Lung abscess is defined as necrosis of the pulmonary tissue and formation of cavities containing necrotic debris or fluid caused bymicrobial infection. The formation of multiple small (< 2 cm) abscesses is occasionally referred to as necrotizing pneumonia or lung gangrene. Both lung abscess and necrotizing pneumonia are manifestations of a similar pathologic process.
Classification of lung abscess
Lung abscesses can be classified based on the duration and the likely etiology.
•Acute abscesses are less than 4-6 weeks old, whereas chronic abscesses are of longer duration.
•Primary abscess is infectious in origin, caused by aspiration or pneumonia in the healthy host.
•Secondary abscess is caused by a preexisting condition (eg, obstruction), spread from an extrapulmonary site, bronchiectasis, and/or an immunocompromised state.
Lung abscesses can be further characterized by the responsible pathogen, such as
•Staphylococcus lung abscess and
•Anaerobic or Aspergillus lung abscess.
Lung abscess likely occur in elderly patients because of increased incidence of periodontal disease and the increased prevalence of dysphagia and aspiration.
Individuals of any race can be affected by lung abscess.
The bacterial infection may reach the lungs in several ways. The most common is aspiration of oropharyngeal contents.
•Patients at the highest risk for developing lung abscess have the following risk factors:
•Other patients at high risk for developing lung abscess include individuals with an inability to protect their airways from massive aspiration because of a diminished gag or cough reflex, caused by a state of impaired consciousness (eg, from alcohol or other CNS depressants, general anesthesia, or encephalopathy).
•Infrequently, the following infectious etiologies of pneumonia may progress to parenchymal necrosis and lung abscess formation:
S aureus (may result in multiple abscesses)
•An abscess may develop as an infectious complication of a preexisting bulla or lung cyst.
•An abscess may develop secondary to carcinoma of the bronchus; the bronchial obstruction causes postobstructive pneumonia, which may lead to abscess formation.
•Fever, cough with sputum production, night sweats, anorexia and weight loss.
•Patient develops symptoms like hemoptysis or pleurisy.
•The sputum which is expectorated is of foul smell and bad tasting.
•Symptoms of pneumonia are seen.
•Patient will present with indolent symptoms that evolve over a period of weeks to months.
Laboratory tests to be done are as follows:-
•A complete white blood cell count with differential may reveal leukocytosis and a left shift.
•Obtain sputum for Gram stain, culture, and sensitivity.
•If tuberculosis is suspected, acid-fast bacilli stain and mycobacterial culture is requested.
•Blood culture may be helpful in establishing the etiology.
•Obtain sputum for ova and parasite whenever a parasitic cause for lung abscess is suspected.
Other tests to be helpful are as follows:-
•CT scan of chest.
•Ultrasonography of chest.
•Endoscopic lung abscess drainage.
•Lobectomy or pneumonectomy.
Complications of lung abscess are as follows
•Pleural cutaneous fistula.
•Ruptured into pleural space causing empyema.
The prognosis for lung abscess following antibiotic treatment is generally favorable.
Over 90% of lung abscesses are cured with medical management alone, unless caused by bronchial obstruction secondary to carcinoma.
•Patient cannot breathe with head low.
•Suffocative catarrh with rattling in chest.
•Violent, hacking cough after every meal.
•Puffy rattling breathing suffocative catarrh.
•Patient suffers from suppurative tuberculosis.
•Dyspnea with sharp pain in left lung.
•Patient suffers from shortness of breath ongoing upstairs.
•Short breathe from uterine displacements.
•Cough shattering from a dry spot in larynx with stitching pain in lumbar region worse cold, winter.
•Expectoration, muco-purulent, yellow, bitter, offensive, smeary accompanied with sweat.
•Painless hoarseness worse in the morning.
•Shortness of breathe.
•Tickling cough as from dust or feather in throat.
•Cough worse inspiration, playing on piano, eating.
•Suffocative spells, tightness, burning and soreness in chest.
•Expectoration only during day, thick, yellow, sour mucus.
•Bronchitis of old exhausted people.
•Loose cough, bloody or thick, yellow tenacious sputum, raises much mucus.
•Breathing difficult worse lying on left side.
•Loose voice and coughs when exposed to dry, cold winds.
•Cough troublesome when walking.
•Dry, hoarse cough.
•Cough excited whenever any part of the body gets cold or uncovered or from eating anything cold.
•Dry, hard cough about 3 am with stiching pains and dryness of pharynx.
•Pleurisy, asthmatic, wheezing, worse least motion or walking, alternating with diarrhea with vertigo.
•Leaning forward relieves chest symptoms.
•Expectoration must be swallowed, cheesy taste, copious offensive, and lump.