Comparison of Efficacy of Erector Spinae Plane Block with Paravertebral Block for Postoperative Analgesia in Patients Undergoing Breast Cancer Surgery

Background: Patients undergoing modified radical mastectomy (MRM) experience acute pain. Inadequate acute postoperative pain control may lead to anxiety, hemodynamic imbalance and development of chronic pain syndrome. Hence analgesia is extremely important for favourable outcome. This study was undertaken to compare the efficacy of ultrasound guided thoracic paravertebral block (TPVB) versus ultrasound guided thoracic erector spinae plane block (ESPB) with clonidine as an adjuvant to local anaesthetic for post-operative analgesia in modified radical mastectomy. Method: This prospective randomized interventional comparative trial, involving 60 patients were undergoing modified radical mastectomy for breast cancer surgery, was conducted in a tertiary care teaching hospital over 18 months. Sixty patients undergoing MRM for breast cancer under general anaesthesia were enrolled. The patients were randomly allocated into one of the two groups. Group E received ultrasound guided erector spinae block and Group P received Paravertebral block at the level of 4th thoracic vertebra (T4). Both the groups were given 21 mL of 0.5% ropivacaine and 1 μg/kg of clonidine diluted in 1 mL of saline (making total volume of up to 22 mL). Primary outcome measure was to compare duration of analgesia, that is from the time of block administration till the time to first rescue analgesia demanded by the patients. Secondary outcome measures were mean visual analogue scale (VAS) score at rest as well as during abduction of ipsilateral arm at various time points, total intraoperative fentanyl and tramadol requirement up to 24 hours postoperatively; postoperative nausea and vomiting; patients satisfaction at the end of 24 hours postoperatively. Statistical method used: Quantitative variables were compared using Independent t-test/Mann-Whitney Test (when the data sets were not normally distributed). Qualitative variables were compared using Chi-Square test /Fisher’s exact test.A p value of <0.05 was considered statistically significant. Results: Duration of analgesi, that is, time of first rescue analgesia from the administration of the block was comparable between the two study groups. The mean (SD) duration of analgesia in group E was 22.78 (3.31) hours and in group P was 22.88 (3.34) hours (P = 0.914). Both the groups were comparable in terms of fentanyl requirement and total 24 hours tramadol requirement Other parameters like postoperative nausea vomiting, effect on hemodynamic and overall patient satisfaction were also comparable between the two groups. Conclusions: Both ultrasound guided ESPB and TPVB are equally efficacious in providing postoperative analgesia in patients undergoing modified radical mastectomy.