Nerve Injury Complicating Ultrasound/Electrostimulation-Guided Supraclavicular Brachial Plexus Block:

Intertruncal versus classical approach to the ultrasound-guided supraclavicular brachial plexus block for upper extremity surgery: study protocol for a randomized non-inferiority trial

Background

Ultrasound-guided intertruncal approach (IA) to the supraclavicular block (SB) is recently proposed as a new approach for local anesthetic (LA) injection in terms of the classical approach (CA) at the level of the first rib. The CA-SB has been proven to result in satisfying sensorimotor block, but associate with a high risk of intraneural injection. The aim of this randomized non-inferiority study is to explore whether IA-SB can obtain similar block dynamics, as the CA-SB, but avoiding an intraneural injection during the whole nerve block procedure.

Methods

The total 122 patients undergoing elective upper extremity surgery will be randomly allocated to receive either an IA-SB or a CA-SB using a double-injection (DI) technique. In the IA-SB group, a portion of LA (15 mL) is injected accurately to the intertruncal plane between the middle and lower trunks under real-time ultrasound guidance; then, the remaining volume (10 mL) is carefully distributed to the other intertruncal plane between the upper and middle trunks. In the CA-SB group, the DI technique will be carried out as described in Tran’s study. The primary outcome is the percentage of patients with a complete sensory blockade at 20 min with a predefined non-inferiority margin of − 5%. The secondary outcomes include the sensory-motor blockade of all 4 terminal nerves, onset times of the individual nerves within 30 min, block-related variables, and adverse events.

Discussion

The results will provide sensory-motor blockade-related parameters and safety of the ultrasound-guided intertruncal approach to the supraclavicular block, thereby promoting clinical practice.

Trial registration

Chinese Clinical Trial Registry ChiCTR2000040199. Registered on 25 November 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06029-x.

Real-Time Injection Pressure Sensing and Minimal Intensity Stimulation Combination During Ultrasound-Guided Peripheral Nerve Blocks: An Exploratory Observational Trial

BACKGROUND

Nerve damage can occur after peripheral nerve block (PNB). Ultrasound guidance does not eliminate the risk of intraneural injection or nerve injury. Combining nerve stimulation and injection pressure (IP) monitoring with ultrasound guidance has been suggested to optimize needle tip location in PNB. In this prospective observational study, we hypothesized that measured pairs of IP and minimum intensity of stimulation (MIS) might differentiate successive needle tip locations established by high-resolution ultrasound during PNB.

METHODS

For this exploratory study, 240 observations for 40 ultrasound-guided PNBs were studied in 28 patients scheduled for orthopedic surgery. During the progression of the needle to the nerve observed by ultrasonography, the IP was measured continuously using a computerized pressure-sensing device with a low flow rate of solution. Stimulation thresholds and electrical impedance were obtained by an impedance analyzer coupled to the nerve stimulator at 6 successive needle positions. The median (quartile) or mean (95% confidence interval [CI]) was reported. A mixed model analysis was used, and the sample was also explored using a classification and regression tree (CART) algorithm.

RESULTS

Specific combinations of IP and MIS were measured for subcutaneous, epimysium contact, intramuscular, nerve contact (231 mm Hg [203-259 mm Hg] and 1.70 mA [1.38-2.02 mA]), intraneural location (188 mm Hg [152-224 mm Hg] and 0.58 mA [0.46-0.70 mA]), and subparaneural location (47 mm Hg [41-53 mm Hg] and 1.35 mA [1.09-1.61 mA]). The CART algorithm shows that the optimal subparaneural needle tip position might be defined by the lowest pressure (<81.3 mm Hg) and MIS (<1.5 mA) cutoffs.

CONCLUSIONS

Our exploratory study evaluated concepts to generate hypotheses. The combinations of IP and MIS might help the physician during a PNB procedure. A low IP and low MIS might confirm a subparaneural location, and a high IP and a low MIS might be an alert for the intraneural location of the needle tip.

Comparison between Conventional and Ultrasound-Guided Supraclavicular Brachial Plexus Block in Upper Limb Surgeries

Introduction:

Brachial plexus blockade is a time-tested technique for upper limb surgeries. The classical approach using paresthesia technique is a blind technique and may be associated with a higher failure rate and injury to the nerves and surrounding structures. To avoid some of these problems, use of peripheral nerve stimulator and ultrasound techniques were started which allowed better localization of the nerve/plexus. Ultrasound for supraclavicular brachial plexus block has improved the success rate of the block with excellent localization as well as improved safety margin. Hence, this study was planned for comparing the efficacy of conventional supraclavicular brachial plexus block with ultrasound-guided technique.

Subjects and Methods:

After obtaining the Institutional ethical committee approval and patient consent total of 60 patients were enrolled in this prospective randomized study and were randomly divided into two groups: US (Group US) and C (Group C). Both groups received 0.5% bupivacaine. The amount of local anesthetic injected calculated according to the body weight and was not crossing the toxic dosage (injection bupivacaine 2 mg/kg). The parameters compared between the two groups were lock execution time, time of onset of sensory and motor block, quality of sensory and motor block success rates were noted. The failed blocks were supplemented with general anesthesia.

Results:

Demographic data were comparable in both groups. The mean time taken for the procedure to administer a block by eliciting paresthesia is less compared to ultrasound, and it was statistically significant. The mean time of onset of motor block, sensory blockade, the duration of sensory and motor blockade was not statistically significant. The success rate of the block is more in ultrasound group than conventional group which was not clinically significant. The incidence of complications was seen more in conventional method.

Conclusion:

Ultrasound guidance is the safe and effective method for the supraclavicular brachial plexus block. Incidence of complications are less as ultrasound provides real-time visulaization of underlying structures and the spread of local anaesthetic.

High Opening Injection Pressure Is Associated With Needle-Nerve and Needle-Fascia Contact During Femoral Nerve Block

BACKGROUND AND OBJECTIVES

High opening injection pressures (OIPs) have been shown to predict sustained needle tip contact with the roots of the brachial plexus. Such roots have a uniquely high ratio of fascicular versus connective tissue. It is unknown if this relationship is preserved during multifascicular nerve blockade. We hypothesized that OIP can predict needle-nerve contact during femoral nerve block, as well as detect needle contact with the fascia iliaca.

METHODS

Twenty adults scheduled for femoral block were recruited. Using ultrasound, a 22-gauge needle was sequentially placed in 4 locations: indenting the fascia iliaca, advanced through the fascia iliaca while lateral to the nerve, slightly indenting the femoral nerve, and withdrawn from the nerve 1 mm. At each location, the OIP required to initiate an injection of 1 mL D5W (5% dextrose in water) at 10 mL/min was recorded. Blinded investigators performed evaluations and aborted injections when an OIP of 15 psi was reached.

RESULTS

Opening injection pressure was 15 psi or greater for 90% and 100% of cases when the needle indented the femoral nerve and fascia iliaca, respectively. Opening injection pressure was less than 15 psi for all 20 patients when the needle was withdrawn 1 mm from the nerve as well as at the subfascial position (McNemar χ2 P < 0.001).

CONCLUSIONS

Opening injection pressure greater than 15 psi was associated with a block needle tip position slightly indenting the epineurium of the femoral nerve (90%) and the fascia iliaca (100%). Needle tip positions not indenting these structures were associated with OIP of less than 15 psi (100%).

Ultrasound-guided Continuous Axillary Brachial Plexus Block Using a Nerve Stimulating Catheter: EpiStim® Catheter

Brachial plexus block (BPB) under ultrasound guidance has come to be widely used. However, nerve injury has been reported following ultrasound-guided BPB. We hypothesized that BPB under ultrasound guidance in conjunction with real-time electrical nerve stimulation would help us prevent nerve injury and do more successful procedure. Here, we report the successful induction and maintenance of ultrasound-guided BPB and the achievement of good peri- and postoperative pain control using a conductive catheter, the EpiStim®.

Comparison Between Ultrasound-Guided Supraclavicular and Interscalene Brachial Plexus Blocks in Patients Undergoing Arthroscopic Shoulder Surgery: A Prospective, Randomized, Parallel Study

Although supraclavicular brachial plexus block (SCBPB) was repopularized by the introduction of ultrasound, its usefulness in shoulder surgery has not been widely reported. The objective of this study was to compare motor and sensory blockades, the incidence of side effects, and intraoperative opioid analgesic requirements between SCBPB and interscalene brachial plexus block (ISBPB) in patients undergoing arthroscopic shoulder surgery. Patients were randomly assigned to 1 of 2 groups (ISBPB group: n = 47; SCBPB group: n = 46). The side effects of the brachial plexus block (Horner's syndrome, hoarseness, and subjective dyspnea), the sensory block score (graded from 0 [no cold sensation] to 100 [intact sensation] using an alcohol swab) for each of the 5 dermatomes (C5-C8 and T1), and the motor block score (graded from 0 [complete paralysis] to 6 [normal muscle force]) for muscle forces corresponding to the radial, ulnar, median, and musculocutaneous nerves were evaluated 20 min after the brachial plexus block. Fentanyl was administered in 50 μg increments when the patients complained of pain that was not relieved by the brachial plexus block. There were no conversions to general anesthesia due to a failed brachial plexus block. The sensory block scores for the C5 to C8 dermatomes were significantly lower in the ISBPB group. However, the percentage of patients who received fentanyl was comparable between the 2 groups (27.7% [ISBPB group] and 30.4% [SCBPB group], P = 0.77). SCBPB produced significantly lower motor block scores for the radial, ulnar, and median nerves than did ISBPB. A significantly higher incidence of Horner's syndrome was observed in the ISBPB group (59.6% [ISBPB group] and 19.6% [SCBPB group], P < 0.001). No patient complained of subjective dyspnea. Despite the weaker degree of sensory blockade provided by SCBPB in comparison to ISBPB, opioid analgesic requirements are similar during arthroscopic shoulder surgery under both brachial plexus blocks. However, SCBPB produces a better motor blockade and a lower incidence of Horner's syndrome than ISBPB.

Pressure Monitoring of Intraneural an Perineural Injections Into the Median, Radial, and Ulnar Nerves; Lessons From a Cadaveric Study

Background:

Nerve damage after regional anesthesia has been of great concern to anesthetists. Various modalities have been suggested to recognize and prevent its incidence. An understudied area is the measurement of intraneural pressure during peripheral nerve blockade. Previous investigations have produced contradicting results with only one study being conducted on human cadavers.

Objectives:

The purpose of this investigation was to systematically record intraneural and perineural injection pressures on the median, ulnar, and radial nerves exclusively as a primary outcome.

Materials and Methods:

Ultrasonography-guided injections of 1 mL of 0.9% NaCl over ten seconds were performed on phenol glycerine embalmed cadaveric median, ulnar, and radial nerves. A total of 60 injections were performed, 30 intraneural and 30 perineural injections. The injections pressure was measured using a controlled disc stimulation device. Anatomic dissection was used to confirm needle placement.

Results:

Intraneural needle placement produced significantly greater pressures than perineural injections did. The mean generated pressures in median, radial, and ulnar nerves were respectively 29.4 ± 9.3, 27.3 ± 8.5, and 17.9 ± 7.0 pound per square inch (psi) (1 psi = 51.7 mmHg) for the intraneural injections and respectively 7.2 ± 2.5, 8.3 ± 2.5, and 6.7 ± 1.8 psi for perineural injections. Additionally the intraneural injection pressures of the ulnar nerve were lower than those of the median and radial nerves.

Conclusions:

Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves. Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia. Peripheral nerves “pressure mapping” hypothetically might show difference amongst various nerves depending on anatomic location, histologic structure, and ultrasonographic appearance.

[Ultrasound and nerve stimulator guided continuous femoral nerve block analgesia after total knee arthroplasty: a multicenter randomized controlled study]

BACKGROUND AND OBJECTIVES

Postoperative analgesia is crucial for early functional excise after total knee arthroplasty. To investigate the clinical efficacy of ultrasound and nerve stimulator guided continuous femoral nerve block analgesia after total knee arthroplasty.

METHODS

46 patients with ASA grade I-III who underwent total knee arthroplasty received postoperative analgesia from October 2012 to January 2013. In 22 patients, ultrasound and nerve stimulator guided continuous femoral nerve block were performed for analgesia (CFNB group); in 24 patients, epidural analgesia was done (PCEA group). The analgesic effects, side effects, articular recovery and complications were compared between two groups.

RESULTS

At 6h and 12h after surgery, the knee pain score (VAS score) during functional tests after active exercise and after passive excise in CFNB were significantly reduced when compared with PCEA group. The amount of parecoxib used in CFNB patients was significantly reduced when compared with PCEA group. At 48h after surgery, the muscle strength grade in CFNB group was significantly higher, and the time to ambulatory activity was shorter than those in PCEA group. The incidence of nausea and vomiting in CFNB patients was significantly reduced when compared with PCEA group.

CONCLUSION

Ultrasound and nerve stimulator guided continuous femoral nerve block provide better analgesia at 6h and 12h, demonstrated by RVAS and PVAS. The amount of parecoxib also reduces, the incidence of nausea and vomiting decreased, the influence on muscle strength is compromised and patients can perform ambulatory activity under this condition.

Anesthesia for Vascular access Surgery

The type of anesthesia chosen is an integral part of the decision-making process for arteriovenous access construction. We discuss the different types of anesthesia used, with emphasis on brachial plexus block, which is potentially safer than general anesthesia in this fragile patient population with end-stage renal disease. Brachial plexus block is superior to local anesthesia and enables the use of a tourniquet to minimize potential damage to the blood vessels during anastomosis using microsurgery techniques, and does not lead to the vasospasm that may be seen with local anesthesia. Regional anesthesia has a beneficial sympathectomy-like effect that causes vasodilation with increased blood flow during surgery and in the fistula postoperatively that may prevent early thrombosis and potentially improve outcome.

Brachial plexus injury as a complication after nerve block or vessel puncture

Brachial plexus injury is a potential complication of a brachial plexus block or vessel puncture. It results from direct needle trauma, neurotoxicity of injection agents and hematoma formation. The neurological presentation may range from minor transient pain to severe sensory disturbance or motor loss with poor recovery. The management includes conservative treatment and surgical exploration. Especially if a hematoma forms, it should be removed promptly. Comprehensive knowledge of anatomy and adept skills are crucial to avoid nerve injuries. Whenever possible, the patient should not be heavily sedated and should be encouraged to immediately inform the doctor of any experience of numbness/paresthesia during the nerve block or vessel puncture.

Opening Injection Pressure Consistently Detects Needle–Nerve Contact during Ultrasound-guided Interscalene Brachial Plexus Block

Background:

Needle trauma may cause neuropathy after nerve blockade. Even without injection, nerve injury can result from forceful needle–nerve contact (NNC). High opening injection pressures (OIPs) have been associated with intrafascicular needle tip placement and nerve damage; however, the relationship between OIP and NNC is unclear. The authors conducted a prospective, observational study to define this relationship.

Methods:

Sixteen patients scheduled for shoulder surgery under interscalene block were enrolled if they had clear ultrasound images of the brachial plexus roots. A 22-gauge stimulating needle was inserted within 1 mm of the root, and 1-ml D5W injected at 10 ml/min by using an automated pump. OIP was monitored using an in-line pressure manometer and injections aborted if 15 psi or greater. The needle was advanced to displace the nerve slightly (NNC), and the procedure repeated. Occurrence of evoked motor response and paresthesia were recorded.

Results:

Fifteen patients had at least one clearly visible root. OIP at 1 mm distance from the nerve was less than 15 psi (mean peak pressure 8.2 ± 2.4 psi) and the 1-ml injection could be completed in all but two cases (3%). In contrast, OIP during NNC was 15 psi or greater (mean peak pressure 20.9 ± 3.7 psi) in 35 of 36 injections. Aborting the injection when OIP reached 15 psi prevented commencement of injection in all cases of NNC except one.

Conclusion:

High OIP (≥15 psi) consistently detected NNC, suggesting that injection pressure monitoring may be useful in preventing injection against nerve roots during interscalene block.

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.

Regional blockade of the shoulder: approaches and outcomes

The article reviews the current literature regarding shoulder anesthesia and analgesia. Techniques and outcomes are presented that summarize our present understanding of regional anesthesia for the shoulder. Shoulder procedures producing mild to moderate pain may be managed with a single-injection interscalene block. However, studies support that moderate to severe pain, lasting for several days is best managed with a continuous interscalene block. This may cause increased extremity numbness, but will provide greater analgesia, reduce supplemental opioid consumption, improve sleep quality and patient satisfaction. In comparison to the nerve stimulation technique, ultrasound can reduce the volume of local anesthetic needed to produce an effective interscalene block. However, it has not been shown that ultrasound offers a definitive benefit in preventing major complications. The evidence indicates that the suprascapular and/or axillary nerve blocks are not as effective as an interscalene block. However in patients who are not candidates for the interscalene block, these blocks may provide a useful alternative for short-term pain relief. There is substantial evidence showing that subacromial and intra-articular injections provide little clinical benefit for postoperative analgesia. Given that these injections may be associated with irreversible chondrotoxicity, the injections are not presently recommended.

Is there still a place for the use of nerve stimulation?

The introduction of nerve stimulation as a method of nerve localization sparked a new beginning in regional anesthesia. It was an epochal development akin to the utilization of ultrasound in more recent times. Many experts now consider ultrasound-guided peripheral nerve blockade to be more efficient, less painful, and more successful than landmark and nerve stimulation techniques. However, inadvertent intraneural injection continues to occur despite the widespread use of ultrasound and nerve stimulation. Both of these technologies allow for only limited elucidation of needle position relative to the target nerve and are unable to reliably identify intraneural position of the needle. This article will review the role of nerve stimulation in modern regional anesthesia techniques in light of the introduction of ultrasound technology.

Spread of local anesthetic during an ultrasound-guided interscalene block: does the injection site influence diffusion?

BACKGROUND

During interscalene block (ISB) placement, ultrasound guidance (USG) enables the practitioner to measure the spread of local anesthetic around the nerve trunks or roots, and to adjust the needle position in order to optimize diffusion. Moreover, USG helps determine the best injection level, i.e. the point from which diffusion gives the most complete brachial plexus block. The aim of this study was to compare C5 and C6 level injections and to determine which level allows the best diffusion.

METHODS

Sixty randomized patients scheduled for shoulder surgery were divided into two groups. In group C5, injection was directed toward C5 while in group C6, the C6 nerve root was targeted. Block performance time was recorded. The onset of motor and sensory block of each nerve distribution was evaluated every 10 min over a 30-min period.

RESULTS

The average time taken to perform a nerve block was 6.2+2.6 min in Group C6 and 6.0+2.1 min in Group C5 (NS). At 30 min, the number of patients with a satisfactory musculocutaneous and axillary nerve block was not notably greater in either group. By contrast, a significantly higher success rate was observed for other nerves in the C6 group as compared to the C5 group: ulnar nerve block: 93% vs. 19%, radial nerve block: 96% vs. 28%, median nerve block: 96%, vs. 69%.

CONCLUSIONS

During USG ISB placement, injection below the C6 level provided the same efficiency in analgesia after shoulder surgery as an injection cranial to the C5 nerve root but a greater success rate of anesthesia in all distal nerve areas. This technique could be very interesting for trauma cases as an alternative to a supraclavicular block and offers a high success rate and is simple to perform, potentially promoting wide use and quicker learning for beginners.