The Application And Analysis Of Combining Low Dose Naloxone And Ropivacaine In Supraclavicular Brachial Plexus Block

Objective:To observe the effect of low dose naloxone combine with ropivacaine for supraclavicular brachial plexus block,then discuss the related mechanism of low dose naloxone in enhancing analgesia by observing the dynamic changes of plasma concentration of?-endorphin and interleukin-10.Methods:A randomized double-blind control design was used in this experiment.Seventy ASA physical status ? and ? patients aged 18~65 years scheduled for elective upper limb surgery under supraclavicular brachial plexus block in the Second Hospital of Lanzhou University from January to June of 2017 were included.Using a randomization list,patients were allocated into 2groups of thirty five patients each.Group R(Group ropivacaine)received 15 ml of 0.75%ropivacaine diluted with 15 ml normal saline to 30 ml.Group N(Group naloxone)received 15 ml of0.75% ropivacaine and naloxone 10ug(1ml)diluted with 14 ml normal saline to30 ml.Supraclavicular brachial plexus block was performed under the guidance of ultrasound in both groups.The mean arterial pressure(MAP),heart rate(HR)and respiratory rate(RR)were recorded at five time points as follows,before the block begins(T0),at the end of the block(T1),antisepsis(T2),surgical skin cut(T3)and the end of the operation(T4).Furthermore,The onset and duration time of sensory and motor blockade,visual analog score(VAS)of3,6,12,18,24 h postoperatively,time of first request for dezocine and total amount of dezocine needed in 24 h after surgery,the incidence of postoperative nausea and vomiting and patient's satisfaction score for analgesia were measured.At the same time,the plasma Beta-endorphin(?-EP)and interleukin-10(IL-10)concentrations were measured at three time points: before block,6hours after operation and 24 hours after operation.Results:There was no significant difference between the two groups in the onset time of sensory or motor nerve block and the vital signs at different time points(P>0.05).The duration of sensory and motor blockade,time of first request for dezocine were prolonged in Group N compared to Group R,differences are statistically significant(P<0.05).The 6,12 h postoperatively VAS of Group N was lower than that of Group R,the 18 h postoperatively VAS is higher than that of Group R,differences are statistically significant(P<0.05).Total amount of dezocine needed in 24 h after surgery and the incidence of PONV were lower in Group N compared to Group R,differences are statistically significant(P<0.05).Ptients' satisfaction score for analgesia in24 h after surgery were higher in Group N compared to Group R,differences are statistically significant(P<0.05)..At 6h postoperatively,the concentration of plasma ?-EP in Group N was lower than that in Group R,the plasma IL-10 level was higher than that of Group R,differences are statistically significant(P < 0.05).Conclusion:Low dose naloxone(10ug)combine with ropivacaine for supraclavicular brachial plexus block,prolonged the duration of sensory and motor blockade,the dosage of adjuvant analgesic drugs and the occurrence of drug-related adverse reactions,without affecting the onset time of sensory and motor nerve block.As a result,provided patients with satisfactory postoperative analgesia,is a safe and effective drug combination scheme.