Internal Medicine Respiratory System Lec.5 (Pneumonia) PDF

PNUMONIA. DR. TAMER ABDULLAH MOQBEL Pneumonia. It is an acute respiratory illness associated with recently developed radiological pulmonary shadowing that may segmental, lobar or multilobar. Classified into: 1. Community acquired pneumonia. 2. Hospital acquired pneumonia. 3. Suppurative and...

PNUMONIA. DR. TAMER ABDULLAH MOQBEL Pneumonia. It is an acute respiratory illness associated with recently developed radiological pulmonary shadowing that may segmental, lobar or multilobar. Classified into: 1. Community acquired pneumonia. 2. Hospital acquired pneumonia. 3. Suppurative and aspirational pneumonia, and lung abscess. 4. Pneumonia in immunocompromised. Pneumonia. Radiologically and pathologically classified as: 1. Lobar pneumonia: is a radiological and pathological term referring to homogenous consolidation of one or more of lung lobes often with associated pleural inflammation. 2. Bronchopneumonia: is more patchy alveolar consolidation associated with bronchial and bronchiolar inflammation often affecting both lower lobes. Community acquired pneumonia. “CAP” It is a pneumonia which acquired out of the hospital. May affects all age groups but is commonest at the extremities of age. Most cases are spread by droplet infection. Affects previously healthy individuals. However ,many factors may impair the effectiveness of local defense and predispose to CAP. Streptococcus pneumoniae is the most common infecting agent. Organisms causing community-acquired pneumonia Bacteria: Viruses:  Streptococcus pneumoniae.  Influenza, parainfluenza.  Mycoplasma pneumoniae.  Measles.  Legionella pneumophila.  Herpes simplex.  Chlamydia pneumoniae.  Varicella.  Hemophilus influenzae.  Adenovirus.  Staphylococcus aureus.  Cytomegalovirus.  Chlamydia psittaci.  Coronaviruses (SARS-CoV-2 and  Coxiella burnetii (Q fever). MERS-CoV)  Klebsiella pneumoniae. Clinical features: Pulmonary symptoms and signs: Systemic symptoms and signs:  cough with or without sputum.  Fever.  Rusty sputum in Streptococcus  Rigors. pneumoniae.  Shivering.  Pleuritic pain.  Malaise.  Hemoptysis in occasion.  Myalgia.  Dyspnea.  Anorexia.  Upper abdominal pain or tenderness.  Headache.  Delirium especially in old age.  Clinical Chest findings:  During consolidation:  Dullness on percussion.  Bronchial breathing and whispering pectoriloquy.  Crackles.  Increase tactile or vocal fremitus. Different organisms often give similar clinical and radiological findings but may be a clue to the likely organism from the clinical context Mycoplasma pneumoniae is more common in Youngs and rare in old age. Haemophilus influenzae common in older people particularly with underlying lung disease.  Legionella pneumophila occurs in local outbreak centered in contaminated cooling tower in hospitals, hotels and industries.  Staphylococcus aureus is common following an episode of influenza.  Klebsiella pneumonia occurs in alcoholics and presents with severe bacteremic illness and cavitation. Clinical features: Differential diagnosis of pneumonia: Pulmonary infarction. Pulmonary/pleural TB. Pulmonary edema. Pulmonary eosinophilia. Malignancy bronchoalveolar cell carcinoma.  Cryptogenic organizing pneumonia/Bronchiolitis obliterans organizing pneumonia (COP/BOOP). Investigations: The object of investigations is:  To confirm the diagnosis.  To assess the severity.  To identify the development of complications. Lobar pneumonia of right upper lobe CURB 65 SCORE : to assess severity C CONFUSION. U UREA >7mmol/L or >19mg/dl. R RESPIRATORY RATE 30 BEAT/MIN OR MORE. B BLOOD PRESSURE SYSTOLIC38.3°C And,  A leukocytosis or leucopenia.  The clinical features and radiographic signs are variable and non specific raising a broad differential diagnosis.  Microbiological confirmation should be sought whenever possible. investigations: Sputum. Chest imaging. Blood culture. In case of bacteremia. Full blood count. Blood chemistry. ABG. As needed. Management:  Oxygen therapy.  Fluid balance.  Antibiotics:  The choice of empirical antibiotics is challenging.  The choice of initial antibiotics depends on the local pattern of microbiology and resistance.  Once the organism identified, antibiotic therapy should be refined. Prevention of “HAP”  Despite appropriate management, the mortality from HAP is high about 30% mandating prevention when possible by: Washing hand and any equipment used. Minimise chance of aspiration and limit the use of PPI. Oral antiseptic (chlorhexidine 2%) to decontaminate the upper airway. Suppurative pneumonia, aspiration pneumonia and pulmonary abscess.  Suppurative pneumonia is characterized by destruction of the lung parenchyma by the inflammatory process.  Pulmonary abscess formation: is a lesion in which large localized collection of pus or a cavity lined by chronic inflammatory tissue. Predisposing and risk factors:  Inhalation of septic material during operations of mouth, nose and throat under general anesthesia.  Vomiting during anesthesia or coma.  Bulbar or vocal cord palsy, achalasia and esophageal reflux.  Alcoholism. Continue;  Aspiration tends to localize to dependent areas of the lung, such as the apical segment of the lower lobe in a supine patient.  Infections are usually due to mixture of aerobes and anaerobes along with typical flora of the mouth and upper respiratory tract.  Good response to treatment.  Residual fibrosis and bronchiectasis are common but no serious complications. Clinical context Infective organism Suppurative pneu. And lung abscess in Staph. aureus or Klebsiella pneumoniae. previously healthy lung. Suppurative infection with poor dental Actinomyces spp. hygiene. Infection of pulmonary infarct or collapsed Strep. pneumoniae, Staph. aureus, lobe. Streptococcus pyogenes, H. influenzae, sometimes anaerobes. Severe necrotizing suppurative pneumonia Staph. aureus often community-acquired with suppurative skin infection MRSA (CA-MRSA) Lemierre syndrome Fusobacterium necrophorum. Lung abscess often with endocarditis in staphylococci and streptococci. fungi such as injecting drug users Candida spp. Investigations: Radiological findings Homogeneous lobar or segmental consolidation. Abscesses: cavitation with air fluid level. Infected emphysema. Management:  Aspiration pneumonia can usually be treated with amoxicillin in and metronidazole.  CA-MRSA is usually susceptible to a variety of oral non-β-lactam antibiotics, such as trimethoprim–sulfamethoxazole, clindamycin, tetracyclines and linezolid.  IV vancomycin or IV linezolid can be used too. Fusobacterium necrophorum: Is highly susceptible to β-lactam antibiotics and to metronidazole, clindamycin and third-generation cephalosporins. Management pulmonary actinomycosis treated by intravenous or oral penicillin for 6- 12months. Tetracycline is an alternative for allergic patients penicillin.  Physiotherapy is of great value. Surgery if no response to optimal medical therapy. Removal of any obstructive endobronchial lesion. Pneumonia in the immunocompromised patient.  Seen in patient immunocompromised by drugs or disease like HIV.  Pneumonia is the leading cause of death in HIV group.  The majority caused by same bacteria affecting immunocompetent.  Patient profoundly immunocompromised ,affected by ‘opportunistic’ organisms. continue; Possible causative organisms:  Gram-negative bacteria especially pseudomonas aeruginosa.  Viruses.  Fungi.  Mycobacterium.  Nocardia ssp. Clinical features:  Typically include fever, cough and breathlessness but are influenced by the degree of immunosuppression.  The onset of symptoms tend to be swift in bacterial infection but more gradual with opportunistic organisms such as Pneumocystis jiroveci and mycobacterial infections.  In P. jiroveci pneumonia, symptoms of cough and breathlessness can be present several days or weeks before the onset of systemic symptoms or the appearance of radiographic abnormality.  Investigations:  Depend on the clinical context and severity of illness as many patients too ill to undergo invasive procedures safely.  Induced sputum: relatively safe to obtain microbiological sample.  HRCT scan. Management:  In theory, treatment should be based on an established etiological diagnosis.  In practice, however, the causative agent is frequently unknown.  For suspected bacterial infection: commence broad spectrum antibiotics. e.g. 3rd generation cephalosporin or quinolone , plus anti-staphylococcal antibiotic, or: Antipseudomonal penicillin plus aminoglycoside. Thereafter : According to investigations and clinical response ADD antifungal , antiviral according to the clinical context. Pneumonia. Thanks. Good luck.