Impact of fentanyl on acute and chronic pain and its side effects when used with epidural analgesia after thoracic surgery in multimodal analgesia: a retrospective cohort study - Miyoshi, Hirotsugu; Nakamura, Ryuji; Kido, Hiroyuki; Narasaki, Soushi; Watanabe, Tomoyuki; Yokota, Mayuko; Ishii, Tomomi; Kato, Takahiro; Saeki, Noboru; Tsutsumi, Yasuo M. (Annals of Palliative Medicine; Vol 10, No 5 (May 29, 2021): Annals of Palliative Medicine, 2021)