A comparison of single versus multiple injections on the extent of anesthesia with coracoid infraclavicular brachial plexus block

A Randomized Controlled Trial to Compare the Efficacy of Single versus Triple Injection Technique for Ultrasound-Guided Infraclavicular Block in Upper Limb Surgeries

Introduction

The ultrasound-guided infraclavicular brachial plexus block by triple-point injection method was aimed at blocking the three individual cords in the infraclavicular region. Recently, a single-point injection method which does not require visualization of cords to produce nerve block has been introduced. This study compared the block onset time, performance time, patient's satisfaction, and complications between the ultrasound guided triple-point injection and single-point injection methods.

Patients and Method

This randomized controlled trial was conducted in a tertiary care hospital. Sixty patients were divided into two groups - Group S: 30 patients received single-point injection method of infraclavicular block. Group T: 30 patients received triple-point injection method of infraclavicular block. Drugs used were 0.5% ropivacaine with 8 mg dexamethasone.

Results

The sensory onset time was significantly longer in Group S (11.13 ±1.83 min) than Group T (6.20 ±1.19min). No statistically significant difference was found between the two groups regarding mean motor onset time. The composite sensorimotor onset time was similar between the groups. The mean time to perform the block was significantly lesser in Group S (1.35 ±0.38 min) when compared to group T (3.44 ±0.61min). The patient satisfaction score, conversion to general anesthesia and complications were not significant among the two groups.

Conclusion

We concluded that single-point injection method had a shorter performance time and similar total onset time with less procedural complications compared with triple point injection method.

Blood flow changes in the forearm arteries after ultrasound-guided costoclavicular brachial plexus blocks: a prospective observational study

Background

An increase in blood flow in the forearm arteries has been reported after brachial plexus block (BPB). However, few studies have quantitatively analysed the blood flow of the forearm arteries after BPB or have studied only partial haemodynamic parameters. The purpose of the present study was to comprehensively assess blood flow changes in the distal radial artery (RA) and ulnar artery (UA) after BPB performed via a new costoclavicular space (CCS) approach using colour Doppler ultrasound.

Methods

Thirty patients who underwent amputated finger replantation and received ultrasound-guided costoclavicular BPB were included in the study. The haemodynamic parameters of the RA and UA were recorded before the block and 10 min, 20 min, and 30 min after the block using colour Doppler ultrasound to determine the peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (V_mean), pulsatility index (PI), resistance index (RI) and area. The volumetric flow rate (VFR) was calculated using the formula Q = area×V_mean. The aforementioned parameters were compared not only before and after the BPB but also between the RA and UA.

Results

Compared with those of the respective baselines, there was a significant increase in the PSV, EDV, V_mean, area, and VFR and a significant decrease in the PI and RI of the RA and UA 10 min, 20 min, and 30 min post-block. The increase 30 min post-block in EDV (258.68 % in the RA, 279.63 % in the UA) was the most notable, followed by that in the V_mean (183.36 % in the RA, 235.24 % in the UA), and the PSV (139.11 % in the RA, 153.15 % in the UA) changed minimally. The V_mean and VFR of the RA were significantly greater than those of the UA before the BPB; however, there was no significant difference in the VFR between the RA and UA after the BPB.

Conclusions

A costoclavicular BPB can increase blood flow in the forearm arteries. The RA had a higher volumetric flow rate than the UA before the BPB; however, the potential blood supply capacity of the UA was similar to that of the RA after a BPB.

Trial registration

This study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/searchproj.aspx, clinical trial number: ChiCTR 1900023796, date of registration: June 12, 2019) 

Critical structures in the needle path of the costoclavicular brachial plexus block: a cadaver study

PURPOSE

The costoclavicular block is a relatively novel alternative to the infraclavicular block. We aimed to determine the anatomical structures vulnerable to needle injury during a costoclavicular block.

METHODS

The needle path consistent with a costoclavicular block approach was performed bilaterally on four lightly embalmed cadavers using ultrasound guidance. Careful dissection was performed with 18-G Tuohy needles in situ and photographs were taken.

RESULTS

The needle penetrated the deltoid in six of eight cases and the pectoralis minor in three of eight cases. The subclavius tendon or its fascia were punctured in two of eight cases. The lateral cord was in contact with the needle in six procedures and punctured in three. The posterior cord was contacted in two instances, and the medial cord in one. In a single dissection, the needle was in contact with the medial antebrachial cutaneous nerve. The needle was close to the medial brachial cutaneous nerve in one case and close to the pectoral nerves in two of eight cases. While the cephalic vein and thoracoacromial artery were consistently nearby, there were no cases of vascular puncture.

CONCLUSION

We found that the needle path may be close to the medial antebrachial cutaneous nerve, medial brachial cutaneous nerve, and pectoral nerves but did not traverse any critical structures aside from the lateral cord. This suggests relative safety when compared with other approaches to the infraclavicular brachial plexus. Structures dans la trajectoire de l'aiguille du bloc de plexus brachial costoclaviculaire : une étude cadavérique.

Median Effective Volume of 0.5% Ropivacaine for Ultrasound-guided Costoclavicular Block

BACKGROUND

The median effective dose of ropivacaine required for producing an effective costoclavicular block has not yet been determined. The authors conducted this dose-finding study with the objective of determining the median effective dose of 0.5% ropivacaine required to produce a successful costoclavicular block for surgical anesthesia in 50% of the patients (ED50) as well as the calculated dose required for effective blockade in 95% of the patients (ED95).

METHODS

This single-armed prospective study was conducted on 40 American Society of Anesthesiologists physical status I or II patients, aged 18 to 60 yr, with a body mass index of 18 to 30 kg/m2, scheduled to undergo forearm and hand surgeries under ultrasound-guided costoclavicular block. A volume of 0.5% ropivacaine administered in the costoclavicular space was determined using the sample up-and-down sequential allocation study design of binary response variables. The first patient received a volume of 26 ml of 0.5% ropivacaine. After a successful or unsuccessful block, the volume of local anesthetic was decreased or increased, respectively, by 2 ml in the next patient. Evaluation of sensory and motor block was performed every 5 min for 30 min and graded using a 3-point scale. Surgical anesthesia was considered to be successful if a minimum score of 14 was achieved and the surgeon was able to proceed with surgery without needing to supplement anesthesia.

RESULTS

The volume of local anesthetic administered ranged from 8 to 26 ml. Centered isotonic regression with a bias-corrected Morris 95% CI derived by bootstrapping showed ED50 of 13.5 ml (95% CI, 11.5 to 15.4 ml) and ED95 of 18.9 ml (95% CI, 17.9 to 27.5 ml).

CONCLUSIONS

A 19-ml dose of 0.5% ropivacaine is likely to produce an effective ultrasound-guided costoclavicular block for providing adequate surgical anesthesia to 95% of the patients.

EDITOR’S PERSPECTIVE

Comparison of the onset time between 0.375% ropivacaine and 0.25% levobupivacaine for ultrasound-guided infraclavicular brachial plexus block: a randomized-controlled trial

At centers with pressure on rapid operating room turnover, onset time is one of the important considerations for choosing a local anesthetic drug. To hasten the onset of the block, higher concentrations of local anesthetics are sometimes used. However, the use of diluted local anesthetics may be safer. Therefore, we aimed to compare the onset times of equipotential levobupivacaine and ropivacaine at low concentrations for infraclavicular brachial plexus block. Adult patients undergoing upper extremity surgery under ultrasound-guided infraclavicular brachial plexus block at our center were randomly allocated to the levobupivacaine and ropivacaine groups. Infraclavicular brachial plexus block was induced with 0.25% levobupivacaine or 0.375% ropivacaine depending on the assigned group. The degrees of sensory and motor blockade were assessed for 40 min after the administration of local anesthetics. A total of 46 patients were included in the analysis. Infraclavicular brachial plexus block with 0.25% levobupivacaine and 0.375% ropivacaine provided sufficient surgical anesthesia. The sensory onset time of 0.375% ropivacaine was shorter than that of 0.25% levobupivacaine (group R, 15 [15.0–22.5] min; group L, 30 [17.5–35.0] min, p = 0.001). There were no significant differences in other block characteristics and clinical outcomes between the two groups. Thus, when a quicker block onset is required, 0.375% ropivacaine is a better choice than 0.25% levobupivacaine.

Trial registration ClinicalTrials.gov (NCT03679897).

[The need for supplemental blocks in single versus triple injections in infraclavicular brachial plexus blocks with a medial approach: a clinical and anatomic study]

BACKGROUND AND OBJECTIVES

To evaluate the single-injection and triple-injection techniques in infraclavicular blocks with an ultrasound-guided medial approach in terms of block success and the need for supplementary blocks.

METHODS

This study comprised 139 patients who were scheduled for elective or emergency upper-limb surgery. Patients who received an infraclavicular blocks with a triple-injection technique were included in Group T (n=68). Patients who received an infraclavicular blocks with a single-injection technique were included in Group S (n=71). The number of patients who required supplementary blocks or had complete failure, the recovery time of sensory blocks and early and late complications were noted.

RESULTS

The block success rate was 84.5% in Group S, and 94.1% in Group T without any need for supplementary nerve blocks. The blocks were supplemented with distal peripheral nerve blocks in 8 patients in Group S and in 3 patients in Group T. Following supplementation, the block success rate was 95.8% in Group S and 98.5% in Group T. These results were not statistically significant. A septum preventing the proper distribution of local anesthetic was clearly visualized in 4 patients. The discomfort rate during the block was significantly higher in Group T (p <0.05).

CONCLUSION

In ultrasound-guided medial-approach infraclavicular blocks, single-injection and triple-injection techniques did not differ in terms of block success rates. The need for supplementary blocks was higher in single injections than with triple injections. The presence of a fascial layer could be the reason for improper distribution of local anesthetics around the cords.

The need for supplemental blocks in single versus triple injections in infraclavicular brachial plexus blocks with a medial approach: a clinical and anatomic study

Background and objectives

Methods

Results

Conclusion

The effect of dexmedetomidine in coracoid approach brachial plexus block under dual stimulation

BACKGROUND

Coracoid approach brachial plexus block (CABPB) is safe and effective for clinical anesthesia and analgesia. Dual stimulation can enhance the block effect of CABPB when using nerve stimulator. Dexmedetomidine is a highly selective α-adrenoceptor agonist and it can prolong the duration of anesthesia when it is added into local anesthetics. The aim of this study was to assess the effects of dexmedetomidine on the duration of anesthesia and the effective postoperative analgesia time when it was mixed with ropivacaine for CABPB under dual stimulation.

METHODS

A total of 60 patients were randomly assigned into 2 groups (groups D and C), 30 patients in each group. CABPB were guided by nerve stimulator under dual stimulation. Each patient received 40 mL of 0.375% ropivacaine (group C), or 40 mL of 0.375% ropivacaine mixed with 1 μg/kg dexmedetomidine (group D). The duration of anesthesia, the effective postoperative analgesia time, sensory and motor block onset time, visual analog scale (VAS), and the cumulative dose 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 (759 vs 634 minutes, P < .05) and the effective postoperative analgesia time was longer in group D as compared with group C (986 vs 789 minutes, P < .05) too. The onset time of sensory and motor blocks were not significantly different between the 2 groups (P > .05). The VAS was similar in the 2 groups at 6 and 12 hours after block (P > .05), but it was lower in group D at 24 hours after block as compared to group C (P < .05). The cumulative dose of rescue tramadol during the first 48 hours postoperative period was significantly lower in group D as compared to group C (P < .05). No significant changes were observed in vital signs in either group.

CONCLUSION

The addition of 1 μg/kg dexmedetomidine to ropivacaine extends the duration of anesthesia and the effective postoperative analgesia time for CABPB under dual stimulation. The VAS at 24 hours after block and the demand for rescue tramadol during the first 48 hours postoperative period are lower as well without side effects in the study group.(Registered in ClinicalTrials.gov id. NCT02961361).

Bloqueio do plexo braquial em um tamanduá-mirim (Tamandua tetradactyla) utilizando estimulador de nervos periféricos: relato de caso

RESUMO Objetivou-se relatar a utilização do neurolocalizador para bloqueio do plexo braquial bilateral em tamanduá-mirim (Tamandua tetradactyla). O animal, pesando 5kg, atendido pelo Centro de Reabilitação de Animais Silvestres, foi encaminhado ao Hospital Veterinário da Universidade Federal de Mato Grosso do Sul para realização de exames complementares, sendo, posteriormente, encaminhado para cirurgia de osteossíntese de úmero e rádio/ulna esquerdo e colocação de fio de cerclagem em olécrano direito. O paciente foi pré-medicado com cetamina S (5mg/kg) + midazolam (0,15mg/kg), indução anestésica com propofol (5mg/kg) e manutenção anestésica com isoflurano, com o auxílio de máscara. Os parâmetros cardiovasculares e respiratórios foram monitorados durante todo o procedimento. Realizou-se o bloqueio do plexo braquial em ambos os membros utilizando-se estimulador de nervos periféricos. Os anestésicos locais empregados foram lidocaína 2% sem vasoconstritor (3mg/kg) + ropivacaína 0,75% sem vasoconstritor (1mg/kg). O bloqueio foi realizado primeiramente no membro torácico direito, e, após realização do procedimento cirúrgico, o mesmo bloqueio foi realizado no membro contralateral. O paciente teve recuperação tranquila ausente de vocalização e expressão álgica, e a soltura ocorreu após 120 dias.

Role of positioning posterior cord on coracoid approach brachial plexus block guided by nerve stimulator: Compared with guided by ultrasound

BACKGROUND

Coracoid approach is efficient and safe for brachial plexus block, and is guided by nerve stimulator or ultrasound in general. Many trials have proved that ultrasonic guidance was more efficacious than nerve stimulator guidance. We hypothesized that positioning posterior cord could enhance the anesthesia effect of coracoid approach brachial plexus block (CABPB) guided by nerve stimulator.

METHODS

Eighty patients were randomized into 2 groups to receive CABPB with positioning posterior cord guided by nerve stimulator (group A) or CABPB guided by ultrasound (group B). Success rate, procedure time, and onset time of sensory or motor block were recorded.

RESULTS

Success rate was similar in 2 groups (89.7% in group A vs 87.5% in group B, P > .05). Procedure time was longer in group A (8 minutes), as compared with group B (4 minutes; P < .05). The difference of onset time of sensory and motor block was not significant between the 2 groups. The onset time of sensory and motor block for musculocutaneous nerve was significantly shorter in group A, as compared with group B (P < .05).

CONCLUSION

The 2 technologies are equivalent regarding success rate, safety, and onset time of sensory or motor block. Positioning posterior cord in CABPB guided by nerve stimulator is efficacious for upper extremity surgery.(URL: http://www.chictr.org.cn/listbycreater.aspx ID: ChiCTR-INR-16009091 DATE: 25/8/2016).

Ultrasound-Guided Costoclavicular Brachial Plexus Block: Sonoanatomy, Technique, and Block Dynamics

BACKGROUND AND OBJECTIVES

This study aimed to describe in detail the relevant sonoanatomy, technique, and block dynamics of an ultrasound-guided costoclavicular brachial plexus block (BPB).

METHODS

Thirty patients scheduled for hand or forearm surgery under a BPB underwent transverse ultrasound imaging of the medial infraclavicular fossa to identify the cords of the brachial plexus at the costoclavicular space (CCS). An ultrasound-guided BPB was then performed at the CCS with 20 mL of 0.5% ropivacaine. Sensory-motor blockade of the ipsilateral median, radial, ulnar, and musculocutaneous nerves were assessed at regular intervals for 30 minutes after the injection. Successful block was defined as being able to complete surgery under the BPB.

RESULTS

The CCS was visualized as a well-defined intermuscular space lying deep and posterior to the mid-point of the clavicle. The cords of the brachial plexus were clustered together lateral to the axillary artery within the CCS. The costoclavicular BPB was successfully performed in all patients, and the median onset time for sensory and motor blockade of all the 4 nerves was 5 [5-15] and 5 [5-10] minutes, respectively. Complete sensory blockade of all the 4 nerves was achieved in 30 [20-30] minutes, and the BPB was successful in 29 (97%) of 30 patients. There were no complications directly related to the technique or the local anesthetic injection.

CONCLUSIONS

This report describes a novel technique of infraclavicular BPB at the costoclavicular space that produces rapid onset of BPB. Future research should compare the safety and efficacy of this new technique with the traditional lateral sagittal infraclavicular BPB.

Anatomic Basis for Brachial Plexus Block at the Costoclavicular Space: A Cadaver Anatomic Study

BACKGROUND AND OBJECTIVES

The costoclavicular space (CCS), which is located deep and posterior to the midpoint of the clavicle, may be a better site for infraclavicular brachial plexus block than the traditional lateral paracoracoid site. However, currently, there is paucity of data on the anatomy of the brachial plexus at the CCS. We undertook this cadaver anatomic study to define the anatomy of the cords of the brachial plexus at the CCS and thereby establish the anatomic basis for ultrasound-guided infraclavicular brachial plexus block at this proximal site.

METHODS

The anatomy and topography of the cords of the brachial plexus at the CCS was evaluated in 8 unembalmed (cryopreserved), thawed, fresh adult human cadavers using anatomic dissection, and transverse anatomic and histological sections, of the CCS.

RESULTS

The cords of the brachial plexus were located lateral and parallel to the axillary artery at the CCS. The topography of the cords, relative to the axillary artery and to one another, in the transverse (axial) plane was also consistent at the CCS. The lateral cord was the most superficial of the 3 cords and it was always anterior to both the medial and posterior cords. The medial cord was directly posterior to the lateral cord but medial to the posterior cord. The posterior cord was the lateral most of the 3 cords at the CCS and it was immediately lateral to the medial cord but posterolateral to the lateral cord.

CONCLUSIONS

The cords of the brachial plexus are clustered together lateral to the axillary artery, and share a consistent relation relative to one another and to the axillary artery, at the CCS.

Comparison of dexamethasone and clonidine as an adjuvant to 1.5% lignocaine with adrenaline in infraclavicular brachial plexus block for upper limb surgeries

BACKGROUND AND AIMS

The role of clonidine as an adjuvant to regional blocks to hasten the onset of the local anesthetics or prolong their duration of action is proven. The efficacy of dexamethasone compared to clonidine as an adjuvant is not known. We aimed to compare the efficacy of dexamethasone versus clonidine as an adjuvant to 1.5% lignocaine with adrenaline in infraclavicular brachial plexus block for upper limb surgeries.

MATERIAL AND METHODS

Fifty three American Society of Anaesthesiologists-I and II patients aged 18-60 years scheduled for upper limb surgery were randomized to three groups to receive 1.5% lignocaine with 1:200,000 adrenaline and the study drugs. Group S (n = 13) received normal saline, group D (n = 20) received dexamethasone and group C (n = 20) received clonidine. The time to onset and peak effect, duration of the block (sensory and motor) and postoperative analgesia requirement were recorded. Chi-square and ANOVA test were used for categorical and continuous variables respectively and Bonferroni or post-hoc test for multiple comparisons. P < 0.05 was considered significant.

RESULTS

The three groups were comparable in terms of time to onset and peak action of motor and sensory block, postoperative analgesic requirements and pain scores. 90% of the blocks were successful in group C compared to only 60% in group D (P = 0.028). The duration of sensory and motor block in group S, D and C were 217.73 ± 61.41 min, 335.83 ± 97.18 min and 304.72 ± 139.79 min and 205.91 ± 70.1 min, 289.58 ± 78.37 min and 232.5 ± 74.2 min respectively. There was significant prolongation of sensory and motor block in group D as compared to group S (P < 0.5). Time to first analgesic requirement was significantly more in groups C and D as compared with group S (P < 0.5). Clinically significant complications were absent.

CONCLUSIONS

We conclude that clonidine is more efficacious than dexamethasone as an adjuvant to 1.5% lignocaine in brachial plexus blocks.

The emergence level of the musculocutaneous nerve from the brachial plexus: implications for infraclavicular nerve blocks

BACKGROUND

In this cadaveric study we assessed the level of the emergence of the musculocutanous nerve (MCN) relative to needle insertion site during infraclavicular block.

METHODS

Forty brachial plexi from 20 embalmed adult cadavers were dissected. The MCN was exposed from its origin on the lateral cord to its penetration into the coracobrachialis muscle. The point of emergence of the MCN from the lateral cord relative to a line drawn directly caudad from the anteromedial tip of the coracoid process was measured. A needle was placed predissection using our previously described technique, and the distance from the needletip to the emergence of the MCN was measured.

RESULTS

MCN often emerged distal to the coracoid process. At the needle insertion site, 80% of MCN had already emerged from the lateral cord. The distance of emergence ranged from 8.5 cm proximal to 12 cm distal to the coracoid process.

CONCLUSION

This anatomical study suggests that MCN may be one of the factors explaining MCN block failure for the single-injection technique of infraclavicular block using lateral needle trajectory.

Comparison of two approaches of infraclavicular brachial plexus block for orthopaedic surgery below mid-humerus

The brachial plexus in infraclavicular region can be blocked by various approaches. Aim of this study was to compare two approaches (coracoid and clavicular) regarding success rate, discomfort during performance of block, tourniquet tolerance and complications. The study was randomised, prospective and observer blinded. Sixty adult patients of both sexes of ASA status 1 and 2 requiring orthopaedic surgery below mid-humerus were randomly assigned to receive nerve stimulator guided infraclavicular brachial plexus block either by lateral coracoid approach (group L, n = 30) or medial clavicular approach (group M, n = 30) with 25–30 ml of 0.5% bupivacaine. Sensory block in the distribution of five main nerves distal to elbow, motor block (Grade 1–4), discomfort during performance of block and tourniquet pain were recorded by a blinded observer. Clinical success of block was defined as the block sufficient to perform the surgery without any supplementation. All the five nerves distal to elbow were blocked in 77 and 67% patients in groups L and M respectively. Successful block was observed in 87 and 73% patients in groups L and M, respectively (P > 0.05). More patients had moderate to severe discomfort during performance of block due to positioning of limb in group M (14 vs. 8 in groups M and L). Tourniquet was well tolerated in most patients with successful block in both groups. No serious complication was observed. Both the approaches were equivalent regarding success rate, tourniquet tolerance and safety. Coracoid approach seemed better as positioning of operative limb was less painful, coracoids process was easy to locate and the technique was easy to learn and master.

Single stimulation of the posterior cord is superior to dual nerve stimulation in a coracoid block

BACKGROUND

Both multiple injection and single posterior cord injection techniques are associated with extensive anesthesia of the upper limb after an infraclavicular coracoid block (ICB). The main objective of this study was to directly compare the efficacy of both techniques in terms of the rates of completely anesthetizing cutaneous nerves below the elbow.

METHODS

Seventy patients undergoing surgery at or below the elbow were randomly assigned to receive an ICB after the elicitation of either a single radial nerve-type response (Radial group) or of two different main nerve-type responses of the upper limb, except for the radial nerve (Dual group). Forty milliliters of 1.5% mepivacaine was given in a single or a dual dose, according to group assignment. The sensory block was assessed in each of the cutaneous nerves at 10, 20 and 30 min. Block performance times and the rates of complete anesthesia below the elbow were also noted.

RESULTS

Higher rates of sensory block of the radial nerve were found in the Radial group at 10, 20 and 30 min (P<0.05). The rates of sensory block of the ulnar nerve at 30 min were 97% and 75% in the Radial and in the Dual groups, respectively (P<0.05). The rate of complete anesthesia below the elbow was also higher in the Radial group at 30 min (P<0.05).

CONCLUSIONS

Injection of a local anesthetic after a single stimulation of the radial nerve fibers produced more extensive anesthesia than using a dual stimulation technique under the conditions of our study.

Single vs. double stimulation during a lateral sagittal infraclavicular block

BACKGROUND

The objective of this study was to evaluate the influence of single vs. dual control during an ultrasound-guided lateral sagittal infraclavicular block on the efficacy of sensory block and the time of block onset.

METHODS

In a prospective manner, 60 adult patients scheduled for distal upper limb surgery were randomly allocated to single (Group S) or double stimulation (Group D) groups. A local anesthetic (LA) mixture of 20 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml with 5 microg/ml epinephrine (total 40 ml) was administered in both groups. In the Group S following a median, an ulnar or a radial nerve response, the entire LA was administered at a single site. In Group D 10 ml of LA was administered following the electrolocation of the musculocutaneous nerve and 30 ml LA was injected following median, ulnar or radial nerves. A successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Sensory and motor blocks were tested at 5-min intervals for 30 min.

RESULTS

The block was successful in 27 patients in Group S and 28 patients in Group D. The time from starting the block until satisfactory anesthesia was significantly shorter in Group D than in Group S (19.3 vs. 23.2 min) (P<0.05). Total sensory scores were significantly higher in the double stimulation group at 20 and 30 min after the block performance (P<0.05).

CONCLUSIONS

Although the block performance time was longer in the double stimulation group, block onset time and extent of anesthesia were more favorable in the double stimulation group.

Ultrasound-guided regional anesthesia and analgesia: a qualitative systematic review

Ultrasound guidance has become popular for performance of regional anesthesia and analgesia. This systematic review summarizes existing evidence for superior risk to benefit profiles for ultrasound versus other techniques. Medline was systematically searched for randomized controlled trials (RCTs) comparing ultrasound to another technique, and for large (n > 100) prospective case series describing experience with ultrasound-guided blocks. Fourteen RCTs and 2 case series were identified for peripheral nerve blocks. No RCTs or case series were identified for perineural catheters. Six RCTs and 1 case series were identified for epidural anesthesia. Overall, the RCTs and case series reported that use of ultrasound significantly reduced time or number of attempts to perform blocks and in some cases significantly improved the quality of sensory block. The included studies reported high incidence of efficacy of blocks with ultrasound (95%-100%) that was not significantly different than most other techniques. No serious complications were reported in included studies. Current evidence does not suggest that use of ultrasound improves success of regional anesthesia versus most other techniques. However, ultrasound was not inferior for efficacy, did not increase risk, and offers other potential patient-oriented benefits. All RCTs are rather small, thus completion of large RCTs and case series are encouraged to confirm findings.

Upper extremity regional anesthesia: essentials of our current understanding, 2008

Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine's commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research.

Ultrasound as the only nerve localization technique for peripheral nerve block

Ultrasound facilitates the performance of peripheral nerve blocks and may increase block quality parameters. In this report, we show that ultrasonographic guidance makes peripheral nerve blocks possible in patients in whom the traditional methods of nerve localization are limited. Four cases are described in which conventional end points for successful blocks would have been impossible to use, whereas ultrasound guidance was successful and safe. The latter method increases applicability in a larger group of patients.

Brachial plexus blocks: a review of approaches and techniques

PURPOSE

The purpose of this narrative review is to summarize the evidence derived from randomized controlled trials (RCTs) regarding established approaches and techniques for brachial plexus anesthesia.

SOURCE

Using the MEDLINE (January 1966 to November 2006) and EMBASE (January 1980 to November 2006) databases, key words "brachial plexus", "nerve blocks", "interscalene", "cervical paravertebral", "suprascapular", "supraclavicular", "infraclavicular", "axillary", "brachial canal" and "humeral canal" were searched for full text articles pertaining to the evaluation of recognized approaches and techniques for brachial plexus anesthesia. The search was limited to RCTs involving human subjects and published in the English language. Seventy-six RCTs were identified.

PRINCIPAL FINDINGS

Many of the published studies were underpowered and contained various methodological limitations. We found that, for shoulder and proximal humeral surgery, interscalene and cervical paravertebral approaches to the brachial plexus appear to provide equally effective surgical anesthesia. Intersternocleidomastoid supraclavicular blocks are not associated with improved postoperative analgesia despite eliciting more complete anesthesia of the brachial plexus. For surgery at or below the elbow, an infraclavicular block may result in decreased performance time and block-related pain while providing similar efficacy compared to (multiple-stimulation) axillary and brachial canal approaches. With respect to technique, it is unclear if nerve stimulation provides a more effective interscalene block than elicitation of paresthesiae. For supraclavicular blocks, nerve stimulation with a minimal threshold of 0.9 mA is recommended, whereas a double-stimulation technique is optimal for infraclavicular blocks. For the axillary approach, a triple-stimulation technique, involving injections of the musculocutaneous, median and radial nerves, is the most effective option.

CONCLUSIONS

Published reports of RCTs provide evidence to formulate limited recommendations regarding optimal approaches and techniques for brachial plexus anesthesia. Further well-designed and meticulously executed RCTs are warranted, particularly in light of new techniques involving ultrasound or combining neurostimulation and echoguidance.

Neurostimulation in Ultrasound-Guided Infraclavicular Block: A Prospective Randomized Trial

Ultrasound guidance (USG) for infraclavicular blocks provides real time visualization of the advancing needle and local anesthetic distribution. Whether visualization of local anesthetic spread can supplant neurostimulation as the end point for local anesthetic injection during USG block has never been formally evaluated. Therefore, for this prospective randomized study, we recruited 72 patients scheduled for hand or forearm surgery and compared the speed of execution and quality of USG infraclavicular block with either USG alone (Group U) or USG combined with neurostimulation (Group S). In Group U, local anesthetic was deposited in a U-shaped distribution posterior and to each side of the axillary artery using as few injections as possible (1, 2, and 3 injections in 29, 6, and 3 patients, respectively). In Group S, a single injection was made after obtaining a distal motor response with a stimulating current between 0.3 and 0.6 mA. The anesthetic solution consisted of 0.5 mL/kg of lidocaine 1.5%, bupivacaine 0.125%, and epinephrine 1:200 000 (final concentrations). Procedure times were significantly shorter in Group U compared with Group S (3.1 +/- 1.6 min and 5.2 +/- 4.7 min, respectively; P = 0.006). In Group S, anesthetic spread was mainly anterior to the axillary artery in 37% of patients and mainly posterior in 63% of patients. Thirty minutes after the injection, 86% of patients in Group U had complete sensory block in the musculocutaneous, median, radial, and ulnar nerve territories compared with 57% in Group S (P = 0.007). Patients blocked in Group U with a single injection had the same rate of complete block (86%) as those blocked with more than one injection (86%). Block supplementation rates were 8% in Group U versus 26% in Group S (P = 0.049). Block failure occurred in one patient in Group S because of an inability to obtain a distal stimulation after 20 min. We conclude that USG infraclavicular block is more rapidly performed and yields a higher success rate when visualization of local anesthetic spread is used as the end point for injection. Posterolateral spread of local anesthetic around the axillary artery predicts successful block, circumventing the need for direct nerve visualization.

The Optimal Motor Response for Infraclavicular Brachial Plexus Block

BACKGROUND

In this prospective study we compared the success of the infraclavicular brachial plexus block using double-stimulation in regard to the second nerve response elicited with neurostimulation.

METHODS

Six-hundred-twenty-eight patients undergoing emergency upper limb surgery using infraclavicular brachial plexus block were included in this study. The musculocutaneous nerve was initially blocked and the groups were then evaluated according to the second nerve located, which was radial in 54%, median in 35%, and ulnar in 11% of patients. Blocks were performed using lidocaine 1.5% with 1/400,000 epinephrine 40 mL in all cases. The block was assessed every 5 min for 30 min after completion of the block.

RESULTS

The success rate was 96% for the radial response group, 89% for the median response group, and 90% for the ulnar response group (P < 0.05). Time to perform the block and the onset time were not significantly different among groups. No serious complications were observed.

CONCLUSION

We conclude that having initially located and blocked the musculocutaneous nerve, subsequent injection on a radial response resulted in a slightly more reliable success rate than injection with an ulnar or median response.

Sonographically guided infraclavicular brachial plexus block in adults: a retrospective analysis of 1146 cases

OBJECTIVE

The aim of this study was to analyze our experience in 1146 cases of sonographically guided infraclavicular brachial plexus block (ICBPB) performed over 32 months.

METHODS

Anesthetic records of 1146 cases of sonographically guided ICBPB performed by our staff were studied retrospectively with the use of a database created by an automated anesthesia record-keeping system. The rates of successful blocks, failed blocks necessitating conversion to general anesthesia or requiring supplementation with local anesthetics, those requiring larger-than-usual doses of sedation, and complications were determined. Analysis included an attempt to determine the possible causes of inadequate blocks and complications.

RESULTS

In 1138 patients (99.3%), the block was successful. Six patients had incomplete blocks requiring general anesthesia, and another 2 patients needed local anesthetic supplementation by the surgeons. Ninety-seven percent of the blocks were performed by residents directly supervised by an attending anesthesiologist who held the ultrasound probe. The mean age+/-SD of the patients was 39+/-15 years; the mean duration of surgery was 165+/-114 minutes; and the male-female ratio was 4:1. More than 50% of patients were obese. There were no reported cases of nerve injury, pneumothorax, or local anesthetic toxicity. Arterial punctures occurred in 8 (0.7%) patients, but all were inconsequential.

CONCLUSIONS

The data from this retrospective study suggest that sonographic guidance provides a high success rate (99.3%) and improved safety for ICBPB. The increased operator team experience virtually eliminates failure and complications.

Double- vs. single-injection infraclavicular plexus block in the emergency setting

BACKGROUND AND OBJECTIVES

Infraclavicular plexus block has many advantages of particular interest in the emergency setting. However, the number of nerve stimulations needed to optimize the technique remains unclear. We evaluated both the local anaesthetic requirement and the success rate of Sim's derived infraclavicular plexus block performed with a nerve stimulator when either one or two responses were sought.

METHODS

In this prospective study, 50 patients who presented for distal upper limb surgery were randomized into two groups: in Group 1, ropivacaine 0.75% 40 mL was injected when nerve stimulation elicited a distal motor response (median, ulnar or radial). In Group 2, only 30 mL of the same local anaesthetic was injected, 7 mL to the musculocutaneous nerve and 23 mL to the median, ulnar or radial nerves. Sensory and motor blocks were tested at 5-min intervals over 30 min.

RESULTS

The time to perform the block was similar in both groups. The success rate of the block increased from 80% in the single-stimulation group to 92% in the double-stimulation group (not significant). The onset time of sensory and motor block was shorter and block extension was greater in ulnar, antebrachial cutaneous and brachial cutaneous nerve distributions in the multistimulation group (P < 0.05).

CONCLUSIONS

We conclude that only 30 mL of local anaesthetic seems to be sufficient to ensure a high level of success when performing an infraclavicular block with stimulation of both the musculocutaneous nerve and median, ulnar or radial nerve.

Bloc plexique infraclaviculaire en monostimulation : l'injection au contact du faisceau postérieur permet de réduire le volume d'anesthésique local

OBJECTIVES

To assess the efficiency of a posterior secondary trunk single stimulation, low volume (30 ml 1.5% mepivacaine) infraclavicular brachial plexus block (ICB) technique.

STUDY DESIGN

Prospective study.

PATIENTS AND METHODS

One hundred consecutive patients scheduled for hand, forearm or elbow surgery were included. ICB was placed using a single stimulation technique. 30 ml 1.5% mepivacaine was injected when an evoked distal radial motor type response was elicited for 0.3-0.6 mA intensity current. Based upon both sensory and motor distribution ICB, characteristics and performance were assessed.

RESULTS

No patient required general anesthesia conversion. Success rate was 92%. 8 patients required a total amount of 10 complementary distal troncular blocks. No specific complication of ICB technique was accoutered. All patients completed full neurological recovery from ICB 24 hours after surgery.

CONCLUSION

30 ml mepivacaine 1.5% ICB is suitable for upper limb surgery.

Einfluss der Blockade mit Lokalanästhetika auf die Stimulierbarkeit eines Nerven mit der peripheren Nervenstimulation

In the present study we examined the influence of local anesthetics on the ability to stimulate a nerve by means of peripheral nerve stimulation. In 35 patients either 5 ml saline (group 1, n=18) or local anesthetics (group 2, n=17) were injected close to the sciatic nerve in a randomized and double-blind manner. The current needed to stimulate the nerve was measured 30 s and 2 min after injection. The results showed that 30 s and 2 min after injection of local anesthetics there is a strong local anesthetic effect. Therefore nerve damage might occur despite the use of peripheral nerve stimulation. Thus, the multiple injection technique in a close anatomical area has to be considered critically, because anesthetized or partially anesthetized nerves have a lower stimulating ability and could be damaged by a second or third puncture.