title: A comparison of intrathecal dexmedetomidine, clonidine, and fentanyl as adjuvants to hyperbaric bupivacaine for lower limb surgery: A double blind controlled study.
abstract: BACKGROUND
  Various adjuvants are being used with local anesthetics for prolongation of intraoperative and postoperative analgesia. Dexmedetomidine, the highly selective 2 adrenergic agonist is a new neuraxial adjuvant gaining popularity.
  
  
  METHODS
  The study was conducted in prospective, double blind manner. It included 120 American Society of Anesthesiology (ASA) class I and II patients undergoing lower limb surgery under spinal anesthesia after approval from hospital ethics committee with written and informed consent of patients.
  
  
  METHODS
  The patients were randomly allocated into four groups (30 patients each). Group BS received 12.5 mg hyperbaric bupivacaine with normal saline, group BF received 12.5 mg bupivacaine with 25 g fentanyl, group BC received 12.5 mg of bupivacaine supplemented 30 g clonidine, and group BD received 12.5 mg bupivacaine plus 5 g dexmedetomidine. The onset time to reach peak sensory and motor level, the regression time of sensory and motor block, hemodynamic changes, and side effects were recorded.
  
  
  RESULTS
  Patients in Group BD had significantly longer sensory and motor block times than patients in Groups BC, BF, and BS with Groups BC and BF having comparable duration of sensory and motor block. The mean time of two segment sensory block regression was 147 ± 21 min in Group BD, 117 ± 22 in Group BC, 119 ± 23 in Group BF, and 102 ± 17 in Group BS (P > 0.0001). The regression time of motor block to reach modified Bromage zero (0) was 275 ± 25, 199 ± 26, 196 ± 27, 161 ± 20 in Group BD, BC, BF, and BS, respectively (P > 0.0001). The onset times to reach T8 dermatome and modified Bromage 3 motor block were not significantly different between the groups. Dexmedetomidine group showed significantly less and delayed requirement of rescue analgesic.
  
  
  CONCLUSIONS
  Intrathecal dexmedetomidine is associated with prolonged motor and sensory block, hemodynamic stability, and reduced demand of rescue analgesics in 24 h as compared to clonidine, fentanyl, or lone bupivacaine.
authors.affiliation: Department of Anaesthesiology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India.
authors.forename: Vidhi
authors.initials: V
authors.lastname: Mahendru
authors.forename: Anurag
authors.initials: A
authors.lastname: Tewari
authors.forename: Sunil
authors.initials: S
authors.lastname: Katyal
authors.forename: Anju
authors.initials: A
authors.lastname: Grewal
authors.forename: M Rupinder
authors.initials: MR
authors.lastname: Singh
authors.forename: Roohi
authors.initials: R
authors.lastname: Katyal
keywords: adrenoreceptor agonist; bupivacaine; clonidine; dexmedetomidine; fentanyl; spinal anesthesia; α2