Fig. 2. Onset time and duration time of symptoms during 24 hours after discontinuation or de-escalation of opioid infusion. (A) Onset time of remifentanil group. (B) Onset time of fentanyl group. (C) Onset time of morphine group. (D) Duration time of remifentanil group. (E) Duration time of fentanyl group. (F) Duration time of morphine group.

OWS = opioid withdrawal syndrome, CAM = Confusion Assessment Method, CI = confidence interval, GCS = Glasgow Coma Scale, RASS = Richmond Agitation-Sedation Scale, RR = respiratory rate, HR = heart rate.

^avs. the remifentanil group; ^bvs. the morphine group.