Q: Which is more sensitive bedside diagnostic in ruling out Pneumothorax - CXR or ultrasound (Choose one)?
Answer: Ultrasound
It is now pretty much establish that bedside ultrasound (can be easily learn and perform by intensivist) is more sensitive in detecting pneumothorax.
(see video in this regard in our videos section)
Reference:
Wilkerson RG, Stone MB (January 2010). "Sensitivity of bedside ultrasound and supine anteroposterior chest radiographs for the identification of pneumothorax after blunt trauma". Acad. Emerg. Med. 17 (1): 11–17