Why mucous plugs commonly cause left lung collapse?

Abstract

Sixty cases, with atelectasis/pneumonic consolidation associated with/without emphysema, aged three months to four years, were subjected to bronchoscopy. There was a preponderance of left lung pathology (40) over the right one (20). Of the 40 cases with left lung pathology, the lower lobe was involved in 88%, and the upper in 12%. Of the cases with right lung pathology upper lobe was involved in 40%, the middle lobe in 40% and the lower in 20%. There was no relationship of the laterality of the pathology attributable to the usual posture of the child during suckling. About 50% of the cases were benefited by bronchoscopic procedures. The preponderance of left lung pathology over the right in the pediatric age group is explained by the fact that an endogenous foreign body e.g. mucous plug, is more difficult to be expectorated out from the left lung than the right one because of anatomical differences. This results in retention of the blocking agent, leading to atelectasis/consolidation.