Abstract:Objective To explore the effects of ultrasound-guided serratus anterior plane block (SAPB) and thoracic paravertebral block (TPVB) on opiate dosage and stress response in patients undergoing thoracoscopic radical resection of lung cancer. Methods A total of 130 patients undergoing elective thoracoscopic radical resection of lung cancer in Changshu Second Peoples Hospital between June 2019 and January 2022 were enrolled. According to the random number table method, they were divided into SAPB group (65 cases, ultrasound-guided SAPB before anesthesia induction) and TPVB group (65 cases, ultrasound-guided TPVB before anesthesia induction). After surgery, all underwent patient-controlled intravenous analgesia with analgesia pumps. The timepoints including preoperative, thoracic closure, and postoperative 2, 6, and 24 hours were set as T₁, T₂, T₃, T₄ and T₅, respectively, and the intraoperative blood loss and fluid supplement, operation time, intraoperative dosages of sufentanil and propofol, and postoperative cumulative dosages of sufentanil at T₃, T₄ and T₅ in the two groups were recorded. At T₃, T₄ and T₅, pain changes were evaluated by Prince-Henry scores. The levels of prostaglandins E₂ (PGE₂), norepinephrine (NE) and cortisol (Cor) were detected by enzyme-linked immunosorbent assay. The partial pressure of arterial oxygen was detected by a blood gas analyzer, and oxygenation index (OI) was calculated. The occurrence of postoperative adverse events (PAEs) in the two groups was recorded. Results From T₃ to T₅, levels of PGE₂, NE, and Cor in SAPB group were significantly lower than those in TPVB group (P＜0.05). OI at T₂ to T₄ was significantly lower than that at T₁, while OI at T₅ was significantly higher than that at T₂, T₃, and T₄ in both groups (P＜0.05). From T₂ to T₄, OI in SAPB group was significantly higher than that in TPVB group (P＜0.05). Compared with TPVB group, the cumulative consumption of sufentanil in SAPB group slightly decreased from T₃ to T₅, but the differences were not statistically significant (P>0.05). The incidences of nausea and vomiting (6.15% vs 18.46%, χ²=4.561, P=0.033), atelectasis(3.08% vs 12.31%, χ²=3.900, P=0.048) and hypotension (7.69% vs 20.00%, χ²=4.127, P=0.042) in SAPB group were lower than those in TPVB group. Conclusion Compared with TPVB, ultrasound-guided SAPB can relieve stress response, promote the recovery of pulmonary oxygenation and reduce PAEs in patients undergoing thoracoscopic radical resection of lung cancer, but whether it can significantly reduce the dosage of opiates needs to be further explored.