Correlation Study Of Ropivacaine Concentration In Continuous Erector Spinae Plane Block With Patient-Controlled Analgesia

Objective To observe the influence of analgesic effect,systemic inflammation,enhanced recovery after surgery,adverse reactions and chronic pain by different ropivacaine concentration in continuous erector spinae plane block with patient-controlled analgesia after thoracoscope surgery.Meanwhile further research effective and lower ropivacaine concentration in this new technology to reduce use of local anesthetic and increase safety,in order to guide the erector spinae plane block techniqueMethods 120 patients,who were aged 16 to 75 years with American Society of Anesthesiologists(ASA)physical status ?-?,and with New York Heart Association(NYHA)class ?-?,and with body mass index(BMI)of 17 to 28,and scheduled for thoracoscopic surgery in our hospital from January 2018 to October 2018 were randomly divided into 0.15%ropivacaine group(A group),0.2%ropivacaine group(B group),0.3%ropivacaine group(C group)and 0.4%ropivacaine group(D group).A group(n=30)received ultrasound guided continuous erector spinae plane block with patient-controlled nerve analgesia,with continuous infusion of 0.15%ropivacaine and 35ml of 0.0.15%ropivacaine for the first does;B group(n=30)received ultrasound guided continuous erector spinae plane block with patient-controlled nerve analgesia,with continuous infusion of 0.2%ropivacaine and 35ml of 0.2%ropivacaine for the first does;C group(n=30)received ultrasound guided continuous erector spinae plane block with patient-controlled nerve analgesia,with continuous infusion of 0.3%ropivacaine and 35ml of 0.3%ropivacaine for the first does;D group(n=30)received ultrasound guided continuous erector spinae plane block with patient-controlled nerve analgesia,with continuous infusion of 0.4%ropivacaine and 35ml of the same ropivacaine for the first does.Postoperative visual analogue scale(VAS)and prince henry pain scale(PHPS)and Bruggrmann comfort scale(BCS)were recorded at 1 hour(T1),4 hour(T2),8 hour(T3),24 hour(T4),2 days(T5),3 days(T6),4 days(T7),30 days(T8),60 days(T9)after surgery.The time of postoperative first out-of-bed activity,passage of gas by anus,bowel movement,chest tube removal,discharge were recorded.Moreover,sleep quality scale,adverse reactions and chronic pain were also recorded.The serum white blood cells(WBC)and neutrophils and C-reactive protein(CRP)levels and changes at pre-op and the first three days after surgery were recorded as well.Results The PCA was less in group D compared with group B,and the cumulative consumption of ropivacaine between 60h after surgery was less in group C and D compared with group A and B(P<0.05).Compares to group A,the resting and the upper arm activity and the deep breathing and coughing VAS score and PHPS score in group D at several different time point after surgery were lower(P<0.05).And no statistically significant difference among four groups in time of postoperative first out-of-bed activity,passage of gas by anus,bowel movement,chest tube removal,discharge(P>0.05).Furthermore,group C had better postoperative sleep quality compared with group A.Compares with group A,the neutrophil counts difference between postoperative day and preoperative of other groups was lower(P<0.05).No significant differences in postoperative WBC counts and CRP levels among four group(P>0.05).Compares to non-PTPS patients,the postoperative day,the difference between postoperative day and preoperative,the mean of 1 to 3 days after surgery of content of CRP was higher than PTPS patients(P<0.05).Besides,the neutrophil counts difference between postoperative day and preoperative,postoperative CRP levels was relative to the occurrence of PTPS(P<0.01).Conclusion Choose 0.15%to 0.4%ropivacaine be used for continuous erector spinae plane block after thoracoscopic surgery can reduce postoperative pain,adverse reactions and enhance recovery after surgery and save medical resources.Compares to low concentration Irom 0.15%to 0.2%ropivacaine,the high concentration from 0.3%to 0.4%ropivacaine lore likely to help increase the effect of analgesia,improve sleep,decrease the inflammatory response and the occurrence of PTPS.Thus improve patient comfort,satisfaction and quality of life.Because there is no differences between 0.3%ropivacaine and 0.4%ropivacaine,so with the further increase of ropivacaine concentration dose will not enhance the effect,but will increase the risk of local anesthetic poisoning.Besides,if we can lower growth of the postoperative neutrophil counts and CRP levels,it will decrease risk of PTPS.