Efficacy of programmed intermittent bolus epidural analgesia in thoracic surgery: a randomized controlled trial.

This randomized prospective study was approved by the Institutional Review Board (IRB No. 15-9-06) of the Fukuoka University Hospital, Fukuoka, Japan, and was registered in the clinical trials database UMIN ( ID 000019904 ) on 24 November 2015. Written informed consent was obtained from all patients.