ICD-11

Compensatory emphysema is a condition in which one portion of the lung increases in size and function, when another portion is destroyed or temporarily useless. It occurs, for instance, in association with pneumonias, pleural effusions and pneumothorax. Anatomically, there is found an enlargement of the normal lung; there are no variations from the normal structure; the unaffected lung, as a result of distention, has an increased vital capacity and is able to perform a greater amount of work than when in its usual condition. The tissues show no similarity to those truly emphysematous. This change is in no way related to true emphysema and the term should not be used, as it creates great confusion in the literature. Its use is no more justified than that of speaking of the compensatory enlargement of a kidney, when the opposite kidney has been removed, as of a compensatory nephritis. True emphysema can never compensate for diseased lung tissue, because the emphysematous lung is totally or almost totally functionless.