Chapter 16 Lung Abscess 1
EDA PM C AFC RB A B Figure 16-1. Lung abscess. A, Cross-sectional view of lung abscess. B, Consolidation and (C) excessive bronchial secretions are common secondary anatomic alterations of the lungs. AFC, Air-fluid cavity; EDA, early development of abscess; PM, pyogenic membrane; RB, ruptured bronchus (and drainage of the liquefied contents of the cavity). 2
Anatomic Alterations of the Lungs Alveolar consolidation Alveolar-capillary and bronchial wall destruction Tissue necrosis Cavity formation Fibrosis and calcification of the lung parenchyma Bronchopleural fistulae and empyema Atelectasis Excessive airway secretions and empyema 3
Etiology Predisposing factors for aspiration Alcohol abuse Seizure disorders General anesthesia Head trauma Cerebrovascular accident Swallowing disorders 4
Table 16-1 Organisms Known to Cause Lung Abscess Common Organisms Aspirations Anaerobic gram positive cocci Peptococci Peptostreptococci Anaerobic gram negative bacilli Bacteroides fragilis Prevotella melaninogenica Fusobacterium sp 5
Table 16-1 Organisms Known to Cause Lung Abscess (Cont d) Less Common Organisms Klebsiella Staphylococcus Mycobacterium tuberculosis Histoplasma capsulatum Coccidioides immitis Blastomyces Aspergillus fumigatus 6
Table 16-1 Organisms Known to Cause Lung Abscess (Cont d) Some Parasites Paragonimus Echinococcus Entamoeba histolytica On rare occasions Streptococcus pneumonia Pseudomonas aeruginosa Legionella pneumophila 7
Overview of the Cardiopulmonary Clinical Manifestations Associated with Lung Abscess The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Alveolar Consolidation Excessive Bronchial Secretions 8
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Clinical Data Obtained at the Patient s Bedside 11
The Physical Examination Vital Signs Increased Respiratory rate (tachypnea) Heart rate (pulse) Blood pressure 12
The Physical Examination (Cont d) Chest pain/decreased chest expansion Cyanosis Cough, sputum production, and hemoptysis 13
The Physical Examination (Cont d) Chest Assessment Findings Increased tactile and vocal fremitus Crackles and rhonchi The following may be noted directly over the abscess: Dull percussion note Bronchial breath sounds Diminished breath sounds Whispered pectoriloquy Pleural friction rub (if abscess is near pleural surface) 14
Clinical Data Obtained from Laboratory Tests and Special Procedures 15
Pulmonary Function Test Findings Severe and Extensive Cases (Restrictive Lung Pathophysiology) Forced Expiratory Flow Rate Findings FVC FEV T FEV 1 /FVC ratio FEF 25%-75 N or N or * N or FEF 50% FEF 200-1200 PEFR MVV N or N or N or N or * May be down when airway obstruction is present 16
Pulmonary Function Test Findings Moderate to Severe (Restrictive Lung Pathophysiology) Lung Volume & Capacity Findings VT IRV ERV RV VC N or IC FRC TLC RV/TLC ratio N 17
Arterial Blood Gases Mild to Moderate Lung Abscess Acute Alveolar Hyperventilation with Hypoxemia (Acute Respiratory Alkalosis) ph PaC0 2 HCO 3 Pa0 2 (slightly) 18
PaO 2 and PaCO 2 trends during acute alveolar hyperventilation. 19
Arterial Blood Gases Severe Lung Abscess Acute Ventilatory Failure with Hypoxemia (Acute Respiratory Acidosis) ph PaC0 2 HCO 3 Pa0 2 (Slightly) 20
PaO 2 and PaCO 2 trends during acute or chronic ventilatory failure. 21
Oxygenation Indices Q S /Q T D02 V02 C(a-v)02 02ER Sv02 N N 22
Abnormal Laboratory Tests and Procedures Abnormal sputum examination (see Overview section) 23
Radiologic Findings Chest Radiograph Increased opacity Cavity formation Cavities with air-fluid levels Fibrosis and calcification Pleural effusion 24
Figure 16-2. Reactivation tuberculosis with a large cavitary lesion containing an air-fluid level in the right lower lobe. Smaller cavitary lesions are seen in other lobes. 25
General Management of Lung Abscess Antibiotics are the primary treatment for a lung abscess see Appendix III. 26
Respiratory Care Treatment Protocols Oxygen Therapy Protocol Bronchopulmonary Hygiene Therapy Protocol Lung Expansion Therapy Protocol 27