Causeno. of Patients (%)malignant Condition Kaposi's Sarcoma Other Infection Aerobic Bacteria35 Causes Ofpleural Effusion In75 Hiv-infected Patients Management Ofmassive Subcutaneous Emphysema

condition Kaposi's sarcoma Other Infection Aerobic bacteria35 32 3 26 11(57) (52) (5) (43 18Myco t rium tuberculosis915Opportunistic agent610 with tissue infiltration of fluid from the proximal port was more probable than catheter-tip erosion through central venous structures in our patient series. All catheters were sutured to the skin to prevent migration, and seven ofthe eight patients had radiographic evidence of sufficient catheter insertion to avoid positioning of the proximal port within chest-wall tissues. In the remaining patient, the right subclavian catheter tip was positioned just below the clavicular head. This position may have contributed to pleural effusion formation by the infiltration of fluid infused through a proximal port. Radiographic contrast material infused through the distal port of this catheter, however, demonstrated extravasation into the mediastinum and erosion of the catheter tip through the medial wall of the right brachiocephalic vein. In all four patients who underwent contrast infusion, the contrast was instilled through the distal port of the catheter and demonstrated catheter erosion through central venous structures. Dr. BacWsrecent report lends support to another mechanism of pleural fluid formation in patients with poorly secured central venous catheters undergoing migratory withdrawal. His observa tions, however, do not exclude the importance ofcatheter-tip erosion when catheters move in the opposite direction.