W. Nathanael Holmes MD, Presenter: Nothing to Disclose

Julie H. Song MD, Abstract Co-Author: Nothing to Disclose

To determine if routine chest radiograph (CXR) is necessary following ultrasound (US)-guided thoracentesis.

Five hundred and seven thoracenteses were performed with US-guidance for diagnostic or therapeutic purpose over a 2-year period. We retrospectively reviewed the reports of US, post-procedure CXR or computed tomography, and medical records. The size of the catheter, volume removed, development of pneumothorax, and new symptoms were documented. Eighteen cases were excluded due to the presence of pre-existing pneumothorax, chest tube or concurrent pleural biopsy. The remaining 489 procedures were performed on 372 patients including 20 intubated patients. Small volumes of 100 cc or less were removed in 112 of the procedures, and 374 procedures involved removal of more than 100 cc. A vacuum bottle was typically used in the large volume cases.

Pneumothorax from thoracentesis was documented in 3.5% (17 of 489) of the procedures. There was no significant difference (P=0.20) in the volume removed from patients with or without pneumothorax (mean volume of 841.5 cc vs 674.6 cc). None of the intubated patients developed pneumothorax. Of the 17 cases of pneumothorax, 4 cases were recurrent in 2 patients with chronic pleural effusion. The incidence of pneumothorax from small volume thoracentesis was 1.8% (2 of 112) compared to 4.0% (15 of 374) from large volume thoracentesis (P=0.29). Eight of 17 patients (47.1%) with pneumothorax were symptomatic while pneumothorax was not suspected in 52.9%. Four of 17 patients with pneumothorax (23.5%), constituting 0.8 % of all US-guided thoracenteses, required chest tube placement.

Routine post-procedural CXR is not indicated following US-guided thoracentesis, unless the patient develops symptoms that suggest possible complication. The risk of pneumothorax in large-volume thoracentesis is not significantly different from small-volume thoracentesis.

Holmes, W, Song, J, US-guided Thoracentesis: Is Post-procedural Chest Radiography Necessary?.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4407988.html