What is pneumatocele?

Condition analysis:
Pulmonary pneumatoceles are thin-walled, air-filled cysts that develop within the lung parenchyma. They can be single emphysematous lesions but are more often multiple, thin-walled, air-filled, cystlike cavities. Most often, they occur as a sequela to acute pneumonia, commonly caused by Staphylococcus aureus. However, pneumatocele formation also occurs with other agents, including Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli, group A streptococci, Serratia marcescens, Klebsiella pneumoniae, adenovirus, and tuberculosis. Pneumatoceles are generally observed soon after the development of pneumonia but can be observed on the initial chest radiograph.

Noninfectious etiologies include hydrocarbon ingestion, trauma, and positive pressure ventilation.

In premature infants with respiratory distress syndrome, pneumatoceles result mostly from ventilator-induced lung injury.

In most circumstances, pneumatoceles are asymptomatic and do not require surgical intervention. Treatment of the underlying pneumonia with antibiotics is the first-line therapy. Close observation in the early stages of the infection and periodic follow-up care until resolution of the pneumatocele is usually adequate treatment. The natural course of a Pneumatocele is slow resolution with no further clinical sequelae. Invasive approaches should only be reserved for patients who develop complications.

Instructions:
Mortality/Morbidity: Although mortality from the initial pneumonia can be significant, mortality associated with pneumatoceles is quite low. Complete resolution without long-term sequelae is typical; however, rare complications can occur, including the following:

-- Tension pneumatocele
-- Pneumothorax
-- Secondarily infected pneumatocele