Effect Of Dexamethasone And Dexmedetomidine On Intercostal Nerve Block For Thoracoscopic Pneumonectomy

Objective: Peripheral nerve block is widely used in clinical practice.Studies have shown that the addition of dexamethasone or dexmedetomidine to local anesthetics may prolong the duration of peripheral nerve block.Here,we investigated whether combining ropivacaine with two adjuvants(dexamethasone and dexmedetomidine)can further prolong the duration of analgesia.Methods: Eighty patients received general anesthesia undergoing thoracoscopic pneumonectomy with intercostal nerve block were randomly allocated into four groups(n = 20,each):(1)ropivacaine Group(Group R): 0.5% ropivacaine 30 ml for intercostal nerve block;(2)ropivacaine combined with dexamethasone Group(Group RS): 0.5% ropivacaine combined with 10 mg dexamethasone 30 ml for intercostal nerve block;(3)ropivacaine combined with dexemedetomidine Group(Group RM): 0.5% ropivacaine combined with 1 μg/kg dexemedetomidine 30 ml for intercostal nerve block;(4)ropivacaine combined with dexamethasone and dexemedetomidine Group(Group RSM): 0.5% ropivacaine combined with 10 mg dexamethasone and 1 μg/kg dexemedetomidine 30 ml for intercostal nerve block.At the end of the surgery,the intercostal nerve block was performed by the surgeon under thoracoscopic direct vision.Demographic data of sex,age,body mass index,operation time and extubation time were recorded.The duration of analgesia and total postoperative fentanyl consumption were recorded.VAS score and Ramsay score were recorded at 6,12,24,36,48 h after surgery.MAP and HR were recorded before surgery and 6,12,24,36,48 h after surgery.Adverse effects such as respiratory depression,nausea and vomiting were also recorded.Results: No significant differences in patient characteristics were evident between each group.The duration of analgesia in Group RSM(824.2 ± 105.1 min)was longer than that in Group RS(611.5 ± 133.0 min),Group RM(602.5 ± 108.5 min)and Group R(440.0 ± 109.6 min)(P < 0.001).Total postoperative fentanyl consumption was lower in Group RSM(106.0 ± 84.0 μg)compared to Group RS(243.0 ± 175.2 μg),Group RM(237.0 ± 98.7 μg)and Group R(369.0 ± 134.2 μg)(P < 0.001).At 6 h postoperatively,VAS in Group R was higher than those in the other three groups(P < 0.001)and no statistical difference among Group RS,Group RM and Group RSM.At 12 h postoperatively,VAS in Group RSM was lower compared with Group RS,Group RM and Group R(P < 0.001).At 48 h postoperatively,VAS was lower in Group RSM compared with Group R(P = 0.043).No significant differences was observed in the incidences of hypotension,bradycardia,vomiting,nausea,and dizziness among the four groups.Conclusion: Ropivacaine combined with dexamethasone or dexmedetomidine for intercostal nerve block prolong the duration of analgesia and reduce the total postoperative fentanyl consumption compared with ropivacaine alone in patients undergoing thoracoscopic pneumonectomy;The addition of two adjuvants(dexmedetomidine and dexamethasone)to ropivacaine for intercostal nerve block can further prolong the duration of analgesia and reduce the total postoperative fentanyl consumption,compared with each adjuvant alone with ropivacaine in patients undergoing thoracoscopic pneumonectomy.