The accuracy of postoperative, non-invasive Air-Test to diagnose atelectasis in healthy patients after surgery: a prospective, diagnostic pilot study.

Objective: To assess the diagnostic accuracy of peripheral capillary oxygen saturation (SpO) while breathing room air for 5 min (the 'Air-Test') in detecting postoperative atelectasis.

Design: Prospective cohort study. Diagnostic accuracy was assessed by measuring the agreement between the index test and the reference standard CT scan images.