A Comparative Study Between Different Volumes During Erector Spinae Block for Pain Control

Since its first description by Forero et al. there have been many articles and case reports including an increasingly number of indications for the ESP block: chronic and acute pain treatment, rib fractures management in the emergency setting, treatment of abdominal surgical pain, hip arthroplasty , analgesic management in breast surgery,or in spinal surgery.Although ESP block successfully reduced postoperative opioid consumption in clinical reports, no studies thus have investigated the optimum volume of bupivacaine for ESP block as regard a review of the medical literature on December 27th, 2017 that searched terms in 14 articles clearly stated the volume of the bolus and the spread of the anesthetic after an injection of LA, the volume needed to cover one dermatome widely varies from 2.5 mL to 6.6 mL, with a median value of 3.4 mL. Furthermore, the maximum number of dermatomes reached by a single bolus in ESP was of 9 dermatomes after a 30 mL bolus. Thus, in this study, the investigators evaluate the effect of ESP block which will be performed by using three different volumes (2.5, 3.4 ,6.6 ml/segment) of bupivacaine with the same concentration ,technique ,site of injection and operation.