Effectiveness of Ultrasound-Guided Retrolaminar Block and Erector Spinae Plane Block in Retroperitoneal Laparoscopic Surgery: A Randomized Controlled Trial

Abstract

Purpose: Retrolaminar block (RLB) and erector spine plane block (ESPB) share a similar block site, but their analgesia principle may differ. This study compared the postoperative analgesic effects of ultrasound-guided RLB and ESPB for retroperitoneal laparoscopic surgery.

Patients and methods: The study included patients who scheduled for laparoscopic nephrectomy from July 2020 to January 2021. Patients in RLB group received a three-point block at the posterior surface of T8-T10 lamina, and those in ESPB group received at the T9 level. The primary result was the score of visual analogue scale (VAS). Secondary results included information on intraoperative and postoperative analgesia consumption and rescue analgesia usage, skin temperature, serum interleukin (IL)-1β, prostaglandin E2 (PGE2) level and the occurrence of safety events.

Results: There was no significant difference between the two groups in the postoperative VAS scores at both the rest and cough state (All P>0.05). The skin surface temperature of the affected side and the healthy side in ESPB group was higher than that in the RLB group at the end of the surgery (P=0.002) and after surgery (P=0.016). The RLB group had a higher ephedrine usage than the ESPB group (P=0.027). Compared with the ESPB group, the RLB group had a shorter time to exhaust (P=0.045) and lower serum IL-1β level (P=0.049). Patients in neither group developed severe adverse event.

Conclusion: Ultrasound-guided RLB and ESPB can provide safe and effective postoperative analgesia for retroperitoneal laparoscopic surgery. ESPB has more stable intraoperative hemodynamics, while RLB has more potential research value for patients' rapid recovery.

Keywords: anesthetics; laparoscopy; nerve block; perioperative care.

Figure 1

Schematic diagram of nerve block puncture: (A) The seventh thoracic vertebra (T7) that located at inferior angle of the scapula was first specified, and then T8, T9, T10 were successively marked. The laminae corresponding to the T8, T9 and T10 were identified according to the marked vertebra by ultrasound scanning. (B) Convex array probe of 1–5Hz is placed at the median transverse section of the centrum and is used to identify the lamina, pleura, spinous process (SP), and transverse process (TP). (C) A puncture needle is introduced in the plane. Local anesthetic is injected behind the lamina, and the spread of local anesthetic is observed in real-time. (D) The seventh thoracic vertebra (T7) that located at inferior angle of the scapula was first specified, and then T8, T9, T10 were successively marked. The laminae corresponding to the T8, T9 and T10 were identified according to the marked vertebra by ultrasound scanning. (E) Convex array probe of 1–5Hz is placed at the paravertebral sagittal view to identifying TP through the long spinal axis. (F) A puncture needle is introduced in the plane. A local anesthetic is injected at the erector spinal plane, and the spread of the local anesthetic is observed in real-time.

Figure 2

A flow chart illustrating patient inclusion.

Figure 3

Volume monitoring indexes: Data are expressed as mean±standard deviation, and compared by t-test between groups and one-way analysis of variance within groups. (A and B) There was no significant difference in the inferior vena cava diameter (IVCD) and inferior vena cava collapsibility index (IVC-CI) between the two groups after patients entered the operating room and at the beginning of induction. # Significant difference in the CO level of both groups after the induction and at the end of surgery compared to other time points; * Significant difference in the SVV level of both groups at the end of surgery compared to other time points. (C) There is no significant difference in SVV between the two groups at each time point for analysis between groups. At the end of the surgery, SVV in both groups is lower than other time points in the same group. (D) There is no significant difference in CO between the two groups at each time point for analysis within groups. After induction and at the end of surgery in both groups, CO is higher than other time points in the same group.

Figure 4

Comparison of heart rate and blood pressure: Data are expressed as mean±standard deviation, and compared by t-test between groups. (A) There is no significant difference in heart rate between the two groups at each time point. (B) Heart rate is lower in the RLB group than in the ESPB group at 10 minutes after the surgery starts, and heart rate at other time points shows no significant difference between the two groups.

Figure 5

Comparison of postoperative VAS score: The VAS score at each time point is expressed as the median (interquartile range) and compared by rank-sum test between two groups. (A) There is no significant difference in VAS scores at each time point in the rest state between the two groups. (B) There is no significant difference in VAS scores at each time point in cough state between the two groups. Summary data of VAS scores at all time points are expressed as mean±standard deviation. (C) There is no significant difference in the mean VAS scores and maximum VAS scores in the rest state between the two groups. (D) There is no significant difference in the mean VAS scores and maximum VAS scores in cough states between the two groups.