COMMUNITY ACQUIRED PNEUMONIA :COMMUNITY ACQUIRED PNEUMONIA Dr. MAULIK SHAH ICU REGISTRAR CRITICAL CARE DEPT.


Pneumonia :Pneumonia Definition : It is defined as the infection of lung parenchyma. Types : CAP (Community acquired pneumonia) HAP (Hospital acquired pneumonia) VAP (Ventilator associated pneumonia)


PNEUMONIA :PNEUMONIA CAP


ETIOLOGY :ETIOLOGY Agent Factors   Typical pathogens : Streptococcus pneumoniae Haemophilus influenza S. aureus GNB – Klebsiella Pneumoniae Pseudomonas aeruginosa


Slide 5:Atypical pathogens : Chlamydiaophila pneumoniae Mycoplasma pneumoniae Legionella spp. Respiratory viruses – Influenza Adeno RSV


Slide 6:Rare pathogens : Fungi Protozoa New viruses - Hantavirus Metapneumovirus Coronavirus (SARS) Changing trends : MDR strains of GNB and CA – MRSA can cause necrotising pneumonia


HOST FACTORS :HOST FACTORS Breach of mechanical or immunological defences makes a host susceptible to infection


POSSIBLE ETIOLOGICAL AGENT ACCORDING TO SUSCEPTIBILITY :POSSIBLE ETIOLOGICAL AGENT ACCORDING TO SUSCEPTIBILITY Alcoholism - Klebsiella pneumoniae, oral anaerobes,S Pneumoniae, M. Tb COPD and/or Smoking – H. influenza, Moraxella catarrhalis,Pseudomonas, S. Pneumoniae Structural lung disease – Pseudomonas aeruginosa,Burkholderia cepacia,S. aureus  Decreased level of consciousness – Oral anaerobes, gram neg bacilli


Slide 9:Exposure to birds – Chlamydia psittaci H. capsulatum Stay in hotel or on cruise ship in previous 2 weeks – Legionella


PATHOPHYSIOLOGY :PATHOPHYSIOLOGY Host defences trigger inflammatory response which lead to clinical syndrome of pneumonia Inflammatory mediators from macrophages and neutrophils create alveolar capillary leak equivalent to that seen in ARDS.


PATHOLOGY :PATHOLOGY Intact immunity or typical pathogen– Localisation of infection and so lobar pneumonia pattern 4 Stages : Edema Red Hepatization-Erythrocytes Gray Hepatization-neutrophils Resolution-Macrophages Immunocompromised or atypical pathogens- Bronchopneumonia pattern


CLINICAL MANIFESTATIONS :CLINICAL MANIFESTATIONS CAP can vary from mild diseases to fatal in severity Symptoms : Cough, dyspnea, chestpain if parietal pleura involved Others : Fever, constitutional symptoms Signs


DIAGNOSIS :DIAGNOSIS Clinical Radiological Etiological : Gram stain and culture of sputum Blood cultures Antigen tests PCR Serology


DIFFERENTIAL DIAGNOSIS :DIFFERENTIAL DIAGNOSIS Acute exacerbation of COPD Heart Failure Pulmonary embolism Radiation Pneumonitis Acute Bronchitis


TREATMENT :TREATMENT Principles : Decide according to severity whether the patient is a candidate for outpatient or inhospital treatment Try to cover organism as per local epidemiological pattern Keep in mind the drug resistance patterns IV drugs when hospitalised Cover for pseudomonas and MRSA when suspected


Inhospital/Outpatient treatment decided as per PSI/CURB-65 criteria :Inhospital/Outpatient treatment decided as per PSI/CURB-65 criteria PSI (Pneumonia Severity Index) variables : 20 in number   CURB variables : C-Confusion U-Urea(>7 mmols) R-Respiratory rate (>30) B-Blood pressure (<90 sys or <60 diastolic)


Slide 18:Outpatient treatment – PSI class 1&2 CURB score 0 Inhospital treatment – PSI class 4&5 CURB score >2


ANTIBIOTIC GROUPS :ANTIBIOTIC GROUPS Macrolides-Covers atypical org. but DRSP cases ineffective B-Lactams-No atypical coverage but DRSP cases effective Fluroquinolones-Less resistance and covers both Aminoglycosides-Add on drug for pseudomonas Drugs for MRSA


Slide 21:Bacteremic Pneumococcal Pneumonia – Dual therapy preferred


Definitive Treatment :Definitive Treatment What if organism isolated sensitive to Penicillins and we have started with B lactum+Macrolide or Fluroquinolones What if no response and drug resistant to FQ+Macrolides+Penicillins (MDR)


DURATION OF THERAPY :DURATION OF THERAPY Uncomplicated CAP : 5-day course suffices Bacteremic CAP/Virulent organism – 10-14 days


Response to treatment in otherwise uncomplicated CAP: :Response to treatment in otherwise uncomplicated CAP: Fever- Falls in 2 days Leucocytosis-decreases in 4 days Physical findings persist slightly longer Chest radiographic abnormalities may take 4-12 weeks to resolve


What if patient fails to improve? :What if patient fails to improve? Consider – Noninfectious condition Resistance to drug Superinfection with new nosocomial pathogen


COMPLICATIONS :COMPLICATIONS Seen usually when MDR pathogens present Respiratory Failure Shock and Multiorgan failure with DIC Metastatic infection Lung Abscess Complicated pleural effusion


PROGNOSIS :PROGNOSIS Depends on – Age Presence of co-morbidities Site of treatment


PREVENTION :PREVENTION Immunocompromised/Susceptible –Vaccination Community outbreak – Chemoprophylaxis+Vaccination


Slide 29:I hope I was not boring !!!!!