Transcript محاضرة 5
Introduction
0 Pneumonia is an inflammation of the lung parenchyma
(i.e. alveoli rather than the bronchi) of infective origin.
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0 It is the most common infectious cause of death.
0 It is usually characterized by consolidation.
0 Consolidation is a pathological process in which the
alveoli are filled with a mixture of inflammatory exudate,
bacteria & WBC
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EPIDEMIOLOGY
0 Occurs throughout the year
0 Results from different etiological agents
varying with the seasons
0 Occurs in persons of all ages
0 Clinical manifestations severe in very
young, elderly & in chronically ill patients
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CLASSIFICATION
Classified based on two types
1. Type 1
0 Lobar pneumonia
0 Bronchopneumonia
2. Type 2
0 Community- acquired pneumonia (CAP)
0 Hospital-acquired pneumonia (HAP)
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Lobar pneumonia
0 Lobar pneumonia is acute bacterial infection of a part of
lobe the entire lobe, or even two lobes of one or both
the lungs.
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Bronchopneumonia
0 Bronchopneumonia is infection of the terminal
bronchioles that extends into the surrounding alveoli
resulting in patchy consolidation of the lung.
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Community Acquired
Pneumonia (CAP)
Pneumonia which develops in an otherwise healthy
person outside of hospital or have been in hospital for
less than 48hrs
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Nosocomial pneumonia
(HAP)
Pneumonia that was not incubating upon admission
developing in a patient hospitalized for greater than
48 hrs.
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PATHOPHYSIOLOGY
Microbial invasion of the normally sterile lower respiratory
tract
Three routes0 Inhaled as aerosolized particles
0 Haematogenous spread from an extrapulmonary site of
infection
0 Aspiration of oropharyngeal contents
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Various defence mechanisms
that protects lung from
infection
0 Anatomic barriers –epiglottis, larynx
0 Cough reflexes
0 Tracheobronchial secretions
0 Mucocilliary lining
0 Cell & humoral mediated immunity
0 Dual phagocytic system-alveolar macrophages &
neutrophils
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Invasion occurs as a result of
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Defect in host defence mechanism
0 Overwhelming inocculum
0 Lung infection with viruses suppress the
antibacterial activity of the lung by impairing
alveolar macrophage function & mucocilliary
clearance thus setting the stage for secondary
bacterial pneumonia.
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Clinical Manifestations
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Indolent to fulminant in presentation
Mild to fatal in severity
Typical symptoms –
Fever
Chills
Cough
Rust coloured sputum
Mucopurulent sputum
Dyspnea ( shortness of breath)
Pleuritic chest pain
Elevated WBC
Bacteraemic
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Chest X-ray
For Lobar Pneumonia
Consolidation
confined to
one or more
lobes (or
segments of
lobes) of
lungs.
Lobarpneumonia
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Chest X-ray
For Bronchopneumonia
•Patchy
consolidation
usually in the
bases of both
lungs.
Bronchopneumonia
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Diagnosis
Clinical diagnosis
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History
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Signs & symptoms
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Chest x-ray
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CT
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Diagnosis
Etiological diagnosis
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Gram's Stain and Culture of Sputum
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Blood Cultures
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Antigen Tests
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Polymerase Chain Reaction
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Serology
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Bronchoalveolar lavage
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Bronchoscopy
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Complications
Possible complications include:
0 Acute respiratory distress syndrome (ARDS)
0 Fluid around the lung (pleural effusion)
0 Lung abscesses
0 Respiratory failure (which requires a breathing
machine or ventilator)
0 Sepsis, which may lead to organ failure
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COMMUNITY ACQUIRED
PNEUMONIA
Pneumonia is most common in winter because of seasonal
increase in viral infections
Mortality
1%- Non hospitalized patients
13.7%-Hospiatalized patients
19.6%-Bacteremic patients
<36.5%- Intensive care unit
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Risk factors
1.
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3.
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Comorbidity- Neoplastic disease, neurological
problem
Alcoholism
Advanced age
Asthma
Immunosuppression
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Etiology
Potential etiologic agents in CAP - Bacteria
Viruses
Fungi
Protozoa
Potential bacteriologic causes can be divided into two
types
0 Typical bacterial pathogens
0 Atypical bacterial pathogens
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Typical bacterial pathogens
0 Streptococcus pneumoniae – 30% to 60% ,Severe
illness, death
0 Haemophilus influenzae - 10%
0 S. aureus (in selected patients)
0 gram-negative bacilli –
Klebsiella pneumoniae
Pseudomonas aeruginosa
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Atypical bacterial pathogens
0 Mycoplasma pneumoniae
0 Chlamydophila pneumoniae
0 Legionella pneumophillia
0 These organisms are intrinsically resistant to all - B
lactam agents macrolide, a fluoroquinolone, or a
tetracycline.
0 Poor dental hygiene-anaerobes
0 HIV- p.carnii
0 Birds- Chlamydia psittaci
0 Cattle or parturient cat-Coxiella burnetti
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HOSPITAL ACQUIRED
PNEUMONIA
0 Pneumonia that was not incubating upon admission
developing in a patient hospitalized for greater than 48
hrs
0 10-15% of all hospital acquired pneumonia, usually
presenting with sepsis or&/or respiratory failure
0 50% acquired on ICU
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Predisposing features
Reduced host defence against bacteria
0 Reduced immune defences (Corticosteroid treatment,
diabetes, malignancy)
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Reduced cough reflux (Post operative)
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Disordered mucocilliary clearance (Anaesthetic agents)
Aspiration of nasopharyngeal or gastric secretions
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Immobility or reduced conscious level
0 Vomiting, Dysphagia,
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0 Most bacterial nosocomial infection occur by
microaspiration of bacteria colonizing the patients
oropharynx or upper GI tract
0 Most common pathogen – Aerobic gram negative bacilli
0 Most commonly exposed to multiresistant hospital
pathogen
0 86% nosocomial infection-mechanical ventilation
0 Mortality-0 to 50%
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Bacterial introduction into LRT
Endotracheal intubation
Infected ventillatiors / nebuliser /bronchoscopy
Dental or sinus infection
Bacteraemia
Abdominal sepsis
Intravenous canula
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Causative organisms
Common organisms
Gram negative bacteria0
Escherichia coli
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Klebsiella sp.
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Pseudomonas aeruginosa
Gram positive bacteria0
Streptococcus pneumoniae
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Staphylococcus aureus
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Less common organisms
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Gram negative bacilli
other coliforms:Enterobacter sp.
Proteus sp.
Seratia marcescens
Citrobacter sp.
Acinobacter sp.
Legionella pneumophillia
Anaerobic bacteria
Fungi- Candida albicans Aspergillus fumigatus
Viruses- Cytomegalovirus (CMV), Herpes simplex
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Treatment
Goals of therapy-
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Eradication of the offending organism.
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Selection of an appropriate antibiotic.
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To minimize associated morbidity.
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General approach to treatment
0 Adequacy of respiratory function
0 Humidified oxygen for hypoxemia
0 Bronchodilators (albuterol)
0 Chest physiotherapy with postural drainage
0 Adequate hydration if necessary
0 Expectorants such as guaifenesin
0 Chest pain- analgesics
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Selection of an antimicrobial
agent
0 Empirical use of relatively broad spectrum antibiotic
0 Narrow spectrum antibiotics to cover specific
pathogen
0 Potential pathogens involved
0 Age
0 Previous ¤t medication history
0 Underlying disease
0 Present clinical status
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Antibiotic doses for treating pneumonia
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Treatment for special cases
1. Patient less than 60 years & without comorbidities:Azithromycine ( 500mg OD) *1day
( 250mg OD) *4days
Norfloxacin/Levofloxacin (400mg OD) *7days
2. Outpatient greater than 65 years:Norfloxacin (400mg OD) *7days or
Ceftriaxon (1-2 g/day) / Cifixim (2-4 g/day) 3rd gen
cefalosporins
+
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Macrolides like Azithromycin ( 500mg OD) *1day
( 250mg OD) *4days
3. Patient is hospitalised but not severely ill:Combination of 3rd gen cefalosporins + Macrolides
Ceftriaxone + Azithromycin
OR
Norfloxacin/Levofloxacin (400mg OD)
4. If the patient is hospitalised but not severely ill:Combination of 3rd gen cefalosporins + Macrolides
Ceftriaxone + Azithromycin
and newer fluroquinolones (Gatifloxacin)
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5. Patient hospitalised & severely ill:-
Combination of 3rd gen cefalosporins + Macrolides
Ceftriaxone + Azithromycin
and newer fluroquinolones (Gatifloxacin)
We can add Vancomycin.
6. Patient with icu admission:3rd gen cefalosporins + Fluroquinolones
(Gatifloxacin)
+
Nutritional supplements + Saline
Vancomycin/Meropenam
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7. For HAP:-
Cephalosporins + Aminoglycocides
8. For antipseudomons cephalosporins:-
Ceftazidime + Cefexime
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Drugs with usual doses
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