Lung Infections Of Surgical Importance Flashcards
What is bronchiectasis?
Bronchiectasis is the abnormal permanent dilation of one or more bronchi or bronchioles due to the destruction of the muscular and elastic components of the wall.
What has contributed to the increased incidence of post-infectious bronchiectasis?
The emergence of drug-resistant microorganisms and multi-drug-resistant tuberculosis (MDR-TB).
What are the congenital causes of bronchiectasis?
Congenital cystic bronchiectasis, IgA deficiency, primary hypogammaglobulinemia, cystic fibrosis, alpha-1 antitrypsin deficiency, Kartagenerโs syndrome, congenital deficiency of bronchial cartilage, and bronchopulmonary sequestration.
What are the acquired causes of bronchiectasis?
Infections, bronchial obstruction (intrinsic: tumors, foreign bodies; extrinsic: enlarged lymph nodes), middle lobe syndrome, and acquired hypogammaglobulinemia.
What is the central factor in the pathophysiology of bronchiectasis?
An infectious process combined with impaired bronchial drainage, airway obstruction, and impaired host defense.
Which lobes are most commonly affected in bronchiectasis?
The left lower lobe, followed by the lingula and right middle lobe.
What are the morphological types of bronchiectasis?
Cylindrical (tubular), varicose, and saccular (cystic) bronchiectasis.
What bacteria are commonly associated with bronchiectasis?
Mycobacterium tuberculosis, Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, anaerobes, and Haemophilus influenzae.
What fungal infection is associated with bronchiectasis?
Allergic bronchopulmonary aspergillosis (ABPA).
What are the clinical features of bronchiectasis?
Chronic expectoration of large quantities of foul-smelling sputum, dyspnea, pleuritic chest pain, hemoptysis, wheezing, fever, and weight loss.
What are general and chest examination findings in bronchiectasis?
General findings: digital clubbing, cyanosis, wasting. Chest examination: crackles, rhonchi (unilateral or bilateral), and advanced disease may present with cor pulmonale.
What are the key investigations for bronchiectasis?
Full blood count, sputum analysis (Gram stain, culture, sensitivity, AFB), pulmonary function test, chest X-ray, bronchogram, and CT scan (gold standard).
What are the complications of bronchiectasis?
Acute exacerbations, recurrent pneumonia, empyema, lung abscess, brain abscess, massive hemoptysis, respiratory failure, and cor pulmonale.
What are the medical treatment options for bronchiectasis?
Antibiotic therapy, anti-inflammatory therapy, airway clearance (bronchodilators, mucolytics, postural drainage, and chest physiotherapy).
When is surgical treatment indicated for bronchiectasis?
For localized disease (segmental or lobar), severe symptoms, foreign body, massive hemoptysis, or recurrent infections.
What is a lung abscess?
A circumscribed cavity within the lung parenchyma filled with purulent material and air.
What are the primary causes of lung abscesses?
Aspiration due to impaired consciousness, severe periodontal disease, dysphagia syndromes, GERD, necrotizing pneumonia, and immunocompromised states.
What are the secondary causes of lung abscesses?
Bronchial obstruction (tumor, foreign body, lymphadenopathy), cavitating lesions (neoplasm, pulmonary infarct, emphysema), direct extension (amebiasis, subphrenic abscess), and hematogenous spread.
What are the three pathological phases of lung abscess formation?
Pre-eruptive phase (consolidation), liquefactive necrosis phase, and eruptive phase (bronchial erosion with air-fluid level formation).
What lobes are most commonly affected by lung abscesses?
Right lower lobe (33%), right upper lobe (25%), left lower lobe (20%), left upper lobe (12%), and right middle lobe (10%).
What are the common bacterial causes of lung abscesses in ambulatory patients?
Hemolytic Streptococcus, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus viridans.
What are the common bacterial causes of lung abscesses in nosocomial settings?
Proteus species, E. coli, Pseudomonas aeruginosa, Enterobacter, and Eikenella.
What are the clinical features of a lung abscess?
Cough, fever, malaise, pleuritic chest pain, hemoptysis, weight loss, copious foul-smelling sputum, and features of sepsis.
What is the medical treatment for lung abscesses?
Targeted antibiotic therapy for 6-8 weeks, postural drainage, chest physiotherapy, and percutaneous drainage if needed.
When is surgical intervention required for lung abscesses?
For bronchopleural fistula, empyema, significant hemoptysis, persistent disease (>6 cm after 8 weeks of treatment), foreign body, or underlying malignancy.
What is empyema thoracis?
Accumulation of pus in the pleural cavity.
What are the main causes of empyema thoracis?
Pneumonia (most common), ruptured lung abscess, esophageal rupture, chest trauma, mediastinitis, bronchogenic carcinoma, postoperative infection, and hematogenous spread.
What is the most common bacterial cause of empyema in infants and children?
Staphylococcus aureus (90% of cases).
What are the three pathological stages of empyema thoracis?
- Exudative stage (1-3 days): thin fluid, pH >7.2, glucose >60 mg/dL, negative culture. 2. Fibrinopurulent stage (4-14 days): thick opaque fluid, positive culture, fibrin deposits, loculations, and declining pH/glucose. 3. Organizing stage (>14 days): fibroblast ingrowth, thick pus, and lung entrapment.
What are the treatment options for empyema thoracis?
Intercostal tube thoracostomy, intrapleural streptokinase, video-assisted thoracoscopy (VATS), decortication via thoracotomy, and Eloesser flap drainage.
What is pneumonia?
Infection of the lower respiratory tract, involving the respiratory bronchioles to the alveoli.
What are the types of pneumonia based on etiology?
Typical and atypical pneumonias.
What are the types of pneumonia based on clinical presentation?
Community-acquired pneumonia (CAP), nosocomial pneumonia, and aspiration pneumonia.
What are the common pathogens of community-acquired pneumonia?
Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, and respiratory viruses.
What is nosocomial pneumonia?
Pulmonary infection occurring within 48-72 hours of hospital admission, often in intubated patients.
What is ventilator-associated pneumonia (VAP)?
Nosocomial pneumonia developing in patients on mechanical ventilation for at least 48 hours.
What are the treatment options for pneumonia?
Early onset: 2nd/3rd generation cephalosporins, fluoroquinolones, aminopenicillins with beta-lactam inhibitors, ertapenem. Late onset: cephalosporins, carbapenems, beta-lactam inhibitors plus aminoglycosides, antipseudomonal agents plus MRSA coverage.
What are the lung infections of surgical importance?
Bronchiectasis, lung abscess, empyema thoracis, and pneumonia.
What is the pathophysiology of bronchiectasis?
Destruction of bronchial cilia, mucosa, and musculoelastic tissue leads to loss of elasticity, bronchial dilation, secretion retention, recurrent infections, fibrosis, and progressive lung volume loss.
What are the three main morphological types of bronchiectasis?
Cylindrical (tubular), varicose, and saccular (cystic).
What is the gold standard imaging for bronchiectasis?
High-resolution CT (HRCT) scan.
What is the most common site of involvement in bronchiectasis?
The left lower lobe, followed by the lingula and right middle lobe.
What is a key differentiating factor between lung abscess and hydropneumothorax on imaging?
In lung abscess, the air-fluid level is equal in both PA and lateral views, whereas in hydropneumothorax, it is not.
What is the difference between primary and secondary lung abscess?
Primary lung abscess occurs due to aspiration or infection, while secondary lung abscess occurs due to bronchial obstruction, cavitating lesions, direct extension, or hematogenous spread.
What is the most common risk factor for aspiration pneumonia?
Impaired consciousness, leading to inhalation of gastric or esophageal contents.
What is the most common cause of empyema thoracis?
Bacterial pneumonia leading to parapneumonic effusion.
What are the clinical stages of empyema thoracis?
Acute stage (within 2 weeks) and chronic stage (after 2 weeks or with thick peel and loculations).
What is the first-line drainage method for early-stage empyema thoracis?
Intercostal tube thoracostomy (chest tube drainage).
What is the most common bacterial cause of community-acquired pneumonia?
Streptococcus pneumoniae.
What are the risk factors for nosocomial pneumonia?
Mechanical ventilation, prolonged hospital stay, immunosuppression, prior antibiotic use, and aspiration risk.
What is the primary difference between early-onset and late-onset nosocomial pneumonia treatment?
Early-onset is treated with broad-spectrum cephalosporins, fluoroquinolones, or aminopenicillins, while late-onset requires carbapenems, anti-pseudomonal agents, and MRSA coverage.
What are the common complications of pneumonia?
Pleural effusion, empyema, lung abscess, sepsis, and respiratory failure.
What is chronic destructive pneumonia?
A chronic suppurative lung infection leading to fibrosis and loss of lung volume.
What are the risk factors for chronic destructive pneumonia?
Recurrent lung infections, bronchiectasis, and tuberculosis.
What are the surgical options for bronchiectasis?
Lobectomy, segmentectomy, or lung transplantation in severe cases.
What is the function of an Eloesser flap in empyema management?
It creates a one-way drainage system for chronic empyema, particularly in debilitated patients.
What are the radiological features of empyema on CT scan?
Loculated fluid collections, pleural thickening, and increased Hounsfield units distinguishing exudate from transudate.
