title: Effects of perineural administration of dexmedetomidine in combination with bupivacaine in a femoral-sciatic nerve block.
abstract: OBJECTIVE
  Perineural administration of dexmedetomidine, a α2-adrenoceptor agonist, prolongs the duration of analgesia. We hypothesized that adding dexmedetomidine to bupivacaine would prolong postoperative analgesia after below knee surgery.
  
  
  METHODS
  After ethical approval, 60 patients scheduled for below knee surgery under combined femoral-sciatic nerve block were randomly allocated into two groups to have their block performed using bupivacaine 0.5% alone (group B) or bupivacaine 0.5% combined with 100 μg bupivacaine-dexmedetomidine (group BD). Motor and sensory block onset times; durations of blockades and analgesia were recorded.
  
  
  RESULTS
  Sensory and motor block onset times were shorter by 20% in group BD than in group B (P < 0.01). Sensory and motor blockade durations were longer in group BD (+45% and +40%, respectively) than in group B (P < 0.01). Duration of analgesia was longer in group BD by 75% than in group B (P < 0.01). Systolic, diastolic arterial blood pressure levels, and heart rate were significantly less in group BD, six patients in group BD, and no patients in group B developed bradycardia (P < 0.05).
  
  
  CONCLUSIONS
  The addition of dexmedetomidine 100 μg to bupivacaine 0.5% during ultrasound-guided combined femoral and sciatic block for below knee surgery was associated with a prolonged duration of analgesia. However, this may be associated with significant bradycardia requiring treatment.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Menoufia University, Shebin El Kom, Menoufia, Egypt.
authors.forename: Safaa M
authors.initials: SM
authors.lastname: Helal
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Menoufia University, Shebin El Kom, Menoufia, Egypt.
authors.forename: Ashraf M
authors.initials: AM
authors.lastname: Eskandr
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Menoufia University, Shebin El Kom, Menoufia, Egypt.
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Gaballah
authors.affiliation: Department of Anesthesiology, King Fahd Hospital of the University of Dammam, Al Khobar, Saudi Arabia.
authors.forename: Ihab S
authors.initials: IS
authors.lastname: Gaarour
keywords: Analgesia; below knee surgery; combined femoral-sciatic nerve block; dexmedetomidine; ultrasound