Fig. 2From: Oxycodone vs. tramadol in postoperative parent-controlled intravenous analgesia in children: a prospective, randomized, double-blinded, multiple-center clinical trialComparison of parent satisfaction scores between oxycodone and tramadol group. * P < 0.05. +: mean; oxy: oxycodone group; tra: tramadol groupBack to article page