malaise, weight loss.
• It may present with hemoptysis, because of necrotizing
effect of the primary infection on lung parenchyma and
vasculature
• On physical examination the patient may have features of
advanced pneumonia or pleural effusion, with low to high
grade fever, many patients have evidence of gingival disease
and dental carries. Also features of consolidation may be
present (dullness to percussion, bronchial breath sounds,
course inspiratory crackles, contra-lateral shift of the
mediastinum, dullness to percussion, and absent breath

6. Bronchiectasis
• Bronchiectasis is an abnormal and permanent dilatation of
bronchi, most often secondary to an infectious process.
• It may be either focal or diffuse. The affected ciliated epithelium
is then replaced by squamous cells. The mucus present
becomes a site for chronic infection with the formation of large
amounts of purulent and often offensive sputum.
• There is permanent, abnormal dilation and destruction of
bronchial walls with chronic inflammation, airway collapse, and
ciliary loss/dysfunction leading to impaired clearance of
secretions.
• The following are pathogens that cause infectious inflammatory
destruction of Lung parenchyma in Bronchiectasis:
• Adenovirus and Influenza virus
• Staphylococcus aureus, Klebsiella, and anaerobes
• Pulmonary Tuberculosis, HIV infection
• Risk increases with; endobronchial neoplasms, Foreign-body
aspiration, Immunoglobulin deficiency, Cystic fibrosis

7. Clinical Features
• Depending on acuteness and severity Signs and
symptoms, include;
• Cough, Hemoptysis, Fever, chills, cyanosis.
• Chest tightness, chest pain,
• Dyspnea, Shortness of breath, wheezing indicate
chronic obstructive pulmonary disease.
• Constitutional symptoms: fatigue, malaise, weight
loss.
• On physical examination the patient may have
features of advanced pneumonia crackles, rhonchi,
and wheezes, Also features of consolidation may be
present (dullness to percussion, bronchial breath
sounds, course inspiratory crackles, dullness to
percussion, and absent breath sounds)

8. Investigations
Diagnosis is based on medical history and symptoms
but imaging and blood tests are also done
• Oxygen saturation – <93% indicates hypoxia
• Arterial Blood gases (ABG) Analysis
• Chest X- ray; look for thick-walled cavitation with
air–fluid levels, poorly ventilated lobes.
• Spirometry
• Full blood picture
• Sputum for culture and sensitivity
• Sputum for AFB if productive cough

9. Management
• Hospitalization is often required if lung abscess is
found. Postural drainage should be performed.
• Antimicrobial therapy.
• Antibiotic regimens include coverage for the
following:
• Gram-positive cocci—ampicillin or
amoxicillin/clavulanic acid, ampicillin/
sulbactam, or vancomycin for S. aureus.
• Anaerobes—clindamycin or metronidazole.
• If gram-negative organisms are suspected, add
a fluoroquinolone or ceftazidime.
• Continue antibiotics until the cavity is gone or until
CXR findings have improved considerably, this
may take months!

10. Evaluation
• Define Lung abscess
• Define Bronchiectasis
• Outline complications of Lung abscess
• Outline clinical fatures of Lung abscess
• Provide measures to prevent and control
of Bronchiectasis

11. References
• Davidson, S, (2014) - Principles and Practice of
Medicine, 22nd Edition, Churchill Livingstone.
• Longmore, M, et al, (1999), Oxford Handbook of
Clinical Medicine, 6th Edition, Oxford
• Swash, M., & Glynn, M. (2007). Hutchinson’s Clinical
Methods: An Integrated Approach to Clinical Practice:
22nd Edition. Philadelphia, PA: Saunders Elsevier
• Trouse, (2000) Short textbook of Medicine University
Press
• MoHCDGEC Standard treatment guidelines & national
essential medicines list tanzania mainland 2017
• MoHCDGEC/ NACTE (2016). Curriculum for
Technician Certificate (NTA Level 5) Curriculum,
Dodoma.