**4.3.2 Bullae**

Bullae are marked focal dilation of respiratory air spaces that may result from coalescence of adjacent areas of severe panacinar emphysema, or from a ball-valve effect in the bronchi

Current Overview of COPD with Special Reference to Emphysema 125

Some pediatric conditions display emphysematous pathologic findings resulting from a variety of developmental abnormalities in alveogenesis leading to impaired septation and alveolarization with consequent enlarged air spaces. Some are briefly described as below:

It is characterized by hyperinflation of one or more of the pulmonary lobes resulting from congenital deficiency of the bronchial cartilage, external compression by aberrant vessels, bronchial stenosis, redundant bronchial mucosal flaps or kinking of the bronchus caused by herniation into the mediastinum. The disease usually becomes apparent in the neonatal period but are delayed for as long as 5-6 mo in 5% of patients. The disease primarily involves lower lobes and occurs in familial preponderance. Treatment by immediate surgery and excision of the lobe may lifesaving, but some patients respond to medical treatment or

Rarely produced by anomalous location of the left pulmonary artery impinging on the right main stem bronchus or occassionally with absent pulmonary valve type of tetralogy of Fallot and secondary aneurysmal dilatation of the pulmonary artery. Some neonates have

A form of chronic lung disease that develops in preterm neonates treated with oxygen and positive-pressure ventilation. Injury to small airways and pulmonary vasculature can interfere with alveolarization (alveolar septation), leading to alveolar simplification and reduction in the overall surface area for gas exchange. Premature birth and subsequent events (eg, exposure to oxygen, mechanical ventilation, inflammatory agents, infection) shifts the lung development towards premature maturation with an arrest in development

Collection of gases outside of the normal air passages and inside the connective tissue of the peribronchovascular sheaths, interlobular septa, and visceral pleura may result from alveolar or bronchiolar rupture commonly in premature infants on mechanical ventilation. It is a radiographic and pathologic diagnosis frequently in conjunction with respiratory distress syndrome, meconium aspiration syndrome, amniotic fluid aspiration and infection.

Usually reported in infants and children secondary to a number of clinical conditions affecting bronchioles, including asthma, cystic fibrosis, acute bronchiolitis, interstitial pneumonitis, atypical forms of acute laryngotracheobronchitis, aspiration of zinc stearate powder, chronic passive congestion secondary to a congenital cardiac lesion, and miliary

lobar overinflation while on assisted ventilation, suggesting an acquired cause.

**4.4 Pediatric conditions with emphysema** 

**4.4.1 Congenital lobar emphysema** 

selective intubation of the unaffected lung.

**4.4.3 Broncho-pulmonary dysplasia** 

and a loss of future gas exchange area.

tuberculosis.

**4.4.4 Pulmonary interstitial emphysema** 

**4.4.5 Acute generalized overinflation of the lung** 

**4.4.2 Overinflation of all three lobes of the right lung** 

supplying an emphysematous area(Reid.1967;Thurlbeck,1976,1991 as cited in Shapiro SD,2010).
