title: Effect of adding clonidine to intrathecal bupivacaine on the quality of subarachnoid block: A prospective randomized double-blind study.
abstract: BACKGROUND
  The purpose of adding an adjuvant to local anesthetic in a central neuraxial blockade is to augment the desirable pharmacological actions of the agent and/or to minimize its undesirable pharmacological effects. Clonidine is an alfa-2 receptor agonist which has gained popularity in recent times as an adjuvant in spinal anesthesia.
  
  
  OBJECTIVE
  To evaluate the influence of clonidine on the hemodynamic stability and the duration of anesthesia when added to intrathecal hyperbaric bupivacaine.
  
  
  METHODS
  Prospective randomized double blind study.
  
  
  METHODS
  Fifty patients scheduled for spinal anesthesia were randomized into two Groups A and B with 25 in each. Group A patients received 3 ml 0.5% heavy bupivacaine + 30 μg (0.2 ml) clonidine and Group B patients received 3 ml 0.5% heavy bupivacaine + 0.2 ml normal saline in the subarachnoid space. The blood pressure and heart rate were closely monitored. The time for attaining peak sensory block, time for two segment regression, decrease in the heart rate, total requirement of mephentermine to counter the hypotension, and the number of patients requiring mephentermine in each group was tabulated and analyzed.
  
  
  METHODS
  Descriptive and inferential statistical methods were used to analyse the data. The power of the study was calculated using online power calculator for two independent sample study.
  
  
  RESULTS
  The time for attaining peak sensory block was similar in both the groups. The time for two segment regression in Group A was 62.6 min and in Group B was 38.08 min. Twelve percent of patients in Group A and 52% of patients in Group B required mephentermine with the mean consumption being 0.72 mg in Group A and 5.65 mg in Group B.
  
  
  CONCLUSIONS
  Addition of low-dose clonidine to intrathecal bupivacaine not only prolonged the duration of spinal anesthesia but also provided a stable intraoperative hemodynamic profile.
authors.affiliation: Department of Anaesthesiology, NRI Medical College, Guntur, Andhra Pradesh, India.
authors.forename: Srivishnu Vardhan
authors.initials: SV
authors.lastname: Yallapragada
authors.affiliation: Department of Anaesthesiology, NRI Medical College, Guntur, Andhra Pradesh, India.
authors.forename: Nagendra Nath
authors.initials: NN
authors.lastname: Vemuri
authors.affiliation: Department of Anaesthesiology, NRI Medical College, Guntur, Andhra Pradesh, India.
authors.forename: Mastan Saheb
authors.initials: MS
authors.lastname: Shaik
keywords: Adjuvant; clonidine; hemodynamic stability; intrathecal; spinal anesthesia