1. Infections of the Respiratory Tract
Dr. Raid Jastania

2. Infections of the Respiratory Tract
Upper Respiratory Tract
Lower Respiratory Tract
Bacterial, Viral, Fungal, T.B, Parasitic
Most URT infections are viral
Most LRT infections are bacterial

3. Upper Respiratory Tract Infections
Common cold (Acute coryza)
Viral infection of URT
Organisms:
Rhinoviruses: Coronaviruses, Enteroviruses, Adenoviruses, Respiratory syncytial virus)
Influenza A and B
Croup (Parainfluenza 1,2,3)

4. Upper Respiratory Tract Infections
Tonsillitis (mostly bacterial)
Otitis media (mostly bacterial)
Epiglottitis
Laryngitis
Laryngotrachiobronchitis
Bronchitis
Bronchiolitis
Pneumonia

5. Pneumonia
Pneumonia is inflammation of the lung (lower respiratory tract) caused mainly by infection.
Pneumonia can be caused by Bacterial infection and less commonly by other organisms eg. Viruses, Fungi
The term Pneumonia is sometimes used to indicated inflammation of lungs due to other causes eg. Including interstitial lung disease (interstitial pneumonia)

6. Types of Pneumonia Different ways of classification
Problematic, confusing
Classification is Based on
etiology,
anatomic site involved,
clinical presentation,
pathological type of inflammation

8. Types of Pneumonia One of the classification divides pneumonia into:
Primary (community-acquired)
Secondary
Others

9. Types of Pneumonia One of the classification divides pneumonia into:
Primary (community-acquired)
Typical pneumonia
Lobar pneumonia
Bronchopneumonia
Atypical pneumonia
Secondary
Aspiration pneumonia
Nosocomial (hospital-acquired) pneumonia
Pneumonia in immunosuppression
Others:
Chronic pneumonia
Necrotizing pneumonia/Supporative pneumonia/Lung Abscess

10. Risk of Pneumonia Underlying disease Immunodeficiency
COPD
Heart failure
Diabetes
Immunodeficiency
Absent splenic function (sickle cell disease)

11. Primary, Community-Acquired Pneumonia Typical Pneumonia

12. Clinical Presentation
Fever, rigor, malaise, weakness, vomiting, loss of appetite, headache
Cough with sputum
Dyspnea
Chest pain, pleuritic pain
Sick, ill , distressed
High respiratory rate >30 / mint
In lobar pneumonia: localized area of dullness on percussion, increased tactile fremitus, bronchial breath sounds, and crepitation, pleural rub

13. Morphology Common in lower lobes and right middle lobe
In Lobar pneumonia: there is a localized area of inflammation
Stages:
Congestion
Vascular congestion, edema, few neutrophils
Red hepatization
Fibrin, RBC, neutrophils in alveolar spaces
Gray hepatization
Fibrin, RBC lysis
Resolution

15. Bronchopneumonia
Inflammation of the bronchi and bronchioles with collapse of the distal airspaces
Multiple, patchy bilateral small infiltrates
Affect lower lobes usually

16. Outcome and complications
Resolution
Fibrosis
Abscess
Empyema
Dissemination of infection
Meningitis, arthritis, endocarditis

17. Investigations CBC Arterial blood gases Radiological exam: chest x-ray
Sputum exam and culture
Nose and throat swabs
Blood culture
Serological tests

18. Pneumonia: Features of different organisms (community-acquired pneumonia)
Strep. Pneumoniae
commonest
Staph. Aureus
Common following viral infection
Risk of complications: abscess
Common in IV drug abusers
Legionella
Legionnaire’s disease, epidimics
Grow in water reservoir, humidifiers
People with heat disease, renal disease, immunosuppressed
Presentation with GIT symptoms, mental confusion
Hemophilus influenzae
Common in COPD, chronic bronchitis, bronchiectasis, cystic fibrosis
Klebsiella
Chronic alcoholics and malnourished persons

19. Primary, Community-Acquired Pneumona Atypical Pneumonia

20. Atypical Pneumonia Viruses, Mycoplasma, Chlamydia
Fever and malaise precede the respiratory symptoms by few days
Severe headache, malaise, anorexia
No localized sings on chest exam, No consolidation on chest x-ray
Spleen may be enlarged
WBC normal, cultures negative
No improvement with Penicillin

21. Atypical Pneumonia (community-acquired)
Mycoplasma
Sporadic or epidemics
Viruses
Influenza, Parainfluenza, Adenovirus, respiratory syncytial virus, measles, chicken pox
Chlamydia

22. Atypical pneumonia Morphology: Patchy or involve whole lobe
Inflammation is confined to the alveolar walls
Widening of alveolar walls by edema, mononuclear cell infiltration (lymphocytes, plasma cells, macrophages)

24. Secondary Pneumonia

25. Secondary pneumonia Aspiration pneumonia
Nosocomial (hospital-acquired) pneumonia
Pneumonia in immunosuppression

26. Secondary Pneumonia
Pre-existing disease of lung or factors increasing the risk of infection
Low virulence organisms: Hemophilus infleunzae, viruses, fungi
Anaerobic bacteria
Gram negative bacteria
Staph aureus
All the others in commuity-acquired

27. Aspiration Pneumonia Aspiration of gastric contents
During surgery, anesthesia, surgery of tonsils, dental work
Infection following Aspiration of vomitus in coma, anesthesia, or sleep
Ineffective coughing (post operative)
Can result in severe hemorrhage in lungs
Chemical injury + infection (Anaerobic)
Destruction of lung parenchyma with cavitations

28. Nosocomial Pneumonia Patients admitted to hospital Organisms
Same as community acquired and
Gram-negative (Klebsiella, E.coli, Pseudomonas)
Staph. Aureus

29. Pneumonia in Immunosuppression
Congenital or acquired
AIDS, Immunosuppression
Humoral and Cellular immunity
Infection by
Pneumocystis carinii
Gram negative bacteria
The common bacteria
Opportunistic pathogens: CMV, Herpes, Aspergillus, TB, mycobacteria

30. Lung Abscess Suppurative pneumonia Necrotizing pneumonia Cavity
Localized suppurative necrosis

31. Lung Abscess Mechanisms:
Aspiration of infective material: teeth, tonils, coma, alcoholics
Aspiration of gastric conetnets
Complication of necrotizing pneumonia
Bronchial obstruction
Septic emboli
Hematogenous spread

32. Lung Abscess Morphology Cavity 1-2mm to 5-6 cm
Filled with pus, cellular debris
Surrounded by fibrosis and chronic inflammation
Aspiration tend to involve the right lung
May rupture in airways resulting in Air-fluid levels
May rupture in pleura resulting in pneumothorax and empyema