Just fat or also fat headed.

摘要

The more senior of us remember the pickwickian syndrome of hypercapnia and sleepiness that was based on the Charles Dickens character, 'Joe', the rotund boy who was always dozing. Now the term is used only in editorials and the pickwickian syndrome is now the obesity hy-poventilation syndrome. The name change however has not explained why only a fraction of those with obesity and not necessarily the fattest develop hypercapnia. Increased weight does affect lung function, particularly reducing functional residual capacity and expiratory reserve volume . Increases in body mass do reduce lung volumes, as recently demonstrated by Jones and Nzekwu , but they frequently remain within the normal range. The ratio of forced expiratory volume in 1 s (FEV_1/forced vital capacity (FVC) can also be within the normal range but sometimes the fat patient with obstructive lung disease is considered to have the obesity hypoventilation syndrome [2, 3]. Sufficiently great obesity can increase the closing volume, blocking small airways leading to V/ Q abnormalities and hypoxia . Also decreased chest wall compliance has been observed increasing somewhat the work of breathing . However, these changes do not by themselves explain the hypercapnia since considerably greater abnormalities may occur in the thin patient with chronic obstructive pulmonary disease (COPD) without producing CO_2 retention. Also, obesity does not seem to be a risk factor for airway hyperresponsiveness .