Analgesic effect of the ultrasound-guided thoracolumbar paravertebral block in patients undergoing robot-assisted laparoscopic nephrectomy: a randomized controlled trial

Background: Paravertebral block has similar effect as epidural anesthesia, and has good somatic and visceral analgesic effect. Paravertebral block is widely used in thoracic surgery, but rarely used in abdominal surgery.

Aims: This study aimed to evaluate the analgesic effect of thoracolumbar paravertebral block in patients undergoing robot-assisted laparoscopic nephrectomy.

Methods: One hundred patients undergoing elective robot-assisted laparoscopic nephrectomy were included in this study. Based on whether the thoracolumbar paravertebral block was performed, the patients were randomly divided into the thoracolumbar paravertebral block combined with general anesthesia group (TL-PVB group) and simple general anesthesia group (NO-PVB group). Oxycodone was administered for patient-controlled intravenous analgesia (PCIA). The primary outcomes included the amount of remifentanil used during surgery, the amount of oxycodone used in 24 and 48 h after surgery. Secondary outcomes included the changes of heart rate (HR) and mean arterial pressure (MAP), time for the first analgesia administration, visual analog score (VAS) of pain during rest and movement, and time of postoperative recovery.

Results: Compared to the NO-PVB group, the amount of remifentanil used during surgery in patients with TL-PVB group was significantly reduced (1.78 ± 0.37 mg vs. 3.09 ± 0.48 mg, p < 0.001), the amount of oxycodone used 24 h after surgery was significantly reduced (8.70 ± 1.70 mg vs. 13.79 ± 2.74 mg, p < 0.001), and the amount of oxycodone used 48 h after surgery was remarkably reduced (21.83 ± 4.28 mg vs. 27.27 ± 4.76 mg, p < 0.001). There were significant differences in the changes of HR and MAP between the two groups (p < 0.001). The first analgesic requirement time of TL-PVB group was significantly longer than that of NO-PVB group (468.56 ± 169.60 min vs. 113.48 ± 37.26 min, p < 0.001). The postoperative VAS during rest and movement of TL-PVB group were significantly lower than that of NO-PVB group (p < 0.01). Compared with NO-PVB group, patients in TL-PVB group needed shorter time to awaken from anesthesia, leave the operating room, anal exhaust, get out of bed, and had shorter length of postoperative hospital stay (p < 0.001). The incidence of postoperative adverse reactions were lower in the TL-PVB group than that in the NO-PVB group (p < 0.05).

Conclusions: Ultrasound-guided thoracolumbar paravertebral block significantly reduces intraoperative and postoperative opioid consumption, and provides better analgesia in patients undergoing robot-assisted laparoscopic nephrectomy, which is a recommendable combined anesthesia technique.

Trial registration: ChiCTR2200061326, 21/06/2022.