Sato, MD, T., Kikura, MD, M., & Sato, MD, PhD, S. (2013). The characteristics of postoperative fentanyl effect-site concentration during intravenous fentanyl analgesia after posterior lumbar spine fusion. Journal of Opioid Management, 9(5), 335–342. https://doi.org/10.5055/jom.2013.0176