[Comparison of the post-operative analgesic effect of ultrasound-guided serratus anterior plane block combined with pectoral nerves block I and thoracic paravertebral block in radical mastectomy].

Objective: To investigate the serratus anterior plane block combined with pectoral nerves block I can produce a non-inferior analgesic effect compared with thoracic paravertebral block for radical mastectomy. Methods: From October 2020 to February 2021, Sixty-four patients of Beijing Tongren Hospital, Capital Medical University scheduled for radical mastectomy with general anesthesia,were divided into two groups (n = 32 each) using a random number table method: thoracic paravertebral block group (TPVB group) and serratus anterior plane block combined with pectoral nerves block I group (S&P group). All patients received patient controlled intravenous analgesia (PCIA) postoperatively. The numerical rating scale (NRS) at post anesthesia care unit (PACU), 4, 8, 12, 24, 48 h after operation were compared between the two groups. Sufentanil cumulative dosage of PCIA in 24 h and 48 h, first press time after operation, total press times, the dosage of propofol, remifentanil and vasoactive drugs during operation, intraoperative blood pressure and heart rate, the operation time of block and adverse effects were all compared. Non-inferiority could be claimed if the difference of sufentanil cumulative dosage in 24 h between S&P group and TPVB group is higher than the negative value (-3.8) of the non-inferiority effect. Results: There was no significant difference in postoperative NRS at PACU, 4, 8, 12, 24, 48 h after operation, first press time after operation, total press times, propofol and remifentanil dosage, sufentanil cumulative dosage of PCIA in 24 h and 48 h, and adverse effects (all P>0.05). The sufentanil cumulative dosage of PCIA in 24 h of S&P group and of TPVB group were (15.8±4.7) μg and (15.2±3.2) μg. The 95% confidence interval (CI) of the difference between S&P group and of TPVB group was -1.478 to 2.694, and the lower limit was greater than non-inferiority margin -3.8. The mean arterial pressure of TPVB patients after induction and at the beginning of the operation were (63±7) mmHg and (70±7) mmHg, which were significantly lower than the (77±5) mmHg and (79±8) mmHg at the same time in the combination group (both P<0.05). The frequency of vasoactive drugs usage in TPVB group was 56.3%, which was statistically significant higher than the 18.8% in S&P group (P<0.01). Nerve block time in TPVB group was 10 (9, 11) min, which was significantly longer than 8 (6, 10) min in S&P group (P<0.01). Conclusion: The serratus anterior block combined with pectoral nerves block I can produce a non-inferior analgesic effect compared with thoracic paravertebral block for radical mastectomy, and the intraoperative hemodynamics is more stable and the block time is shorter than that of thoracic paravertebral block for radical mastectomy.