Paravertebral block versus erector spinae plane block for analgesia in modified radical mastectomy: a randomized, prospective, double-blind study

BACKGROUND: Pain control after breast surgery is crucial and supported with regional techniques. Paravertebral block (TPVB) is shown to be effective in postoperative pain management. Erector spinae plane block (ESPB) is assumed to have a similar analgesic effect as an easier and safer block. Our aim was to compare TPVB and ESPB for modified radical mastectomy (MRM) in terms of analgesic efficiency and dermatomal spread.METHODS: Patients were randomized into Group E (ESPB) and Group P (TPVB). Total 83 patients completed study 42 in Group E and 41 in Group P. Blocks were performed under ultrasonography with 20 mL 0.375% bupivacaine at T4 prior to surgery. T1-10 dermatomal block was examined via pin-prick sensation on the midaxillary and midclavicular lines. Primary outcome was 24-hour morphine consumption. Dermatomal coverage, postoperative 0th minute, 30th minute, 1st, 4th, 6th, 12th and 24th hours pain scores, rescue analgesia requirement and adverse events were secondary outcomes.RESULTS: Morphine consumption was lower in Group P (19.2±2.9 vs. 21±3.1, P=0.007; mean difference 1.8 mg, 95%CI=0.48-3.1 mg). The number of dermatomes with total loss of sensation was higher in Group P. Pain scores were significantly lower in Group P at all time points. The incidence of complications and adverse events was similar in both groups.CONCLUSIONS: Thoracal paravertebral block reduced morphine consumption compared to ESPB after MRM, albeit a small difference. A through coverage of TPVB may be preferred with experienced operators in MRM due to lower pain scores.