Pneumonia

Pneumonia is an inflammatory condition of the lung affecting primarily the small air sacs known as alveoli. Typically symptoms include some combination of productive or dry cough, chest pain, fever, and trouble breathing. Severity is variable.

Pneumonia is usually caused by infection with viruses or bacteria and less commonly by other microorganisms, certain medications and conditions such as autoimmune diseases. Risk factors include cystic fibrosis, chronic obstructive pulmonary disease (COPD), asthma, diabetes, heart failure, a history of smoking, a poor ability to cough such as following a stroke, and a weak immune system. Diagnosis is often based on the symptoms and physical examination. Chest X-ray, blood tests, and culture of the sputum may help confirm the diagnosis. The disease may be classified by where it was acquired with community, hospital, or health care associated pneumonia.

Vaccines to prevent certain types of pneumonia are available. Other methods of prevention include handwashing and not smoking. Treatment depends on the underlying cause. Pneumonia believed to be due to bacteria is treated with antibiotics. If the pneumonia is severe, the affected person is generally hospitalized. Oxygen therapy may be used if oxygen levels are low.

Pneumonia affects approximately 450 million people globally (7% of the population) and results in about four million deaths per year. Pneumonia was regarded by William Osler in the 19th century as "the captain of the men of death". With the introduction of antibiotics and vaccines in the 20th century, survival improved. Nevertheless, in developing countries, and among the very old, the very young, and the chronically ill, pneumonia remains a leading cause of death. Pneumonia often shortens suffering among those already close to death and has thus been called "the old man's friend"

1. PNEUMONIA “The captain of the men of death.”  “The old man's friend" — Sir William Osler

2. Pneumonia An acute respiratory illness associated with recently d eveloped radiological pulmonary shadowing which may be segmental, lobar or multilobar . (o r ) Inflammation in the lung characterized by accumulation of secretions and inflammatory cells in alveoli.

3. Pneumonia remains common cause of Death Globally Pneumonia ranked 6th CAP is most common cause of Severe Sepsis Despite introduction of Antibiotics, Imaging modalities and Biomarker testing, mortalities related to CAP has not changed significantly.

4. CLASSIFI C A TION

5. Pneumonia: Classifications Clinically Community-acquired pneumonia : (Typical/Atypical) Onset in community or during 1 st 2 days of hospitalization (Strep. pneumoniae most common) Hospital-acquired Pneumonia(HAP/nosocomial): Occurring 48 hrs after hospitalization Suppurative & Aspiration pneumonia Pneumonia in immunocompromised patient: caused by opportunistic organisms (Pneumocystis jirovecii).

6. Pneumonia: Classifications.. Anatomically Lobar pneumonia if one or more lobe is involved Broncho-pneumonia (Lobular) more patchy alveolar consolidation associated with bronchial and bronchiolar inflammation often affecting both lower lobes the pneumonic process has originated in one or more bronchi and extends to the surrounding lung tissue

7. Pneumonia: Classifications.. According to causes Bacterial (the most common cause of pneumonia) Viral pneumonia Fungal pneumonia Aspiration pneumonia Chemical pneumonia (ingestion of kerosene or inhalation of irritating substance)

8. Various defence mechanisms that protects lung from infection Anatomic barriers –epiglottis, larynx C ough reflexes Tracheobronchial secretions Mucociliary lining Cell & humoral mediated immunity Dual phagocytic system-alveolar macrophages & neutrophils 8

9. Factors that predispose to pneumonia Reduced host defences against bacteria • Reduced immune defences (e.g. corticosteroid treatment, diabetes, malignancy) • Reduced cough reflex (e.g. post-operative) • Disordered mucociliary clearance (e.g. anaesthetic agents) • Bulbar or vocal cord palsy

10. Factors that predispose to pneumonia Aspiration of nasopharyngeal or gastric secretions • Immobility or reduced conscious level • Vomiting, dysphagia, achalasia or severe reflux • Nasogastric intubation Bacteria introduced into lower respiratory tract • Endotracheal intubation/tracheostomy • Infected ventilators/nebulisers/bronchoscopes • Dental or sinus infection

11. COMMUNITY-ACQUIRED PNEUMONIA (CAP)

12. Community-acquired pneumonia (CAP) Acc. to BTS Guidelines CAP is defined as, Acute lower respiratory tract infection accompanied by new infiltrates on chest radiograph or auscultatory findings consistent with pneumonia in a patient not hospitalized or residing in a long term care facility for more than 2 weeks before onset of symptoms.

13. Community-acquired pneumonia (CAP).. Most cases are spread by droplet infection. May occur in previously healthy individuals. Streptococcus pneumoniae remains the most common infecting agent. Other organisms may be involved which depends on the age of the patient and the clinical context. Viral infections are important causes of CAP in children, and their contribution to adult CAP is increasingly recognized

14. Community-acquired pneumonia (CAP).. Mycoplasma pneumoniae is more common in young people and rare in the elderly. Haemophilus influenzae is more common in the elderly, particularly when underlying lung disease is present. Legionella pneumophila occurs in local outbreaks centred on contaminated cooling towers in hotels, hospitals and other industrial buildings. Staphylococcus aureus is more common following an episode of influenza.

15. Community-acquired pneumonia (CAP).. Cigarette smoking Upper respiratory tract infections Alcohol Corticosteroid therapy Old age Recent influenza infection Pre-existing lung disease HIV Indoor air pollution Factors that predispose to pneumonia

16. Community-acquired pneumonia (CAP).. Bacteria Streptococcus pneumoniae Mycoplasma pneumoniae Legionella pneumophila Chlamydia pneumoniae Haemophilus influenzae Staphylococcus aureus Chlamydia psittaci Coxiella burnetii (Q fever, ‘querry’ fever) Klebsiella pneumoniae (Freidländer’s bacil us) Actinomyces israelii Influenza, parainfluenza Measles Herpes simplex Varicella Adenovirus Cytomegalovirus (CMV) Coronavirus (Urbani SARS- associated coronavirus) Organisms causing CAP V i r u s e s

17. PA THOPHYSIOLO G Y

18. PATHOLOGY CONGESTION •Presence of a proteinaceous exudate-and often of bacteria- in the alveoli

19. RED HEPATIZATION Presence of erythrocytes in the cellular intraalveolar exudate. Neutrophils are also present Bacteria are occasionally seen in cultures of alveolar specimens collected

20. GRAY HEPATIZATION No new erythrocytes are extravasating, and those already present have been lysed and degraded. Neutrophil is the predominant cell Fibrin deposition is abundant Bacteria have disappeared Corresponds with successful containment of the infection & improvement in gas exchange

21. RESOLUTION Macrophage is the dominant cell type in the alveolar space. Debris of neutrophils, bacteria, and fibrin has been cleared.

22. Summary Four stages: - Congestion – Vasodilatation – Red Hepatization – Exudation + RBC – Gray Hepatization - Neutro & Macrophages. – Resolution – few macrophages, normal.

23. CLINICAL FEATURES

24. SYMPTOMS GENERAL SYMPTOMS ADDITIONAL SYMPTOMS • High grade fever • Cough-productive • Pleuritic chest pain • Breathlessness • Sharp or stabbing chest pain • Headache • Excessive sweating and clammy skin • Loss of appetite and fatigue • Confusion, especially in older people

25. GENERAL SIGNS Febrile Tachypnoea Tachycardia Cyanosis-central Hypotension Altered sensorium Use of accessory muscles of respiration Confusion- advanced cases

26. SIGNS OF CONSOLIDATION Percussion-dull Bronchial Breath sounds Crackles Increased VF & VR Aegophony & Whispering Pectoriloquy Pleural Rub

27. Differential diagnosis of pneumonia Pulmonary infarction Pulmonary/pleural TB Pulmonary oedema (can be unilateral) Pulmonary eosinophilia Malignancy: bronchoalveolar cell carcinoma Rare disorders: cryptogenic organising pneumonia/ bronchiolitis obliterans organising pneumonia (COP/BOOP) Venous thromboembolism, Pulmonary haemorrhage ARDS Drug toxicity

28. INVESTIGATIONS

29. Investigations The aims of investigation are Confirm the diagnosis Exclude other conditions Assess the severity Identify the development of complications Clinical diagnosis History Signs & symptoms Chest x-ray CT Etiological diagnosis Gram's Stain and Culture of Sputum Blood Cultures Antigen Tests Polymerase Chain Reaction Serology Bronchoalveolar lavage

30. Investigations.. Full blood count Very high (> 20 × 109/L) or low (< 4 × 109/L) white cell count: marker of severity Neutrophil leucocytosis > 15 × 109/L: suggests bacterial aetiology Haemolytic anaemia: occasional complication of Mycoplasma Erythrocyte sedimentation rate/C-reactive protein: Non- specifically elevated Blood culture: Bacteraemia: marker of severity

31. Investigations.. Urea and electrolytes: Urea > 7 mmol/L (~20 mg/dL): marker of severity Hyponatraemia: marker of severity Liver function tests: Abnormal if basal pneumonia inflames liver Hypoalbuminaemia: marker of severity Serology: Acute and convalescent titres for Mycoplasma, Chlamydia, Legionella and viral infections Cold agglutinins: Positive in 50% of patients with Mycoplasma Arterial blood gases: Measure when SaO2 < 93% or when severe clinical features to assess ventilatory failure or acidosis

32. Investigations.. Sputum Sputum samples Gram stain, culture and antimicrobial sensitivity testing , AFB, KOH mount Oropharynx swab PCR for Mycoplasma pneumoniae and other atypical pathogens

33. Investigations.. Urine Pneumococcal and/or Legionella antigen Pleural fluid Always aspirate and culture when present in more than trivial amounts, preferably with ultrasound guidance

34. Investigations.. Chest X-ray Lobar pneumonia Patchy opacification evolves into homogeneous consolidation of affected lobe Air bronchogram (air-filled bronchi appear lucent against consolidated lung tissue) may be present. Bronchopneumonia: Typically patchy and segmental shadowing Complications: Para-pneumonic effusion, intrapulmonary abscess or empyema Staph. aureus: Suggested by multilobar shadowing, cavitation, pneumatocoeles and abscesses

35. Assessment Of Severity

36. ***intensive respiratory or vasopressor support

37. MANAGEMENT

38. M a na g eme n t The principles of management focusing on Adequate oxygenation Appropriate fluid balance Antibiotics In severe or prolonged illness, Nutritional support may be required Evaluate the effectiveness of administered medications Explain all procedures to the patient and family

39. Management… Oxygen Oxygen should be administered to all patients with tachypnoea, hypoxaemia, hypotension or Acidosis The aim of maintaining the PaO2 at or above 60mmHg or the SaO2 at or above 92%.

40. Management…. Oxygen High concentrations (35% or more), preferably humidified, should be used in all patients who do not have hypercapnia associated with COPD. Continuous positive airway pressure (CPAP) should be considered in those who remain hypoxic despite this and these patients should be managed in a high- dependency or intensive care environment, where mechanical ventilation can be rapidly employed.

41. Management… Intravenous fluids These should be considered in patients with severe illness, older patients and those who are vomiting. Otherwise, an adequate oral intake of fluid should be encouraged. Inotropic support may be required in patients with shock

42. Management… Antibiotics Prompt administration of antibiotics improves the outcome. The initial choice of antibiotic is guided by clinical context, severity assessment, local knowledge of antibiotic resistance patterns any available epidemiological information. The choice of empirical antibiotic therapy is considerably more challenging, due to Diversity of pathogens Drug resistance.

43. Management… Uncomplicated CAP: Outpatient Treatment (empirical) Previously healthy and no antibiotics in past 3 months * A macrolide (clarithromycin or azithromycin or Doxycycline ) Comorbidities or antibiotics in past 3 months: R esp i r a t o r y fl u o r oqui n olon e [ m o xifl o x aci n ,l e v ofl o x aci n ] o r β - lactam ( high-dose amoxicillin or amoxicillin/clavulanate)

44. Management… Inpatient Treatment- Non ICU: A respiratory fluoroquinolone [moxifloxacin ,levofloxacin ] β -lactam [cefotaxime ,ceftriaxone ,ampicillin] plus a macrolide [oral clarithromycin or azithromycin) Inpatient Treatment- ICU: β -lactam plus Azithromycin or a fluoroquinolone

45. Management… Pseudomonas: MRSA If MRSA, add linezolid or vancomycin An antipneumococcal, antipseudomonal β-lactam [piperacillin/tazobactam, cefepime , imipenem , meropenem plus flouroquinolon e s ] Above β-lactams plus an aminoglycoside and azithromycin Above β-lactams plus an aminoglycoside plus an antipneumococcal fluoroquinolone

46. Management… Pain It is important to relieve pleural pain, as it may prevent the patient from breathing normally and coughing efficiently. For the majority, simple analgesia with paracetamol, co-codamol or NSAIDs is sufficient. In some patients, opiates may be required but these must be used with extreme caution in patients with poor respiratory function, as they may suppress ventilation. Physiotherapy May help expectoration in those who suppress cough because of pleural pain.

47. Prevention

48. Preventive measures Current smokers should be advised to stop smoking Influenza Vaccine & Pneumococcal Vaccine should be considered in selected pts In developing countries, tackling malnutrition & Indoor air pollution Immunization against measles, pertussis & Haemophillus influenzae type b in children Legionella pneumophila has important public health implications and usually requires notification to the appropriate health authority.

49. COMPLICATIONS

50. Complication of pneumonia Para-pneumonic effusion – common Empyema Retention of sputum causing lobar collapse Broncho-pleural Fistula Organizing Pneumonia Bronchiectasis Deep vein thrombosis and pulmonary embolism

51. Complication of pneumonia… Hypoxemia Pneumothorax, particularly with Staph. aureus Suppurative pneumonia/lung abscess ARDS, renal failure , multi- organ failure . Atelectasis Respiratory failure (which requires mechanical ventilator) Ectopic abscess formation ( Staph. aureus) Hepatitis, pericarditis, myocarditis, meningoencephalitis

52. Always take proper detailed history of a patient.