***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND AND OBJECTIVES High-dose transarterial technique results in highly effective axillary block . The multiple nerve stimulation technique ( MNS ) requires more time and experience . This prospect i ve study aim ed at comparing onset and success rate of multiple-injection axillary brachial plexus block using two methods of nerve location : transarterial or multiple nerve stimulation technique . METHODS Axillary block was initially induced with 800 mg lidocaine with epinephrine . The transarterial group received deeply injected 30 mL of 1.6 % lidocaine with epinephrine , and 20 mL superficially to the axillary artery . For the multiple nerve stimulation group , three terminal motor nerves were electrolocated and blocked with 20 mL , 20 mL and 10 mL. Blockade was considered effective when analgesia was present in all sensory nerves distal to the elbow . RESULTS Onset ( 8.8 + /- 2.3 min versus 10.2 + /- 2.4 min ; p-value = 0.010 ) was significantly shorter in the transarterial group . Complete sensory block of all four nerves ( median , ulnar , radial and musculocutaneus ) was achieved in 92.5 % versus 83.3 % for multiple nerve stimulation group and transarterial group , respectively , without significant difference ( p = 0.68 ) . Musculocutaneous nerve was significantly easier to be blocked with the aid of peripheral nerve stimulator ( p = 0.034 ) . CONCLUSIONS Both MNS technique for axillary block with nerve stimulator ( 3 injections ) and transarterial technique ( 2 injections ) promote similar results . Musculocutaneous nerve is more easily blocked with the aid of peripheral nerve stimulator . MNS technique has required less supplementary blocks and has delayed beginning of surgery Background and Objectives : A triple-injection technique ( injections at the median , musculocutaneous , and radial nerves ) for axillary block affords a high incidence of complete block ( all the nerves below the elbow ) . However , in certain surgeries , only 1 or 2 nerves are involved in the surgical field . The aim of this prospect i ve r and omized study was to test the effectiveness of surgical anesthesia of a " selective " approach in which only the nerves involved in surgery were electrically located and injected . Methods : Three types of surgery were selected . Type 1 included surgery on the fifth finger , type 2 included superficial surgery ( without bone involvement ) on the palm or on the dorsum of the h and , and type 3 included any surgery on the first 3 fingers . For each type , 138 patients were enrolled and divided into 2 groups : group SEL in which only the nerves involved in the surgical field ( 1 or 2 ) were located and injected and group TNS in which a st and ard triple-nerve stimulation technique was used . Results : A lower rate of surgical anesthesia ( 84 % vs 92 % ; P < 0.05 ) was recorded in group SEL considered as a whole : this was mainly due to the significant difference recorded in type 2 surgery ( 75 % vs 93 % ; P < 0.05 ) . More patients needed intravenous administration of fentanyl for tourniquet pain ( 18 % vs 8 % ; P < 0.005 ) and of midazolam for intraoperative anxiety ( 20 % vs 8 % ; P < 0.005 ) in group SEL considered as a whole . In type 1 , improved patient comfort at block performance ( P < 0.05 ) , a 7-min saving on total anesthetic time ( P < 0.001 ) , and a higher need for midazolam administration ( P < 0.05 ) were recorded in group SEL . In type 2 , a higher need for midazolam administration ( P < 0.05 ) was recorded in group SEL . In type 3 , no clinical ly significant differences between the groups were recorded . Conclusions : A st and ard triple-nerve stimulation technique seems to be preferable to the selective approach even when a limited number of nerves are involved in the surgical field The perivascular technique of axillary brachial plexus block results in incomplete block of radial and musculocutaneous nerves in 10 - 20 % of patients . With the transarterial technique and a large dose of mepivacaine , success rates of 99 % have been reported . We have compared the clinical efficacy of these techniques in 50 patients using 1 % mepivacaine 45 ml with adrenaline . If required , the block was supplemented with additional blocks of single nerves or i.v . alfentanil . Additionally , eight patients in each group were studied with  computed tomography  after contrast medium was added to 0.5 % bupivacaine 40 ml . There were no statistically significant differences in sensory or motor block between the groups at 20 min or in the plasma concentrations of mepivacaine measured 0 - 45 min after injection . In the CT scans , both proximal and distal spread of the contrast medium were more common after perivascular than after transarterial block . The distribution of the contrast medium was not related to the efficacy of the block Perivascular axillary blockade was performed on 90 patients with the aid of a catheter technique . The patients were r and omly allocated to receive either 40 , 50 or 60 ml of 1 % mepivacaine with adrenaline 1:200,000 . Blood concentrations of mepivacaine were measured up to 90 min after injection in seven , eight and ten of the patients from the three groups . Sensory and motor blockade was evaluated 20 , 30 and 40 min after injection . All groups showed the same temporal development of the blockade , i.e. improval of the blockade during the period from 20 to 40 min after injection , but no difference was found in the sensory or motor blockade between the three groups . However , a further analysis of the incomplete blockades showed a better quality of the sensory blockade in the groups given 50 and 60 ml than in the group given 40 ml . None of the 90 patients showed any signs of systemic toxic reactions . The mean peak values of blood concentrations were 0.5‐1.0 μg/ml higher in the groups A given 50 ml and 60 ml than in the group given 40 ml . On the basis of the present and two previous investigations on the dose response in perivascular axillary blockade , a dose of 50 ml 1 % mepivacaine with adrenaline or I r another equivalent drug with vasoconstrictor is recommended Endoscopic carpal tunnel release has the advantage over open release of reduced tissue trauma and postoperative morbidity . Limited open carpal tunnel release has also been shown to have comparable results , but is easier to perform and is safer . We have compared the results of both techniques in a prospect i ve , r and omised trial . Thirty patients with bilateral carpal tunnel syndrome had simultaneous bilateral release . The technique of release was r and omly allocated to either two-portal endoscopic release ( ECTR ) or limited open release using the Strickl and instrumentation ( LOCTR ) . The results showed that the outcome was similar at follow-up of one year using both techniques . However , the LOCTR group had significantly less tenderness of the scar at the second and fourth postoperative week ( p < 0.01 ) . There was also less thenar and hypothenar ( pillar ) pain after LOCTR . Subjective evaluation showed a preference for LOCTR OBJECTIVE To investigate the clinical effects and safety of the technique of axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture . METHODS Eighty patients scheduled for elective operation were r and omly divided into 2 equal groups to undergo axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture technique ( Group U ) or nerve stimulator-guided brachial plexus blocking ( Group N ) . The main branches of brachial plexus ( radial , median , ulnar , and musculocutaneous nerves ) were localized by ultrasound-guided or nerve stimulator-guided techniques . In Group U 8 ml of mixed anesthetic solution containing isovolumetric 0.75 % ropivacaine and 2 % lidocaine was injected into the 4 main branches of brachial plexus , with a total volume of 32 ml . The ultrasonic manifestations of the brachial plexus and its surrounding tissues were observed . The values of diameter and depth of the 4 nerves and the distance of the musculocutaneous nerve to the midpoint of axillary artery were measured . The manipulation time , onset time , maintaining time , efficacy of blocking , and incidence of complication were recorded . RESULTS The manipulation time of Group U was 5.2 + /- 2.1 min , significantly shorter than that of Group N ( 14.6 + /- 3.2 min , P = 0.000 ) , The onset times of the median , radial , and ulnar nerves of Group U were 3.3 + /- 1.9 min , 3.0 + /- 1.7 min , and 3.4 + /- 1.9 min respectively , all significantly shorter than those of Group N ( 4.6 + /- 2.0 min , 7.3 + /- 7.4 min , and 6.4 + /- 6.1 min respectively , P < 0.01 or P < 0.05 ) . The anesthetic success rate of Group U was 100 % , significantly higher than that of Group N ( 77.5 % , P = 0.005 ) . The rate of accidental puncture to blood vessel of Group U was 0 , significantly lower than that of Group N ( 40 % , P = 0.000 ) . CONCLUSION With significantly higher anesthetic success rate , shorter manipulation time and onset time , and lower complication rate , the technique of axillary approach brachial plexus blocking by ultrasound-guided four points via one-puncture is a safe and reliable blocking method in comparison with the nerve stimulator-guided method Perivascular  axillary blockade  was performed on 90 patients with the aid of a catheter technique . All blockades were performed by the same anaesthetist , who practised perivascular axillary blockade three or four times a day . The patients were r and omly allocated to three groups . The injected volume of local anaesthetic was constant in each group : 40 ml mepivacaine with adrenaline . The concentration and , consequently , the amount ( mg ) were variable factors : ½% ( 200 mg ) , 1 % ( 400 mg ) and 1½% ( 600 mg ) . Sensory and motor blockade were tested 30 min after each injection . All three groups showed a high incidence of analgesia ( 70%‐100 % ) in all cutaneous segments , and none of the blockades showed total failure of the sensory blockade . The lowest incidence of sensory blockade was found in the areas innervated by the axillary , the radial and the musculocutaneous nerves , but no difference was found between the groups . However , the motor blockade was found to improve with increasing concentration of local anaesthetic solution BACKGROUND Axillary plexus blocks are usually guided by ultrasound , but alternative methods may be used when ultrasound equipment is lacking . For a nonultrasound-guided axillary block , the need for three injections has been question ed . OBJECTIVES Could differences in block success between single , double and triple deposits methods be explained by differences in local anaesthetic distribution as observed by MRI ? DESIGN A blinded and r and omised controlled study . SETTING Conducted at Oslo University Hospital , Rikshospitalet , Norway from 2009 to 2011 . PATIENTS Forty-five ASA 1 to 2 patients scheduled for surgery were r and omised to three equally sized groups . All patients completed the study . INTERVENTIONS Patients in the single-deposit group had an injection through a catheter parallel to the median nerve . In the double-deposit group the patients received a transarterial block . In the triple-deposit group the injections of the two other groups were combined . Upon completion of local anaesthetic injection the patients were scanned by MRI , before clinical block assessment . The distribution of local anaesthetic was scored by its closeness to terminal nerves and cords of the brachial plexus , as seen by MRI . The clinical effect was scored by the degree of sensory block in terminal nerve innervation areas . MAIN OUTCOME MEASURES Sensory block effect and MRI distribution pattern . RESULTS The triple-deposit method had a higher success rate ( 100 % ) than the single-deposit method ( 67 % ) and the double-deposit method ( 67 % ) in blocking all cutaneous nerves distal to the elbow ( P = 0.04 ) . The patients in the triple-deposit group most often had the best MRI scores . For any nerve or cord , at least one of the single-deposit or double-deposit groups had a similarly high MRI score as the triple-deposit group . CONCLUSION Distal to the elbow , the triple-deposit method had the highest sensory block success rate . This could be explained to some extent by analysis of the magnetic resonance images . TRIAL REGISTRATION Clinical Trials.gov identifier : NCT01033006 This prospect i ve , r and omized , double-blind study was undertaken to evaluate the success rates of axillary brachial plexus block  performed with the help of a peripheral nerve stimulator when either one , two or four of the major nerves of the brachial plexus were located . Seventy-five patients undergoing upper limb surgery were r and omly allocated to one of 
    Output:
    
Subgroup analysis by method of nerve location showed that the effect size was greater when neurostimulation was used rather than the transarterial technique .
Otherwise there were no statistically significant differences between groups in any of the three comparisons on secondary analgesia failure , complications and patient discomfort .
AUTHORS ' CONCLUSIONS This review provides evidence that multiple-injection techniques using nerve stimulation for axillary plexus block produce more effective anaesthesia than either double or single-injection techniques .
However , there was insufficient evidence to draw any definitive conclusions regarding differences in other outcomes , including safety