Paravertebral Block: A Comparative Study Evaluating Performance of Direct Surgical And Classic Technique

Introduction: Thoracic paravertebral block (TPVB) has been employed for post operative analgesia in thoracotomy. Paravertebral block can be given by various techniques, two most commonly used techniques include direct surgical and classic technique yet the relative efficacy of one technique over alternate has not been accessed so far. This study has been intended to look at the performance of both these techniques on different imperative criteria's. namely analgesic efficacy, technical difficulties and procedure time. Methodology: This study was conducted in a prospective, randomized, double blind fashion. Sixty adult patients of ASA I & II status underwent unilateral thoracotomy. divided into two groups, Group S and Group C and randomly allocated. Paravertebral catheter was placed at an appropriate level just before the closure of thoracotomy either by surgical or classic technique and was activated by 15 ml of ropivacaine 0.3%. Time taken to perform the block was noted down. After recovery from GA, pain was assessed by VAS at pre-fixed intervals. The patients were administered top up dose through paravertebral catheter as soon as VAS score exceeded 4. Total requirement of ropivacaine and rescue analgesia (Morphine) consumption in 24 hours were noted down. Technical problems of both the techniques were documented by the surgeon or anesthetist who performed the block. Result: Out of sixty patients three patients were excluded. Patients in Group C experienced better analgesia compared to Group S. Mean VAS scores at rest were lower at all measured intervals in Group C compared to Group S. Mean total consumption of ropivacaine was (91.72 ± 9.85) mg in Group C and (127.14 ± 9.58) mg in Group S (p<0.0001) over 24 hrs. Rescue analgesia (Morphine) consumption was higher in Group S vs. Group C (Group S 10.75 ± 2.6 vs. Group C 6.56 ± 1.44, p-value = 0.0001) over 24 hrs. Average procedure time in Group S 29.39±5.92 was almost double than Group C 15.90 ± 3. Technique related problems in Group S included difficult pleural stripping, local anesthetic leak, catheter fixation and pleural reattachment while in Group C difficult catheterization was the only problem encountered. Conclusion: Paravertebral block by classic technique provides superior analgesia in thoracotomy, takes less time to execute than direct surgical technique and has fewer technical troubles.