6. Definition
• Pneumonia is an acute
infectionofthe
parenchyma of the
lung, caused by bacteria,
fungi,virus,parasite etc.
• Pneumoniamayalsobe
causedby otherfactors
including X-ray,
chemical,allergen
9. Bacterialpneumonia
(1) Aerobic Gram-positive bacteria,such as streptococcus
pneumoniae, staphy- lococcus aureus, Group A hemolytic
streptococci
(2) Aerobic Gram-negative bacteria, such as klebsiella
pneumoniae, Hemophilus influenzae, Escherichia coli
(3) Anaerobicbacteria
10. Atypical pneumonia
Including Legionnaies pneumonia ,
Mycoplasmal pneumonia ,chlamydia pneumonia.
Fungal pneumonia
Fungal pneumonia is commonly caused by
candida and aspergilosis
11. Viral pneumonia
Viral pneumonia may be caused by adenoviruses, respiratory
syncytial virus , influenza, cytomegalovirus, herpes simplex
12. Ⅱ.Classification by anatomy
1. Lobar: Involvement of an entire lobe
2. Lobular: Involvement of parts of the lobe only, segmental
or of alveoli contiguous to bronchi (bronchopneumonia).
3. Interstitial
17. Overview
◆ Pneumonia can result from a variety of causes,
including infection with bacteria, viruses, fungi,
parasites, and chemical or physical injury to the
lungs
◆ Source of Infection
◆ Aerosol
◆ Aspiration of amniotic fluid
◆ Blood-borne infection across the placenta
20. Overview
◆ The risk factors for pneumonia include:
smoking, age>65, immuno-suppression,
exposure to chemicals, and underlying lung
disease.
21. Risk Factors
◆ AirwayObstruction
◆ When part of the airway (bronchi)leading to the alveoli is obstructed, lead to
infection of the fluid resulting in community-acquired pneumonia (CAP)
◆ Another cause of obstruction is lungcancer
◆ LungDisease
◆ Smoking, and diseases such as emphysema, result in more frequent and severe
bouts of CAP
◆ ImmuneCompromise
◆ more likely to get CAP
◆ active malignancy,immuno-suppression, neurological disease, congestive
heart failure, coronaryartery disease, and diabetes mellitus
23. Clinicalmanifestations(1)
• Many patients have had an upperrespiratoryinfectionfor
several days before the onset of pneumonia
• Onset usually is sudden, half caseswith a shaking
chill
• The temperature rises during the first few hours to 39-
40℃
24. Clinicalmanifestations(2)
• Typically, patients have the symptoms of high
fever , shaking chill, sharp chest pain, cough,
dyspnea and blood-flecked sputum.
• But in some cases, especially those at age
extremes symptoms may be more insidious.
25. • The pulse accelerates
• Sharp pain in the involved hemi thorax
• The cough is initially dry with pinkish or
blood-flecked sputum
• Gastrointestinal symptoms such as,
anorexia, nausea, vomiting abdominal
pain, diarrhea may be mistaken as acute
abdominal inflammation
Clinicalmanifestations(3)
29. • A lung abscess is a localized
area of destruction of lung
parenchyma (usually >2 cm in
diameter)
• Infection by pyogenic
organisms results in tissue
necrosis
• Manifested radiologically as
a cavity with air fluid level
Definition
30. Classification
Lung abscess may be single or multiple and they
frequently containair-fluid levels
Lung abscesses can be classified based on the
duration & the likely etiology
Acute abscess
Chronic abscess
31. Acute
patient presents with symptoms of <2weeks
duration
more likely to have an infection caused by a
virulent aerobic bacterial agent (e.g. S. aureus)
32. Acute Lung Abscess
CXR of a patient who had foul-smelling & bad tasting sputum, an almost
diagnostic feature of anaerobic lung abscess
33. Classification…
Clinically useful during initial evaluation
Chronic:
A chronic lung abscess is defined by symptoms lasting for > 4 to 6 weeks.
Patients more like to have an underlying neoplasm or infection with a less
virulentanaerobicagent
34. Primary abscess
caused by aspirationor pneumonia in the healthy
host
Mostly result from necrosis in an existing
parenchymal process, usually untreated or
aspiration pneumonia
35. Classification…
Secondary abscess is caused by
Pre-existing condition eg bronchiectasis
Bronchial obstruction (eg- aspirated foreign body)
An immuno-compromised state
Spread from an extra-pulmonary site
Abscess that complicates either a septic vascular
embolus (eg- right sided endocarditis)
37. Causes of Lung abscess (A) Aspiration
A) Aspiration of infected material containing
oropharyngeal flora (commonest cause)
Organisms are anaerobic and
aerobic May be due to
Dental/ periodontal sepsis esp following tooth
extraction, tonsillectomy and nasal operation
Paranasal sinus infection
44. Symptoms …
Patients present with
Severe cough with
Profuse foul smelling sputum, may be foetid
There may be large amounts of purulent sputum once a
bronchial communication has been established
Putrid sputum is a highly specific symptoms
pathognomonic for anaerobic infection
although present in only 50-60% of patients
that is
Haemoptysis (25% of patients) – not uncommon and may be life-
threatening
45. Symptoms …
Chest pain (pleuritic or deep-seated aching discomfort) – 60% of patients
Fever – usually high with chill & rigor, profuse night sweating
Constitutional upset like- malaise, weakness
Weight loss (60% of patients) – with an average loss of between 15 & 20
lbs
Anorexia
Symptoms of associated disease process eg-
Bronchial obstruction due to lung cancer
Oesophageal obstruction due to achalasia
Right-sided endocarditis
Dyspnoea
46. Symptoms …
In most patients, presentation is insidious with symptoms lasting at
least 2 weeks before presentation
History
Includes risk factors for aspiration, eg-
Alcoholism
Drug overdose
Seizures
Head injury
Stroke
Absence of such risk factors should prompt a search for a diagnosis
other than primary lung abscess
47. Signs
There is no signs specific for lung abscess
Patient is toxic with high temperature & Halitosis
Clubbing may develop within few weeks if treatment is
inadequate
usually in 10% cases after 3 weeks
48. Signs…
On chest exam
Evidence of consolidation
Dullness to percussion and diminished breath sounds, if the abscess
is large and situated near the surface of the lung
The ‘amorphic’ or ‘cavernous’ breath sound traditionally associated
with lung cavities are rarely elicited in modern practice
49. Features Of Severe Aspiration Pneumonia
Chest radiographic findings
50% increase in the infiltrate in
48 hours
Respiratory rate >30 breaths/min SIRS (systemic inflammatory
Presence of shock
Urine output <<20 mL/h
Bilateral multilobar involvement Severe lung injury (PaO2/FIO2
response syndrome) or need for
vasopressors to support blood
pressure
ratio <<250 mm Hg)
Acute renal failure requiring
dialysis
56. Imaging Studies…
X-ray chest
Radiographic abnormality may start with
a pneumonic infiltrate
followed by the development of one or
more spherical areas of more
homogeneous density in which air-fluid
levels often arise
indicating the formation of a bronchial
communication
59. Treatment
Principles:
Sputum is sent for C/S
& broad-spectrum antibiotic should be started
Postural drainage & chest physiotherapy
Surgery
Treatment of the cause if any
60. Treatment…
Antimicrobials
Currently the mainstay of therapy is antimicrobial therapy
Antibiotics should be given according to the culture & sensitivity
for prolonged period
Commonly sputum is sent for C/S and a broad-spectrum antibiotic
should be started
61. Treatment…
The majority of patients are treated empirically
Most lung abscess pathogens are sensitive to conventional
antimicrobial therapy
Majority of lung abscesses are related to aspiration and are caused by
anaerobes
About 90% of patients with anaerobic lung abscess responds to
medical treatment
62. Treatment…
Clindamycin associated with fewer treatment failure & a shorter
time to symptom resolution than penicillin
May be preferable to other agents. Dose is 600 mg IV every 6-8
hourly
Switching to oral therapy at a dose of 300 mg every 6-8 hourly
when the patient improves
66. Differential diagnosis/Clinically
Consolidation (during resolution stage), usually no clubbing
Bronchiectasis
Bronchial carcinoma, usually Squamous cell carcinoma
Pulmonary tuberculosis (without causing abscess)
Rare infections, including – Actinomycosis, Nocardiasis, Fungal
pneumonia
67. Differential diagnosis (Contd)
In Lung abscess
Fever, systemic complaints
purulent sputum
and WBC count >11x109/L more likely to be
found
Response to antibiotic therapy
68. Differential diagnosis…/Radiologically
Necrosis in a lung tumour
Age more than 50 years
No history
suggestive of
aspiration
Lesions need not be situated
in a typically dependent
segment of the lung
In CXR: an eccentric cavity
with thick irregular walls
69. Lung abscess Empyema
Fever, systemic complaints Purulent infection ,confined to pleural space
Purulent sputum Can developed as a complication, or be a cause, of a
lung abscess
WBC count >11x109/L If an empyema contains an air-fluid level,
then a broncho-pleural fistula is likely to be
present
Response to
antibiotic therapy
Often difficult to distinguish radiographically between
a localized empyema with a bronchopleural fistula and
a lung abscess.
In CT - wall is of varying
thickness with an
irregular itraluminal
margin and exterior
surface.
Seen on the lateral Chest X-ray as a D- shaped
opacity with the convexity projecting Anteriorly
from the Posterior Chest wall.
Differential diagnosis…/Radiologically
71. Prevention
Prevention of aspiration is important to minimize the risk of lung abscess
Vomiting patients should be placed on their sides
Improving oral hygiene and dental care in elderly and debilitated patients
Positioning the supine patient at a 30° reclined angle minimizes the risk of
aspiration
Early intubation in patients who have diminished ability to protect the airway
from massive aspiration (cough, gag reflexes), should be considered
