Highlights from AAST - What to do with a pneumothorax that is only seen on CT scan?

This study from Canada shows that only 2% of occult PTX go on to tension PTX, while there is a 15% complication rate from chest tubes that are inserted for PTX that are only seen on CT scan.

OCCULT PNEUMOTHORACES IN CRITICAL CARE (OPTICC): A PROSPECTIVE MULTI-CENTRE RANDOMIZED TRIAL OF PLEURAL DRAINAGE FOR VENTILATED TRAUMA PATIENTS WITH OCCULT PNEUMOTHORACES Andrew Kirkpatrick, Sandro Rizoli*, MD, JF Ouellet, Marco Sirois, Corina Tiruta, Kevin Laupland, Maureen Meade, Vincent Trottier, Chad Ball*, Assistant Professor, University of Calgary Sponsor: Chad Ball* Invited Discussant: J. Wayne Meredith Introduction: The treatment of occult pneumothoraces (OPTXs), identified on CT but not supine CXR, remains controversial; limited to small or uncontrolled series; and unfocused on patients (PTS) undergoing positive pressure ventilation (PPV). PTS may be at risk from tension pneumothoraces (TPTXs) without drainage, or pleural drainage complications if treated. Methods: Adults with traumatic OPTXs and requiring PPV were randomized to pleural drainage or observation (one side only enrolled if bilateral). All subsequent care and method of pleural drainage was per attending discretion. Primary outcome was a composite of respiratory distress (RD; need for urgent pleural drainage, acute/sustained increases in O2 requirements, ventilator dysynchrony, and charted respiratory events). Results: Ninety-five severely injured (mean ISS 33 + 11) PTS were enrolled at 4 Centres; Calgary (57), Toronto (28), Quebec (7), and Sherbrooke (3), with 3 exclusions. Forty were randomized to drainage (TT selected in all); 52 to observation. Rates of RD were 42 versus 30% in treated versus observed (p = 0.2254). In those observed, 21% required subsequent pleural drainage (45% PTX progression, 44% pleural fluid, 18% worsening pneumonia). One (2%) observed PTS had TPTX, treated with urgent TT and otherwise without sequelae. Serious drainage complications occurred on the study side in 15% of those randomized to drainage, with sub-optimal TT position noted in a further 15%. There were no differences in death; ICU, ventilator, or hospital; days between groups. Conclusion: OPTXS can be safely observed in hemodynamically stable patients undergoing PPV, although 1/5 may eventually require drainage, and TPTXs still occur. Complications of pleural drainage remain unacceptably high and future work should attempt to identify who among those observed warrant prophylactic drainage.