Clinical Study On The Application Of Small Dose Of Hypobaric Ropivacaine With Combined Spinal-epidural Anaesthesia In Elderly Patients Undergoing Total Hip Arthroplasty

Objective To observe the small dose, hypobaric and volume of different concentrationsof ropivacaine with combined spinal-epidural anesthesia (CSEA)in the clinical effectand safety of70years old patients with total hip arthroplasty, and provide theoreticalbasis for clinical rational drug usage.Methods Choose ASAⅠ-Ⅱ, age70-100years old, weight45-75kg,75cases withcombined spinal-epidural anesthesia for elective tota hip arthroplasty were selected inour hospital, divided into three groups (I, II, III group, n=25): group Ⅰ, theconcentration of ropivacaine is0.15%which is prepared by0.75%ropivacaine1ml andsaline4ml; group Ⅱ, the concentration of ropivacaine is0.25%which is prepared by0.75%ropivacaine1ml and saline2ml; group III,the concentration of ropivacaine is0.5%which is prepared by0.75%ropivacaine2ml and saline1ml. Each spinalanesthesia volume was3ml. Limb upward, using a combination of Nanchang BioTekCorporation block matching in L3-4or L2-3gap puncture, confirm the needle into theepidural, insert the25G NIB type lumbar puncture needle, withdrawing after asuccessful puncture which confirmed by the cerebrospinal fluid flow, then injected3mldifferent concentrations of the ropivacaine. Lateral8min after anesthesia is fixed on oneside and then placed in position and disinfection. Regression of spinal anesthesia effect(about30-40minutes after lumbar anesthesia administered) of epidural with0.25%ropivacaine4-5ml, observe the analgesic onset time, motor block onset time, block levelhighest pain, duration of anesthesia, the maximum degree of motor block, pain andrecovery time, Bromage score, MAP, HR changes after treatment, surgery bleedingvolume and the incidence of adverse reactions.Results After Spinal anesthesia onset，Compared with group I and group II, the HR,MAP in group III were changed significantly after spinal anesthesia onset(P <0.05);there were no significant differences between the3groups of sensory block onsettime, The0.5%concentration group had the effect of the most high sharp pain block (P<0.05), Compared with group Ⅰ, the duration of anesthesia in group III and groupⅡwere longer(P <0.05); motor block onset time in group Ⅲ Shorter than groupⅡ (P<0.05),And also shorter than group I(P<0.01); the highest Bromage score of theipsilateral in group Ⅲ was3points, groupⅡand group Ⅰ were2or below2(P <0.05).As the concentration of ropivacaine increased, the level of anesthesia subsided to belowT10time and lower extremity motor recovery time prolonged, The difference betweenthe groups were significant(P<0.05); ompared with group Ⅱ, the intraoperativehemorrhage volume in group Ⅲ were higher(P<0.05), there was no significantdifference between group II and group Ⅰ.Conclusion The most suitable concentration of ropivacaine for70years old patientswith tota hip arthroplasty was0.25%, compared with0.15%ropivacaine, the effect ofthis concentration is better. compared with0.5%ropivacaine, this concentration wasmuch more safe, lumbar anesthesia effects subside before epidural0.25%ropivacaine3-4ml external connection can keep good anesthetic effect.