Lung Ultrasound After Transbronchial Biopsy for Pneumothorax Screening in Post-Lung Transplant Patients.

Background: Lung ultrasound has been suggested as an alternative to routine chest radiography (CXR) to screen for pneumothorax after transbronchial lung biopsy. In post-lung transplant patients, who may have altered anatomy and pleural adhesions, the validity of lung ultrasound to screen for postbiopsy pneumothoraces has not been investigated.

Methods: Lung ultrasound using an ultraportable handheld device was performed in a standardized manner 2-hour after biopsy in post-lung transplant patients. Ultrasound assessment was then compared with CXR performed immediately after lung ultrasound.

Results: In total, 165 patients were enrolled in the study. Eight pneumothoraces were diagnosed by image intensifier or CXR before lung ultrasound. There were 8 pneumothoraces diagnosed on CXR 2-hour postbiopsy. Lung ultrasound had a sensitivity of 75% and specificity of 93%. Positive predictive value was 35% and negative predictive value was 99%. The mean number of biopsies taken in patients with and without a pneuomothorax on CXR was 10.6 (±3.1) and 10.9 (±2.1), respectively (P=0.79). The overall pneumothorax rate was 9.7%.

Conclusions: Lung ultrasound is a valid tool in excluding penumothoraces after lung biopsy. Ultrasound scans with features of a pneumothorax or patients with symptoms should still undergo CXR. The high false positive rate may be due to small pneumothoraces being seen or the presence of pleural adhesions and altered lung anatomy in post-lung transplant patients.