PULMONARY ABSCESS

Huai Liao Pulmonary department, the 1st affiliated hospital of Sun Yat-sen university

Backgrounds

A necrotizing parenchymal lung infection generally caused by aspiration

Clincal fectures: high fever, sputum

Radiograph: cavity>2cmMobidity: male>female Incidence:↓

Etiology

Organisms: the flora of upper respiratory

tract, ～ 90% anaerobicOut of hospital: anaerobes colonized the

mouth, pneumococci, staphylococci, enteric gram negatives (in elderly)

In hospital: both anaerobes and aerobes, usually S aureus and enteric gram negative bacilli

Categories

Aspiratory lung abscessSecondary lung abscessHematogenous lung abscess

Aspiratory lung abscess

Predisposing Conditions– Unconscious state– Aspiration of a Large Bacterial Inoculums– Loss of Cough Refle– …

Common Segments

Gravitational forces and position of the patient determine the site

1) sitting position –RLL

2) supine position –RLL

3) right lateral decubitus position --RUL

Bacteriology

Common pathogens

1) gram positive anaerobes -- peptococci and peptostreptococci

2) gram negative anaerobes

Secondary abscess

Secondary to preexisting conditionsBronchial cysts, carcinoma, TB cavityFood and foreign bodyThe lesion of adjacent organ

– Subphrenic abscess– Perinephric abscess– Amebic as abscess of the liver

Secondary abscess

Hematogenous lung abscess

Extrapulmonary infections Via bloodstreamRadiographPathogen: staphylococcus aureus,

stapphylococcus epidermidis, or streptococcus

Hematogenous lung abscess

Common Segment--multiple,in fringe of lung

Common pathogens--staphylococcus aureus

Pathology

The abscess is characterized by destruction of lung tissue forming a cavity

The cavity is filled with pus (necrotic debris/liquid) or pus and gas (air)

The abscess(s) may occur in any part of the lung

Pathology (Early)

begin as local infections

Pathology (Later)

suppuration and necrosisCavity with fluid level forms

Pathology (Later)

Pyopneumothorax or empyema

Chronic lung abscessAngioma: haemoptysis

Clinical Picture

1. Acute onset2. High fever, chills, productive cough with

sputum, chest pain, anorexia, malaise, 3. Coughing up a large amount of pus4. Haemoptysis (1/3)5. Pleuritic pain, dyspnea6. Chronic abscess: persistent symptoms, Weight

loss and anemia7. Hermatogenous abscess: primary infection,

pyemia, followed by a cough, rarely haemoptysis

Clinical Picture

Physical finding Early phases: those of pneumonia, with

or without a pleural effusion Later stage: amphoric or cavernous

breath sounds, pleural effusions, empyema

Laboratory examination

Blood Rt: WBC↑ ， N%↑; anemia Sputum Gram Stain Bacterial cultures: Bronchoscopy Fine Needle Aspiration Bronchoscopy: Diagnosis Specimen Collection Drainage of Pus

Laboratory examination

Chest radiograph

--a parenchymal infiltrate with a cavity containing an air-fluid level

Bronchoscopy

Diagnostic value: Exclude carcinoma and

foreign bodyCollect specimenTherapeutic value

Diagnosis

Symptoms, sign, and Roentgenographic finding

differentiate from:

1)pneumonia

2)lung cancer

3)pulmonary tuberculosis

4)infected cyst

Differential diagnosis

Pneumonia– Chest X-ray: infiltration without cavity– Short course

Pulmonary TB– Sputum smear for TB bacilli– bronchoscopy

Differential diagnosis

Bronchial carcinoma– Obstructive pneumonia– Cavitated bronchial carcinoma

Infected lung cyst– Chest X-ray: thin walled, prior radiograph

Treatment

Antibiotic1.Antibiotic of Choice : 1) Penicillin 2) Metronidazole 3) Clindamycin 4) Others2.The expected response: decrease fever within 3~7d, elimination of fever within

7~14d, resolves the putrid odor of the sputum within 3~10d.

3.Prolonged treatment 8~12 weeks

Treatment

Methods of Drainage

1) Postural Drainage

2) Percussion on back

3) BronchoscopyRole of Surgery

– Chonic abscess– Massive haemoptysis

Prevention

Risk factorsEarly treatmentAdequate course