Upper limb nerve blocks

Brachial plexus blockade is used for a variety of upper limb surgical procedures. Ultrasound guidance is generally considered to be the gold-standard technique, although large-scale studies examining efficacy and complications of ultrasound-guided techniques compared with nerve stimulation are still needed. Interscalene block remains the approach of choice for shoulder surgery, although phrenic nerve blockade is common even using low volumes of local anaesthetic. Of the currently available studies comparing the other approaches, there seems to be little difference in efficacy between axillary, supraclavicular and infraclavicular approaches for elbow, forearm and hand surgery when equivalent levels of expertise are used. The major features influencing block choice and performance are discussed.     

Upper limb nerve blocks

Brachial plexus blockade is commonly used for a variety of upper limb surgical procedures and the introduction of ultrasound guidance has led to re-evaluation of many of the approaches. Large-scale studies examining both efficacy and complications of ultrasound-guided techniques compared with nerve stimulation are lacking, but there is a growing body of research to support the routine use of ultrasound. Interscalene block remains the approach of choice for shoulder surgery but phrenic nerve blockade remains common, even using low volumes of local anaesthetic. Of the currently available studies comparing the other approaches, there seems to be little difference in efficacy between axillary, supraclavicular and infraclavicular approaches for elbow, forearm and hand surgery when equivalent levels of expertise are used. Recently, the growth of ambulatory surgery has influenced the increased use of peripheral nerve blocks for analgesia. The major features influencing block choice and performance are discussed here.     

Thoracic paravertebral analgesia

Thoracic paravertebral nerve blockade, although once widely practised, has now only a few centres which contribute to the literature. Data production has, however, continued and this review correlates this new information with existing knowledge. Its history, taxonomy, anatomy, indications, techniques, mechanisms of analgesia, efficacy, contraindications, toxicity, side effects and complications are reviewed. Thoracic paravertebral analgesia is advocated for surgical procedures of the thorax and abdomen, especially wherever the afferent input is predominantly unilateral eg. thoracotomy, cholecystectomy and nephrectomy. It is also of benefit in the prevention and management of chronic pain. It is a simple undertaking with impressive efficacy. Plasma local anaesthetic levels are acceptable and its side effect and complication rates are low. No mortality has been reported. For unilateral surgery of the chest or trunk, thoracic paravertebral analgesia should be considered as the afferent block of choice. For bilateral surgery, its efficacy may be limited by the doses of local anaesthetic which could safely be used and further study in this area in particular is required. This form of afferent blockade deserves greater consideration and investigation.     

Regional anesthesia for orthopedic procedures: What orthopedic surgeons need to know

Regional anesthesia is an integral component of successful orthopedic surgery. Neuraxial anesthesia is commonly used for surgical anesthesia while peripheral nerve blocks are often used for postoperative analgesia. Patient evaluation for regional anesthesia should include neurological, pulmonary, cardiovascular, and hematological assessments. Neuraxial blocks include spinal, epidural, and combined spinal epidural. Upper extremity peripheral nerve blocks include interscalene, supraclavicular, infraclavicular, and axillary. Lower extremity peripheral nerve blocks include femoral nerve block, saphenous nerve block, sciatic nerve block, iPACK block, ankle block and lumbar plexus block. The choice of regional anesthesia is a unanimous decision made by the surgeon, the anesthesiologist, and the patient based on a risk-benefit assessment. The choice of the regional block depends on patient cooperation, patient positing, operative structures, operative manipulation, tourniquet use and the impact of post-operative motor blockade on initiation of physical therapy. Regional anesthesia is safe but has an inherent risk of failure and a relatively low incidence of complications such as local anesthetic systemic toxicity (LAST), nerve injury, falls, hematoma, infection and allergic reactions. Ultrasound should be used for regional anesthesia procedures to improve the efficacy and minimize complications. LAST treatment guidelines and rescue medications (intralipid) should be readily available during the regional anesthesia administration.     

Distal peripheral nerve blockade for patients undergoing hand surgery: a pilot study

BackgroundData are limited regarding the use of peripheral nerve blockade at the level of the forearm, and most studies regard these procedures as rescue techniques for failed or incomplete blocks. The purpose of the study was to investigate patients undergoing hand surgery with distal peripheral nerve (forearm) blocks and compare them with patients having similar procedures under more proximal brachial plexus blockade. No investigations comparing distal nerve blockade to proximal approaches are currently reported in the literature.MethodsMedical records were retrospectively reviewed for patients who had undergone hand surgery with a peripheral nerve block between November 2012 and October 2013. The primary outcome was the ability to provide a primary anesthetic without the need for general anesthesia or local anesthetic supplementation by the surgical team. Secondary outcome measures included narcotic administration during the block and intraoperative procedures, block performance times, and the need for rescue analgesics in the post anesthesia care unit (PACU).ResultsNo statistical difference in conversion rates to general anesthesia was observed between the two groups. Total opiate administration for the block and surgical procedure was lower in the forearm block group. There was no difference in block performance times or need for rescue analgesics in the PACU.ConclusionsForearm blocks are viable alternatives to proximal blockade and are effective as a primary anesthetic technique in patients undergoing hand surgery. Compared to the more proximal approaches, these blocks have the benefits of not causing respiratory compromise, the ability to be performed bilaterally, and may be safer in anticoagulated patients.     

Regional techniques for pediatric day surgery

Regional blocks provide effective pain relief in pediatric day surgery, but local anesthetics are part of a concept that also includes nonsteroidal anti-inflammatory drugs. The choice of the regional technique is crucial to avoid unnecessary motor blockade and other side effects leading to prolonged hospital stay. For many interventions simple wound infiltration is therefore the optimal choice. For inguinal incisions, caudal anesthesia with approximately 1 mL/kg of bupivacaine 0.125% with epinephrine or ilioinguinal nerve block is widely used. Although ilioinguinal nerve block is preferable in older children, caudal anesthesia seems preferable for infants and toddlers. For penile surgery, penile block is the gold standard; the subpubic technique is described in detail. For extremity procedures, axillary brachial plexus block or intravenous regional anesthesia can be used in selected children. Copyright © 2000 by W.B. Saunders Company     

Lower extremity blocks for day surgery

A combined block of the lower extremity offers many advantages over spinal or epidural anesthesia, such as less hypotension, no bladder paralysis or postspinal headache, and fewer concerns regarding coagulation problems. Furthermore, the extent of sensory and motor blockade of the lower extremity achieved with a combination of a sciatic and a dorsal lumbar plexus nerve block, by using a peripheral nerve stimulator, is by all means comparable to a central nerve block when used for knee surgery. For the surgery distal to tuberositas tibiae, the popliteal sciatic nerve block, alone or combined with a saphenous nerve block is a reasonable choice; for foot surgery an ankle block is probably the best method, so far as regional anesthesia is considered. The choice of local anesthetics is mostly directed by the duration of the surgery but the attention should be paid to the possibility of systemic toxicity because combined proximal nerve blocks of the lower extremity frequently require amounts approximate to the maximal recommended doses. The increased time investment, the impossibility of blocking all nerves of the lower extremity from one injection site, and certain failure rate which have to be accepted are frequently raised as arguments against the use of peripheral nerve blocks for day surgery. However, by adequate explanation of the procedure to the patient, proper organization of the time-frame table, and home transportation facilities, most of traditional restraints regarding peripheral nerve blocks for ambulatory surgery can be overcome or even acclimated. Copyright © 2000 by W.B. Saunders Company     

Sciatic Nerve Block via Posterior Labat Approach Is More Efficient Than Lateral Popliteal Approach Using a Double-injection Technique: A Prospective, Randomized Comparison

Background: For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine.

Methods: A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery.

Results: A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05).     

Use of ultrasound for thoracic paravertebral block

Thoracic paravertebral block is the technique of injecting local anesthetic adjacent to the intervertebral foramina, resulting in unilateral somatic and sympathetic nerve blockade. Previous studies have reported its effectiveness for thoracic surgery including breast surgery and relief of postoperative and chronic pain of unilateral origin from the chest and abdomen. The technique is relatively easy to learn and safer than thoracic epidural. Its clinical advantages include the inhibition of stress and pressor responses to surgical stimuli, maintenance of hemodynamic stability, low incidence of complication, long duration of analgesia, and few contraindications. Recent advances in ultrasound technology can further increase the effectiveness and the safety of thoracic paravertebral block, although identification of the nerve and needle is not still possible.     

Anesthesia for Dupuytren's contracture.

Despite the potential complications of brachial plexus blockade, it remains a reliable and safe form of anesthesia for surgery of the upper extremity. The site of the surgery dictates which of the four approaches to the brachial plexus should be used. When the choice matches the site of surgery, the blocks should be successful in approximately 80% of cases. When supplemented with an additional peripheral block, the success rate is greater than 90% using the axillary and supraclavicular approaches. The duration of the blocks varies from 1 to 12 hours, depending on the choice of anesthetic agent. The addition of epinephrine to the anesthetic agent decreases the rate of tissue uptake of the drug, thereby both lengthening the duration of the block and decreasing the toxicity of the agent. Alkalinizing lidocaine with sodium bicarbonate decreases the latency time and increases the intensity and spread of the block. Surgeons should be aware of the advantages and capabilities of regional anesthesia and should discuss anesthesia options with patients and anesthesiologists.     

False aneurysm of the axillary artery following brachial plexus block

Brachial plexus blockade is a commonly used technique for providing surgical anesthesia for the upper extremity. Although various approaches have been described, the axillary approach is the safest and most frequently used. Most complications associated with axillary nerve block are related to local or systemic anesthetic toxicity, bleeding, infection, and nerve damage. A case of false aneurysm of the axillary artery following axillary nerve block is reported. The possible occurrence of this complication should be kept in mind to avoid permanent neurologic sequelae.     

Sciatic nerve block via posterior Labat approach is more efficient than lateral popliteal approach using a double-injection technique: a prospective, randomized comparison

BACKGROUND: For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine. METHODS: A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery. RESULTS: A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05). CONCLUSION: A double injection with a relatively low volume of 0.75% ropivacaine generated a higher success rate and a shorter onset time of sensory and motor blockade after the classic Labat approach than after a lateral popliteal approach.     

Transscalene brachial plexus block: a new posterolateral approach for brachial plexus block

Depending on the approach to the upper brachial plexus, severe complications have been reported. We describe a novel posterolateral approach for brachial plexus block which, from an anatomical and theoretical point of view, seems to offer advantages. Twenty-seven patients were scheduled to undergo elective major surgery of the upper arm or shoulder using this new transscalene brachial plexus block. The success rate was 85.2% for surgery. Two patients required additional analgesia with IV sufentanil. In two others, regional anesthesia was inadequate. The side effects of this technique included reversible recurrent laryngeal nerve blockade in two patients and a reversible Horner syndrome in one patient. Further studies are needed to compare the transscalene brachial plexus block with other approaches to the brachial plexus.     

经斜角肌臂丛神经阻滞：一种后侧入路臂丛神经阻滞的新方法

现有文献报道指出高位臂丛神经阻滞存在许多严重并发症。此文描述了一种从后侧方入路的臂丛神经阻滞新方法．该方法在解剖学上和理论上都有许多优点。27例拟行择期上臂或者肩部较大手术的患者接受了这种新的阻滞方法。成功率达到了85．2％。有两例患者加用静脉舒芬太尼镇痛，另有两例患者阻滞效果不佳。这种方法的副作用包括：两例患者出现了可逆的喉返神经阻滞，一例患者出现了可逆的Homer综合征。还需要进一步的研究将这种经斜角肌臂丛神经阻滞的方法与其他方法进行比较。     

Efficacy of single-dose, multilevel paravertebral nerve blockade for analgesia after thoracoscopic procedures

BACKGROUND: Although video-assisted thoracoscopic surgery for pulmonary resection is increasingly chosen over thoracotomy, the optimal analgesia regimen for thoracoscopy is unknown. The purpose of this trial was to compare the efficacy of analgesia from preoperative bupivacaine paravertebral nerve blockade with that from placebo injections. METHODS: Eighty adult patients undergoing unilateral thoracoscopic procedures were enrolled in a prospective, double-blinded, randomized clinical trial of preoperative, multilevel, single-dose paravertebral nerve blockade. Patients received six paravertebral injections with 5 ml of either 0.5% bupivacaine with 0.0005% epinephrine (treated, n = 40) or preservative-free saline (control, n = 40). Cumulative weight-adjusted intraoperative fentanyl and postoperative patient-controlled morphine usage, visual analog pain scores, and spirometry were used to compare efficacy of analgesia between groups. RESULTS: The treated group received significantly less intraoperative fentanyl compared with the control group (P = 0.003) and had a 31% smaller cumulative patient-controlled morphine dose (P = 0.03) in the 6 h after block placement. Within 6 h, treated patients also reported lower maximum pain scores (P = 0.02) and demonstrated less pain score variability (P = 0.01). No statistically significant difference in cumulative morphine usage existed at 12 or 18 h after block placement. No significant difference in spirometry, cortisol levels, or cytokine production was found between treatments. CONCLUSIONS: Single-dose paravertebral nerve blockade with bupivacaine is effective in reducing pain after thoracoscopic surgery, but only during the first 6 h after nerve blockade. Because of the limited duration of effect with currently available local anesthetic agents, the current data suggest that, at present, this technique is not indicated in the setting of thoracoscopic surgery.     

Comparison of the Different Approaches to Saphenous Nerve Block

Background: The authors compared the efficacy of the different approaches to saphenous nerve block.

Methods: The following approaches to saphenous nerve block were compared in 10 volunteers: perifemoral, transsartorial, block at the medial femoral condyle, below-the-knee field block, and blockade at the level of the medial malleolus. Each volunteer underwent all five blocks, and the interval between blocks was 3-7 days. The sequence of injection was randomized by Latin square design. Sensory blockade at the medial aspects of the leg and foot and the strength of the anterior thigh muscles were noted.

Results: The transsartorial, perifemoral, and below-the-knee field block approaches were more effective than block at the medial femoral condyle in providing sensory anesthesia to the medial aspect of the leg. The transsartorial approach was more effective than block at the medial femoral condyle and below-the-knee field block in providing sensory anesthesia to the medial aspect of the foot. Compared with the perifemoral approach, the transsartorial approach did not cause weakness of the hip flexors and the knee extensors. In volunteers with partial numbness in the medial aspect of the foot, supplemental block of the medial dorsal cutaneous branch of the superficial peroneal nerve resulted in complete sensory blockade.     

Techniques of Popliteal Nerve Regional Anesthesia

Regional anesthesia for blockade of the sciatic nerve in the popliteal fossa is a useful adjunct to pain management in the perioperative setting for foot and ankle surgeons. The present tip aimed to provide a review of the relevant anatomy and technique for popliteal nerve block from the posterior and lateral approaches and to provide discussion and images of the use of peripheral nerve stimulation and ultrasound guidance as adjuvant methods to improve efficacy and reproducibility.     

The effects of three different approaches on the onset time of sciatic nerve blocks with 0.75% ropivacaine

We studied three different injection techniques of sciatic nerve block in terms of block onset time and efficacy with 0.75% ropivacaine. A total of 75 patients undergoing foot surgery were randomly allocated to receive sciatic nerve blockade by means of the classic posterior approach (group classic; n = 25), a modified subgluteus posterior approach (group subgluteus; n = 25), or a lateral popliteal approach (group popliteal; n = 25). All blocks were performed with the use of a nerve stimulator (stimulation frequency, 2 Hz; intensity, 2-0.5 mA) and 30 mL of 0.75% ropivacaine. Onset of nerve block was defined as complete loss of pinprick sensation in the sciatic nerve distribution with concomitant inability to perform plantar or dorsal flexion of the foot. In the three groups, an appropriate sciatic stimulation was elicited at <0.5 mA. The failure rate was similar in the three groups (group popliteal: 4% versus group classic: 4% versus group subgluteus: 8%). The onset of nerve block was slower in group popliteal (25 +/- 5 min) compared with group classic (16 +/- 4 min) and group subgluteus (17 +/- 4 min; P < 0.001). There was no significant difference in the onset of nerve block between group classic and group subgluteus. No differences in the degree of pain measured at the first postoperative administration of pain medication were observed among the three groups. We conclude that the three approaches resulted in clinically acceptable anesthesia in the distribution of the sciatic nerve. The subgluteus and classic posterior approaches generated a significantly faster onset of anesthesia than the lateral popliteal approach. IMPLICATIONS: Comparing three different approaches to the sciatic nerve with 0.75% ropivacaine, the classic and subgluteal approaches exhibited a faster onset time of sensory and motor blockade than the lateral popliteal approach.     

Ultrasound-guided regional anesthesia for upper limb surgery

Purpose

The purpose of this module is to review the main ultrasound-guided approaches used for regional anesthesia of the upper limb.

Principal findings

The anatomical configuration of the upper limb, with nerves often bundled around an artery, makes regional anesthesia of the arm both accessible and reliable. In-depth knowledge of upper limb anatomy is required to match the blocked territory with the surgical area. The interscalene block is the approach most commonly used for shoulder surgery. Supraclavicular, infraclavicular, and axillary blocks are indicated for elbow and forearm surgery. Puncture techniques have evolved dramatically with ultrasound guidance. Instead of targeting the nerves directly, it is now recommended to look for diffusion areas. Typically, local anesthetics are deposited around vessels, often as a single injection. Phrenic nerve block can occur with the interscalene and supraclavicular approaches. Ulnar nerve blockade is almost never achieved with the interscalene approach and not always present with a supraclavicular block. If ultrasound guidance is used, the risk for pneumothorax with a supraclavicular approach is reduced significantly. Nerve damage and vascular puncture are possible with all approaches. If an axillary approach is chosen, the consequences of vascular puncture can be minimized because this site is compressible.

Conclusions

Upper limb regional anesthesia has gained in popularity because of its effectiveness and the safety profile associated with ultrasound-guided techniques.     

Long-term neurological complications associated with surgery and peripheral nerve blockade: outcomes after 1065 consecutive blocks

Peripheral nerve blockade is gaining popularity as an analgesic option for both upper or lower limb surgery. Published evidence supports the improved efficacy of regional techniques when compared to conventional opioid analgesia. The incidence of neurological deficit after surgery associated with peripheral nerve block is unclear. This paper reports on neurological outcomes occurring after 1065 consecutive peripheral nerve blocks over a one-year period from a single institution. All patients receiving peripheral nerve blocks for surgery were prospectively followed for up to 12 months to determine the incidence and probable cause of any persistent neurological deficit. Formal independent neurological review and testing was undertaken as indicated. Thirteen patients reported symptoms that warranted further investigation. A variety of probable causes were identified, with peripheral nerve block being implicated in two cases (one resolved at nine months and one remaining persistent). Overall incidence of block-related neuropathy was 0.22%. Persistent postoperative neuropathy is a rare but serious complication of surgery associated with peripheral nerve block. Formal follow-up of all such blocks is recommended to assess causality and allow for early intervention.