Neurological complications after regional anesthesia: contemporary estimates of risk

TXNIP knockdown protects rats against bupivacaine-induced spinal neurotoxicity via the inhibition of oxidative stress and apoptosis

Bupivacaine (BUP) is an anesthetic commonly used in clinical practice that when used for spinal anesthesia, might exert neurotoxic effects. Thioredoxin-interacting protein (TXNIP) is a member of the α-arrestin protein superfamily that binds covalently to thioredoxin (TRX) to inhibit its function, leading to increased oxidative stress and activation of apoptosis. The role of TXNIP in BUP-induced oxidative stress and apoptosis remains to be elucidated. In this context, the present study aimed to explore the effects of TXNIP knockdown on BUP-induced oxidative stress and apoptosis in the spinal cord of rats and in PC12 cells through the transfection of adeno-associated virus-TXNIP short hairpin RNA (AAV-TXNIP shRNA) and siRNA-TXNIP, respectively. In vivo, a rat model of spinal neurotoxicity was established by intrathecally injecting rats with BUP. The BUP + TXNIP shRNA and the BUP + Control shRNA groups of rats were injected with an AAV carrying the TXNIP shRNA and the Control shRNA, respectively, into the subarachnoid space four weeks prior to BUP treatment. The Basso, Beattie & Bresnahan (BBB) locomotor rating score, % MPE of TFL, H&E staining, and Nissl staining analyses were conducted. In vitro, 0.8 mM BUP was determined by CCK-8 assay to establish a cytotoxicity model in PC12 cells. Transfection with siRNA-TXNIP was carried out to suppress TXNIP expression prior to exposing PC12 cells to BUP. The results revealed that BUP effectively induced neurological behavioral dysfunction and neuronal damage and death in the spinal cord of the rats. Similarly, BUP triggered cytotoxicity and apoptosis in PC12 cells. In addition, treated with BUP both in vitro and in vivo exhibited upregulated TXNIP expression and increased oxidative stress and apoptosis. Interestingly, TXNIP knockdown in the spinal cord of rats through transfection of AAV-TXNIP shRNA exerted a protective effect against BUP-induced spinal neurotoxicity by ameliorating behavioral and histological outcomes and promoting the survival of spinal cord neurons. Similarly, transfection with siRNA-TXNIP mitigated BUP-induced cytotoxicity in PC12 cells. In addition, TXNIP knockdown mitigated the upregulation of ROS, MDA, Bax, and cleaved caspase-3 and restored the downregulation of GSH, SOD, CAT, GPX4, and Bcl2 induced upon BUP exposure. These findings suggested that TXNIP knockdown protected against BUP-induced spinal neurotoxicity by suppressing oxidative stress and apoptosis. In summary, TXNIP could be a central signaling hub that positively regulates oxidative stress and apoptosis during neuronal damage, which renders TXNIP a promising target for treatment strategies against BUP-induced spinal neurotoxicity.

Functional recovery of wrist surgery with regional versus general anesthesia: a prospective observational study

PURPOSE

Regional anesthesia may favour postoperative rehabilitation by inhibiting peripheral sensitization and secondary hyperalgesia. The literature on this subject is limited. In the present FUNCTION study, we sought to compare the functional recovery post orthopedic wrist surgery with regional versus general anesthesia.

METHODS

We conducted a single-centre prospective observational cohort study in adult patients with a distal radial fracture. Functional recovery was assessed with validated psychometrics questionnaires (Quick Disabilities of Arm, Shoulder and Hand [QuickDASH] and Patient-Rated Wrist Evaluation [PRWE]), range of motion, and grip strength. We used a linear mixed regression model to assess the impact of the anesthesia technique on functional recovery. Postoperative pain and patient satisfaction were evaluated using a visual analog scale.

RESULTS

We recruited 76 patients. At 12 weeks post surgery, there was no difference between the type of anesthesia and functional recovery with the QuickDASH (higher scores worse; regional anesthesia [RA], 22.7 vs general anesthesia [GA], 19.3; adjusted mean difference [aMD], -0.3; 95% confidence interval [CI], -9.6 to 9.0; P = 0.9) and PRWE (higher scores worse; RA group, 21.0 vs GA group, 20.5; aMD, -3.3; 95% CI, -12.1 to 5.6; P = 0.93) questionnaires. Range of motion, satisfaction, and postoperative pain were similar between groups. Right-hand grip strength was higher in the GA group.

CONCLUSION

Regional anesthesia was not associated with improved functional recovery compared with general anesthesia. The dominance of the operated limb was a confusion factor in all evaluation modalities. Further research taking into account the dominance of the hand is necessary to establish the effects of regional anesthesia on functional recovery.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04541745); registered 9 September 2020.

Local Anesthetics, Local Anesthetic Systemic Toxicity (LAST), and Liposomal Bupivacaine

Local anesthetics have played a vital role in the multimodal analgesia approach to patient care by decreasing the use of perioperative opioids, enhancing patient satisfaction, decreasing the incidence of postoperative nausea and vomiting, decreasing the length of hospital stay, and reducing the risk of chronic postsurgical pain. The opioid-reduced anesthetic management for perioperative analgesia has been largely successful with the use of local anesthetics during procedures such as peripheral nerve blocks and neuraxial analgesia. It is important that practitioners who use local anesthetics are aware of the risk factors, presentation, and management of local anesthetic systemic toxicity (LAST).

Nerve Injury Following Regional Nerve Block: A Literature Review of Its Etiologies, Risk Factors, and Prevention

PURPOSE OF REVIEW

Postoperative nerve injury after nerve block is complex and multifactorial. The mechanisms, etiologies, and risk factors are explored. This review article conducts a literature search and summarizes current evidence and best practices in prevention of nerve injury.

RECENT FINDINGS

Emerging technology such as ultrasound, injection pressure monitors, and nerve stimulators for peripheral nerve block have been incorporated into regular practice to reduce the rate of nerve injury. Studies show avoidance of intrafascicular injection, limiting concentrations/volumes of local anesthetic, and appropriate patient selection are the most significant controllable factors in limiting the negative consequences of nerve block. Peripheral nerve injury is an uncommon occurrence after nerve block and is obscured by surgical manipulation, positioning, and underlying neural integrity. Underlying neural integrity is not always evident despite an adequate history and physical exam. Surgical stress, independently of nerve block, may exacerbate these neurologic disease processes and make diagnosing a postoperative nerve injury more challenging. Prevention of nerve injury by surgical teams, care with positioning, and avoidance of intrafascicular injection with nerve block are the most evidence-based practices.

The Safety of Peripheral Nerve Blocks: The Role of Triple Monitoring in Regional Anaesthesia, a Comprehensive Review

Regional anaesthesia, referred to as regional blocks, is one of the most frequently used methods of anaesthesia for surgery and for pain management. Local anaesthetic drug should be administered as close to the nerve as possible. If administered too far away, this may result in insufficient block. If it is administrated too close, severe nerve damage can occur. Neurostimulation techniques and ultrasound imaging have improved the effectiveness and safety of blockade, but the risk of nerve injury with permanent nerve disfunction has not been eliminated. Intraneural administration of a local anaesthetic damages the nerve mechanically by the needle and the high pressure generated by the drug inside the nerve. In many studies, injection pressure is described as significantly higher for unintended intraneural injections than for perineural ones. In recent years, the concept of combining techniques (neurostimulation + USG imaging + injection pressure monitoring) has emerged as a method increasing safety and efficiency in regional anaesthesia. This study focuses on the contribution of nerve identification methods to improve the safety of peripheral nerve blocks by reducing the risk of neural damage.

Diabetic Neuropathy and Minimum Effective Anesthetic Concentration of Mepivacaine for Axillary Brachial Plexus Block: A Prospective Observational Study

Nerves in patients with diabetic neuropathy (DN) show increased susceptibility to local anesthetics, potentially requiring a decreased dose. We investigated whether the minimum effective anesthetic concentration (MEAC) of mepivacaine for successful axillary block is lower in patients with DN than in those without. This prospective observational study included patients with DN (n = 22) and without diabetes (n = 22) at a tertiary care center. Patients received an ultrasound-guided axillary block with 30 mL of mepivacaine for anesthesia. The mepivacaine concentration used in each patient was calculated using Dixon's up-and-down method. A block was considered successful if all four sensory nerves had a score of 1 or 2 within 30 min with no pain during surgery. The primary outcome was the MEAC of mepivacaine, and the secondary outcomes included the minimal nerve stimulation intensity for the musculocutaneous nerve and the occurrence of adverse events. The MEAC50 was 0.55% (95% CI 0.33-0.77%) in patients without diabetes and 0.58% (95% CI 0.39-0.77%) in patients with DN (p = 0.837). The MEAC90 was 0.98% (95% CI 0.54-1.42%) in patients without diabetes and 0.96% (95% CI 0.57-1.35%) in patients with DN (p = 0.949). The stimulation threshold for the musculocutaneous nerve was significantly different between groups (0.49 mA vs. 0.19 mA for patients with vs. without diabetes; p = 0.002). In conclusion, the MEAC of mepivacaine for a successful axillary block is not lower in patients with DN.

No evidence of fascicular injury following a low-volume intraneural injection of the median nerve: a cadaveric study

BACKGROUND

The test dose or hydrolocation technique allows rapid detection of spread location. Though its primary aim is to enhance safety in peripheral nerve blocks, evidence on the potential risks of an intraneural test aliquot is lacking. We conducted a cadaveric study to evaluate the risk of fascicular injury following a low-volume (<1 mL) intraneural injection of the median nerve.

METHODS

Ten upper limbs from fresh unembalmed human cadavers were studied. In-plane ultrasound-guided intraneural injections of the median nerve were performed at mid, proximal, and distal locations using 1 mL of methylene blue and heparinized blood solution. Nerves were extracted and samples immersed in 10% buffered formalin for 4 weeks. Perpendicular 3 mm slices were obtained for H&E staining and light microscopy analysis. Our main objective was to assess the number of injured fascicles. Secondarily, we evaluated the pattern of intraneural spread. Fascicular injury was defined as the presence perineurium or axonal disruption and/or the presence of erythrocytes inside a nerve fascicle.

RESULTS

Thirty injections were performed in 10 median nerves. Sonographic swelling was confirmed in 100% of the cases. 352 histological sections were analyzed to assess study outcomes. The mean number of fascicles on each section of median nerve was 20±6 covering 49%±7% of the nerve area. No evidence of axonal disruption nor intra-fascicular erythrocytes was found in any of the analyzed sections.

CONCLUSIONS

Low-volume intraneural injections do not result in evident fascicular injury. Our findings support the use of a test dose in ultrasound-guided regional anesthesia.

Neurological injury following peripheral nerve blocks: a narrative review of estimates of risks and the influence of ultrasound guidance

BACKGROUND

Peripheral nerve injury or post-block neurological dysfunction (PBND) are uncommon but a recognized complications of peripheral nerve blocks (PNB). A broad range of its incidence is noted in the literature and hence a critical appraisal of its occurrence is needed.

OBJECTIVE

In this review, we wanted to know the pooled estimates of PBND and further, determine its pooled estimates following various PNB over time. Additionally, we also sought to estimate the incidence of PBND with or without US guidance.

EVIDENCE REVIEW

A literature search was conducted in six databases. For the purposes of the review, we defined PBND as any new-onset sensorimotor disturbances in the distribution of the performed PNB either attributable to the PNB (when reported) or reported in the context of the PNB (when association with a PNB was not mentioned). Both prospective and retrospective studies which provided incidence of PBND at timepoints of interest (>48 hours to <2 weeks; >2 weeks to 6 weeks, 7 weeks to 5 months, 6 months to 1 year and >1 year durations) were included for review. Incidence data were used to provide pooled estimates (with 95% CI) of PBND at these time periods. Similar estimates were obtained to know the incidence of PBND with or without the use of US guidance. Additionally, PBND associated with individual PNB were obtained in a similar fashion with upper and lower limb PNB classified based on the anatomical location of needle insertion.

FINDINGS

The overall incidence of PBND decreased with time, with the incidence being approximately 1% at <2 weeks' time (Incidence per thousand (95% CI)= 9 (8; to 11)) to approximately 3/10 000 at 1 year (Incidence per thousand (95% CI)= 0. 3 (0.1; to 0.5)). Incidence of PBND differed for individual PNB with the highest incidence noted for interscalene block.

CONCLUSIONS

Our review adds information to existing literature that the neurological complications are rarer but seem to display a higher incidence for some blocks more than others. Use of US guidance may be associated with a lower incidence of PBND especially in those PNBs reporting a higher pooled estimates. Future studies need to standardize the reporting of PBND at various timepoints and its association to PNB.

Fibular (peroneal) neuropathy

Fibular neuropathy has variable presenting features depending on the site of the lesion. Anatomical features make it susceptible to injury from extrinsic factors, particularly the superficial location of the nerve at the head of the fibula. There are many mechanisms of compression or other traumatic injury of the fibular nerve, as well as entrapment and intrinsic nerve lesions. Intraneural ganglion cysts are increasingly recognized when the mechanism of neuropathy is not clear from the medical history. Electrodiagnostic testing can contribute to the localization as well as the characterization of the pathologic process affecting the nerve. When the mechanism of injury is unclear from the analysis of the presentation, imaging with MRI and ultrasound may identify nerve lesions that warrant surgical intervention. The differential diagnosis of foot drop includes fibular neuropathy and other neurologic conditions, which can be distinguished through clinical and electrodiagnostic assessment. Rehabilitation measures, including ankle splinting, are important to improve function and safety when foot drop is present. Fibular neuropathy is less frequently painful than many other nerve lesions, but when it is painful, neuropathic medication may be required. Failure to spontaneously recover or the detection of a mass lesion may require surgical management.

Epidural Abscess Complicating Tunneled Caudal Epidural Catheter in an Infant for Postoperative Pain Management of Open Abdominal Surgery

Regional anesthesia is being used more frequently in pediatric anesthesia practice, including the perioperative care of neonates and infants. Adverse effects may be encountered during epidural needle placement, with catheter advancement, or subsequently during infusion of local anesthetic agents. Despite applying standard practice of care regarding placement of epidural catheter, epidural catheter-related infections may still occur. We present the rare occurrence of an epidural abscess in a 4-month-old infant after placement and subsequent use of a tunneled caudal epidural catheter for postoperative pain management following abdominal surgery. Magnetic resonance imaging (MRI) was the gold standard diagnostic imaging modality and was used to identify the abscess. Management included intravenous antibiotic therapy as well as hemilaminectomy with evacuation of the epidural abscess and hematoma. The patient continued to progress well with no deficits noted on neurological examination. There were no other postoperative concerns. When there is a concern for epidural catheter-related infection, the catheter should be removed immediately. The epidural catheter tip as well as any purulent discharge from the insertion site should be sent for culture and sensitivity. Urgent neurosurgical and infectious disease consultation is suggested to provide opinions regarding surgical intervention and antibiotic therapy.

Bibliometric Evaluation of the 100 Top-Cited Articles on Anesthesiology

This review is a bibliometric analysis based on anesthesiology, which is a medical specialty that deals with a patient's complete preoperative, intraoperative, and postoperative care. The objective of the review attempts to analyze the bibliometric characteristics of the 100 most top-cited articles on anesthesiology. The meta-data of the study were collected from the Core Collection of Web of Science database. A title search option was employed, and "Anesthesia" and "Anesthesiology" were typed in two different search boxes separated with the Boolean operator ''OR''. Further, the data were sorted by highest citation order; later, "article" was selected from the filter of document type, and all other types of documents were excluded. Finally, downloaded the bibliographic details of the 100 top-cited articles. VOSviewer Software (version 1.6.10 by van Eck and Waltman) was used for bibliometric network analysis for co-authors and keywords. Pearson chi-square test was used for statistical analysis. The 100 top-cited articles were published between the years of 1971 and 2018. These articles gained a maximum of 1006 to a minimum of 276 citations with an average of 384.57 cites/article. Open accessed articles gained a slightly higher ratio of citations, while more than half of the articles were published in the two leading journals of "Anesthesiology" and "Anesthesia and Analgesia". There was no statistically significant difference in both citation analysis among open and closed access journals and Anesthesia vs Non-Anesthesia journals. Thirty-six articles were published in journals not specifically related to Anesthesia. Most of the top-cited articles were contributed by the United States, whereas Surgery and General Anesthesia were the two most occurred keywords.  We conclude that all the top-cited articles in anesthesiology were contributed by authors who belonged to the developed nations and the United States outclassed the rest of the world. This bibliometric analysis would be valuable to practitioners, academics, researchers, and students to understand the dynamics of progress in the field of anesthesiology.

Neurological Complications of Local Anesthesia in Dentistry: A Review

Local anesthesia is a technique that temporarily desensitizes a specific body area, typically for a surgical procedure, dental work, or pain management. It is described as a sensation loss in a specific area of the body due to depression of excitation in the nerve endings or due to the inhibition of the conduction process within the peripheral nerves. It allows for safer and more comfortable medical procedures, reducing the need for general anesthesia and facilitating faster recovery. Local anesthesia is generally safe, but like any medical intervention, it carries potential risks and side effects. The complications related to local anesthetics can be assessed in terms of neurological, vascular, local, systemic, and neurological. In this review article, we discussed the neurological complications of local anesthesia related to the ophthalmic nerve, maxillary nerve, mandibular nerve, branches of the trigeminal nerve, and facial nerve. These include diplopia, ptosis, paralysis of the eye, blindness, paresthesia, trismus, soft tissue lesions, edema, hematoma, facial blanching, infection, allergy, overdose, neuralgia, facial palsy, etc.

Peripheral neuropathies after shoulder arthroscopy: a systematic review

Purpose

Peripheral neuropathies after shoulder arthroscopy are rare, though likely under-reported. Many resolve spontaneously, but some patients are left with permanent neurological deficits. The purpose of this study was to review the literature to better characterize this patient population, diagnostic tests performed, the timing and type of surgical intervention, and report clinical outcomes.

Methods

A systematic literature review was performed. Articles in English were identified from PubMed, EMBASE, and CINAHL in August 2021. Article titles and abstracts were screened for relevance by two authors and discordant abstracts were resolved by the senior author. Data were subsequently extracted from the included articles.

Results

Seventeen articles were identified yielding a total of 91 patients. The average age was 53 ± 12 years, and most patients were male (72%). Rotator cuff repair (62%) was the most common procedure performed. A peripheral neuropathy was identified an average of 80 ± 81 days from the index procedure (range, 0-240 days). Most commonly, peripheral nerve injury presented as a mononeuropathy, with the median nerve (39%) and ulnar nerve (17%) affected predominantly. Seventeen percent of patients underwent a secondary surgery at an average of 232 ± 157 days after the index procedure. At the final follow-up, 55% of neuropathies had resolved, 14% partially improved, and 22% showed no clinical improvement. The most proposed etiologies were postoperative immobilization (29%) and intraoperative positioning (20%), but several possible etiologies have been suggested.

Conclusions

Peripheral neuropathies after arthroscopic shoulder procedures are rare. While most spontaneously resolve, up to 1 in 5 patients may have persistent neuropathic symptoms. A high index of suspicion should be maintained throughout the postoperative period. When neurologic deficits are identified, patients should undergo a thorough diagnostic workup and be referred to a subspecialist in a timely manner.

"Knowing It Before Blocking It," the ABCD of the Peripheral Nerves: Part B (Nerve Injury Types, Mechanisms, and Pathogenesis)

Selander emphatically said, "Handle these nerves with care," and those words still echo, conveying a loud and clear message that, however rare, peripheral nerve injury (PNI) remains a perturbing possibility that cannot be ignored. The unprecedented nerve injuries associated with peripheral nerve blocks (PNBs) can be most tormenting for the unfortunate patient and a nightmare for the anesthetist. Possible justifications for the seemingly infrequent occurrences of PNB-related PNIs include a lack of documentation/reporting, improper aftercare, or associated legal implications. Although they make up only a small portion of medicolegal claims, they are sometimes difficult to defend. The most common allegations are attributed to insufficient informed consent; preventable damage to a nerve(s); delay in diagnosis, referral, or treatment; misdiagnosis, and inappropriate treatment and follow-up care. Also, sufficient prospective studies or randomized trials have not been conducted, as exploring such nerve injuries (PNB-related) in living patients or volunteers may be impractical or unethical. Understanding the pathophysiology of various types of nerve injury is vital to dealing with them further. Processes like degeneration, regeneration, remyelination, and reinnervation can influence the findings of electrophysiological studies. Events occurring in such a process and their impact during the assessment determine the prognosis and the need for further interventions. This educational review describes various types of PNB-related nerve injuries and their associated pathophysiology.

Ferrostatin-1 ameliorates Bupivacaine-Induced spinal neurotoxicity in rats by inhibiting ferroptosis

Bupivacaine (BUP) has previously been shown to trigger neurotoxicity after spinal anesthesia. Further, ferroptosis has been implicated in the pathological processes associated with various central nervous system diseases. Although the impact of ferroptosis on BUP-induced neurotoxicity in the spinal cord has not been fully understood, this research aims to investigate this relationship in rats. Additionally, this study aims to determine whether ferrostatin-1 (Fer-1), a potent inhibitor of ferroptosis, can provide protection against BUP-induced spinal neurotoxicity. The experimental model for BUP-induced spinal neurotoxicity involved the administration of 5% bupivacaine through intrathecal injection. Then, the rats were randomized into the Control, BUP, BUP + Fer-1, and Fer-1 groups. BBB scores, %MPE of TFL, and H&E and Nissl stainings showed that intrathecal Fer-1 administration improved functional recovery, histological outcomes, and neural survival in BUP-treated rats. Moreover, Fer-1 has been found to alleviate the BUP-induced alterations related to ferroptosis, such as mitochondrial shrinkage and disruption of cristae, while also reducing the levels of malondialdehyde (MDA), iron, and 4-hydroxynonenal (4HNE). Fer-1 also inhibits the accumulation of reactive oxygen species (ROS) and restores the normal levels of glutathione peroxidase 4 (GPX4), cystine/glutamate transporter (xCT), and glutathione (GSH). Furthermore, double-immunofluorescence staining revealed that GPX4 is primarily localized in the neurons instead of microglia or astroglia in the spinal cord. In summary, we demonstrated that ferroptosis play a pivotal role in mediating BUP-induced spinal neurotoxicity, and Fer-1 ameliorated BUP-induced spinal neurotoxicity by reversing the underlying ferroptosis-related changes in rats.

Tranexamic acid-associated intrathecal toxicity during spinal anaesthesia: A narrative review of 22 recent reports

Therapeutic use of tranexamic acid (TXA) to minimise blood loss is common during a wide range of surgical procedures. This review aims to explore the clinical features of the accidental intrathecal administration of TXA and to identify contributory factors that might prevent future incidents. The author searched published reports of accidental intrathecal administration of TXA using Medline and Google Scholar databases from July 2018 to September 2022, including error reports in any language but excluding errors via nonintrathecal routes. The human factors analysis classification system (HFACS) framework was used to examine and classify the human and systemic factors that contributed to the errors. Twenty-two errors of accidental intrathecal administration were reported during the search period. The analysis showed that the outcome was death in eight patients (36%) and permanent harm in four (19%). The fatality rate was higher among female individuals (6/13 versus 2/8 male individuals). Two-thirds of errors (15/22) occurred during orthopaedic surgery (10) and lower segment caesarean sections (5). Nineteen of 21 patients developed refractory or super refractory status epilepticus, requiring mechanical ventilation and intensive care for 3 days to 3 weeks for those who survived the initial few hours. Severe sympathetic stimulation resulting in refractory ventricular arrhythmias was the final event in some patients, with death within a few hours. Lack of familiarity with clinical characteristics caused delayed diagnosis or confusion with other clinical conditions. A proposed plan to manage intrathecal TXA toxicity is presented, including immediate cerebrospinal fluid lavage; however, there is no specific approach. The HFACS suggested mistaking look-alike TXA ampoules for local anaesthetic was the predominant cause. The author concludes that inadvertent intrathecal TXA is associated with mortality or permanent harm in more than 50% of patients. The HFACS demonstrates that all errors are preventable.

A Comprehensive Review on the Efficacy of Nerve Blocks in Reducing Postoperative Anesthetic and Analgesic Requirements

The purpose of this article review is to investigate whether or not nerve blocks are beneficial in minimizing the amount of postoperative anesthetic and analgesic medication required, hence improving patient outcomes and reducing healthcare costs. This review investigates several different kinds of nerve blocks, their administration techniques, and the anatomical and physiological aspects that influence nerve block effectiveness. It analyzes the impact of nerve blocks on opioid use, postoperative pain scores, and the incidence of opioid-related adverse effects by compiling the findings of numerous large-scale, randomized, controlled trials. Infection, hematoma, nerve injury, and systemic toxicity are some potential complications of nerve blocks discussed in the article. It concludes with recommendations for optimizing nerve block techniques in clinical practice and identifies areas that require further research, such as the development of new anesthetics and the identification of patient subgroups that would benefit the most from nerve blocks. In addition, it provides recommendations for optimizing nerve block techniques in clinical practice.

Functional recovery with peripheral nerve block versus general anesthesia for upper limb surgery: a systematic review

BACKGROUND

Peripheral nerve block is a common anesthetic technique used during orthopedic upper limb surgery. Injection of local anesthetics around the target nerve inhibits the action of voltage-dependent sodium channels, inhibiting neurotransmission of pain impulses and providing motor immobility. Compared to general anesthesia, it could improve functional recovery by inhibiting nociceptive impulses and inflammation, thus reducing postoperative pain and immobilization and improving postoperative rehabilitation. This systematic review evaluates the impact of peripheral nerve block versus general anesthesia on postoperative functional recovery following orthopedic upper limb surgery.

METHODS

We searched CENTRAL, MEDLINE, CINHAL, EMBASE, and Scopus trial databases from inception until September 2021 for studies comparing peripheral nerve block to general anesthesia. We collected data on functional recovery, range of motion, patient satisfaction, quality of life, and return to work. We pooled studies using a random-effects model and summarized the quality of evidence with the GRADE approach.

RESULTS

We assessed 373 citations and 19 full-text articles for eligibility, and included six studies. Six studies reported on functional recovery, but failed to detect a significant superiority of peripheral nerve block over general anesthesia (3 RCT studies, N = 160; SMD -0.15; CI at 95% -0.60-0.3; I² = 45%; p = 0.07; low quality of evidence and 3 observational studies, N = 377; SMD -0.35; CI at 95% -0.71-0.01; I² = 64%; p = 0.06; very low quality of evidence).

CONCLUSIONS

Current literature is limited and fails to identify the benefit of peripheral nerve block on functional recovery. More studies are needed to assess the impact on long-term recovery. Considering the potential impact on clinical practice and training, a prospective study on functional recovery is ongoing (NCT04541745).

TRIAL REGISTRATION

PROSPERO ID CRD42018116298. Registered on December 4, 2018.

Successful Glenohumeral Shoulder Reduction With Combined Suprascapular and Axillary Nerve Block

BACKGROUND

Anterior glenohumeral dislocation is a common injury seen in the emergency department (ED) that sometimes requires procedural sedation for manual reduction. When compared with procedural sedation for dislocation reductions, peripheral nerve blocks provide similar patient satisfaction scores but have shorter ED length of stays. In this case report, we describe the first addition of an ultrasound-guided axillary nerve block to a suprascapular nerve block for reduction of an anterior shoulder dislocation in the ED.

CASE REPORT

A 34-year-old man presented to the ED with an acute left shoulder dislocation. The patient was a fit rock climber with developed muscular build and tone. An attempt to reduce the shoulder with peripheral analgesia was unsuccessful. A combined suprascapular and axillary nerve block was performed with 0.5% bupivacaine, allowing appropriate relaxation of the patient's musculature while providing excellent pain control. The shoulder was then successfully reduced without procedural sedation. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Procedural sedation for reduction of anterior shoulder dislocations is time consuming, resource intensive, and can be risky in some populations. The addition of an axillary nerve block to a suprascapular nerve block allows for more complete muscle relaxation to successfully reduce a shoulder dislocation without procedural sedation.

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.

Regional anaesthesia: what surgical procedures, what blocks and availability of a “block room”?

PURPOSE OF REVIEW

With an expected rise in day care procedures with enhanced recovery programs, the use of specific regional anaesthesia can be useful. In this review, we will provide insight in the used regional block and medication so far known and its applicability in a day care setting.

RECENT FINDINGS

Regional anaesthesia has been improved with the aid of ultrasound-guided placement. However, it is not commonly used in the outpatient setting. Old, short acting local anaesthetics have found a second life and may be especially beneficial in the ambulatory setting replacing more long-acting local anaesthetics such as bupivacaine.To improve efficiency, a dedicated block room may facilitate the performance of regional anaesthesia. However, cost-efficacy for improved operating time, patient care and hospital efficiency has to be established.

SUMMARY

Regional anaesthesia has proven to be beneficial in ambulatory setting. Several short acting local anaesthetics are favourable over bupivacaine in the day care surgery. And if available, there are reports of the benefit of an additional block room used in a parallel (monitored) care of patients.

Intraoperative Needle Tip Tracking with an Integrated Fibre-Optic Ultrasound Sensor

Ultrasound is an essential tool for guidance of many minimally-invasive surgical and interventional procedures, where accurate placement of the interventional device is critical to avoid adverse events. Needle insertion procedures for anaesthesia, fetal medicine and tumour biopsy are commonly ultrasound-guided, and misplacement of the needle may lead to complications such as nerve damage, organ injury or pregnancy loss. Clear visibility of the needle tip is therefore critical, but visibility is often precluded by tissue heterogeneities or specular reflections from the needle shaft. This paper presents the in vitro and ex vivo accuracy of a new, real-time, ultrasound needle tip tracking system for guidance of fetal interventions. A fibre-optic, Fabry-Pérot interferometer hydrophone is integrated into an intraoperative needle and used to localise the needle tip within a handheld ultrasound field. While previous, related work has been based on research ultrasound systems with bespoke transmission sequences, the new system-developed under the ISO 13485 Medical Devices quality standard-operates as an adjunct to a commercial ultrasound imaging system and therefore provides the image quality expected in the clinic, superimposing a cross-hair onto the ultrasound image at the needle tip position. Tracking accuracy was determined by translating the needle tip to 356 known positions in the ultrasound field of view in a tank of water, and by comparison to manual labelling of the the position of the needle in B-mode US images during an insertion into an ex vivo phantom. In water, the mean distance between tracked and true positions was 0.7 ± 0.4 mm with a mean repeatability of 0.3 ± 0.2 mm. In the tissue phantom, the mean distance between tracked and labelled positions was 1.1 ± 0.7 mm. Tracking performance was found to be independent of needle angle. The study demonstrates the performance and clinical compatibility of ultrasound needle tracking, an essential step towards a first-in-human study.

Prevalence, management, and outcomes of nerve injury after shoulder arthroplasty: a case-control study and review of the literature

Background

Neurologic injury is a rare and potentially devastating complication of shoulder arthroplasty. Patients typically present with a mixed plexopathy or mononeuropathy, most commonly affecting the axillary and radial nerves. Given the paucity of studies available on the topic, our goal was to elucidate the prevalence of nerve injury after shoulder arthroplasty and to describe the treatment course and outcomes of neurologic injuries.

Methods

This is a retrospective case-control study performed at a single, urban, academic institution. Consecutive patients who underwent anatomic total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (RSA) by a single surgeon from 2014 to 2020 were reviewed, and patients with a documented nerve injury were identified. A control group of patients without nerve injury were selected in a 2:1 ratio controlling for age and procedure type (TSA vs. RSA; primary vs. revision). Data collected included demographics, comorbidities as per the Charlson Comorbidity Index, radiographic evaluations, surgical and implant details, patient-reported outcome measures, and perioperative complications.

Results

Of 923 patients, 33 (3.6%) sustained an iatrogenic nerve injury: 10 (2.1%) after TSA, 23 (5.0%) after RSA, and 3 (7.8%) after revision arthroplasty. Axillary mononeuropathy was most common (42%), followed by brachial plexopathies (18%). There was no significant difference in age, sex, race, body mass index, and preoperative diagnoses between groups. Patients with nerve injury had fewer comorbidities (Charlson Comorbidity Index <3, 33 vs. 65%, P<.001). Patients with nerve injury had higher rates of cervical spine pathology (15 vs. 6%; P = .15) and increased postoperative lateralization (8.9 mm [7.2] vs. 5.5 mm [7.3]; P<.06). The majority (91%) were managed with observation alone. Three (9%) underwent an additional procedure: carpal tunnel release (1, 3%), ulnar nerve decompression (1, 3%), and ulnar nerve transposition (1, 3%) for peripheral compressive neuropathies. At the final follow-up, 19 (57%) nerves fully recovered, and 14 (43%) showed mild residual sensorimotor dysfunction. The mean time to first sign of recovery and ultimate recovery were 11 (7.2) and 36 (23.5) weeks, respectively. At the final follow-up, patients with nerve injury performed worse on patient-reported outcomes, including visual analog score pain (2.2 vs. 1.0, P<.001), American Shoulder and Elbow Surgeons score (67.8 vs. 84.8, P<.001), and Single Assessment Numeric Evaluation scores (62 vs. 77, P = .009).

Discussion

Nerve injury after shoulder arthroplasty is rare, occurring in 3.6% of our patient population. Axillary mononeuropathy and brachial plexopathies are the most common. Most patients can be managed expectantly with observation and will recover at least partial nerve function, although clinical outcomes remain inferior to those without nerve complication.

Efficacy and safety of wound infiltration modalities for postoperative pain management after cesarean section: a systematic review and network meta-analysis protocol

BACKGROUND

Postoperative pain after a cesarean section has negative consequences for the mother during the postoperative period. Over the years, various postoperative pain management strategies have been used following cesarean section. Opioid-based analgesics and landmark approaches have negative side effects, while ultrasound-based regional analgesia necessitates resources and experience, but various wound infiltration adjuvants are innovative with few side effects and are simple to use. The efficacy and safety of each adjuvant, however, are unknown and require further investigation.

OBJECTIVE

This network meta-analysis is intended to provide the most effective wound infiltration drugs for postoperative management after cesarean section.

METHOD

A comprehensive search will be conducted in PubMed/MEDLINE, Cochrane Library, Science Direct, CINHAL, and LILACS without date and language restrictions. All randomized trials comparing the effectiveness of wound infiltration drugs for postoperative pain management after cesarean section will be included. Data extraction will be conducted independently by two authors. The quality of studies will be evaluated using the Cochrane risk of bias tool, and the overall quality of the evidence will be determined by GRADEpro software.

DISCUSSION

The rate of postoperative acute and chronic pain is very high which has a huge impact on the mother, family, healthcare practitioners, and healthcare delivery. It is a basic human right to give every patient with postoperative pain treatment that is realistic in terms of resources, technique, cost, and adverse event profile.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021268774.

Outcomes After Orthopedic Trauma Surgery - What is the Role of the Anesthesia Choice?

The body of literature concerning the influence of anesthetic type on many perioperative outcomes has grown considerably in recent years. Most studies have suggested that particularly in orthopedic patients, regional anesthesia may be associated with improved perioperative outcomes. Orthopedic trauma presents itself as a field that might benefit from increased utilization of regional techniques with the goal to improve outcomes. This narrative review concludes that, indeed, regional anesthesia seems to provide benefits for morbidity, pain control, and improved return to function in hip fracture, rib fracture, and isolated extremity fracture patients.

Ultrasound is better than injection pressure monitoring detecting the low-volume intraneural injection

INTRODUCTION

Inadvertent intraneural injection is not infrequent during peripheral nerve blocks. For this reason, injection pressure monitoring has been suggested as a safeguard method that warns the clinician of a potentially hazardous needle tip location. However, doubts remain whether it is superior to the sonographic nerve swelling in terms of earlier detection of the intraneural injection.

METHODS

An observational cadaveric study was designed to assess injection pressures during an ultrasound-guided intraneural injection of the median nerve. We hypothesized that the evidence of nerve swelling occurred prior to an elevated injection pressure (>15 pound per square inch) measured with a portable in-line monitor. 33 ultrasound-guided intraneural injections of 11 median nerves from unembalmed human cadavers were performed at proximal, mid and distal forearm. 1 mL of a mixture of local anesthetic and methylene blue was injected intraneurally at a rate of 10 mL/min. Following injections, specimens were dissected to assess spread location. Video recordings of the procedures including ultrasound images were blindly analyzed to evaluate nerve swelling and injection pressures.

RESULTS

31 injections were considered for analysis (two were excluded due to uncertainty regarding needle tip position). >15 pound per square inch was reached in six injections (19%) following a median injected volume of 0.6 mL. Nerve swelling was evident in all 31 injections (100%) with a median injected volume of 0.4 mL. On dissection, spread location was confirmed intraneural in all injections.

DISCUSSION

Ultrasound is a more sensitive and earlier indicator of the low-volume intraneural injection than injection pressure monitoring.

Traumatic needle damage to nerves during regional anesthesia: presentation of a novel mechanotransduction hypothesis

Despite advances in needle positioning techniques, nerve damage still occurs after regional anesthesia. Recognized causes include local anesthetic toxicity, subperineural injection, high subepineural fluid injection pressures and subepineural hematoma after forceful needle--nerve contact.We hypothesize that subperineural injection is still possible, but less likely to be the cause of nerve damage because needle penetration of fascicles and mechanical damage is difficult to achieve. High-resolution (75 µm) 40 MHz micro-ultrasound images of pig axillae show short-bevelled 22 g, 0.7 mm wide block needles that are three times larger than the average fascicle. Fascicular bundles are extremely difficult to puncture because they spin away on needle contact. Histology from fresh cadavers after supposed intrafascicular injection shows fluid spread within perineurium and intrafascicular perineural septae, but no breach of endoneurium or axons.We propose that mechanotransduction, the cellular changes that occur in response to force, contributes to nerve damage. Piezo ion channel proteins transduce force into electrical activity by rapid entry of cations into cells. Excessive Ca2+ influx into cells has the potential to inhibit nerve regeneration. Cellular changes include regulation of gene expression. The forces associated with purposeful needle insertion are generally unknown. Our experiments in the soft embalmed Thiel cadaver showed a lognormal range of forces between 0.6 N and 16.8 N on epineural penetration.We hypothesize that forceful needle injury may cause nerve damage by activation of Piezo receptors and release of intracellular Ca2.

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.

Surgeon administered direct adductor canal block is as good as ultrasound guided adductor canal block in pain management in knee replacements- A retrospective case-control study

Aim

The aim of this study is to assess the feasibility of the DACB in a clinical setting and compare the efficacy of postoperative pain relief after TKR in the patients administered DACB versus USG guided ACB. Also to see efficacy and safety of USACB in patients operated with medial parapatellar and subvastus approach.

Material and methods

250 consecutive patients operated with TKR between Jan 2019 to March 2022 were included. Group A included patients operated with medial parapatellar approach and received USACB, Group B included patients operated with medial parapatellar approach and received DACB while Group C included patients operated with subvastus approach and received USACB. VAS scores between three groups were compared at 12 and 24 h. All three groups of patients were otherwise treated identically in the hospital.

Results

The mean age and BMI was not statistically significant between the three groups. The mean VAS pain score at rest at 12 h was 3.06 ± 1.49 (Group A) vs 1.58 ± 1.19 (Group B) [p < 0.0001] and 3.06 ± 1.49 (Group A) vs 1.88 ± 1.18 (Group C) [p < 0.0001]; and at 24 h was 1.88 ± 1.31 (Group A) vs 2.39 ± 1.27 (Group B) [p = 0.023] and 1.88 ± 1.31 (Group A) vs 2.19 ± 1.29 (Group C) [p = 0.16]. The mean theatre time was 151.9 ± 11.37 min (Group A) vs 141.02 ± 19.46 min (Group B) (p = 0.0003) and 151.9 ± 11.37 min (Group A) vs 150.4 ± 28.74 min (Group C) (p = 0.72). Hospital stay was 3.82 ± 0.80 (Group A) vs 4.0 ± 1.09 (Group B) [p = 0.30] and 3.82 ± 0.80 (Group A) vs 2.7 ± 0.69 (Group C) [p < 0.0001]. Group B and Group C had one complication each.

Conclusion

USG ACB irrespective of approach used remains the gold standard in providing consistent pain relief and thereby facilitating early discharge. However, increased operating room turnover time and repeated top-ups remain a disadvantage. Both the quantum of pain relief and the potential downsides remained the same irrespective of the surgical approach used and whether or not steroid was added to the cocktail used for infiltration. On the other hand, DACB provides a short lasting (24 h) adequate pain relief after TKR with similar low complication rates. The technique of DACB may have a potential for a wider use especially in centres where outpatient arthroplasties are performed, if newer longer acting anaesthetic/analgesic combinations are devised.

Local Anesthetics, Local Anesthetic Systemic Toxicity (LAST), and Liposomal Bupivacaine

Local anesthetics have played a vital role in the multimodal analgesia approach to patient care by decreasing the use of perioperative opioids, enhancing patient satisfaction, decreasing the incidence of postoperative nausea and vomiting, decreasing the length of hospital stay, and reducing the risk of chronic postsurgical pain. The opioid-reduced anesthetic management for perioperative analgesia has been largely successful with the use of local anesthetics during procedures such as peripheral nerve blocks and neuraxial analgesia. It is important that practitioners who use local anesthetics are aware of the risk factors, presentation, and management of local anesthetic systemic toxicity (LAST).

Comparison of in vitro and in vivo Toxicity of Bupivacaine in Musculoskeletal Applications

The recent societal debate on opioid use in treating postoperative pain has sparked the development of long-acting, opioid-free analgesic alternatives, often using the amino-amide local anesthetic bupivacaine as active pharmaceutical ingredient. A potential application is musculoskeletal surgeries, as these interventions rank amongst the most painful overall. Current literature showed that bupivacaine induced dose-dependent myo-, chondro-, and neurotoxicity, as well as delayed osteogenesis and disturbed wound healing in vitro. These observations did not translate to animal and clinical research, where toxic phenomena were seldom reported. An exception was bupivacaine-induced chondrotoxicity, which can mainly occur during continuous joint infusion. To decrease opioid consumption and provide sustained pain relief following musculoskeletal surgery, new strategies incorporating high concentrations of bupivacaine in drug delivery carriers are currently being developed. Local toxicity of these high concentrations is an area of further research. This review appraises relevant in vitro, animal and clinical studies on musculoskeletal local toxicity of bupivacaine.

Patient-Controlled Intravenous Analgesia With Tramadol and Lornoxicam After Thoracotomy: A Comparison With Patient-Controlled Epidural Analgesia

Objective

To determine efficacy and safety of patient-controlled intravenous analgesia (PCIA) with tramadol and lornoxicam for postoperative analgesia, and its effects on surgical outcomes in patients after thoracotomy.

Summary of background data

Adequate pain relief after thoracic surgery is of particular importance, not only for keeping patients comfortable but also for reducing the incidence of postoperative complications. PCIA with tramadol and lornoxicam could be an acceptable alternative to patient-controlled epidural analgesia (PCEA) for pain management after thoracotomy.

Methods

The records of patients who underwent thoracotomy for lung resection between January 2014 and December 2014 at our institution were reviewed. The patients were divided into 2 groups according to postoperative pain treatment modalities. Patients of PCEA group (n = 63) received PCEA with 0.2% ropivacaine plus 0.5 μg/mL sufentanil, while patients in PCIA group (n = 48) received PCIA with 5 mg/mL tramadol and 0.4 mg/mL lornoxicam. Data were collected for quality of pain control, incidences of analgesia-related side effects and pulmonary complications, lengths of thoracic intensive care unit stay and postoperative hospital stay, and in-hospital mortality.

Results

Pain at rest was controlled well in both groups during a 4-day postoperative period. Patients in PCIA group reported significantly higher pain scores on coughing and during mobilization in the first 2 postoperative days. The incidences of side effects and pulmonary complications, in-hospital mortality, and other outcomes were similar between groups.

Conclusions

PCIA with tramadol and lornoxicam can be considered as a safe and effective alternative with respect to pain control and postoperative outcomes after thoracotomy.

Evaluation of Rhomboid Intercostal Block in Video-Assisted Thoracic Surgery: Comparing Three Concentrations of Ropivacaine

Background: Ultrasound-guided rhombic intercostal block (RIB) is a novel regional block that provides analgesia for patients who have received video-assisted thoracoscopic surgery (VATS). The anesthetic characteristics of ultrasound-guided RIB with different concentrations of ropivacaine are not known. This research primarily hypothesizes that ultrasound-guided RIB, given in combination with the same volume of different concentrations of ropivacaine, would improve the whole quality of recovery-40 (QoR-40) among patients with VATS.

Approaches: This double-blinded, single-center, prospective, and controlled trial randomized 100 patients undergoing VATS to receive RIB. One hundred patients who have received elective VATS and satisfied inclusion standards were fallen into four groups randomly: control group with no RIB and R_0.2%, R_0.3%, and R_0.4%; they underwent common anesthesia plus the RIB with ropivacaine at 0.2%, 0.3%, and 0.4% in a volume of 30 ml.

Outcomes: Groups R_0.2%, R_0.3%, and R_0.4% displayed great diversities in the overall QoR-40 scores and QoR-40 dimensions (in addition to psychological support) by comparing with the control group (Group C) (p < 0.001 for all contrasts). Groups R_0.3% and R_0.4% displayed great diversities in the overall QoR-40 scores and QoR-40 dimensions (in addition to psychological support) by comparing with the R_0.2% group (p < 0.001 for all contrasts). The overall QoR-40 scores and QoR-40 dimensions [physical comfort (p = 0.585)] did not vary greatly between Groups R_0.3% and R_0.4% (p > 0.05 for all contrasts). Groups R_0.2%, R_0.3%, and R_0.4% showed significant differences in numerical rating scales (NRS) score region under the curve (AUC) at rest and on movement in 48 h when compared with the Group C (p < 0.001 for all contrasts). Groups R_0.3% and R_0.4% displayed great diversities in NRS score AUC at rest and on movement in 48 h when compared with the R_0.2% group (p < 0.001 for all contrasts). The NRS mark AUC at rest and, on movement in 48 h, did not vary greatly between the Group R_0.3% and R_0.4% (p > 0.05 for all contrasts).

Conclusion: In this study it was found that a dose of 0.3% ropivacaine is the best concentration for RIB for patients undergoing VATS. Through growing ropivacaine concentration, the analgesia of the RIB was not improved greatly.

Clinicaltrials.gov Registration:https://clinicaltrials.gov/, identifier ChiCTR2100046254.

Accuracy of ultrasonography predicting spread location following intraneural and subparaneural injections: a scoping review

INTRODUCTION

Ultrasonography is useful for detecting intraneural injections. However, the reliability of the sonographic findings of intraneural and subparaneural injections in terms of true spread location and their association with intrafascicular deposits has not been systematically evaluated.

EVIDENCE ACQUISITION

Our objectives were: i) to explore the reliability of sonographic findings of intraneural and subparaneural injections when validated with tests of true spread such as histology, dissection or imaging, and ii) to evaluate their association with intrafascicular deposits. A Scoping Review was conducted according to Joanna Briggs guidelines. Cinahl, PubMed, ProQuest, ScienceDirect, Scopus and Cochrane databases were searched for studies on adults, cadavers and animal models. Paediatric studies were excluded.

EVIDENCE SYNTHESIS

The search strategy found 598 citations. Following screening, 19 studies were selected. Intraneural injections occurred in the brachial plexus, sciatic, femoral and median nerves. Subparaneural injections in popliteal, supraclavicular and interscalene blocks. Sixteen different ultrasound findings were used to label injection location. Subepineural deposits within individual nerves occurred occasionally following subparaneural injections, regardless of nerve expansion. Overall five studies reported intrafascicular deposits, two of which frequently, following intraneural and subparaneural injections. None of the currently used ultrasound findings was predictive of intrafascicular deposits.

CONCLUSIONS

Our results suggest that sonographic parameters of intraneural and subparaneural injections are reliable in terms of detecting spread location. Intrafascicular injectate deposition may occur, albeit infrequently, particularly in the proximal brachial plexus. Our findings support the judicious interrogation of sonographic parameters suggestive of incipient intraneural injection.

Ultrasound-Guided Anterior Quadratus Lumborum Block Reduces Postoperative Opioid Consumption and Related Side Effects in Patients Undergoing Total Hip Replacement Arthroplasty: A Propensity Score-Matched Cohort Study

Quadratus lumborum block (QLB) has been shown to be effective for pain relief after hip surgery. This study evaluated the efficacy of ultrasound-guided anterior QLB in pain control after total replacement hip arthroplasty (TRHA). A total of 115 patients receiving anterior QLB were propensity score-matched with 115 patients who did not receive the block. The primary outcome was opioid consumption at 24, 24-48, and 48 postoperative hours. Secondary outcomes included pain scores at the post-anesthesia care unit (PACU), 8, 16, 24, 32, 40, and 48 h length of hospital stay, time to first ambulation, and the incidence of opioid-related side effects. Postoperative opioid consumption 48 h after surgery was significantly lower in the QLB group. Resting, mean, worst, and the difference of resting pain scores compared with preoperative values were significantly lower in the QLB group during the 48 postoperative hours. The length of hospital stay was shorter in the QLB group. The incidence of postoperative nausea and vomiting was significantly lower in the QLB group during the 48 postoperative hours, except at the PACU. This study suggests that anterior QLB provides effective postoperative analgesia for patients undergoing THRA performed using the posterolateral approach.

Nerve injury following ultrasound-guided nerve root block with 2% lidocaine for shoulder manipulation: a case report

Shoulder manipulation under ultrasound (US)-guided C5 and C6 nerve root block is effective for treating refractory adhesive capsulitis (AC). We herein report the development of cervical nerve root injury following manipulation under anesthesia (MUA) in a patient with AC. A 47-year-old woman underwent shoulder manipulation under US-guided C5 and C6 root block with 2% lidocaine for the management of AC-induced shoulder pain. For the procedure, 3 mL of 2% lidocaine (total of 6 mL) was injected around each C5 and C6 nerve root under US guidance. Seven days after the procedure, the patient visited a university hospital because of severe neuropathic pain (numeric rating scale score of 9) in the right anterior arm, lateral arm, and forearm areas. Sensory deficits in the corresponding C5 and C6 dermatomes and motor weakness of the right shoulder abductor, elbow flexor, and wrist extensor were observed. Electrophysiologic studies demonstrated C5 and C6 nerve root injury. The patient was diagnosed with right C5 and C6 nerve root injury following MUA, and lidocaine toxicity or ischemia was the suspected cause. Clinicians should be mindful of the possibility of this complication.

Effects of prolonged peri-neural bupivacaine infusion in rat sciatic nerves (axon and myelin)

BACKGROUND/OBJECTIVE

Peripheral-nerve blocks (PNBs) using continuous-infusion of local anesthetics are used to provide perioperative analgesia. Yet little research exists to characterize the histopathological effects of continuous long-duration PNBs. Herein we test the hypothesis that continuous peri-neural bupivacaine infusion (3-day vs. 7-day infusion) contributes to histologic injury in a duration-dependent manner using an in vivo model of rat sciatic nerves.

METHODS

We placed indwelling catheters in 22 rats for infusion with low-dose (0.5mg/kg/hr) bupivacaine or normal saline proximal to the right sciatic nerves for 3 or 7 consecutive days. Hind-limb analgesia was measured using Von-Frey nociceptive testing. At infusion end, rats were sacrificed, bilateral nerves were sectioned and stained with hematoxylin and eosin and CD68 for evaluation of inflammatory response, and eriochrome to assess damage to myelin.

RESULTS

Animals receiving continuous infusion of bupivacaine maintained analgesia as demonstrated by significant decrease (50% on average) in nociceptive response in bupivacaine-infused limbs across time points. Both 7-day saline and bupivacaine-infused sciatic nerves showed significantly-increased inflammation by H&E staining compared to untreated native nerve controls (P = 0.0001, P < 0.0001). Extent of inflammation did not vary significantly based on infusate (7-day saline vs. 7-day bupivacaine P > 0.99) or duration (3-day bupivacaine vs 7-day bupivacaine P > 0.99). No significant change in sciatic nerve myelin was found in bupivacaine-infused animals compared to saline-infused controls, regardless of duration.

CONCLUSIONS

Long-duration (7-day) bupivacaine infusion provided durable post-operative analgesia, yet contributed to equivalent neural inflammation as short duration (3-day) infusion of bupivacaine or saline with no evidence of demyelination.

Peripheral nerve block anesthesia/analgesia for patients undergoing primary hip and knee arthroplasty: recommendations from the International Consensus on Anesthesia-Related Outcomes after Surgery (ICAROS) group based on a systematic review and meta-analysis of current literature

BACKGROUND

Evidence-based international expert consensus regarding the impact of peripheral nerve block (PNB) use in total hip/knee arthroplasty surgery.

METHODS

A systematic review and meta-analysis: randomized controlled and observational studies investigating the impact of PNB utilization on major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, thromboembolic, neurologic, infectious, and bleeding complications.Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, were queried from 1946 to August 4, 2020.The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess evidence quality and for the development of recommendations.

RESULTS

Analysis of 122 studies revealed that PNB use (compared with no use) was associated with lower ORs for (OR with 95% CIs) for numerous complications (total hip and knee arthroplasties (THA/TKA), respectively): cognitive dysfunction (OR 0.30, 95% CI 0.17 to 0.53/OR 0.52, 95% CI 0.34 to 0.80), respiratory failure (OR 0.36, 95% CI 0.17 to 0.74/OR 0.37, 95% CI 0.18 to 0.75), cardiac complications (OR 0.84, 95% CI 0.76 to 0.93/OR 0.83, 95% CI 0.79 to 0.86), surgical site infections (OR 0.55 95% CI 0.47 to 0.64/OR 0.86 95% CI 0.80 to 0.91), thromboembolism (OR 0.74, 95% CI 0.58 to 0.96/OR 0.90, 95% CI 0.84 to 0.96) and blood transfusion (OR 0.84, 95% CI 0.83 to 0.86/OR 0.91, 95% CI 0.90 to 0.92).

CONCLUSIONS

Based on the current body of evidence, the consensus group recommends PNB use in THA/TKA for improved outcomes.

RECOMMENDATION

PNB use is recommended for patients undergoing THA and TKA except when contraindications preclude their use. Furthermore, the alignment of provider skills and practice location resources needs to be ensured. Evidence level: moderate; recommendation: strong.

Distinct neurotoxic effects of select local anesthetics on facial nerve injury and recovery

BACKGROUND

Local anesthetic toxicity has been well-documented to cause neuronal injury, death, and dysfunction, particularly in a susceptible nerve.

OBJECTIVE

To determine whether select local anesthetics affect neuron survival and/or functional recovery of an injured nerve.

METHODS

This report describes 6 separate experiments that test immediate or delayed application of local anesthetics in 3 nerve injury models. Adult C57/black6 male mice underwent a facial nerve sham, transection, or crush injury. Local anesthetic or saline was applied to the facial nerve at the time of injury (immediate) or 1 day after injury (delayed). Average percent facial motoneuron (FMN) survival was evaluated four-weeks after injury. Facial nerve regeneration was estimated by observing functional recovery of eye blink reflex and vibrissae movement after facial nerve crush injury.

RESULTS

FMN survival after: transection + immediate treatment with ropivacaine (54.8%), bupivacaine (63.2%), or tetracaine (66.9%) was lower than saline (85.5%) and liposomal bupivacaine (85.0%); crush + immediate treatment with bupivacaine (92.8%) was lower than saline (100.7%) and liposomal bupivacaine (99.3%); sham + delayed treatment with bupivacaine (89.9%) was lower than saline (96.6%) and lidocaine (99.5%); transection + delayed treatment with bupivacaine (67.3%) was lower than saline (78.4%) and liposomal bupivacaine (77.6%); crush + delayed treatment with bupivacaine (85.3%) was lower than saline (97.9%) and lidocaine (96.0%). The average post-operative time for mice to fully recover after: crush + immediate treatment with bupivacaine (12.83 days) was longer than saline (11.08 days) and lidocaine (10.92 days); crush + delayed treatment with bupivacaine (16.79 days) was longer than saline (12.73 days) and lidocaine (11.14 days).

CONCLUSIONS

Our data demonstrate that some local anesthetics, but not all, exacerbate motoneuron death and delay functional recovery after a peripheral nerve injury. These and future results may lead to clinical strategies that decrease the risk of neural deficit following peripheral nerve blocks with local anesthetics.

[Peripheral Regional Anaesthesia for Perioperative Analgesia]

Peripheral Regional Anaesthesia for Perioperative Analgesia Abstract. Peripheral regional anaesthesia is the actual gold standard of opioid-sparing perioperative analgesia and is mainly used for surgery of the shoulder, arm and leg. Well-trained anaesthesiologists are the prerequisite for the correct individual risk-benefit assessment and the performance of the nerve blocks using a combination of ultrasound guidance and peripheral nerve stimulation (dual guidance). The postoperative care of the patients requires trained staff.

Techniques and strategies for regional anesthesia in acute burn care-a narrative review

Burn injuries and their treatments result in severe pain. Unlike traumatic injuries that are characterized by a discrete episode of pain followed by recovery, burn-injured patients endure pain for a prolonged period that lasts through wound closure (e.g. background pain, procedural pain, breakthrough pain, neuropathic pain and itch). Regional anesthesia, including peripheral nerve blocks and neuraxial/epidural anesthesia, offers significant benefits to a multimodal approach in pain treatment. A 'regional-first' approach to pain management can be incorporated into the workflow of burn centers through engaging regional anesthesiologists and pain medicine practitioners in the care of burn patients. A detailed understanding of peripheral nerve anatomy frames the burn clinician's perspective when considering a peripheral nerve block/catheter. The infra/supraclavicular nerve block provides excellent coverage for the upper extremity, while the trunk can be covered with a variety of blocks including erector spinae plane and quadratus lumborum plane blocks. The lower extremity is targeted with fascia iliaca plane and sciatic nerve blocks for both donor and recipient sites. Burn centers that adopt regional anesthesia should be aware of potential complications and contraindications to prevent adverse events, including management of local anesthetic toxicity and epidural infections. Management of anticoagulation around regional anesthesia placement is crucial to prevent hematoma and nerve damage. Ultimately, regional anesthesia can facilitate a better patient experience and allow for early therapy and mobility goals that are hallmarks of burn care and rehabilitation.

Complications Associated with Peripheral Nerve Blocks

Outpatient orthopedic surgery is gradually becoming the standard across the country, as it has been found to significantly lower costs without compromising patient care. Peripheral nerve blocks (PNBs) are largely what have made this transition possible by providing patients excellent pain control in the immediate postoperative period. However, with the increasing use of PNBs, it is important to recognize that they are not without complications. Although rare, these complications can cause patients a significant amount of morbidity. It is important for surgeons to know the risks of peripheral nerve blocks and to inform their patients.

Combination of real-time needle-tip pressure sensing and minimal intensity stimulation limits unintentional intraneural injection during an ultrasound-guided peripheral nerve block procedure: A randomized, parallel group, controlled trial

STUDY OBJECTIVE

Ultrasound guidance does not eliminate the risk of intraneural injection, which must be avoided during PNB. Combining ultrasound guidance (USG), nerve stimulation (NS), and injection pressure monitoring is advocated to prevent nerve injury during PNB. We hypothesized that combining patient-tailored dynamic NS and real-time pressure sensing (RTPS) could reduce the incidence of intraneural injection and nerve puncture during USG PNB compared with a traditional fixed thresholds (Control) procedure.

DESIGN

Randomized, prospective study.

SETTING

Operating room.

PATIENTS

One hundred ASA physical status I to III patients undergoing orthopedic surgery.

INTERVENTIONS

Patient anesthetized using axillary, sciatic or femoral USG PNB were randomized to the PresStim group (Dynamic RTPS and NS set at 1.5 mA then decreased; n = 50) or Control group (fixed thresholds for in-line pressure mechanical manometer and NS at 0.2 mA; n = 50).

MEASUREMENTS

Procedural ultrasound images and videos were recorded, stored and reviewed in random order by two experts in ultrasound-guided PNB blinded to the group. They noted the needle-to-nerve relationship and intraneural injection for all blocked nerves.

MAIN RESULTS

One hundred and twenty-three USG PNBs were performed (56 axillary brachial plexus blocks, 40 femoral nerve blocks and 27 sciatic popliteal nerve blocks); 235 blocked nerves and videos were recorded and analyzed (PresStim, 118; Control, 117). Less paresthesia was noted in the PresStim group (12.7%) compared with the Control group (18.8%). The risk of intraneural injection was significantly higher in the Control group (odds ratio [OR], 17.1; 95% confidence interval [CI], 2.2-135, P = 0.007). The risk of nerve puncture (OR, 22.7; 95% CI, 2.9-175, p = 0.003) and needle-nerve contact (OR, 4.7; 95% CI, 2.4-9.5, p < 0.001) was significantly higher in the Control group than the PresStim group.

CONCLUSIONS

Under the conditions of the study, dynamic triple monitoring combining RTPS, NS and USG decreases intraneural injection and unintentional needle-nerve contact and puncture during a PNB procedure.

Opening injection pressure monitoring using an in-line device does not prevent intraneural injection in an isolated nerve model

BACKGROUND

Injection pressure monitoring using in-line devices is affordable and easy to implement into a regional anesthesia practice. However, solid evidence regarding their performance is lacking. We aimed to evaluate if opening injection pressure (OIP), measured with a disposable in-line pressure monitor, can prevent intraneural (subepineural) injection using 15 pound per square inch (PSI) as the reference safety threshold.

METHODS

An isolated nerve model with six tibial and six common peroneal nerves from three unembalmed fresh cadavers was used for this observational study. A mixture of 0.5% ropivacaine with methylene blue was injected intraneurally at a rate of 10 mL/min, to a maximum of 3 mL. OIP was recorded for each injection as well as evidence of intraneural contrast. Injected volume at 15 and 20 PSI was recorded, and when it leaked out the epineurium, if it occurred.

RESULTS

In all cases, OIP was<15 PSI and intraneural contrast was evident before the safety threshold. The 15-20 PSI mark was attained in 5 of 12 injections (41%), with a median injected volume of 0.9 mL (range 0.4-2.3 mL). Peak pressure of >20 PSI was reached in two injections (at 0.6 mL and 2.7 mL). Contrast leaked out the epineurium in 11 of 12 injections (91%) with a median injected volume of 0.6 mL (range 0.1-1.3 mL).

CONCLUSIONS

Our results suggest that in-line pressure monitoring may not prevent intraneural injection using an injection pressure of 15 PSI as reference threshold. Due to the preliminary nature of our study, further evidence is needed to demonstrate clinical relevance.