title: The effect of dexmedetomidine infusion on propofol requirement for maintenance of optimum depth of anaesthesia during elective spine surgery.
abstract: BACKGROUND
  Maintenance of adequate depth of anaesthesia in spine surgery is vital to prevent awareness, to reduce stress response and possible autonomic instability frequently associated with spine surgery. Dexmedetomidine, a α2-adrenoceptor agonist with analgesic and sedative adjuvant property has been found to reduce dose requirement of multiple anaesthetic agents both for induction and during the maintenance of anaesthesia.
  
  
  OBJECTIVE
  The aim of this study is to observe the effect of dexmedetomidine, on the requirement of propofol for induction and maintenance of adequate depth of anaesthesia during spine surgery.
  
  
  METHODS
  It was a prospective, randomised, double-blinded, parallel group, placebo controlled and open-lebel study in tertiary care hospital. A total of 70 patients aged 20-60 years, American Society of Anaesthesiologists GradeI and II, scheduled for elective spine surgery were randomly allocated into two groups. Each patient of Group D (n=35) received an initial loading dose of dexmedetomidine at 1 μg/kg over 10 min, started 15 min before induction of anaesthesia followed by an infusion at a rate of 0.2 μg/kg/h. Patients of Group P (n=35) received the same volume of 0.9% normal saline solution as placebo. Requirement of propofol at induction and during maintenance was calculated maintaining bispectral index between 40 and 60. P<0.05 was considered to be statistically significant.
  
  
  RESULTS
  Mean requirement of propofol was found to be lessened by 48.08% and 61.87% for induction and maintenance of anaesthesia respectively while using dexmedetomidine.
  
  
  CONCLUSIONS
  Administration of dexmedetomidine significantly reduces the requirement of propofol while maintaining desired depth of anaesthesia without any significant complication.
authors.affiliation: Department of Anaesthesia, Bangur Institute of Neurosciences, Kolkata, West Bengal, India.
authors.forename: Suvadeep
authors.initials: S
authors.lastname: Sen
authors.forename: Jayanta
authors.initials: J
authors.lastname: Chakraborty
authors.forename: Sankari
authors.initials: S
authors.lastname: Santra
authors.forename: Prosenjit
authors.initials: P
authors.lastname: Mukherjee
authors.forename: Bibhukalyani
authors.initials: B
authors.lastname: Das
keywords: Bispectral index monitor; dexmedetomidine; propofol; spine surgery