Abstract:Objective To evaluate the safety and analgesic efficacy of ultrasound-guided rhomboid intercostal and subserratus (RISS) plane block in patients undergoing thoracoscopic surgery.Methods Sixty patients scheduled for elective thoracoscopic surgery in our hospital from July 2019 to November 2019 were enrolled and randomly divided into RP group (n = 30) with combined RISS plane block and patient-controlled intravenous analgesia (PCIA), and LP group (n = 30) with combined local anesthesia at the site of the incision and PCIA. Patients in both groups underwent general anesthesia. For RP group, patients received ultrasound-guided RISS plane block before the general anesthesia. For LP group, patients received local anesthesia at the end of surgery. The range of sensory block at the midclavicular line 20 min after RISS plane block was recorded in RP group. The intraoperative dosage of sufentanil, vasoactive drugs and remifentanil was documented. Postoperative sufentanil consumption, frequency of PCIA pump pressing, incidence of remedial analgesia, Visual Analogue Scale (VAS) scores of patients at rest and during cough at 0 h, 2 h, 6 h, 12 h and 24 h after operation in the post-anesthesia care unit (PACU), and semiquantitative cough strength score (SCSS) at each time point were recorded or evaluated. The length of PACU stay, time to first out-of-bed activity, the time of drainage tube withdrawal, length of postoperative hospital stay, adverse reactions and patient satisfaction were compared between the groups.Results The intraoperative dosage of remifentanil in RP group was lower than that in LP group (P < 0.05). The VAS scores at rest or during cough at each time point after surgery in the RP group were not higher than those in the LP group (P <0.05), while VAS scores during cough were higher than those at rest at each time point after surgery in both RP group and LP group (P < 0.05). The SCSS was significantly different between the two groups (P < 0.05). The postoperative sufentanil consumption, frequency of PCIA pump pressing and the incidence of remedial analgesia were lower in RP group compared with those in LP group (P < 0.05), and the degree of patient satisfaction in RP group was higher (P <0.05). The patients in the RP group exhibited a shorter length of PACU stay and time to first out-of-bed activity (P <0.05). The incidence of dizziness was 3.3% in RP group and 6.7% in LP group, while the incidence of nausea and vomiting was 6.7% in RP group but 26.7% in LP group. One case of hypotension was observed in each group, but there was no respiratory depression or pruritus in either group. Besides, no complications associated with RISS plane block occurred in RP group.Conclusions Ultrasound-guided RISS plane block is safe and effective for patients undergoing thoracoscopic surgery, and could be established as an adjuvant treatment for postoperative analgesia.