Superior Trunk Block

Validation of a novel point-of-care ultrasound method to assess diaphragmatic excursion

INTRODUCTION

Point-of-care ultrasound can assess diaphragmatic function and rule in or rule out paresis of the diaphragm. While this is a useful bedside tool, established methods have significant limitations. This study explores a new method to assess diaphragmatic motion by measuring the excursion of the uppermost point of the zone of apposition (ZOA) at the mid-axillary line using a high-frequency linear ultrasound probe and compares it with two previously established methods: the assessment of the excursion of the dome of the diaphragm (DOD) and the thickening ratio at the ZOA.

METHODS

This is a single-centre, prospective comparative study on elective surgical patients with normal diaphragmatic function. Following research ethics board approval and patient written consent, 75 elective surgical patients with normal diaphragmatic function were evaluated preoperatively. Three ultrasound methods were compared: (1) assessment of the excursion of the DOD using a curvilinear probe through an abdominal window; (2) assessment of the thickening fraction of the ZOA; and (3) assessment of the excursion of the ZOA. The last two methods performed with a linear probe on the lateral aspect of the chest.

RESULTS

Seventy-five patients were studied. We found that the evaluation of the excursion of the ZOA was more consistently successful (100% bilaterally) than the evaluation of the excursion of the DOD (98.7% and 34.7% on the right and left sides, respectively). The absolute values of the excursion of the ZOA were greater than and well correlated with the values of the DOD.

CONCLUSION

Our preliminary data from this exploratory study suggest that the evaluation of the excursion of the ZOA on the lateral aspect of the chest using a linear probe is consistently successful on both right and left sides. Future studies are needed to establish the distribution of normal values and suggest diagnostic criteria for diaphragmatic paresis or paralysis.

TRIAL REGISTRATION NUMBER

NCT03225508.

Diaphragm-sparing efficacy of subparaneural upper trunk block for arthroscopic shoulder surgery: A randomised controlled trial

BACKGROUND

Inter-scalene block (ISB) is associated with an inevitable risk of hemi-diaphragmatic paresis (HDP). To reduce the risk of HDP, an upper trunk block (UTB) has been proposed at the brachial plexus division level.

OBJECTIVE

We hypothesised that UTB would be associated with a lower incidence of HDP than ISB while providing sufficient analgesia following arthroscopic shoulder surgery.

DESIGN

Randomised controlled trial.

SETTING

A tertiary teaching hospital.

PATIENTS

Seventy patients aged 20 to 80 years undergoing arthroscopic rotator cuff repair.

INTERVENTION

Ultrasound-guided ISB or UTB was performed with 5 ml 0.75% ropivacaine.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of complete HDP, assessed by diaphragm excursion using ultrasound, defined as a decrease to 25% or less of baseline or occurrence of paradoxical movement. Postoperative pulmonary function change, pain scores, opioid consumption and pain-related outcomes were the secondary outcomes.

RESULTS

The UTB group had a significantly lower incidence of complete HDP than the ISB group [5.9% (2/34) vs. 41.7% (15/36); absolute difference, 35.8%; 95% confidence interval (CI), 17.8 to 53.7%; P  < 0.001]. The postblockade decline in pulmonary function was more pronounced in the ISB group than that in the UTB group. The pain score at 1 h postoperatively was not significantly different between the groups (ISB vs. UTB group: median 0 vs. 1; median difference, -1; 95% CI, -2 to 0.5). No significant difference was observed in any other secondary outcomes.

CONCLUSION

UTB was associated with a lower incidence of HDP compared with ISB while providing excellent analgesia in arthroscopic shoulder surgery.

TRIAL REGISTRATION

Clinical Trial Registry of Korea ( https://cris.nih.go.kr ) identifier: KCT0007002.

IRB NUMBER

Chungnam National University Hospital Institutional Review Board No. 2021-12-069.

Comparison between low-volume local anesthetic with intravenous dexamethasone and conventional volume without dexamethasone for superior trunk block after arthroscopic shoulder surgery: a randomized controlled non-inferiority trial

INTRODUCTION

This study aimed to investigate whether low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while maintaining the analgesic duration compared with conventional volume of local anesthetic without intravenous dexamethasone when performing ultrasound-guided superior trunk block in patients undergoing arthroscopic shoulder surgery.

METHODS

Eighty-four adult patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly assigned to receive ultrasound-guided superior trunk block using 7 mL of 0.5% ropivacaine with 0.15 mg/kg of intravenous dexamethasone (treatment group), or 15 mL of 0.5% ropivacaine with intravenous normal saline (control group). The co-primary outcomes were (1) the duration of analgesia (time between block completion and onset of surgical pain with a Numeric Rating Scale pain score of 4 or higher), which was compared against a non-inferiority margin of 3 hours, and (2) the incidence of diaphragmatic paresis evaluated using M-mode ultrasonography in the post-anesthesia care unit.

RESULTS

The mean duration of analgesia was 12.4 (6.8) and 11.2 (4.6) hours in the treatment and control groups, respectively (mean difference: -1.2 hours; 95% CI -3.8 to 1.3]; p for non-inferiority<0.001), meeting the non-inferiority criteria. The incidence of diaphragmatic paresis was 45.2% and 85.4% in the treatment and control groups, respectively (relative risk: 0.53; 97.5% CI 0.35 to 0.80; p<0.001).

CONCLUSIONS

Superior trunk block using low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while providing non-inferior analgesic duration compared with the conventional volume of local anesthetic in patients undergoing arthroscopic shoulder surgery.

TRIAL REGISTRATION NUMBER

Clinical Research Information Service of Republic of Korea Registry (KCT0005998).

Ultrasound assessment of diaphragmatic dysfunction in non-critically ill patients: relevant indicators and update

Diaphragm dysfunction (DD) can be classified as mild, resulting in diaphragmatic weakness, or severe, resulting in diaphragmatic paralysis. Various factors such as prolonged mechanical ventilation, surgical trauma, and inflammation can cause diaphragmatic injury, leading to negative outcomes for patients, including extended bed rest and increased risk of pulmonary complications. Therefore, it is crucial to protect and monitor diaphragmatic function. Impaired diaphragmatic function directly impacts ventilation, as the diaphragm is the primary muscle involved in inhalation. Even unilateral DD can cause ventilation abnormalities, which in turn lead to impaired gas exchange, this makes weaning from mechanical ventilation challenging and contributes to a higher incidence of ventilator-induced diaphragm dysfunction and prolonged ICU stays. However, there is insufficient research on DD in non-ICU patients, and DD can occur in all phases of the perioperative period. Furthermore, the current literature lacks standardized ultrasound indicators and diagnostic criteria for assessing diaphragmatic dysfunction. As a result, the full potential of diaphragmatic ultrasound parameters in quickly and accurately assessing diaphragmatic function and guiding diagnostic and therapeutic decisions has not been realized.

Anesthesia for the Patient Undergoing Shoulder Surgery

Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve as the primary anesthetic or can be used for postoperative analgesia. Phrenic nerve blockade is a limitation of the interscalene block and various phrenic-sparing strategies and techniques have been described. Patient positioning is another important anesthetic consideration and can be associated with significant hemodynamic effects and position-related injuries.

Noninferiority trials in acute pain research: a valid approach or a slippery slope?

The conduct and reporting of studies with a noninferiority hypothesis is challenging because of the complexity involved in their design and interpretation. However, studies with a noninferiority design have increased in popularity. A recently published trial reported on the noninferiority of lidocaine infusion to epidural analgesia in major abdominal surgeries. Apart from needing a critical appraisal, this draws attention to improve our understanding of noninferiority study framework and its unique features. Given the increasing focus on using various analgesic adjuncts and multiple approaches to fascial plane blocks to avoid more definitive and standard approaches, it is imperative that particular attention is paid to appropriate execution and reporting of noninferiority studies.

Just the facts: brachial plexus blocks for upper extremity injuries in the emergency department

Ultrasound-guided nerve blocks (UGNBs) are becoming a more common method for pain control in the emergency department. Specifically, brachial plexus blocks have shown promise for acute upper extremity injuries as well as an alternative to procedural sedation for glenohumeral reductions. Unfortunately, there is minimal discussion in the EM literature regarding phrenic nerve paralysis (a well-known complication from brachial plexus blocks). The anatomy of the brachial plexus, its relationship to the phrenic nerve, and why ultrasound-guided brachial plexus blocks can cause phrenic nerve paralysis and resultant respiratory impairment will be discussed. The focus on patient safety is paramount, and those with preexisting respiratory conditions, extremes of age or weight, spinal deformities, previous neck injuries, and anatomical variations are at greater risk. We put forth different block strategies for risk mitigation, including patient selection, volume and type of anesthetic, block location, postprocedural monitoring, and specific discharge instructions. Understanding the benefits and risks of UGNBs is critical for emergency physicians to provide effective pain control while ensuring optimal patient safety.

Shaping the Anesthetic Approach to TricValve Implantation: Insights From a Case Series

OBJECTIVES

Caval valve implantation (CAVI) represents a minimally invasive strategy for managing severe tricuspid regurgitation in high-risk patients unsuitable for surgical or transcatheter tricuspid valve implantation. This case series aimed to assess the anesthesia management challenges and outcomes associated with this procedure, seeking to generate insights that can inform and refine anesthesia protocols.

DESIGN

A case series.

SETTING

At a cardiac catheterization laboratory of a teaching hospital.

PARTICIPANTS

Eight patients undergoing CAVI with the Tricvalve system INTERVENTIONS: The anesthetic protocol included preprocedural planning, fast-track general anesthesia, and postprocedural debriefing. Intraoperative management involved anesthesia depth monitoring, real-time guidance via transesophageal echocardiography, and hemodynamic stability maintenance. Postoperative analgesia involved preemptive intravenous paracetamol and morphine as needed.

MEASUREMENTS AND MAIN RESULTS

No anesthesia-related or implantation-related complications were observed, with a mean procedure duration of 112 ± 44 minutes. The median hospital stay was 4 days, and only 1 patient required brief intensive care unit monitoring. Postoperative right shoulder pain was reported by half of the patients, and was managed with morphine bolus administration (average dose 4.75 ± 3.6 mg). All patients had the device correctly positioned, as confirmed by postoperative transthoracic echocardiograms. None of the patients required outpatient analgesic therapy upon discharge.

CONCLUSIONS

The authors' study demonstrated the potential of TricValve implantation in effectively managing severe tricuspid regurgitation with no procedure-related complications and a 100% survival rate. A collaborative, interdisciplinary approach and targeted anesthesia management proved crucial for this success. Postoperative shoulder pain emerged as a frequent complication, whose pathogenesis is still not clear, and successfully was managed using targeted analgesic therapy.

The efficacy of ultrasound-guided upper thoracic erector spinae plane block for postoperative analgesia in proximal shoulder surgery and its effect on phrenic nerve function: A prospective exploratory study

Background and Aims

The upper thoracic (T2) erector spinae plane block (UT-ESPB) has been proposed as an alternative to interscalene brachial plexus block for postoperative analgesia in shoulder surgery. The current study was conducted to evaluate the same.

Material and Methods

Patients scheduled for shoulder surgery under general anesthesia (GA) received ultrasound-guided UT-ESPB. The outcomes measured were diaphragmatic movements, block characteristics, and quality of recovery at 24 h.

Results

A total of 43 patients were recruited. The incidence of phrenic nerve palsy was 0%. The sensory level achieved by the maximum number of patients at the end of 30 min was C7-T5 level, and none had a motor block. Forty-two percent of patients did not require rescue analgesia till 24 h postoperative. In the rest of the patients, the mean (SD) duration of analgesia was 724.2 ± 486.80 min, and the mean postoperative requirement of fentanyl was 98.80 ± 47.02 μg. The median pain score (NRS) during rest and movement is 2 to 3 and 3 to 4, respectively. The median quality of recovery score at the end of 24 h after the block was 14 (15-14).

Conclusion

The upper thoracic ESPB resulted in a sensory loss from C7-T5 dermatomes without any weakness of the diaphragm and upper limb. However, the block was moderately effective in terms of the total duration of analgesia, postoperative pain scores, analgesic requirement, and quality of recovery in patients undergoing proximal shoulder surgeries under GA. Further studies are required to establish its role due to its poor correlation with sensory spread.

Continuous Superior Trunk Block versus Single-Shot Superior Trunk Block with Intravenous Dexmedetomidine for Postoperative Analgesia in Arthroscopic Shoulder Surgery: A Prospective Randomized Controlled Trial

Background/Objectives: Intravenous dexmedetomidine (DEX) can increase the analgesia duration of peripheral nerve block; however, its effect in combination with superior trunk block (STB) remains unclear. We examined whether combining single-shot STB (SSTB) with intravenous DEX would provide noninferior postoperative analgesia comparable to that provided by continuous STB (CSTB). Methods: Ninety-two patients scheduled for elective arthroscopic rotator cuff repair were enrolled in this prospective randomized trial. Patients were randomly assigned to the CSTB or SSTB + DEX group. Postoperatively, each CSTB group patient received 15 mL of 0.5% ropivacaine and a continuous 0.2% ropivacaine infusion. Each SSTB group patient received a 15 mL postoperative bolus injection of 0.5% ropivacaine. DEX was administered at 2 mcg/kg for 30 min post anesthesia, then maintained at 0.5 mcg/kg/h till surgery ended. Pain scores were investigated every 12 h for 48 h post operation, with evaluation of rebound pain incidence and opioid consumption. Results: The SSTB + DEX group had significantly higher median pain scores at 12 h post operation (resting pain, 8.0 vs. 3.0; movement pain, 8.0 vs. 5.0) and a higher incidence of rebound pain (56% vs. 20%) than the CSTB group. However, no significant between-group differences were observed in pain scores postoperatively at 24, 36, or 48 h. The CSTB group required less opioids and fewer rescue analgesics within 12-24 h post operation than the SSTB + DEX group. Conclusions: Compared with CSTB, SSTB + DEX required additional adjuvant or multimodal analgesics to reduce the risk and intensity of postoperative rebound pain in patients who underwent arthroscopic rotator cuff repair.

Superior Trunk Block Catheter and 2% Chloroprocaine as a Phrenic Sparing Approach for Awake Arthroscopic Acromioclavicular Joint Surgery: A Case Report

Regional anaesthesia for shoulder surgery remains challenging in patients with pre-existing respiratory comorbidities. Various alternative phrenic sparing techniques have been described in the literature, but to our knowledge, none have explored the benefits of using short-acting local anaesthetics in combination to achieve surgical anaesthesia for awake surgery. This case report describes the successful use of the superior trunk block catheter, a relative phrenic sparing shoulder nerve block, and 2% chloroprocaine, a short-acting local anaesthetic, to provide surgical anaesthesia for awake shoulder surgery in a patient with severe respiratory disease.

[Common and New Regional Anaesthesia Techniques Under Review - From Head to Abdomen]

By implementation of sonography regional anesthesia became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety during needle placement. Thereby new truncal blocks got enabled. Next to the blocking of specific nerve structures, plane blocks got established which can also be described as interfascial compartment blocks. The present review illustrates published and established blocks in daily practice concerning indications and the procedural issues. Moreover, the authors explain potential risks, complications and dosing of local anesthetics.

Effects of propofol versus sevoflurane on surgical field visibility during arthroscopic rotator cuff repair: a randomized trial

BACKGROUND

During arthroscopic rotator cuff repair (ARCR), clear surgical field visibility (SFV) is the basis of successful surgery, but the choice of anesthesia maintenance drugs may have different effects on SFV. In this study, we aimed to compare the effects of propofol- and sevoflurane-based general anesthesia on SFV in patients undergoing ARCR.

METHODS

Patients (n = 130) undergoing elective ARCR in the lateral decubitus position were randomized into either the propofol group or sevoflurane group (65 per group). The duration of surgery and increased pressure irrigation (IPI), Boezaart score, rocuronium consumption and usage of remifentanil were recorded. The time of both spontaneous respiration recovery and extubation and the incidences of postoperative nausea and vomiting and agitation were also recorded.

RESULTS

The Boezaart score, duration of IPI and ratio of the duration of IPI to the duration of surgery (IPI/S ratio) were similar between the groups (P > 0.05). Rocuronium consumption, number of patients requiring remifentanil infusion and total remifentanil consumption were significantly lower in the sevoflurane group (P < 0.05). The spontaneous respiration recovery time was significantly longer in the propofol group (P < 0.05), but there were no differences in the extubation time between the groups(P > 0.05).

CONCLUSIONS

Compared with propofol, sevoflurane provides equally clear SFV while improving the convenience of anesthesia maintenance in ARCR patients with interscalene plexus (ISB) combined with general anesthesia.

TRIAL REGISTRATION

This single-center, prospective, RCT was retrospective registered at Chinese Clinical Trial Registry with the registration number ChiCTR2300072110 (02/06/2023).

Perioperative Diaphragm Dysfunction

Diaphragm Dysfunction (DD) is a respiratory disorder with multiple causes. Although both unilateral and bilateral DD could ultimately lead to respiratory failure, the former is more common. Increasing research has recently delved into perioperative diaphragm protection. It has been established that DD promotes atelectasis development by affecting lung and chest wall mechanics. Diaphragm function must be specifically assessed for clinicians to optimally select an anesthetic approach, prepare for adequate monitoring, and implement the perioperative plan. Recent technological advancements, including dynamic MRI, ultrasound, and esophageal manometry, have critically aided disease diagnosis and management. In this context, it is noteworthy that therapeutic approaches for DD vary depending on its etiology and include various interventions, either noninvasive or invasive, aimed at promoting diaphragm recruitment. This review aims to unravel alternative anesthetic and operative strategies that minimize postoperative dysfunction by elucidating the identification of patients at a higher risk of DD and procedures that could cause postoperative DD, facilitating the recognition and avoidance of anesthetic and surgical interventions likely to impair diaphragmatic function.

Rate of occurrence of respiratory complications in patients who undergo shoulder arthroplasty with a continuous interscalene brachial plexus block and associated risk factors

INTRODUCTION

Continuous interscalene nerve block techniques are an effective form of targeted non-opioid postoperative analgesia for shoulder arthroplasty patients. One of the limiting risks, however, is potential phrenic nerve blockade with resulting hemidiaphragmatic paresis and respiratory compromise. While studies have focused on block-related technical aspects to limit the incidence of phrenic nerve palsy, little is known about other factors associated with increased risk of clinical respiratory complications in this population.

METHODS

A single-institution retrospective cohort study was conducted using electronic health records from adult patients who underwent elective shoulder arthroplasty with continuous interscalene brachial plexus blocks (CISB). Data collected included patient, nerve block, and surgery characteristics. Respiratory complications were categorized into four groups (none, mild, moderate, and severe). Univariate and multivariable analyses were conducted.

RESULTS

Among 1025 adult shoulder arthroplasty cases, 351 (34%) experienced any respiratory complication. These 351 were subdivided into 279 (27%) mild, 61 (6%) moderate, and 11 (1%) severe respiratory complications. In an adjusted analysis, patient-related factors were associated with an increased likelihood of respiratory complication: ASA Physical Status III (OR 1.69, 95% CI 1.21 to 2.36); asthma (OR 1.59, 95% CI 1.07 to 2.37); congestive heart failure (OR 1.99, 95% CI 1.19 to 3.33); body mass index (OR 1.06, 95% CI 1.03 to 1.09); age (OR 1.02, 95% CI 1.00 to 1.04); and preoperative oxygen saturation (SpO2). For every 1% decrease in preoperative SpO2, there was an associated 32% higher likelihood of a respiratory complication (OR 1.32, 95% CI 1.20 to 1.46, p<0.001).

CONCLUSIONS

Patient-related factors that can be measured preoperatively are associated with increased likelihood of respiratory complications after elective shoulder arthroplasty with CISB.

Comparison of the Analgesic Efficacy between Arthroscopically Placed Continuous Suprascapular Nerve Block and Ultrasound-guided Continuous Superior Trunk Block: A Double-blinded Randomized Controlled Trial

BACKGROUND

Single-shot suprascapular nerve block and superior trunk block have been reported to provide a noninferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides noninferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery.

METHODS

100 patients were randomized undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared.

RESULTS

Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a noninferiority margin of 1 (worst pain score: mean difference, 0.9; 95% CI, 0.1 to 1.7; resting pain score: mean difference, 0.5; 95% CI, 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group.

CONCLUSIONS

Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

EDITOR’S PERSPECTIVE

Superior Trunk Block Is an Effective Phrenic-Sparing Alternative to Interscalene Block for Shoulder Arthroscopy: A Systematic Review and Meta-Analysis

The interscalene block (ISB) is the standard regional anesthesia for shoulder arthroscopy. However, the superior trunk block (STB) is an alternative with a potentially safer profile. This meta-analysis aimed to compare the incidence and degree of hemidiaphragmatic paralysis and block efficacy of these techniques. We searched MEDLINE, EMBASE, Scopus, and Cochrane databases to identify randomized controlled trials (RCTs). The main outcome was total hemidiaphragmatic paralysis. We used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework to assess the certainty of evidence. Four RCTs and 359 patients were included. The STB group showed lower total hemidiaphragmatic paralysis (RR 0.07; 95% CI 0.04 to 0.14; p<0.0001). The incidence of subjective dyspnea (p = 0.002) and Horner's syndrome (p<0.001) was significantly lower with STB relative to ISB. There was no significant difference between groups in block duration (p = 0.67). There was a high certainty of evidence in the main outcome as per the GRADE framework. Our findings suggest that STB has a better safety profile than ISB, resulting in lower rates of hemidiaphragmatic paralysis and dyspnea while providing a similar block. Therefore, STB could be preferred to ISB, especially in patients susceptible to phrenic nerve paralysis complications.

Topographic and morphometric anatomy of the proximal part of the dorsal scapular nerve

The dorsal scapular nerve (DSN) entrapment neuropathy has recently been recognized as a common cause of circumscapular pain and cases of winged scapula. Course of the nerve is important because the middle scalene muscle is frequently accessed for surgical treatments. Studies in the literature have not focused on the morphometric relationship of the DSN with the scalene muscles and its relationship with the long thoracic nerve (LTN). The neck regions of 13 adult cadavers were dissected bilaterally. The relationship of DSN with scalene muscles and LTN was evaluated. Cervical spinal nerves involved in the formation of the DSN were identified. Three types of DSN were observed based on the cervical spinal nerves from which it originates, five types of DSN from its relationship with the scalene muscles, and two types of DSN from its relationship with the LTN. The distance from where the nerve pierces the scalene muscle to the mastoid process was found to be greater in DSNs originating from C4 and C5 (93.85 ± 4.11 mm, p = 0.033). In DSNs not connected with LTN, the distance from where the nerve pierces the scalene muscle to the superior trunk/C5 (12.74 ± 7.73 mm, p = 0.008) and the length of the nerve within the scalene muscle (14.94 ± 5.5 mm, p = 0.029) were found to be statistically significantly greater. The topographic and morphometric anatomy of the proximal part of the DSN is important, especially for scalene muscles-focused surgical treatments and interscalene nerve blocks. We believe our results may guide clinical approaches and surgery.

Impact of Peripheral Nerve Block Technique on Incidence of Phrenic Nerve Palsy in Shoulder Surgery

Peripheral nerve blocks are an increasingly common method of providing postoperative analgesia for shoulder surgeries. However, the standard technique, the interscalene block (ISB), inevitably causes hemidiaphragmatic paresis (HDP), secondary to phrenic nerve palsy. This can cause morbidity in patients with preexisting respiratory compromise, prompting investigation into alternative "phrenic-sparing" nerve blocks. The aim of this review was to give an overview of these blocks and critically evaluate the current literature to determine if any are suitable replacements for ISB. The incidence of HDP and analgesic efficacy were considered. We queried four electronic databases and one register. Twenty-eight original articles were selected for review. The use of ultrasound guidance, lower volumes of local anaesthetic (LA), and injection 4 mm outside the brachial plexus fascia reduced HDP incidence for the ISB; however, no single modification did so sufficiently. While the anterior suprascapular nerve block (SSNB) showed comparable analgesic effects to the ISB, HDP prevalence was also high. The posterior SSNB produced consistently low HDP incidences but also inferior analgesia to ISB, except when combined with an infraclavicular brachial plexus block. The superior trunk block (STB) provided equivalent analgesia to the ISB while reducing HDP incidence, but not significantly. Lower LA volumes consistently led to lower HDP incidence across all blocks, likely due to a reduced ability to spread to the phrenic nerve. Further investigation into the minimum effective volumes of the extrafascial ISB, anterior SSNB, STB, and combined posterior SSNB with infraclavicular block is warranted to determine if any of these blocks can successfully balance HDP prevention with analgesic efficacy.

Brachial plexus blockade arising from a combined pectoralis (PECS) 1 and 2 block

We present a case of inadvertent spread of local anaesthetic from combined pectoralis (PECS) 1 and 2 fascial plane blocks that resulted in an incomplete brachial plexus block. An otherwise healthy 42-year-old woman with a body mass index of 23.3 kg.m-2 presented for unilateral mastectomy with immediate prosthetic reconstruction for breast cancer. No axillary dissection was performed. Because of service requirements, the blocks were performed at the conclusion of surgery. This may have resulted in greater cranial spread of the local anaesthetic due to surgical dissection along musculature and placement of the breast implant. Following emergence from general anaesthesia, the patient experienced numbness over the ipsilateral medial forearm extending to the little finger. Further examination with a finger-nose test revealed reduced coordination and joint proprioception of the ipsilateral arm. There was no detectable gross motor weakness. She was reviewed the following day (23 h after the blocks) by which time her symptoms had subsided entirely. We believe that this is the first documented brachial plexus block after injection of local anaesthetic into the pectoralis 1 and 2 fascial planes.

Peri-operative Hemi-diaphragmatic Variations After Brachial Plexus Block Above the Clavicle: A Prospective Observational Study of the Contralateral Side

OBJECTIVE

Hemi-diaphragm palsy after brachial plexus block above the clavicle (BPBAC) occurs frequently, but few patients develop post-operative pulmonary complications (PPC). We hypothesized that contralateral hemidiaphragm function increases after BPBAC. This contralateral function preserves global diaphragmatic function, avoiding PPC in the case of ipsilateral hemi-diaphragm palsy.

METHODS

This prospective observational cohort study included 64 adult patients undergoing shoulder surgery with planned BPBAC (interscalene brachial plexus block and supraclavicular block). The Thickening Fraction (TF) was measured by ultrasound in both hemi-diaphragms, ipsilateral (TF _ipsilateral) and contralateral (TF_{contralateral}) to the BPBAC, before and after the surgery. TF_global is the sum of TF_ipsilateral and TF_{contralateral}. PPC were defined as occurrences of dyspnea, tachypnea, SpO₂ <90% or SpO₂/FiO₂ <315.

RESULTS

TF_{contralateral} increased significantly (an average of 40%) after BPBAC (p = 0.001), and TF_ipsilateral decreased (an average of 72%). After BPBAC, 86% of patients had a decreased TF_ipsilateral and 59% of patients an increased TF_{contralateral} at post-operatively. Only 17% of patients have PPC.

CONCLUSION

After BPBAC, global diaphragm function decreases because of ipsilateral hemi-diaphragm reduction, but less than expected because of increased contralateral hemi-diaphragm function. As a part of diaphragm function, contralateral hemi-diaphragm function must be checked.

Regional Anesthesia Techniques for Shoulder Surgery in High-Risk Pulmonary Patients

Patients with pre-existing pulmonary conditions are at risk for experiencing perioperative complications and increased morbidity. General anesthesia has historically been used for shoulder surgery, though regional anesthesia techniques are increasingly used to provide anesthesia and improved pain control after surgery. Relative to regional anesthesia, patients who undergo general anesthesia may be more prone to risks of barotrauma, postoperative hypoxemia, and pneumonia. High-risk pulmonary patients, in particular, may be exposed to these risks of general anesthesia. Traditional regional anesthesia techniques for shoulder surgery are associated with high rates of phrenic nerve paralysis which significantly impairs pulmonary function. Newer regional anesthesia techniques have been developed, however, that provide effective analgesia and surgical anesthesia while having much lower rates of phrenic nerve paralysis, thereby preserving pulmonary function.

Ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block or interscalene brachial plexus block in clavicle surgery: a single-centre, double-blind, randomized controlled trial

The sensory innervation of the clavicle is complex, and the best regional block technology for clavicular surgery has yet to be determined. The purpose of this study was to compare the application of ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block verses interscalene brachial plexus block in clavicular surgery. Fifty patients undergoing internal fixation surgery for elective clavicle fractures were randomly divided into two groups (n = 25 for each group): group I and group II. Superficial cervical plexus block combined with clavipectoral fascial plane block was used in group I, and superficial cervical plexus block combined with interscalene brachial plexus block was used in group II. The primary outcome measure was the duration of analgesia. The duration of analgesia in group I was significantly longer than that in group II (P < 0.05). The modified Bromage scale function score in group II was lower than that in group I (P < 0.01). There was no significant difference in the skin acupuncture pain score 30 min after block and visual analog scale (VAS) scores at 6 and 12 h after surgery. However, the 24 h VAS score in group I was lower than that in group II (P < 0.05). The incidence of diaphragmatic paralysis was significantly increased in group II (P < 0.01). Ultrasound-guided superficial cervical plexus block combined with clavipectoral fascial plane block can be used for clavicular surgery. It has a long postoperative analgesia time, can retain the motor function of the involved upper limb and does not cause hemidiaphragmatic paresis.Clinical trial number and registry URL: Clinical Trials.gov; Trial registration number: ChiCTR2000039383; Date of registration: 25 October 2020.

Recent advancements in regional anaesthesia

Patient safety, improved quality of care, and better patient satisfaction and functional outcomes are currently the topmost priorities in regional anaesthesia (RA) and all advancements in RA move in this direction. Ultrasonography-guided central neuraxial and peripheral nerve blocks, intracluster and intratruncal injections, fascial plane blocks, diaphragm-sparing blocks, use of continuous nerve block techniques, and continuous local anaesthetic wound infiltration catheters are now topics of popular clinical interest. The safety and efficacy of nerve blocks can be improved with the help of injection pressure monitoring and the incorporation of advanced technology in the ultrasound machine and needles. Novel procedure-specific and motor-sparing nerve blocks have come up. The anaesthesiologist of the current era, with a good understanding of the sonoanatomy of the target area and the microarchitecture of nerves, along with the backup of advanced technology, can be very successful in performing RA techniques. RA is rapidly evolving and revolutionising the practice of anaesthesia.

What Is the Risk of Postoperative Neurologic Symptoms After Regional Anesthesia in Upper Extremity Surgery? A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

The risk of neurologic symptoms after regional anesthesia in orthopaedic surgery is estimated to approach 3%, with long-term deficits affecting 2 to 4 per 10,000 patients. However, current estimates are derived from large retrospective or observational studies that are subject to important systemic biases. Therefore, to harness the highest quality data and overcome the challenge of small numbers of participants in individual randomized trials, we undertook this systematic review and meta-analysis of contemporary randomized trials.

QUESTIONS/PURPOSES

In this systematic review and meta-analysis of randomized trials we asked: (1) What is the aggregate pessimistic and optimistic risk of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery? (2) What block locations have the highest and lowest risk of postoperative neurologic symptoms? (3) What is the timing of occurrence of postoperative neurologic symptoms (in days) after surgery?

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Web of Science, Scopus, and PubMed for randomized controlled trials (RCTs) published between 2008 and 2019 that prospectively evaluated postoperative neurologic symptoms after peripheral nerve blocks in operative procedures. Based on the Grading of Recommendations, Assessment, Development, and Evaluation guidance for using the Risk of Bias in Non-Randomized Studies of Interventions tool, most trials registered a global rating of a low-to-intermediate risk of bias. A total of 12,532 participants in 143 trials were analyzed. Data were pooled and interpreted using two approaches to calculate the aggregate risk of postoperative neurologic symptoms: first according to the occurrence of each neurologic symptom, such that all reported symptoms were considered mutually exclusive (pessimistic estimate), and second according to the occurrence of any neurologic symptom for each participant, such that all reported symptoms were considered mutually inclusive (optimistic estimate).

RESULTS

At any time postoperatively, the aggregate pessimistic and optimistic risks of postoperative neurologic symptoms were 7% (915 of 12,532 [95% CI 7% to 8%]) and 6% (775 of 12,532 [95% CI 6% to 7%]), respectively. Interscalene block was associated with the highest risk (13% [661 of 5101] [95% CI 12% to 14%]) and axillary block the lowest (3% [88 of 3026] [95% CI 2% to 4%]). Of all symptom occurrences, 73% (724 of 998) were reported between 0 and 7 days, 24% (243 of 998) between 7 and 90 days, and 3% (30 of 998) between 90 and 180 days. Among the 31 occurrences reported at 90 days or beyond, all involved sensory deficits and four involved motor deficits, three of which ultimately resolved.

CONCLUSION

When assessed prospectively in randomized trials, the aggregate risk of postoperative neurologic symptoms associated with peripheral nerve block in upper extremity surgery was approximately 7%, which is greater than previous estimates described in large retrospective and observational trials. Most occurrences were reported within the first week and were associated with an interscalene block. Few occurrences were reported after 90 days, and they primarily involved sensory deficits. Although these findings cannot inform causation, they can help inform risk discussions and clinical decisions, as well as bolster our understanding of the evolution of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery. Future prospective trials examining the risks of neurologic symptoms should aim to standardize descriptions of symptoms, timing of evaluation, classification of severity, and diagnostic methods.

LEVEL OF EVIDENCE

Level I, therapeutic study.

The Minimum Effective Analgesic Volume of 0.5% Bupivacaine for Ultrasound-Guided Anterior Suprascapular Nerve Block

Objective The interscalene brachial plexus block (ISBB) constitutes the gold standard for analgesia after shoulder procedures. Ipsilateral phrenic nerve block remains the most common adverse effect after ISBB. Alternative nerve blocks are performed in shoulder surgery in order to prevent hemi-diaphragmatic paralysis (HDP). The purpose of the present study was to investigate the minimum effective local anesthetic volume of 0.5% bupivacaine for postoperative analgesia with an anterior suprascapular nerve block (ASSB). The secondary aim was to investigate diaphragm functions with the local anesthetic doses used while conducting effective volume research. Method This prospective observational study was conducted at the American Hospital of Istanbul, Turkey, from March to July 2022. The initial injected volume of 0.5% bupivacaine was 10 ml. Our clinical experience indicates that this yields a complete sensory block of the anterior suprascapular nerve. In accordance with the up-and-down method, the volume of 0.5% bupivacaine used for a particular patient was determined by the outcome of the preceding block, which represented block success. In case of effective ASSB being achieved, the volume of 0.5% bupivacaine to be administered to the next patient was lowered by 1 ml. In case of block failure, however, the volume of 0.5% bupivacaine to be applied in the subsequent case was increased by 1 ml. Ipsilateral hemi-diaphragmatic movement measurements were taken before (baseline) and 30 minutes after the block. General anesthesia was induced 60 minutes after the completion of the block performance by means of a standardized protocol. Results Sixty-seven patients were included in the study. The ED50 and ED95 calculated for anterior suprascapular nerve block using probit transformation and logistic regression analysis were 2.646 (95% CI, 0.877-2.890) and 3.043 ml (95% CI, 2.771-4.065), respectively. When complete paralysis was defined as 75% or above, partial paralysis as 25-50%, and no paralysis as 25% or less, volumes of 6 ml or lower appeared to cause no paralysis for the anterior suprascapular nerve block. Conclusion We, therefore, recommend using a volume of 6 ml or less in order to achieve diaphragm-sparing features for anterior suprascapular nerve blocks.

An alternative approach for blocking the superior trunk of the brachial plexus evaluated by a single arm clinical trial

BACKGROUND

Interscalene brachial plexus block is associated with phrenic nerve paralysis. The objective of this study was to evaluate an alternative approach to interscalene brachial plexus blocks in terms of efficacy, grade of motor and sensory blockade, and phrenic nerve blockade.

METHODS

The study was prospective and interventional. The ten living patients studied were 18 to 65 years old, ASA physical status I or II, and submitted to correction of rotator cuff injury. A superior trunk blockade was performed at the superior trunk below the omohyoid muscle, without blocking the phrenic nerve. The needle was advanced below the prevertebral layer until contacting the superior trunk. In order to guarantee the correct positioning of the needle tip, an intracluster pattern of the spread was visualized. The block was performed with 5.ßmL of 0.5% bupivacaine in ten patients. In the six cadavers, 5.ßmL of methylene blue was injected. Diaphragmatic excursion was assessed by ultrasonography of the ipsilateral hemidiaphragm. In three patients, pulmonary ventilation was evaluated with impedance tomography. Pain scores and analgesic consumption were assessed in the recovery room for 6.ßhours after the blockade.

RESULTS

In the six cadavers, methylene blue didn...t reach the phrenic nerve. Ten patients underwent arthroscopic surgery, and no clinically phrenic nerve paralysis was observed. No patient reported pain during the first 6.ßhours.

CONCLUSIONS

This study suggests that this new superior trunk approach to block the superior trunk may be an alternative technique to promote analgesia for shoulder surgery in patients with impaired respiratory function.

Ultrasound-guided selective trunk block: Evaluation of ipsilateral sensorimotor block dynamics, hemidiaphragmatic function and efficacy for upper extremity surgery. A single-centre cohort study

BACKGROUND

Selectively locating and blocking the individual trunks of the brachial plexus with small volumes of local anaesthetic, a selective trunk block (SeTB), may produce anaesthesia of the entire upper extremity except for the T2 dermatome.

OBJECTIVE

This study aimed to evaluate the effects of an ultrasound-guided (USG) SeTB on ipsilateral sensorimotor block dynamics, hemidiaphragmatic function, and efficacy as an all-purpose regional anaesthetic technique for upper extremity surgery.

DESIGN

Prospective cohort study.

SETTING

Single-centre, university hospital in Hong Kong, China from February 2021 to July 2021.

PATIENTS

Thirty patients (aged 53.2 ± 14.8 years and BMI 23.8 ± 3.6 kg m - 2 ), ASA physical status I to III, scheduled for upper extremity surgery under a brachial plexus block.

INTERVENTIONS

USG SeTB with 25 ml (7, 8 and 10 ml to the superior, middle and inferior trunks, respectively) of a 1 : 1 mixture of 2% lidocaine with 1 : 200 000 epinephrine and 0.5% levobupivacaine.

MAIN OUTCOME MEASURES

Ipsilateral sensorimotor blockade of the suprascapular (only motor), axillary, radial, ulnar, median and musculocutaneous nerves were assessed at regular intervals for 45 min. Ipsilateral hemidiaphragmatic excursion was also measured, at 30 min after the SeTB, using M-mode ultrasound. The SeTB was considered a success if it was possible to complete surgery without any rescue analgesia or conversion to general anaesthesia.

RESULTS

Complete motor blockade of the suprascapular nerve was achieved in median [range] 5 [5 to 15] min. Complete sensory and motor blockade were achieved in all the other 5 nerves in 17.5 [10 to 30] and 15 [10 to 30] min respectively. The SeTB was successful in 93% and ipsilateral hemidiaphragmatic paresis (HDP) was present in 82%, of patients.

CONCLUSION

SeTB produces sensorimotor blockade of the entire upper extremity, causes ipsilateral HDP, and is effective as the sole anaesthetic for surgery from the proximal humerus to the hand.

TRIAL REGISTRION

ClinicalTrials.gov, Trial Registration No: NCT04752410, Date submitted for Registration: 09 February 2021, Date first posted: 12 February 2021, Dates of patient enrolment: 19 February 2021 to 27 July 2021 ( https://clinicaltrials.gov/ct2/show/NCT04752410 ).

Randomised comparison between superior trunk and costoclavicular blocks for arthroscopic shoulder surgery: A noninferiority study

BACKGROUND

Superior trunk block (STB) provides noninferior analgesia to the interscalene block and reduces the risk of hemidiaphragmatic paralysis (HDP). Recently, supraclavicular spreading has also been shown to occur during costoclavicular block (CCB), presenting as an alternative analgesic technique for shoulder surgery.

OBJECTIVE

The aim of this study was to determine whether there is a difference in postoperative pain scores and HDP incidence between STB and CCB.

DESIGN

Prospective randomised controlled trial.

SETTING

Chungnam National University Hospital in Daejeon from January to July 2021.

PATIENTS

Seventy patients, aged 20 to 70 years with ASA Physical Status classifications I to III and scheduled for elective arthroscopic rotator cuff repair were recruited.

INTERVENTION

Ultrasound-guided STB or CCB was performed with 20 ml 0.5% ropivacaine.

MAIN OUTCOME MEASURES

The primary outcome was the pain score (numeric rating scale, NRS) at 1 h postsurgery. A 1.4 (NRS) noninferiority margin was set a priori . The incidence of HDP, postoperative change of pulmonary function and postoperative opioid use were included as secondary outcomes.

RESULTS

The pain score was higher in the CCB group compared with the STB group at 1 h postoperatively (median difference, 2; 95% confidence interval (CI), 1 to 3; noninferiority was not demonstrated). Two patients in the CCB group received a rescue interscalene block due to severe postoperative pain. The incidence of complete HDP was lower in the CCB group (risk difference, -26%; 95% CI, -6 to -45%; P  < 0.001). The median reduction in forced vital capacity and forced expiratory volume in 1 s were also significantly lower in the CCB group.

CONCLUSION

Although the incidence of HDP was lower, CCB did not show noninferiority in immediate postoperative analgesia compared with STB in arthroscopic shoulder surgery.

CLINICAL TRIAL REGISTRATION

Clinical Trial Registry of Korea (KCT0005822, principal investigator: Boohwi Hong) on 25 January 2021 ( https://cris.nih.go.kr ).

Peripheral Nerve Injury After Upper-Extremity Surgery Performed Under Regional Anesthesia: A Systematic Review

Purpose

Peripheral nerve injury (PNI) is a known adverse event following upper-limb surgery performed under brachial plexus regional anesthesia (RA). When PNI is noted after surgery, patients and providers often have questions about which factors might have contributed to this complication. This systematic review evaluates the literature on hand and shoulder surgeries performed under ultrasound-guided, plexus RA to identify factors potentially associated with PNI, including the surgery location and block type. We hypothesized that shoulder surgery might be associated with an increased risk of PNI compared to hand surgery.

Methods

A systematic review of the relevant literature was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Only prospective studies on the use of ultrasound-guided, preoperative, brachial plexus RA for hand or shoulder surgery on adult patients were included. Study groups were categorized according to surgery location and block type and compared across a number of factors via univariate and multivariate analyses.

Results

A total of 3,037 abstracts were screened; 192 full-text articles were independently reviewed by 2 of the authors; and 53 studies were included in the systematic review analysis. Following hand surgery, PNI was reported at an average rate of 1.35% ± 3.21% across 836 subjects in 40 study groups; after shoulder surgery, the average rate was 0.50% ± 1.57% across 3,383 subjects in 15 study groups. There was no statistically significant correlation between the incidence of PNI and surgery location (P =.70) or any of the most common approaches for brachial plexus anesthesia in the multivariate analysis.

Conclusions

This systematic review of over 50 articles on upper-limb surgery performed under RA shows no association between the incidence of PNI and the location of surgery or type of brachial plexus block.

Type of study/level of evidence

Diagnostic II.

Comparison Between Subparaneural Upper Trunk and Conventional Interscalene Blocks for Arthroscopic Shoulder Surgery: A Randomized Noninferiority Trial

BACKGROUND

Although interscalene nerve block is the standard for shoulder analgesia, the risk of hemidiaphragmatic paralysis restricts its use in patients with compromised pulmonary function. We hypothesized that a novel subparaneural upper trunk block would provide noninferior postoperative analgesia but superior diaphragmatic sparing effect compared to interscalene block.

METHODS

This randomized controlled trial comprised 96 patients who underwent arthroscopic shoulder surgery under either subparaneural upper trunk block (5 mL of 0.5% ropivacaine) or interscalene block (15 mL of 0.5% ropivacaine), followed by supraclavicular nerve block (5 mL of 0.5% ropivacaine). General anesthesia was standardized. The coprimary outcomes were (1) recovery room resting pain score at 30 minutes, measured on an 11-point numerical rating scale, with a prespecified noninferiority margin of 1 point and (2) the incidence of hemidiaphragmatic paralysis, diagnosed using ultrasound. Among secondary outcomes, resting pain scores were assessed with numerical rating scale at 4, 8, and 24 hours postoperatively.

RESULTS

Recovery room resting pain scores at 30 minutes were 0 (0-1) in the subparaneural upper trunk group versus 0 (0-0) in the interscalene group, with a median difference of 0 (95% CI, 0-0); the upper 95% CI limit was lower than the prespecified noninferiority margin (noninferiority P < .001). Hemidiaphragmatic paralysis was observed in 16.7% of patients in the subparaneural upper trunk group versus 100% of those in the interscalene group (RR, 0.17; 95% CI, 0.09-0.31; P < .001), with complete paralysis occurring in 6.3% and 93.7% of patients, respectively. In this study, any reported differences in pain scores at 4, 8, and 24 hours postoperatively were not clinically important.

CONCLUSIONS

The subparaneural upper trunk block compared to interscalene block provided noninferior analgesia at 30 minutes in the recovery room after arthroscopic shoulder surgery but resulted in less hemidiaphragmatic paralysis.

Postoperative neurologic symptoms in the operative arm after shoulder surgery with interscalene blockade: a systematic review

OBJECTIVE

Postoperative neurologic symptoms (PONS) in the operative arm are important complications of shoulder surgery and interscalene blockade (ISB). This systematic review aimed to compare the risk of PONS between ISB and other techniques, and the relative safety of different agents used in ISB.

METHODS

Our systematic review followed Cochrane review methodology and was registered in PROSPERO. A search of MEDLINE (Ovid), EMBASE (Ovid), and CENTRAL (Wiley) from inception to June 2020 was completed. We included randomized or quasi-randomized trials of patients (> five years old) undergoing shoulder surgery with any ISB technique as an intervention, compared with any other nonregional or regional technique, or ISB of alternate composition or technique. The primary outcome was PONS (study author defined) assessed a minimum of one week after surgery.

RESULTS

Fifty-five studies totalling 6,236 participants (median, 69; range, 30-910) were included. Another 422 otherwise eligible trials were excluded because PONS was not reported. Heterogeneity in when PONS was assessed (from one week to one year) and the diagnostic criteria used precluded quantitative meta-analysis. The most common PONS definition, consisting of one or more of paresthesia, sensory deficit, or motor deficit, was only used in 16/55 (29%) trials. Risk of bias was low in 5/55 (9%) trials and high in 36/55 (65%) trials, further limiting any inferences.

CONCLUSION

These findings highlight the need for a standardized PONS outcome definition and follow-up time, along with routine, rigorous measurement of PONS in trials of ISB.

STUDY REGISTRATION

PROSPERO (CRD42020148496); registered 10 February 2020.

Median Effective Analgesic Concentration of Ropivacaine in Ultrasound-Guided Interscalene Brachial Plexus Block as a Postoperative Analgesia for Proximal Humerus Fracture: A Prospective Double-Blind Up-Down Concentration-Finding Study

Background

The innervation of the proximal humerus fracture is complicated and unclear. The use of interscalene nerve block has been effective as postoperative analgesia for patients, but the optimal concentration of usage is unknown.

Method

This study was conducted on 30 patients with ASA I or II, who were planning to undergo a proximal humerus fracture operation. A dosage of 10 ml Ropivacaine was administered for the interscalene brachial plexus block (ISBPB) as determined using the up-and-down sequential method. The initial concentration of Ropivacaine in the first patient to receive ISBPB was 0.3%. After a successful or unsuccessful postoperative analgesia, the concentration of local anesthetic was decreased or increased, respectively, by 0.05% in the next patient. We defined successful postoperative analgesia as a visual analog scale (VAS) score of < 4 at rest, within the initial 8 h after ISBPB. The analytic techniques of linear, linear-logarithmic, exponential regressions, and centered isotonic regression were used to determine the EC50 of Ropivacaine, and the residual standard errors were calculated for the comparison of “goodness of fit.”

Results

The concentration of Ropivacaine ranged from 0.1 to 0.35%. The EC50 (95% confidence interval) from 4 different statistical approaches (linear, linear-logarithmic, exponential regressions, and centered isotonic regression) were 0.222% (0.198%, 0.335%), 0.233% (0.215%, 0.453%), 0.223% (0.202%, 0.436%), and 0.232%, respectively. Among all the 4 models, the linear regression had the least residual standard error (0.1676).

Conclusion

The EC50 from the four statistical models for 10 ml Ropivacaine in ultrasound-guided ISBPB for postoperative analgesia was distributed in a narrow range of 0.222–0.233%.

Trial Registration

www.chictr.org.cn/; registration number: ChiCTR2100047231.

Continuous interscalene versus phrenic nerve-sparing high-thoracic erector spinae plane block for total shoulder arthroplasty: a randomized controlled trial

PURPOSE

The high-thoracic erector spinae plane block (HT-ESPB) has been reported as an effective analgesic modality for the shoulder region without phrenic nerve palsy. The goal of this study was to compare the HT-ESPB as a phrenic nerve-sparing alternative to an interscalene block for total shoulder arthroplasty.

METHODS

Thirty patients undergoing total shoulder arthroplasty at Stanford Health Care (Palo Alto, CA, USA) were enrolled in a double-blind randomized controlled trial. We randomized 28 patients to receive either an interscalene or HT-ESPB perineural catheter preoperatively; 26 patients were included in the final analysis. The study was powered for the primary outcome of incidence of hemidiaphragmatic paralysis in the postanesthesia care unit (PACU). Other outcome measures included incentive spirometry volume, brachial plexus motor and sensory exams, adverse events, pain scores, and opioid consumption.

RESULTS

The incidence of hemidiaphragmatic paralysis in the HT-ESPB catheter group was significantly lower than in the interscalene catheter group (0/12, 0% vs 14/14, 100%; P < 0.001). No statistically significant differences were found in pain scores and opioid consumption (in oral morphine equivalents) between the interscalene and HT-ESPB groups through postoperative day (POD) 2. Nevertheless, the mean (standard deviation) point estimates for opioid consumption for the HT-ESPB group were higher than for the interscalene group in the PACU (HT-ESPB: 24.8 [26.7] mg; interscalene: 10.7 [21.7] mg) and for POD 0 (HT-ESPB: 20.5 [25.0] mg; interscalene: 6.7 [12.0] mg). In addition, cumulative postoperative opioid consumption was significantly higher at POD 0 (PACU through POD 0) in the HT-ESPB group (45.3 [39.9] mg) than in the interscalene group (16.6 [21.9] mg; P = 0.04).

CONCLUSIONS

This study suggests that continuous HT-ESPB can be a phrenic nerve-sparing alternative to continuous interscalene brachial plexus blockade, although the latter provided superior opioid-sparing in the immediate postoperative period. This was a small sample size study, and further investigations powered to detect differences in analgesic and quality of recovery score endpoints are needed.

STUDY REGISTRATION

www.

CLINICALTRIALS

gov (NCT03807505); registered 17 January 2019.

Anesthesia for the Patient Undergoing Shoulder Surgery

Shoulder surgery introduces important anesthesia considerations. The interscalene nerve block is considered the gold standard regional anesthetic technique and can serve as the primary anesthetic or can be used for postoperative analgesia. Phrenic nerve blockade is a limitation of the interscalene block and various phrenic-sparing strategies and techniques have been described. Patient positioning is another important anesthetic consideration and can be associated with significant hemodynamic effects and position-related injuries.

Effect of superior trunk block on diaphragm function and respiratory parameters after shoulder surgery

BACKGROUND

The interscalene brachial plexus block has been used effectively for intraoperative and postoperative analgesia in patients undergoing shoulder surgery, but it is associated with high rates of diaphragmatic dysfunction. Performing the block more distally, at the level of the superior trunk, may reduce the incidence of phrenic nerve palsy. We hypothesized that superior trunk block would result in diaphragmatic paralysis rate of less than 20%.

METHODS

30 patients undergoing arthroscopic shoulder surgery received superior trunk block under ultrasound guidance. Measurements of diaphragm excursion were determined with ultrasound prior to the block, 15 min after the block, and postoperatively in phase II of postanesthesia care unit, in conjunction with clinical parameters of respiratory function.

RESULTS

10 patients (33.3%, 95% CI 17.3% to 52.8%) developed complete hemidiaphragmatic paralysis at the postoperative assessment. An additional eight patients (26.7%) developed paresis without paralysis. Of the 18 patients with diaphragm effects, seven (38.9%) reported dyspnea. 83.3% of patients with abnormal diaphragm motion (56.7% of the total sample) had audibly reduced breath sounds on auscultation. Oxygen saturation measurements did not correlate with diaphragm effect and were not significantly reduced by the postoperative assessment.

CONCLUSION

Although injection of local anesthetic at the superior trunk level is associated with less diaphragmatic paralysis compared with traditional interscalene block, a significant portion of patients will continue to have ultrasonographic and clinical evidence of diaphragmatic weakness or paralysis.

Interscalene Brachial Plexus Block with Liposomal Bupivacaine versus Standard Bupivacaine with Perineural Dexamethasone: A Noninferiority Trial

BACKGROUND

The interscalene nerve block provides analgesia for shoulder surgery. To extend block duration, provide adequate analgesia, and minimize opioid consumption, the use of adjuvants such as dexamethasone as well as the application of perineural liposomal bupivacaine have been proposed. This randomized, double-blinded, noninferiority trial hypothesized that perineural liposomal bupivacaine is noninferior to standard bupivacaine with perineural dexamethasone in respect to average pain scores in the first 72 h after surgery.

METHODS

A total of 112 patients undergoing ambulatory shoulder surgery were randomized into two groups. The liposomal bupivacaine group received a 15-ml premixed admixture of 10 ml of 133 mg liposomal bupivacaine and 5 ml of 0.5% bupivacaine (n = 55), while the bupivacaine with dexamethasone group received an admixture of 15 ml of 0.5% standard bupivacaine with 4 mg dexamethasone (n = 56), respectively. The primary outcome was the average numerical rating scale pain scores at rest over 72 h. The mean difference between the two groups was compared against a noninferiority margin of 1.3. Secondary outcomes were analgesic block duration, motor and sensory resolution, opioid consumption, numerical rating scale pain scores at rest and movement on postoperative days 1 to 4 and again on postoperative day 7, patient satisfaction, readiness for postanesthesia care unit discharge, and adverse events.

RESULTS

A liposomal bupivacaine group average numerical rating scale pain score over 72 h was not inferior to the bupivacaine with dexamethasone group (mean [SD], 2.4 [1.9] vs. 3.4 [1.9]; mean difference [95% CI], -1.1 [-1.8, -0.4]; P < 0.001 for noninferiority). There was no significant difference in duration of analgesia between the groups (26 [20, 42] h vs. 27 [20, 39] h; P = 0.851). Motor and sensory resolutions were similar in both groups: 27 (21, 48) h versus 27 (19, 40) h (P = 0.436) and 27 [21, 44] h versus 31 (20, 42) h (P = 0.862), respectively. There was no difference in opioid consumption, readiness for postanesthesia care unit discharge, or adverse events.

CONCLUSIONS

Interscalene nerve blocks with perineural liposomal bupivacaine provided effective analgesia similar to the perineural standard bupivacaine with dexamethasone. The results show that bupivacaine with dexamethasone can be used interchangeably with liposomal bupivacaine for analgesia after shoulder surgery.

EDITOR’S PERSPECTIVE

Dyspnea induced by hemidiaphragmatic paralysis after ultrasound-guided supraclavicular brachial plexus block in a morbidly obese patient

RATIONALE

Hemidiaphragmatic paralysis (HDP) is a frequent complication of the brachial plexus block, caused by unintentional blockade of ipsilateral phrenic nerve. HDP did not rise enough alarm and attention to most anesthesiologists, because most patients with no coexisting comorbid diseases are asymptomatic and able to tolerate it. However, it may cause severe respiratory complication for patients with preexisting compromised cardiorespiratory function.

PATIENT CONCERNS

A 67-year-old woman with morbidly obesity was planned to receive opening reduction and internal fixation of right humeral shaft fracture under regional anesthesia considering less respiratory and cardiovascular system interference compared with general anesthesia.

DIAGNOSES

After ultrasound guided supraclavicular brachial plexus block, the patient developed severe hypoxia and hypercapnia.Unintentional block of phrenic nerve and diaphragm paralysis was diagnosed by diaphragm ultrasound, which was considered as the main reason of severe hypoxia.

INTERVENTIONS

It led to a conversion from regional anesthesia to general anesthesia with endotracheal intubation for patient's safety and smooth operation.

OUTCOMES

The unintentional phrenic nerve block leads to a prolonged ventilation time, length of stay in intensive care unit and length of stay in hospital.

LESSONS

This case report highlights the risk of diaphragm paralysis in morbidly obese patients. Though new diaphragm sparing brachial plexus block (BPB) methods were developed intended to reduce the risk of HDP, no approaches could absolutely spare phrenic nerve involvement. Therefore, clinicians should always consider the risk of HDP associated with BPBs. For each individual, a detailed preoperative evaluation and sufficient preparation are paramount to avoid serious complications.

Interscalene Block for Analgesia in Orthopedic Treatment of Shoulder Trauma: Single-Dose Liposomal Bupivacaine versus Perineural Catheter

Background

Interscalene brachial plexus block is frequently utilized to provide perioperative analgesia to patients undergoing shoulder surgery to optimize recovery, minimize opioid consumption, and decrease overall hospital length of stay. The use of an indwelling perineural interscalene catheter provides extended analgesia and is efficacious in managing severe postoperative pain following major shoulder surgery. Currently, the only alternative to perineural catheters for extended analgesia with interscalene block involves the perineural infiltration of liposomal bupivacaine. However, there is limited published data regarding the overall analgesic effectiveness of using interscalene liposomal bupivacaine in the setting of shoulder surgery.

Methods

We performed a retrospective review of 43 patients in the acute trauma setting who underwent major shoulder surgery and received extended analgesia via perioperative interscalene brachial plexus block with either an indwelling continuous catheter or single-dose liposomal bupivacaine to determine if comparable analgesia can be achieved. The primary outcomes of interest were postoperative pain scores and opioid consumption. Due to the ability to titrate and bolus local anesthetic infusions to a desired clinical effect, we hypothesized that opioid consumption and pain scores would be lower when using the continuous catheter technique.

Results

After statistical analysis, our results demonstrated no significant difference between the two techniques in regards to opioid consumption as well as numeric pain scores during the 48-hour postoperative period, but did note a higher rate of complications with patients who received perineural interscalene continuous catheters. Secondary outcomes showed an increase in time required to complete the regional block procedure with the use of indwelling catheters.

Conclusion

Interscalene brachial plexus block with liposomal bupivacaine may be a viable alternative to indwelling continuous catheters for providing extended analgesia in patients undergoing major shoulder surgery.

Periarticular liposomal bupivacaine mixture injection vs. single-shot interscalene block for postoperative pain in arthroscopic rotator cuff repair: a prospective randomized controlled trial

BACKGROUND

The pain control efficacy, postoperative opioid requirements, and costs among patients undergoing major shoulder surgery using different perioperative analgesia modalities have been topics of active debate. Several studies have compared periarticular injection (PAI) to interscalene block (ISB) in shoulder arthroplasty, but there is a paucity of data comparing them in arthroscopic rotator cuff repair.

METHODS

Patients aged 18-80 years with full-thickness rotator cuff tears and undergoing primary arthroscopic rotator cuff repair at 2 different shoulder centers were screened and subsequently randomized to receive either periarticular injection (PAI) of liposomal bupivacaine mixed with 0.25% bupivacaine (n = 41) or single-shot interscalene nerve block (ISB) (n = 36). Visual analog scale (VAS) pain scores, oral morphine equivalent (OME) use, Single Assessment Numerical Evaluation (SANE) scores, and costs were collected. Differences with P <.05 were considered statistically significant.

RESULTS

Day of surgery VAS score and OME usage were significantly reduced with ISB vs. PAI (0.69 vs. 4.65, P < .001, and 18.66 vs. 34.39, P < .001, respectively). There were no significant differences between groups regarding VAS score on postoperative days (PODs) 1-3; however, OME usage on PODs 1 (50.5 vs. 38.8, P = .03) and 2 (48.1 vs. 37.8, P = .04) was significantly more in the ISB group. At POD 3, VAS score (4.13 vs. 3.97, P = .60) and OME use (28.60 vs. 31.16, P = .51) were similar. At 6 and 12 weeks, there were also no significant differences between groups regarding VAS and OME use. There was no difference in SANE score at 12 weeks following surgery between groups and no difference between average 12-week cumulative OME use between groups. The average charge for the PAI was $455, and the average charge for ISB was $745.

CONCLUSION

Both ISB and PAI provide acceptable pain control following arthroscopic rotator cuff repair. Patients have less pain on the day of surgery with ISB, but rebound pain is significant after the block wears off, resulting in substantially increased opioid use in the first 2 PODs. However, cumulative opioid use between groups was similar. There were also no significant differences at the end of the 12-week episode of care in any of the other variables studied. The charge per patient for PAI is approximately $300 less than ISB. Thus, PAI may offer surgeons and patients an effective postoperative analgesic modality as an alternative to ISB.

Selective blockade of supraclavicular nerves and upper trunk of brachial plexus "The SCUT block" towards a site-specific regional anaesthesia strategy for clavicle surgeries - A descriptive study

Background and Aims:

Commonly, the superficial cervical plexus and interscalene block were combined to provide surgical anaesthesia for procedures on the clavicle, which are neither selective nor site-specific considering the innervation of the clavicle. The aim was to analyse effectiveness and block dynamics of selectively blocking supraclavicular (SC) nerves and upper trunk (UT) of brachial plexus (SCUT BLOCK) as a site-specific regional anaesthesia strategy for clavicle surgery.

Methods:

SC nerves and UT were blocked with 3-ml and 5-ml local anaesthetic, respectively, in 70 American Society of Anesthesiologists I and II patients aged above 18 years, undergoing clavicle surgery. Sensory-motor conduction blockade was assessed in both the plexus territories, following which surgery ensued. Number of patients who exhibited complete conduction blockade of the targeted nerves, number of surgeries completed under the block, intraoperative rescue analgesics, duration of postoperative analgesia and complications were recorded.

Results:

Sensory and motor mapping showed complete conduction blockade of the targeted nerves in all patients, all other branches were spared. The surgery was completed exclusively under block in 67 (Strategy success rate 96%) out of 70 patients. Intraoperatively, two patients required supplementation of block with a local infiltration and general anaesthesia was administered for one patient. The mean duration of postoperative analgesia was 5 (1.2) hours [mean (standard deviation)]. Only one patient developed ptosis; no other complications were noted.

Conclusions:

“The SCUT block” is an effective site-specific regional anaesthesia strategy for clavicle surgery.

Role of regional anesthesia in Enhanced Recovery After Surgery (ERAS) protocols

PURPOSE OF REVIEW

Enhanced Recovery After Surgery (ERAS) protocols and interventional locoregional anesthesia (LRA) techniques continuously evolve. This review outlines the latest recommendations for the use of regional anesthesia in ERAS protocols and emerging interventional analgesia techniques.

RECENT FINDINGS

Research in ultrasound-guided regional anesthesia has led to a refinement of the traditional techniques and the introduction of a number of new approaches to complement ERAS strategies. The efficacy and versatility of LRA enable its use in an increasing number of ERAS indications.

SUMMARY

The implementation of ERAS protocols in different surgical procedures reduces overall complications and recovery time. Multimodal analgesia strategies with regional anesthesia techniques are some of the key interventions contributing to the improvement in postoperative outcomes.

Respiratory Failure Following Interscalene Block for the Treatment of Shoulder Dislocation in a Patient with COVID-19

Introduction: Guidelines recommend the use of regional anesthesia for patients with COVID-19, when possible. Interscalene block (ISB) is the standard care for analgesia of shoulder surgery. Hemidiaphragmatic paresis due to phrenic nerve block is expected in ISB but is usually well-compensated. We present a patient with pulmonary involvement of COVID-19 candidate for the surgery of shoulder dislocation under ISB who experienced respiratory failure after the block. Case Presentation: A 36-year-old female patient with COVID-19 developed a shoulder dislocation following a seizure. Relocating the joint was successfully attempted under intravenous sedation and ultrasound-guided ISB. The patient developed respiratory distress due to hemidiaphragmatic paresis after the block. She was managed using a continuous positive airway pressure (CPAP) mask for 48 hours until the pulmonary condition improved. Conclusions: Anesthetists should prepare themselves to replace ISB with diaphragm-sparing blocks or apply techniques to reduce the chance of hemidiaphragmatic paresis after ISB in patients with COVID-19.

Effects of Local Anesthetic Volume (Standard Versus Low) on Incidence of Hemidiaphragmatic Paralysis and Analgesic Quality for Ultrasound-Guided Superior Trunk Block After Arthroscopic Shoulder Surgery

BACKGROUND

Relative to interscalene block, superior trunk block (STB) provides comparable analgesia and a reduced risk of hemidiaphragmatic paralysis. However, the incidence of hemidiaphragmatic paralysis remains high when a standard volume (15 mL) of local anesthetic is used. This study aimed to evaluate the effects of local anesthetic volume of STB on the incidence of phrenic nerve palsy, as well as its analgesic efficacy following arthroscopic shoulder surgery.

METHODS

Patients scheduled for elective arthroscopic shoulder surgery were randomized to receive ultrasound-guided STB using either 5- or 15-mL 0.5% ropivacaine before general anesthesia. The primary outcome was the incidence of hemidiaphragmatic paralysis at 30 minutes after block. The secondary outcomes were pulmonary function, grade of sensory and motor blockade, pain score, opioid consumption, adverse effects, and satisfaction.

RESULTS

Relative to standard-volume STB, low-volume STB was associated with a lower incidence of hemidiaphragmatic paralysis after block (14.3 [4.8%-30.3%] vs 65.7 [46.8%-80.9%]; difference 51.4% [95% confidence intervals {CIs}, 29.0%-67.1%]; P < .0001) and at the postanesthesia care unit (9.4% vs 50.0%; difference 40.6 [95% CI, 18.9%-57.7%]; P = .0004). Pulmonary function was also better preserved in the low-volume group than in the standard-volume group. The extent of the sensory and motor blocks was significantly different between the groups. Pain-related outcomes, satisfaction, and any adverse events were not significantly different between the groups.

CONCLUSIONS

Low-volume STB provided a lower incidence of hemidiaphragmatic paralysis with no significant difference in analgesic efficacy relative to standard-volume STB for arthroscopic shoulder surgery.