6Definition & overviewCavitating, infected, necrotic lesion of lung parenchymaSeveral possible causesSingle or MultipleSmall <2cm or largeMost secondary to aspiration of oropharyngeal secretionsMixed growth of organisms, including anaerobes
8Differential Diagnosis Cavitating tumourInfected bronchial cyst/bullaLocalised saccular bronchiectasisAspergillomaWegeners granulomatosisHydatid cystGas-fluid level in oesophagus, stomach or bowel
9MicrobiologyAnaerobes: Peptostreptococcus, Prevotella, Bacteroides spp (usually not B. fragilis), and Fusobacterium spp.Staph Aureus, Klebsiella, Strep MilleriStrep Pneumonia, gram negative bacilliM.TuberculosisFungi
10Clinical Features Most patients present over several weeks Malaise, weight loss, feverCough with copious purulent sputumCan be associated with haemoptysisToxic features prominent in patients with pneumonia or blood borne infectionClubbing often seen
12Treatment AUGMENTIN AMOXIXCILLIN & METRONIDAZOLE CLINDAMYCIN Physiotherapy & postural drainageTrans Thoracic/ endoscopic drainage for large abscessDuration of ABx:3- 4 weeks
13Empyema Pus in pleural space Sequelae of a complicated parapneumonic infection, when bacteria invade pleural spaceUncomplicatedComplicatedFrank Empyema
14Pathogenesis Uncomplicated parapneumonic effusion — occurs when the lung interstitial fluid increases during pneumonia, and is characterized by "exudative" pleural fluid chemistries and an influx of neutrophils into the pleural space.resolve with resolution of the pneumonia.
15Complicated Parapneumonic effusion occurs when there is persistent bacterial invasion of the pleural space.Results in pleural fluid acidosis (anaerobic utilization). Lysis of neutrophils increases the LDH concentration in the pleural fluid to values often in excess of 1000 IU/L.Complicated parapneumonic effusions are often sterile because bacteria can be cleared rapidly from the pleural space. (Loculation )
16Thoracic EmpyemaFormation of empyema is the third stage and is characterized by bacterial organisms seen on gram stain or the aspiration of pus on thoracentesis.A positive culture is not required for diagnosis.
17Bacteriology Mixed bacterial flora Anaerobic bacteria in 36-76% Streptococcus milleri, Staphylococcus aureus, and Enterobacteriaceae.Patients with diabetes mellitus are at increased risk of empyema secondary to Klebsiella pneumoniae.S. pneumoniae and S. aureus (including methicillin-resistant organisms) are the leading causative bacteria in children with empyema.
29Physical Findings Crackles (75 percent) Wheezing (22 percent) were common,Digital clubbing occurred in only 2 percent of patients.
30Pathophysiology Induction of bronchiectasis requires two factors An infectious insultImpaired drainage, airway obstruction, or a defect in host defenseRecurrent infection leads to further scarring, obstruction, and distortion of the airways, as well as temporary or permanent damage to the lung parenchyma.
31Diagnostic workupThe following LAB studies should be part of the initial evaluation of a patient with bronchiectasis:A complete blood count with differentialImmunoglobulin quantitation to measure the levels of the immunoglobulins IgG, IgM, and IgASputum culture and smear for bacteria, mycobacteria, and fungi
32ImagingCXR radiographic findings include linear atelectasis, dilated and thickened airways (ie, tram or parallel lines, ring shadows on cross section) and irregular peripheral opacities that may represent mucopurulent plugs.
33High Resolution CT Thorax Airway dilatationBronchial wall thickeningLack of taperingmucopurulent plugs or debris accompanied by post-obstructive air trapping (tree-in-bud)
34Distribution A central (perihilar) distribution is suggestive of ABPA. predominant upper lobe distribution is characteristic of cystic fibrosismiddle and lower lobe distribution is consistent with PCDlower lobe involvement is typical of idiopathic bronchiectasi
35Spirometry Obstructive picture common Frequently isolated pathogens on CULTURE include Hemophilus influenzae, Pseudomonas aeruginosa (especially mucoid types), and, less frequently, Streptococcus pneumoniae
36Treatment Postural drainage Based on sputum culture & sensitivity Non-Pseudomonas organism:Amoxicillin: 1gm TID 14 daysAugmentin 625 mg TID 14 daysDoxycyline 100mg BD 14 daysCiprofloxacin 750 mg BD 14 days (Pseudomonas)Ceftazidime 2gm TID 7-14 days (Pseudomonas)Nebulised Tobramycin (Pseudomonas)