Quantification of the size of primary spontaneous pneumothorax: Accuracy of the light index

Background. The size of a pneumothorax (PTX) is usually estimated by the Li ght index. Treatment strategies of (primary, spontaneous) PTX partially dep end upon the size of the PTX To our knowledge, the Light index has not yet been correlated with the actual volume of the PTX Objectives: To correlate the estimated size of a primary spontaneous PTX by means of the Light index , with the actual amount of air present in the pleural space. Methods:Actua l PTX volumes were measured by means of manual aspiration of air present in the pleural space in 18 patients with primary spontaneous PTX and correlat ed with the size estimation obtained by the Light index. Results: Light ind ex and volume measurements were strongly correlated (r = 0.84, p < 0.0001). Conclusions: The Light index is a good estimate of the actual size of a (p rimary spontaneous) PTX Copyright (C) 2001 S. Karger AG, Basel.