Observation On Effect Of Ropivacaine Combined With Compound Betamethasone Through Thoracic Paravertebral Block After Off-pump Coronary Artery Bypass Grafting

Objective: In addition to the somatic pain caused by skin incision and sternotomy,cardiac surgery also involves the visceral pain caused by cardiac compression and traction,and the placement of mediastinum and thoracic drainage tube will cause strong postoperative pain,which will cause a series of stress reactions and can compromise respiratory functionin.If the acute pain can not be well controlled,it can even be transformed into chronic pain.Dexamethasone as an adjuvant in ultrasound-guided paravertebral block can improve postoperative pain.Dexamethasone is present in non-particulate form in local anesthetic solution,while betamethasone is partially present in particulate form.The addition of steroids may exert a membrane-stabilizing effect on C fibres and can produce more analgesia.Additionally,steroids have a directanti-inflammatory effect,resulting in a prolonged effect when used on conjunction with local anaesthetics.We aimed to compare ultrasound-guided paravertebral block performed using ropivacaine alone and ropivacaine with betamethasone in terms of the intra and postoperative analgesic requirements and hemodynamics,postoperative complications and ICU stay.Methods: Sixty patients undergoing OPCABG were enrolled in the present randomized,controlled prospective study.All patients were performed paravertebral block under ultrasound-guidance.Group R: 0.2% ropivacaine T4-5 PVB(each side 20ml),Group BR: 0.2% ropivacaine combined with compound betamethasone(5+2mg)T4-5 PVB(each side 20ml).Patients were proceed with induction after paravertebral block worked and none of adverse reactions occurred.Hemodynamics(arterial blood pressure,heart rate)into room,after induction,at sternum incision,before bypass grafting,after bypass grafting,close the sternum,at the end of the surgery,extubation and at 12 h,24h and 48 h postoperatively were recorded.CPOT score at 1h,2h,4h and 6h after surgery were analyzed.Resting and exercising VAS score at 12 h,24h,36 h and 48 h after surgery were also analyzed.The use of other analgesic drugs and the occurrence of complication were recorded.Secondary outcome measures: postoperative nausea and vomiting,postoperative respiratory depression,hyperglycemia,wound infection.Results: There were no statistical differences between the groups regarding CPOT scores and BP,HR.The VAS scores at 12 h,24h,36 h and 48 h after surgery significantly lower in Group BR than in Group R.There were fewer patients who needed rescue analgesia in the Group BR.There was no difference in postoperative nausea/vomiting between the two groups.AEs showed no differences between the two groups.There were no statistical differences among the groups regarding the extubation time,rescue analgesic medication,length of intensive care unit stay,or length of hospital stay.Conclusion: Ropivacaine combined with compound betamethasone in PVB for postoperative analgesia can improve patient satisfaction,prolong the duration of the analgesia and won’t increase the incidence of adverse reaction.