PNEUMONIA COMMUNITY-ACQUIRED PNEUMONIA

RESPIRATORY INFECTIONS URTI – common cold, usually viral. Pharyngitis, tracheitis, rhinitis,sinusitis LRTI – Lower Respiratory Tract Infections of which Pneumonia is one. Others include acute or chronic bronchitis, exacerbation of COPD, bronchiectasis.

CLASSIFICATION BY CAUSATIVE ORGANISM –Bacterial –Viral –Fungal –protozoan BY ANATOMIC DISTRIBUTION

CLASSIFICATION Bacterial Pneumonia  Pyogenic bacteria  Atypical organisms  Anaerobes  Mycobacterium tuberculosis(TB)

BACTERIAL PNEUMONIA COMMUNITY-ACQUIRED HOSPITAL-ACQUIRED (NOSOCOMIAL) THE IMMUNOCOMPROMISED PT. –IMPORTANCE IS IN THE DETERMINATION OF THE MOST LIKELY ORGANISM

COMMUNITY-ACQUIRED PNEUMONIA (CAP) DEFINITION Acute lower respiratory infection that results in inflammation and consolidation of the lung parenchyma Present with acute onset of fever, cough with purulent sputum and chest pain; associated with chest Xray abnormalities showing consolidation

EPIDEMIOLOGY of CAP Usually young fit, previously healthy adults – typically virulent org. eg Strep. pneumoniae, All ages – the elderly and the young – virulent as well as less virulent org. eg. H. influenzae, Strep. pyogenes Post viral infection esp. influenza eg. Strep. pyogenes, Staph. aureus, group B strep. Org Aspiration – coma, seizure, alcoholics, GA- anaerobes, gram negative org.

EPIDEMIOLOGY cont. Increased predisposition Age > 65, increased mortality Alcoholism, Malnutrition Smoking Co-morbidity – eg. Cardiac failure, CNS disease, COPD Diabetes mellitus – gram negative infection, Staph. aureus Institutions eg. nursing homes, prison

CAP COMMON HIGH MORBIDITY AND MORTALITY –7% mortality, increased in the elderly, the young, and higher in developing countries % in KBTH

COMMON ORGANISMS Gram positive Strep. pneumoniae Strep pyogenes, other Strep. organisms Staph aureus Atypical bacteria Atypical organisms Gram negative – CAP H. influenzae Klebsiella pneumoniae Escherichia coli Ps. Aeruginosa Acinetobacter spp Legionella Anaerobes

SYMPTOMS AND SIGNS Classical(Strep. pneumoniae commonest org.) Abrupt onset Fever, chills, chest pain Tachypnoea Cough, rust coloured sputum, pleuritic chest pain

SIGNS Herpes labialis Flaring alae nasi Tachypnoea/dyspnoea Reduced chest movement(splinting) Tachycardia, hypotension Dullness to PN, increased tactile fremitus, crackles, bronchial breath sounds, reduced intensity of BS

INVESTIGATIONS  CXR  SPUTUM gram stain and culture  Sputum AFB - suspect TB in all cases  WCC, FBC  BLOOD C/S  BUE, Cr  RBS, sickling, Hb

ASSESSMENT OF SEVERITY CORE prognostic factors(2 + is severe) C onsciousness level impaired U rea – renal impairment in septicaemia R espiratory rate >30 per minute B P – systolic <90, diastolic <60mmHg -one or less present consider additional/pre- existing risk factors and use clinical judgement

Additional/pre-existing prognostic factors Age > 50 years Co-existing disease Bilateral or multi-lobe involvement on CXR Hypoxaemia – oxygen saturation <92% (with pulse oximeter), or Pao2 <8kPa

Assessment Regular assessment – failure to improve monitor: temp, RR, pulse, BP,O 2 sat, mental status Repeat CXR - complications Leucocytosis CRP BUE, Cr

TREATMENT  OXYGEN 60%, PAIN RELIEF, FLUIDS  EMPIRICAL ANTIBIOTICS Penicillin, amoxycillin,(erythromycin) Beta lactamase resistant org.- 3G cephalosporin (or 2G), co-amoxyclavulanic acid Staph. - flucloxacillin Atypical - erythromycin Aspiration, lung abscess – metronidazole, gentamycin, flucloxacillin/penicillin large doses

MANAGEMENT  Severe – admit  IV if very ill(severe), septicaemic, vomiting, impaired level of consciousness, malabsorption  Non-severe - oral  Not severe – out patient - oral AB  Amoxycillin +/- erythromycin

COMPLICATIONS Septicaemia Meningitis Pericarditis, Mediastinitis Pleural effusion, Empyema Lung abscess Bronchopleural fistula Pneumothorax

COMPLICATIONS  40% of pneumonias develop pleural or parapneumonic effusions  10% go on to develop empyema- S. viridans, K. pneumoniae, anaerobes, other Strep. org, Staph, E. coli  Pneumothorax – often results from Staph pneumonia  Lung abscesses from Staph pneumonia or from Aspiration pneumonia with mixed anaerobes, gram negative and gram positive org.  Bronchopleural fistula between bronchus in infected lung and pleural space - pyopneumothorax