THE LUNG By Dr Raana Akhtar

PULMONARY INFECTIONS URTI PNEUMONIA Impaired local defence mechanisms. - loss of cough reflex,defective mucociliary action,secretions in airways,interference with phagocytosis&pulmonary edema. Decreased resistance of the host. Chronic diseases,immunologic deficiency, immunosuppressive agents and leucopenia.

PNEUMONIA COMMUNITY ACQUIRED ACUTE PNEUMONIA COMMUNITY ACQUIRED ATYPICAL PNEUMONIA HOSPITAL ACQUIRED PNEUMONIA ASPIRATION PNEUMONIA CHRONIC PNEUMONIA NECROTIZING PNEUMONIA &LUNG ABSCESS PNEUMONIA IN IMMUNOCOMPROMISED HOST

COMMUNITY-ACQUIRED ACUTE PNEUMONIAS Streptococcus pnemoniae- gram positive Haemophilus influenzae-gram negative Moraxella catarrhalis Staphlococcus aureus Klebsiella pneumonia Pseudomonas aeruginosa Legionella pneumophila

PNEUMONIA MORPHOLOGY Lobar pneumonia Bronchopneumonia Four Stages Of Inflammatory Response CONGESTION RED HEPATIZATION GREY HEPATIZATION RESOLUTION PLEURITIS

SYMPTOMS OF PNEUMONIAS

COMPLICATIONS OF PNEUMONIA ABSCESS FORMATION EMPYEMA BACTEREMIC DISSEMINATION: Metastatic abscesses,endocarditis,meningitis and suppurative arthritis.

BRONCHOPNEUMONIA

LOBAR PNEUMONIA

COMMUNITY-ACQUIRED ATYPICAL PNEUMONIA Mycoplasma pneumoniae Chlamydia sppc Coxiella burnetti Viruses: Respiratory Syncytial virus Parainfluenza virus Influenza A&B Adenovirus SARS virus

COMMUNITY-ACQUIRED ATYPICAL PNEUMONIA PATHOGENESIS Attachment of the organism to URT epithelium Necrosis of cells and an Inflammatory response Extends to alveoli,interstitial inflammation Damage to epithelium Inhibit mucociliary clearance Secondary becterial infections

COMMUNITY-ACQUIRED ATYPICAL PNEUMONIA Morphology Patchy or lobar Unilateral or bilateral Redblue and congested Interstitial inflammation within the walls of alveoli Alveolar septa widened and edematous Mononuclear infammatory infiltrate of lymphocytes,macrophages and plasma cells Intra-alveolar proteinaceous material&cellular exudate

Viral pneumonia with interstitial lymphocytic infiltrate.s

HOSPITAL- ACQUIRED PNEUMONIA Enterobacteriaceae Pseudomonas S.aureus

ASPIRATION PNEUMONIA Unconscious patients Repeated vomiting Partly chemical pneumonia(gastric acid) Bacterial pneumonia(oral flora) Aerobes and anaerobes Necrotizing pneumonia Fulminating clinical course Lung abscess is a common complication

ASPIRATION PNEUMONIA

LUNG ABSCESS LOCAL SUPPURATIVE PROCESS WITHIN THE LUNG characterized by NECROSIS OF LUNG TISSUE. Etiology & Pathogenesis Streptococci, S.aureus,gram negative organisms.anaerobic organisms in oral cavity Bacteroides,Fusobacterium and Peptococcus species in 60% cases.

LUNG ABSCESS Aspiration of infective material Post-pneumonic abscess formatio Septic embolism Neoplasia(post-obstructive) Miscellaneous: spread of infection from neighboring organ, hematogenous seeding Primary Cryptogenic Lung abscesses

LUNG ABSCESS MORPHOLOGY Few mm to large cavities of 5 to6 cm Single,on right side due to aspiration Multiple,basal due to pneumonia,septic emboli Suppurative debri in abscess cavity Continued infection,large greenblack multiloculated cavities with poorly demarcated margins(gangrene of the lung) SUPPURATIVE DESTRUCTION OF LUNG PARENCHYMA with CENTRAL AREA OF CAVITATION Fibrous wall in chronic cases

LUNG ABSCESS

CHRONIC PNEUMONIAS Inflammatory reaction is granulomatous caused by Bacteria (M.tuberculosis) Fungi(Histoplasma capsulatum, Blastomyces dermatitidis, Coccidiodes immitis)

Histoplasmosis Histoplasma capsulatum infection Acquired by inhalation of dust particles from soil contaminated with bird or bat dropings containing spores Intracellular parasite of macrophages Apical coin lesions on X-ray chest Cough, fever &night sweats Extrapulmonary localized lesion in mediastinum,adrenals,liver and meninges

Histoplasmosis Macrophages (TNF) Helper T-cells(INF gamma) Morphology Epitheloid cell granulomata with caseous necrosis Large areas of consolidation may liquify to form cavities Lesions undergo fibrosis and concentric calcification(tree- bark appearance) 3 to 5 micron meter thin walled yeast may persist in tissues for years. Fulminating Disseminated Histoplasmosis. Macrophages filled with fungal yeast.

BLASTOMYCOSIS Blastomyces dermatitidis Pulmonary,Disseminted& Primary cutaneous Consolidation,multilobar infiltrates,perihilar infiltrates or miliary infiltrates. Suppurative granulomas 5 to15-micron meter yeast cells

Coccidioidomycosis Inhalation of spores of Coccidioides immitis Lung lesions in 10%. Granulomatous lesions Nonbudding sperules filled with small endospores within macrophages and giant cells

Chronic abscessing inflammation

TB LUNG

Pulmonary disease in HIV infection

Pneumocystis carinii jirovesi