Resolution of experimental pneumothorax by room air.

UNLABELLED Observation alone is advised only for primary spontaneous pneumothoraces with less than 20 percent of the lungs collapsed. In such cases, it is the resorption capabilities of the visceral pleura that are solely relied upon. The AIM of the present experimental study was to demonstrate the capabilities of the pleura for pneumothorax resolution by room air. MATERIAL AND METHODS The study was conducted with six laboratory animals (New Zealand white rabbits, weighing 2.5-3.5 kg), in which right total pneumothorax was induced. Conventional chest X-rays at intervals of 2 days were used to monitor the changes in the size of the pneumothorax until its final resolution. The size of the pneumothorax was estimated by the Light index. RESULTS Total resolution of the pneumothorax occurred within 12 days after it was induced. The average rate of pneumothorax resolution was 6.63% (SEM +/- 0.20)/daily. CONCLUSION The study imitates initial clinical observation in pneumothorax. Despite the fact that the study demonstrates resolution of total pneumothorax (100%), observation only is inappropriate as a treatment modality in patients with more than 20% collapse of the lung.