Clinical Research Of Puncture Methods And Local Aneshthetic Dosage Of Obturator Nerve Block

Clinical Research of Puncture Methods and Local Aneshthetic Dosage of Obturator Nerve BlockObturator nerve block (ONB) is an effective method to inhibit the obturator nerve reflex induced by electric stimulation during transurethral resection of bladder tumor(TURBT). ONB methods with more advantages have become the goal of anesthetists’ persuit along with the increasing utilization of ONB. This study is the clinical research of puncuture methods and local anesthetic dosage of ONB.PART1:Clinical Reasearch of the Effects of Suprainguinal Approach and Pubic Tubercle Side Verticle Approach Obturator Nerve Block for Obturator Nerve Reflex Inhibition during TURBTObjective:To compare the efficacy of suprainguinal approach, pubic tubercle side verticle approach and pubic tubercle approach to ONB in patients undergoing TURBT.Methods:75ASA physical status Ⅰ or Ⅱ patients of both sexes, aged41-80yr, with body mass index of17.5-31.0kg/m2, scheduled for elective transurethral resection of bladder tumor, were randomly divided into3groups (n=30) using a random number table:pubic tubercle approach group (group P, n=30), pubic tubercle side verticle approach group (group V, n=15) and suprainguinal approach group (group S). Nerve blocks were performed using a100-mm insulated needle for ONB (21-gauge) under the guidance of a nerve stimulator. In group P, the insertion point of the needle is1.5cm lateral and1.5cm inferior to the pubic tubercle. In V group, the needle insersion point is at one finger beside the pubie tubercle. In S group, the insertion point of the needle is at the midpoint of the line drawn in the inguinal crease between the femoral artery and the inner border of the adductor longus tendon and the needle was advanced3cm cephalad in the major axis of thigh. The number of puncture eliciting contraction of adductor muscle, time taken to elicit contraction of adductor muscle starting from onset of puncture, depth of puncture, and highest Visual analog scale (VAS) pain scores during application of the block were recorded. The myodynamia of adductor muscle was evaluated. The development of complications was also recorded.Results:1st:Compared with group P, the number of puncture, highest VAS scores, and myodynamia of adductor muscle at4and6min of blockade were significantly decreased, the time taken to elicit contraction of adductor muscle was shortened, and the success rate of puncture at first attempt was increased in group S (p<0.05or0.01). There was no significant difference in the incidence of puncture point bleedings between the two groups (p>0.05).2nd:Compared with group P, the number of puncture, the time taken to elicit contraction of adductor muscke was significantly increased and the success rate of puncture at first attempt was decreased in V group (p <0.05or0.01). There was no significant difference in the incidence of puncture point bleedings between the two groups (p>0.05).Conclusion:1:The suprainguinal approach for ONB offers more accurate location, faster onset, lighter degree of noxious stimulation and better safety than the pubic tubercle approach in patients undergoing transurethral resection of bladder tumor.2: Compared with classical pubic tubercle approach, pubic tubercle side verticle approach was with inaccurate location.PART2:Clincal Research of the Effects of Ultrasound and Ultrasound with Nerve Stimulation Guided Obturator Nerve Block for Obturator Nerve Reflex Inhibition during TURBTObjective:To compare the effects of ultrasound and ultrasound with nerve stimulation guided ONB with only nerve stimulation guided ONB in patients undergoing transurethral resection of bladder tumor so as to realize wether there are advantages of ultrasound guided ONB.Methods:1.63ASA physical status I or II patients of both sexes, aged18-80yr, with body mass index of19-30kg/m2, scheduled for elective transurethral resection of bladder tumor, were randomly divided into3groups (n=21) using a random number table:control group (group C, n=21), out-plane group (group O, n=21) and in-plane group (group I, n＝21). Nerve blocks were performed using a100-mm insulated needle for ONB (21-gauge) under the guidance of a nerve stimulator in C group. Out-plane and in-plane technique of ultrasound was used in O group and I group respectively. Equal dosage of1.5%lidocaine was used in each group for ONB. Adductor muscle strength was tried to elicited again by1mA current of a nerve stimulator using classical pubic tubercle approach4minutes and8minutes after the first block of obturator nerve in each group and the result of the elicitation as well as the successful rate of ONB of each group were recorded.2.90ASA1/Ⅱ patients, male or female, age39-77yr, BMI19-30kg/m2undergoing selective TURBT were randomly divided into three groups, named S (nerve stimulater n=30) group; USO (ultrasound and nerve stimulater outplane n=30) group and USI(ultrasound and nerve stimulater inplane n=30) group. Success rate of the first puncture, VAS pain score, insertion-adductor contraction interval (ICI), puncture times corresponding to ICI, adductor strength, incidence of complication and validity were observed during and post ONB.Results:1. Compared with C group, the cases of adductor muscle re-elicitation increased significantly in O group and I group and the cases whose adductor muscle could not be re-elicited again was significantly decreased in I group than that in O group.2.There was no significant difference of the general validity, adductor strength and complication incidence between S and USO groups. The success rate of the first puncture was significantly higher in USO group than that of S group (p<0.01). VAS pain score, ICI and puncture times were significantly lower in US group than those of S group (p<0.05). The success rate of the first puncture was significantly higher in USI group than those of S group and USO group (p<0.05), but the adductor muscle strength decreasion and success rate after ONB are significantly lower than thouse in S group and USO group(p<0.05).Conclusion:1. To inhibit the obturator nerve reflex during TURBT, ONB guided by ultrasound was with longer onset time and less successful rate compared with that guided by nerve stimulator.2.Compared with nerve stimulation guided ONB, ultrasound outplane technique with nerve stimulation guidance was with less puncture time, less pain and more accurate positioning and ultrasound inplane through adductor longus approach with nerve stimulation guidance was with higher incidence of incomplete block of obturator nerve.PART3:Effective Concentration and Effective Volume of1.5%Lidocaine Required to Prevent Obturator Nerve Reflex during TURBT in50%of PatientsObjective:To determine the the effective concentration of lidocaine and the effective volume of1.5%lidocaine required for ONB using a nerve stimulator to prevent obturator nerve reflex during TURBT in50%of patients(ECso&EV50).Methods:1.24ASA Ⅰ or Ⅱ patients aged18-80yr with body mass index19～30kg/m undergoing elective operation of TURBT on lateral wall were enrolled in the study. Selective block of the two branches of the obturator nerve (anterior and posterior) was performed at the above-inguinal level with lidocaine. EC50was determined by up and down sequential trial. The ratio of two consecutive concentrations was1.2.2.36ASA Ⅰ or Ⅱ patients aged41～80yr with body mass index19～35kg/m2undergoing elective operation of TURBT on lateral wall were enrolled in the study. Selective block of obturator nerve was performed with1.5%lidocaine using classical pubic approach with a nerve stimulator. EV50was determined by up and down sequential trial. The ratio of two consecutive concentrations was1.1.Results:1. The EC50of lidocation was0.57%. The confidence interval was0.55%--0.59%.2. The EV50of1.5%lidocaine was5.53ml. The confidence interval was5.10ml-6.00ml.Conclusion:1. The EC50of lidocation for suppression of obturator nerve reflex during TURBT was0.57%.2. The EV50of1.5%lidocaine for suppression of obturator nerve reflex with pubic tubercle approach using a nerve stimulator during TURBT was5.53ml. PART4:Influence of Ultrasound Guidance and Dexmedetomidine on Effective Volume and Effective Concentration of Lidocaine Required to Prevent Obturator Nerve Reflex during TURBT in50%of PatientsObjective:To observe the effects of Dexmedetomidine as an adjuvant on the medium effective concentration(ECso) of lidocaine and the effective volume of1.5%lidocaine required for ONB under B ultrasound and nerve stimulator guidance to prevent obturator nerve reflex during TURBT in50%of patients(EVso).Methods:1.27ASA Ⅰ or Ⅱ patients aged28～76yr with body mass index19～30kg/m2undergoing elective operation of TURBT on lateral wall were enrolled in the study. Selective block of obturator nerve was performed with1.5%lidocaine under B ultrasound and nerve stimulator guidance. EV50was determined by up and down sequential trial. The ratio of two consecutive concentrations was1.2.2.60ASA Ⅰ or Ⅱ patients, male or female, aged18～80yrs with body mass index19～30kg/m2undergoing elective operation of TURBT on lateral wall were divided into two groups named control (C group, n=30) group and dexmedetomidine (D group, n=30) group. Selective block of the two branches of the obturator nerve (anterior and posterior) was performed at the supra-inguinal level with only lidocaine in C group and1μg·kg-1dexmedetomidine combined with lidocaine in D group. EC50was determined by up and down sequential trial. The ratio of two consecutive concentrations was1.2.Results:1. The EV50of1.5%lidocaine was5.26ml. The confidence interval was4.99ml～5.54ml and have no significant difference with EV50under only nerve stimulator.2. The EC50(95%confidence interval) of lidocation was0.57%(0.54%～0.62%) in C group and0.29%(0.28%～0.38%) in D group respectively. The EC50of lidocaine was lower in D group than in C group (p<0.05)Conclusion:1. The EV50of1.5%lidocaine for suppression of obturator nerve reflex by ONB under B ultrasound and nerve stimulator guidance during TURBT was5.26ml and have no significant with EV50under only nerve stimulator.2. Dexmedetomidine1μg·kg-1combined with lidocaine can decrease the EC50of lidocation for obturator nerve block during transurethral resection of bladder tumor. Summary1. Compared with classical pubic tubercle approach, the suprainguinal approach for ONB offers more accurate location and lighter degree of noxious stimulation; but the pubic tubercle side verticle approach was with inaccurate location.2. Compared with nerve stimulator guidedance, ultrasound guidance ONB, to inhibit the obturator nerve reflex during TURBT, was with longer onset time and less successful rate.3. Compared with nerve stimulation guided ONB, ultrasound outplane technique with nerve stimulation guidance was with less puncture time, less pain and more accurate positioning and ultrasound inplane through adductor longus approach with nerve stimulation guidance was with higher incidence of incomplete block of obturator nerve.4. The EC50of lidocation for suppression of obturator nerve reflex during TURBT was0.57%.5. The EV50of1.5%lidocaine for suppression of obturator nerve reflex with pubic tubercle approach using a nerve stimulator during TURBT was5.53ml.6. The EV50of1.5%lidocaine for suppression of obturator nerve reflex by ONB under B ultrasound and nerve stimulator guidance during TURBT was5.26ml and have no significant with EV50under only nerve stimulator.7. Dexmedetomidine1μkg-1combined with lidocaine can decrease the EC50of lidocation for obturator nerve block during transurethral resection of bladder tumor.