Effects of rhomboid intercostal and sub-serratus plane block on perioperative analgesic efficacy and diaphragm excursion in video-assisted thoracic surgery: a prospective, randomized controlled trial.

BACKGROUND

Rhomboid intercostal and sub-serratus plane (RISS) block is a novel nerve block technique that provides good analgesia, but overall research is scarce. This study aimed to investigate the effect of ultrasound-guided RISS block on postoperative analgesia and diaphragmatic excursion (DE) after video-assisted thoracic surgery (VATS) for lung cancer.

METHODS

One hundred patients who underwent VATS lung resection participated in this study and were randomized to a RISS group (Group R) or a control group (Group C). Group R underwent ultrasound-guided RISS block with 0.25% ropivacaine hydrochloride 0.5 ml/kg immediately after surgery. Group C was given standard general anaesthesia, and patient-controlled intravenous analgesia (PCIA) was used in the postoperative period in both groups. The visual analogue scores (VAS) at rest and during movement at 2 hours(h), 24 h, and 48 h postoperatively were used as the primary outcome measures. Secondary outcomes included postoperative consumption of sufentanil; preoperative and postoperative left and right-sided DE during calm and deep breathing, and the occurrence of adverse effects such as postoperative nausea and vomiting (PONV), dizziness, somnolence, puncture site infection, and hematoma.

RESULTS

At 2 h, 24 h, and 48 h postoperatively, patients in Group R had lower VAS scores at rest (median [Q1, Q3]: 1.00 [1.00, 1.00]; 1.00 [1.00, 1.00]; 0.00 [0.00, 1.00]) and during movement (2.00 [2.00, 3.00]; 2.00 [2.00, 2.00]; 2.00 [1.00, 2.00]) than those in Group C (resting: 2.00 [2.00, 2.00]; 2.00 [2.00, 2.00]; 1.00 [1.00, 2.00]; movement: 3.00 [3.00, 4.00]; 3.00 [3.00, 4.00]; 3.00 [2.00, 4.00]) (all P < 0.0001). Sufentanil consumption at 2 h, 24 h, and 48 h postoperatively was also significantly lower in Group R (P = 0.0002, P < 0.0001, P < 0.0001). Preoperatively, no significant difference in DE existed between the groups (P > 0.05). At 30 min post-extubation and 2 h and 24 h postoperatively, during both calm and deep breathing on both sides, Group R had significantly greater DE than Group C (P < 0.05). At 48 h postoperatively, the right-sided DE during calm breathing showed no significant difference between the groups. PONV incidences did not differ significantly (P = 0.2662), and Group R had less dizziness, somnolence, higher satisfaction post-surgery, and showed no cases of puncture site infection or hematoma.

CONCLUSIONS

Ultrasound-guided RISS block can modestly reduce postoperative pain in patients undergoing VATS, with clinically relevant benefits, and may help alleviate diaphragmatic dysfunction caused by surgical or anesthetic factors.

TRIAL REGISTRATION: The trial was registered at the China Clinical Trial Registry ( http://www.chictr.org.cn , ChiCTR2300070842) on 24/04/2023.