lung abscess

Question 1

definition

Answer 1

local suppurative necrosis in lung associated with cavity formation containing necrotic debris/fluid.

Question 2

etiology

Answer 2

1. Bacteria - Pseudomonas aeruginosa, Klebsiella PN, Staphylococcus aureus, Streptococcal PN, Nocardia spp, Haemophilus influenza.
2. Nonbacterial pathogens e.g. parasites (Paragonimus, Entamoeba), fungi (e.g. Aspergillus, Cryptococcus, Histoplasma, Blastomyces) & Mycobacterium
3. Decrease immunized patients,alcoholic.
4. As an outcome of pneumonia and complicated bronchiectasis, septic embolism
5. wounds to the chest, aspiration of foreign bodies and after operation on the upper airwys.
6. lung infarction or presence tumour.
7. Way of spreading - lymphogenic, hematogenic and contact

Question 3

classification

Answer 3

1. Acc to localization – L/R lung/both sides
2. Acc to etiology :
   - 1‘ abscess – infectious origin, caused by aspiration of pneumonia in healthy host
   - 2‘ caused by preexisting conditn (e.g. obstructn), spread fr extrapulm site, bronchiectasis immunocompromised state.
3. Acc to duration :
   - Acute: < 6 mths, abscess has thin wall
   - Chronic: > 6 months, has capsule with pyogenic membrane and fluid
4. Periods:
   - formation of abscess; it continues 10-12 days
   - opening of the purulent abscess into the bronchus

Criteria for 1‘ & 2‘:
- devmt of destruction of lung tissue – intoxication syndrome
- no (+ve) dynamics in clinical pic
- no effects from treatment

Question 4

pathogenesis

Answer 4

• immune insufficiency patient
• aspirated material settles in distal bronchial system and develops localized pneumonitis
• Within 24-48 hours, a large area of inflammation results, consisting of exudate, blood, and necrotic lung tissue. The abscess frequently connects with a bronchus and partially empties
• After pyogenic pneumonitis develops, liquefactive necrosis occur secondary to bacterial proliferation and inflammatory reaction to produce acute abscess
• As the liquefied necrotic material empties through the draining bronchus, a necrotic cavity contain air-fluid level is created
• infection may extend into pleural space and produce an empyema without rupture of the abscess cavity
• infectious process can extend to the hilar and mediastinal lymph nodes, and may become purulent.

Question 5

clinical picture

Answer 5

1. Formation of abscess (10-12 days)
   - Intoxication syndrome, Pain syndrome
   - Cough with little or no sputum
   - Infiltration of lung tissue, Dyspnea, General indisposition

Objective examination
- Vocal fremitus increase at the place of infection
- Infiltration syndrome – bronchial breathing
- diminished vesicular or bronchial breathing, harsh with dry rales (superficial)
- In deep abscess or small size, results of objective examination not changed

2. Opening of purulent abscess into bronchus
   - ↓ Intoxication syndrome (↓ T‘C & chills, ↓ weakness, arthralgia, myalgia↓)
   - Ptt‘s condition improve. slight dyspnea, Pain in the chest
   - Infiltration of lung tissue syndrome
   - full mouthed sputum (~ 500ml) – depends on size of abscess
   - Severe cough with offensive purulent sputum (―full mouth‖): on standing separates into 3 layers: mucous, serous and purulent (from 200 ml to 1-2 L/day)

Objective examination
- dull tympanic sound
- Auscultation: if drainage of abscess (road) & cavity > 3 cm (large abscess) – amphoric breathing
- Additional sounds: small bubbling rales – inflammatory changes/pneumonia
- Unilateral thoracic lagging(affected side)
- VF – increased
- Percussion: tympanic / metallic sound; crackled - pot sound
- Auscultn: bronchial (amphoric / cavernous) breathing; resonant moist rales; gutta cadens (falling – drop sound)

Question 6

main syndrome

Answer 6

1. Infiltration Syndrome
   - asymmetrical movement of chest in respiration
   - dull sound on percussion
2. Intoxication Syndrome
   - fever
   - low appetite
   - weakness
   - myalgia
   - arthralgia
   - loss weight
3. Evacuation Syndrome
   - decrease in temperature
   - absent arthralgia/myalgia
   - normal appetite
   - improvement of condition of patient

Question 7

investigation

Answer 7

1. Blood cultures – neurophilic leucocytosis, shift to the left, increased ESR,
2. Biochemical
   - increase protein inflammation (C-reactive protein, seromucous)
   - decrease albumin
3. Sputum exam :
   - 1st stage – not specific
   - 2nd stage – presence of 3 layers (mucous, serous, purulent), Elastic fibers, Leucocytes and erythrocytes. Dittrich‘s plugs
4. Chest Xray
   - 1st stage – signs of infiltration, > intensive in central part & < intensive in periphery
   - 2nd stage – cavity with air-fluid level
5. Bronchoscopy : differential Dx with tumor, TB. may evacuate fluid if abscess is near large bronchi. bronchitis detection
6. CT scan –abscess walls well defined margin, localization, size, form
7. Specimen obtained by transtracheal aspiration, bronchoscopy or percutaneous transthoracic aspiration with ultrasound guidance

Question 8

treatment

Answer 8

1. 1st stage : intensive antibiotic therapy – combi of 3 AB
   - Penicillins/Cephalosporins for G(+)
   - Metronidazole
   - Aminoglycosides, fluoroquinolones.
   Symptomatic treatment - expectorants and broncholytics. Detoxification therapy by infusion therapy- glucose, Ringer‘s solution, Vits B1, 6, C,
2. 2nd stage
   - mucolytics, expectorants
   - increase drainage – intensive Atbs & detoxification.

Not based on stage:
- Immunocorrection therapy
- Bed rest
- Antibiotics and sulpha drugs – penicillin, streptomycin given with tetracycline.
- Adequate draining, emptying of the cavity.
- Surgical treatment given in a month

Question 9

Indications for surgical treatment

Answer 9

Indications for surgical treatment
- Destruction of wall of abscess with massive hemorrhage
- Septicemia
- Multiple abscesses
- Absent effect from antibiotic therapy
- wide spread development of process
- Conditions lead to amyloidosis of other internal oragans e.g. kidneys