Abstract: Objective To compare the effects of quadrates lumborum block via different approaches on postoperative analgesia, immune function and early recovery in patients undergoing laparoscopic radical gastrectomy. Methods A total of 120 patients selected for laparoscopic radical gastrectomy were randomly divided into group Q1(QLB1), group Q2(QLB2), group Q3(QLB3)and group C, with 30 cases in each group. All groups used the same general anesthesia scheme, but the ultrasound-guided bilateral quadrates lumborum block were through different approaches. The resting and dynamic visual analogue score(VAS)at 0 h, 6 h, 12 h, 24 h and 48 h after operation, use of remedial analgesics within 48 h after operation, and total usage of sufentanil during perioperative period were recoded. The levels of T cell subsets at T0(right before operation), T1(24h after operation)and T2(48h after operation)were recorded. The first time out of bed, first exhaust time, postoperative hospitalization days and incidence of adverse reactions were also recorded. Results At 0 h, 6 h, 12 h, and 2 h after operation, the resting VAS score: group Q2P<0.05), group Q3P<0.05); the dynamic VAS score: group Q2P<0.05). The use of remedial analgesics within 48 hours after operation was lower in group Q2 than in the other three groups(P<0.05). The use of sufentanil was higher in group C than in the other three groups(P<0.05). The levels of T cell subsets at different times: T1 < T0(P<0.05), T2 < T0(P<0.05). At T1, the levels of CD3⁺, CD4⁺ and CD4⁺/CD8⁺: group CP<0.05). At T2, the levels of CD3⁺, CD4⁺ and CD4⁺/CD8⁺: group Q1P<0.05), group CP<0.05). The first time out of bed and first exhaust time: group Q2P<0.05). The postoperative hospital stay was longer in group C than in the other three groups(P<0.05). The incidence of adverse reactions was lower in group Q2 than in group C(P<0.05). Conclusions Ultrasound guided lumbar quadratus block can provide satisfactory analgesia for patients after laparoscopic radical gastrectomy, reduce the effects of surgery on T cell subsets and cellular immunosuppression, accelerate the postoperative rehabilitation and facilitate the prognosis. QLB2 is superior to QLB1 and QLB3 in reducing dynamic pain and immunosuppression.

Key words: Gastric cancer, Quadrates lumborum block via different approaches, Analgesic effect after surgery, T cell subsets, Early recovery