The Clinical Application Of Supraclavicular Fossa Approach Brachial Plexus Block In Upper Limb Surgery

Owing to perfect analgesic,brachial plexus block is widely used for upper limb surgery,especially in elderly or critically ill patients.There are many puncture approaches for brachial plexus block,including inter-scalene approach,supraclavicular approach,infraclavicular approach and axillary artery approach.Inter-scalene block could result in ulnar sparing,and have a bearing on stellate ganglion,vagus nerve and phrenic nerve block.Supraclavicular approach have perfect blockade effect,and patients can tolerate tourniquet well.However,the puncture site is close to the top of pleura,which gives rise to pneumothorax likely.The axillary artery approach locates at the end of brachial plexus and is suitable for forearm or hand surgery,but the blockade effect on radial side is perishing.Infraclavicular brachial plexus block is divided into medial bundle,lateral bundle and posterior bundle,which surround the axillary artery.Compared with supraclavicular and inter-muscular brachial plexus block,the blockade effect of infraclavicular brachial plexus on ulnar nerve is more accurate;compared with axillary block,the blockade effect of infraclavicular brachial plexus on musculocutaneous nerve and radial nerve is more perfect.Therefore,infraclavicular brachial plexus block is an ideal anesthetic method for elbow,forearm and hand surgery.There are several puncture methods for infraclavicular brachial plexus block.However,the puncture points of all methods for infraclavicular brachial plexus block are under the clavicle.When guided by ultrasound,it is not conducive to the development of needle,because the space for needle insertion is narrow and the angle of needle insertion is steep.It is difficult to operate the block.There is potential risk of damaging adjacent tissues.To solve this problem,we chose an ameliorated puncture point which located in supraclavicular fossa.In this series of studies,we performed supraclavicular fossa approach brachial plexus block?SFABPB?,and made some new attempts.In part one,infraclavicular brachial plexus block was under ultrasonic guidance,we punctured through a reformative insertion point?supraclavicular fossa?with a view to the disadvantage of blurred ultrasound imaging of puncture needle in traditional puncture path?infraclavicula?.The practicability of puncturing via supraclavicular fossa approach was investigated for infraclavicular brachial plexus block.In part two,SFABPB was performed under the guidance of ultrasound,and we observed the changes of ulnar artery blood flow and skin temperature,and explored the reliability of the changes of ulnar artery blood flow and skin temperature in predicting the effect of brachial plexus block.In part three,on the basis of part one,we compared the difference of half effective concentration(EC₅₀)of ropivacaine in different age patients,when infraclavicular brachial plexus was punctured via supraclavicular fossa approach.In part four,SFABPB was guided by nerve stimulator,local anesthetics were injected at two different sites after evoking two different muscle movements,and we observed the effect of dexmedetomidine on the effect of brachial plexus block when it was added to ropivacaine.Part one The Application of Supraclavicular Fossa Approach in Brachial Plexus Block Guided by UltrasoundObjective:To evaluate the clinical practicability of supraclavicular fossa approach in brachial plexus block under ultrasonic guidance.Methods:60 patients scheduled for distal upper extremity surgery,were randomly divided into Group A and Group B,30 cases in each group.Infraclavicular brachial plexus block was carried out under ultrasonic guidance.The puncturing point was infraclavicular?Group A?or in supraclavicular fossa?Group B?,and 20ml 0.5%ropivacaine was injected around axillary artery for each patient.The procedure time and the number of needle adjustment were recorded as primary outcome,and the onset time,blockade effect score at 15min after blockade,the success rate of block and the incidence of complications were noted also.Results:The procedure time for brachial plexus block was 120.7±52.1s and 92.0±34.3s in group A and group B,respectively.Compared with group A,the procedure time was shorter in group B?P<0.05?.There was no significant difference in the number of needle adjustment,onset time,blockade effect score at 15min,the success rate of block and incidence of complications between the two groups?P>0.05?.Conclusion:Supraclavicular fossa approach can shorten the procedure time of infraclavicular brachial plexus block guided by ultrasound.It is effective and safe,and does not increase the complications.Part two The Influence of Supraclavicular Fossa Approach Brachial Plexus Block on Ulnar Artery Blood Flow and Skin Temp-eratureObjective:To observe the changes of ulnar artery blood flow and skin temperature after supraclavicular fossa approach brachial plexus block guided by ultrasound,to analyze the correlation between the changes of those and the blockade effect of brachial plexus and to explore the reliability of the changes of ulnar artery blood flow and skin temperature in predicting the effect of brachial plexus block.Methods:Infraclavicular brachial plexus block was carried out under ultrasonic guidance via supraclavicular fossa approach in 50 patients scheduled for distal upper extremity surgery.20ml 0.5%ropivacaine was injected around the axillary artery.The hemodynamic parameters?peak systolic velocity?V_S?,diastolic velocity?V_D?,mean velocity?V_M?,pulsation index?PI?,resistance index?RI?and blood flow?of ulnar artery and skin temperature of different areas in upper extremity were recorded before and 30minutes after blockade.The blockade effect was evaluated.The correlation between hemodynamics,temperature and blockade effect was analyzed.Results:30min after brachial plexus block,blockade effect score was 8.0±1.2.For ulnar artery,V_S?V_D,and V_M increased significantly,PI and RI decreased significantly and the blood flow increased significantly compared with those before block?P<0.05?.The correlation coefficient between the change of V_M and blockade effect was 0.707?P<0.01?.After brachial plexus block,the temperature of hypothenar skin increased significantly compared with that before block by 1.4±0.8??P<0.05?,and the correlation coefficient between the change of temperature in hypothenar skin and blockade effect was-0.072?P=0.618?.The changes of skin temperature in other areas and average temperature were not significant?P>0.05?.Conclusion:Supraclavicular fossa approach brachial plexus block guided by ultrasound can significantly increase the bloodstream velocity and blood flow of upper limbs,but the skin temperature in upper limbs is not significantly increased except the hypothenar area.The change of V_M correlates well with the effect of brachial plexus block?r=0.707?,which can be used as a valuable objective index to predict the effect of brachial plexus block via supraclavicular fossa approach.There was no significant correlation between the change of temperature in hypothenar skin and blockade effect.If skin temperature was used as an index to predict the effect of brachial plexus block,there were many interfering factors and its clinical application value was limited.Part three Median Effective Concentration of Ropivacaine for Supra-clavicular Fossa Approach Brachial Plexus Block in Diffe-rent Age PatientsObjective:To determine the median effective concentration of ropiv-acaine for ultrasound-guided brachial plexus block via supraclavicular fossa approach in young and elderly patients.Methods:Patients scheduled for distal upper extremity surgery,were divided into two groups according to their age:Young Group?20-44 yr?and Elderly Group?65-85 yr?.SFABPA was carried out under ultrasonic guidance.20ml different concentration ropivacaine was injected around axillary artery.Dixon sequential experiment was applied for determining the concentration of ropivacaine.The median effective concentration(EC₅₀)and 95%confidence interval?95%CI?of ropivacaine were calculated using the probit regression method.Relevant complications were also recorded.Results:The EC₅₀?95%CI?of ropivacaine was 0.357%?0.297%-0.467%?and 0.296%?0.233%-0.374%?in Young Group and Elderly Group,respec-tively.The EC₅₀ of ropivacaine in Elderly Group decreased by 17%compared with Young Group.No severe complications,such as punctured blood vessels,local anesthetic toxicity,local anesthetic allergy,pneumothorax,were taken notes.Conclusion:The EC₅₀ of ropivacaine for ultrasound-guided brachial plexus block via supraclavicular fossa approach is as follows:0.357%?0.297%-0.467%?in patients aged 20-44 yr,0.296%?0.233%-0.374%?in patients aged 65-85 yr.The EC₅₀ of ropivacaine for Elderly Group decreased by 17%compared with Young Group.Part four The effect of Dexmedetomidine in Supraclavicular Fossa Approach Brachial Plexus Block under Dual InjectionObjective To assess the effects of dexmedetomidine on the duration of anesthesia and effective postoperative analgesia time when it was mixed with ropivacaine for brachial plexus block via supraclavicular fossa approach guided by a nerve stimulator under dual injection.Methods A total of 60 patients were randomly assigned into 2 groups?groups D and C?,30 patients in each group.SFABPB were guided by nerve stimulator.For each patient,40mL of 0.375%ropivacaine?group C?,or 40mL of 0.375%ropivacaine mixed with 1?g/kg dexme-detomidine?group D?was divided into two injections after evoking two different muscle movements.The duration of anesthesia,effective postoperative analgesia time,sensory and motor block onset time,visual analog scale?VAS?,and cumulative consumption of rescue tramadol were recorded.Results Twenty-eight patients in each group were analyzed.The duration of anesthesia was longer in group D as compared with group C?754±161minutes vs 592±128 minutes,P<0.05?and effective postoperative analgesia time was longer in group D as compared with group C?1014±226 minutes vs842±156 minutes,P<0.05?too.The onset time of sensory and motor blocks were not significantly different between the 2 groups?P>0.05?.The VAS within 24 hours after brachial plexus block was lower in group D as compared to group C?P<0.01?.The cumulative consumption of rescue tramadol during the first 48hours postoperative period was 108±63mg and 170±58mg in group D and group C,respectively.The cumulative consumption of rescue tramadol was significantly lower in group D as compared to group C?P<0.01?.No significant changes were observed in vital signs in either group.Conclusion The addition of 1?g/kg dexmedetomidine to ropivacaine extends the duration of anesthesia and effective postoperative analgesia time for brachial plexus block via supraclavicular fossa approach.The VAS within24 hours after block and the cumulative consumption of rescue tramadol during the first 48hours postoperative period are lower as well without side effects in the study group.But the onset time of sensory and motor blocks were not significantly shorten.