title: Evaluation of the Efficacy of Bupivacaine (0.5%) alone or with Clonidine (1μg/kg) Versus Control in a Single Level Paravertebral Blockin Patients Undergoing PCNL Procedure.
abstract: BACKGROUND
  Percutaneous Nephrolithotomy (PCNL) is a widely used procedure to remove complex upper tract renal calculi by means of a nephroscope. Although less invasive, PCNL is associated with significant pain owing to soft tissue injury. Most of these patients have mild to moderately compromised renal function. An anaesthesia plan that reduces intraoperative requirement of anaesthetics, analgesics, muscle relaxants and postoperative requirement of systemic analgesics is essential. Paravertebral Block (PVB) in combination with general anaesthesia may be an ideal technique for achieving all the goals.
  
  
  OBJECTIVE
  To evaluate the efficacy of Bupivacaine (0.5%) alone or with Clonidine (1ug/kg) versus control in a single level paravertebral block for intra-operative and postoperative analgesia in patients undergoing PCNL procedure.
  
  
  METHODS
  In this prospective, randomized, observer blind study we evaluated the intraoperative as well as postoperative analgesic effects of paravertebrally administered Bupivacaine (0.5%) alone or Bupivacaine±Clonidine (1μg/kg) versus Control (Conventional analgesia with IV Paracetamol). We also evaluated requirement of propofol, haemodynamic parameters, need for rescue analgesics & incidence of adverse effects. Collected data was analysed with SPSS statistical software. One way ANOVA test was applied. All pair wise multiple comparison procedures were analysed by Tukey's Method if equal sample size and by Dunnett's Method if unequal sample size in all groups.
  
  
  RESULTS
  It was observed that paravertebral block is an effective method for providing intra and postoperative analgesia for PCNL surgery. It reduced the requirement of intraoperative propofol, maintained stable intra and postoperative haemodynamics without any adverse effects or complications. Addition of Clonidine as an adjuvant to Bupivacaine enhanced the quality of paravertebral block with better haemodynamic stability, greater reduction in the intraoperative propofol requirement and provided significantly longer postoperative analgesia without any incident of bradycardia, hypotension, sedation or respiratory compromise.
  
  
  CONCLUSIONS
  In conclusion, 0.5% Bupivacaine±1μg/kg Clonidine in a single level paravertebral block is useful, effective and safe for providing intra as well as postoperative analgesia during PCNL surgeries.
authors.affiliation: Senior Resident, Department of Anaesthesia, T.N. Medical College and B.Y.L. Nair Ch. Hospital , Mumbai, Maharashtra, India .
authors.forename: Trupti S
authors.initials: TS
authors.lastname: Kamble
authors.affiliation: Professor, Department of Anaesthesia, T.N. Medical College and B.Y.L. Nair Ch. Hospital , Mumbai, Maharashtra, India .
authors.forename: Charulata Mahesh
authors.initials: CM
authors.lastname: Deshpande
keywords: General anaesthesia; Paravertebral block; Percutaneous nephrolithotomy; Visual analog score