The Clinical Studies Of Different Doses Of Dexmedetomidine For Spinal Anesthesia In Patients

Objective: This study was conducted to evaluate the clinical effect of adding differentdoses of dexmedetomidine to intrathecal bupivacaine on sensory and motor blockadeeffect, hemodynamics, analgesic sedation extent and adverse effects in patients. Toprovide a reference in further clinical applications.Methods: A total of80patients undergoing lower abdomen or lower limb surgery wereallocated to4groups (n=20).the experimental group: D1:0.75%bupivacaine1.5ml+dexmedetomidine5ug+saline diluted to3ml; D2:0.75%bupivacaine1.5ml+dexmedetomidine7.5ug+saline diluted to3ml; D3:0.75%bupivacaine1.5ml+dexmedetomidine10ug+saline diluted to3ml; control group C:0.75%bupivacaine1.5ml+saline diluted to3ml. Acupuncture Method was used to measure sensory blocklevel.modified Bromage score was used to elevate motor block level. The change ofSBP、DBP、 HR and NI (Narcotrend index, NI) were monitored and recorded at timebefore intrathecal injection （T0）and5minute later (T1),10minute later (T2),15minute later (T3),20minute later (T4),30minute later (T5)，60minute later (T6),90minute later (T7)，120minute later (T8) after the start of anesthesia,The onset time toreach peak sensory and motor level, the duration time for sensory and motor block, VASscores and postoperative adverse reactions were observed.To follow-up the complications,post-spinal headache, cauda equine syndrome and transient neurological syndrome untildischarging.Results:1.There were no statistically significant between four groups with regard to age, gender, weight, height and operative time.2.The changes of HR, SBP, DBP, NI index were no significant difference at T0among fourgroups. The value of SBP,DBP and HR showed significantly lower (p <0.05) at each timepoint (T2, T3, T4, T5,). SBP、DBP and HR in group D2and D3were lower than D1at T2–T5, The group D3was lowest(p <0.05); Within group comparsion: The changes of HR,SBP, DBP was decreased in group D1at T3–T5comported to T0; SBP、DBP and HR ingroup D2and D3were decreased at T2–T5comported to T0. there was no change in groupC at T2–T8(p <0.05). Earlier sensory and motor block, the longer duration of sensory andmotor block as well as postoperative analgesia were seen in experimental group (D1、D2、D3) as compared with group C（p<0.05）. The onset time of anesthesia, the longerduration of sensory and motor block of group D3was significantly different to groupD2~D3.3.The NI index was no statistically significant in the experimental group compared withthe control group,（p>0.05）.while there were no significantly difference between theexperimental groups.(p>0.05).The NI at T1-T8was no statistically difference comparingwith T0in group D1、D2and D3.（p>0.05）4.The mean visual analog scale showed a significantly difference at24hourspostoperatively between the experimental group and the control group(p<0.05). The visualanalog scale was lowest in group D3compared with D2and D1(p<0.05).5.The adverse reactions (nausea, vomiting, chills, itching, respiratory depression) in theexperimental group and the control group was statistically significant,(p <0.05).Theincidence of group D1was lowest. Post-spinal headache, cauda equine syndrome andtransient neurological syndrome were nerve visited in four groups.Conclusion:1. This study showed that5ug dexmedetomidine compound of bupivacaine in patientsundergoing lower abdomen or lower limb surgery. It provided hemodynamic stability andenhancedn the effect of local anesthesia. also could prolong postoperative analgesia,reduce the incidence of adverse reactions.2. With increasing doses of dexmedetomidine,The effect of sensory and motor block isenhanced, hemodynamic variables occur simultaneously. 4.Dexmedetomidine composites of bupivacaine intrathecally application does not increasethe incidence of intraoperative and postoperative nausea, vomiting, chills, itching andrespiratory depression.