title: Supraclavicular brachial plexus block: Comparison of varying doses of dexmedetomidine combined with levobupivacaine: A double-blind randomised trial.
abstract: OBJECTIVE
  The ideal dose of dexmedetomidine for brachial plexus block is a matter of debate. This study was carried out to evaluate 50 μg or 100 μg of dexmedetomidine added to 0.5% levobupivacaine, with regard to the duration of analgesia. Our study also sought to assess the onset and duration of sensorimotor blockade, haemodynamic effects, sedation and adverse effects.
  
  
  METHODS
  One hundred adult patients undergoing upper limb surgeries under supraclavicular brachial plexus block were randomly allocated into two groups. Group LD50 received 29 ml of 0.5% levobupivacaine plus 50 μg of dexmedetomidine diluted in 1 ml of normal saline. Group LD100 received 29 ml of 0.5% levobupivacaine plus 100 μg of dexmedetomidine diluted in 1 ml of normal saline. Duration of analgesia was the primary outcome. Onset and duration of sensorimotor blockade, haemodynamic variables, sedation score, and adverse effects were secondary outcomes. The data were analysed with Students't-test and Chi-square test.
  
  
  RESULTS
  The onset of sensory block and motor block was 14.82 ± 3.8 min and 19.75 ± 6.3 min, respectively, in group LD50, while it was 11.15 ± 1.7 min and 14.3 ± 4.2 min, respectively, in group LD100. The duration of analgesia was significantly prolonged in group LD100 (1033.6 ± 141.6 vs. 776.4 ± 138.6 min;P= 0.001). The incidence of bradycardia and sedation was observed in significantly more patients in group LD100. Significantly fewer patients in group LD100 required rescue analgesia.
  
  
  CONCLUSIONS
  The 100 μg dose of dexmedetomidine in brachial plexus block hastens the onset and prolongs the duration of sensorimotor blockade and analgesia, but with higher incidence of bradycardia and sedation.
authors.affiliation: Department of Anaesthesiology and Critical Care, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: Srinivasa Rao
authors.initials: SR
authors.lastname: Nallam
authors.affiliation: Department of Anaesthesiology and Critical Care, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: Sunil
authors.initials: S
authors.lastname: Chiruvella
authors.affiliation: Department of Anaesthesiology and Critical Care, RIMS, Kadapa, Andhra Pradesh, India.
authors.forename: Swetha
authors.initials: S
authors.lastname: Karanam
keywords: Anaesthesia; brachial plexus block; bupivacaine; dexmedetomidine; double-blind method; local