Introduction
fractures, anxiety, pain
Dexmedetomidine (DEX), a highly selective a2-adrenoreceptor agonist, is a relatively new adjuvant drug with sympatholytic, anxiolytic and analgesic properties [Patients hospitalised for fractures have a high risk of pain and anxiety [Another challenge in analgesia is objectively monitoring the analgesia level in real-time to evaluate pain in an unconscious patient. Most trials have been limited by the use of visual analogue scales to evaluate the level of analgesia; however, this is subjective and cannot be used in deeply sedated patients. Our recent studies have shown that the nociception index (IOC2, namely qNOX), a new real-time monitoring index, responds to external noxious stimuli and thus allows us to objectively evaluate analgesic effects and pain intensity in patients under general anaesthesia [This study aimed to quantitatively evaluate the analgesic effects of DEX using IOC2 by determining the rate and time required to attain the target IOC2 (i.e. mean optimal analgesia) in patients who underwent below-knee orthopaedic surgery. Further, the safety and postoperative efficacy of DEX were assessed.