Stellate ganglion block for visceral pain in elderly patients undergoing video-assisted thoracoscopic lung cancer surgery: a randomized, controlled trial

Background: Visceral pain occurs commonly following thoracic surgery, but an effective method to relieve visceral pain in thoracic surgery remains controversial. We test the effect of stellate ganglion blocks (SGB) on perioperative visceral pain following video-assisted thoracoscopic surgery (VATS). Methods: A prospective, randomized, controlled trial enrolled 77 elderly patients undergoing VATS. Patients were randomized to SGB followed by modified intercostal nerve block (Group S, n=37); or modified intercostal nerve block only (Group C, n=40). Remifentanil 0.02–0.2 μg·kg -1 ·min -1 was titrated to keep pain threshold index values between 40-65 and maintain mean arterial pressure or heart rate values around 20% of baseline values. Patient-controlled intravenous analgesia with sufentanil was used in the postoperative period. The co-primary outcomes were the perioperative cumulative opioid consumption and pain scores on movement at 24 h after surgery. Results: Compared with control group, SGB greatly reduced the intraoperative remifentanil consumption[300.00(235.00-450.00)μg versus 710.00(500.00-915.00)μg; P <0.01], with no difference in cumulative sufentanil consumption to 48h post-surgery. There was a statistically significant difference in pain scores on movement at 24h between groups [4.00(3.00-4.00) versus 4.00(3.25-5.00); P =0.01]. Further exploratory analyses showed significant difference for intra-chest pain on movement at 24h [3.00(2.00-3.00) versus 3.00(2.25-4.00); P =0.01]. No significant difference was observed in nausea/vomiting, time to pass flatus and postoperative length of stay. Conclusion: Preoperative stellate ganglion blocks for elderly patients could effectively blunt intraoperative visceral stress and reduce postoperative visceral pain extending 24 h after VATS. This initial finding deserve further investigation.