Ultrasound guidance for peripheral nerve blockade

Shedding Light on Perioperative Nerve Injury: An Investigation Using the SHED (Symptoms Categorization-History Taking-Examination-Diagnostic Evaluations) Approach

Peripheral nerve blocks (PNBs) provide analgesia and anesthesia in diverse surgical procedures. Despite their recognized benefits, the occurrence of complications, particularly peripheral nerve injuries (PNIs), is a noteworthy concern. Prompt identification and intervention for perioperative nerve injuries are crucial to prevent permanent neurological impairment. A meticulous, systematic evaluation centered on the onset and progression of symptoms becomes imperative. The SHED (symptoms categorization-history taking-examination-diagnostic evaluations) approach serves as a valuable tool for diagnosing causative factors, determining the type of nerve injury, and formulating an effective treatment plan to mitigate further harm. This case report employs the SHED approach to elucidate a perplexing instance of PNIs. The patient, experiencing neurological symptoms post-forearm surgery under a PNB, serves as a focal point. The report underscores the significance of a systematic, stepwise approach in managing patients with suspected PNIs. Vigilant patient monitoring, collaborative teamwork, shared responsibilities, and consideration of potential contributing factors beyond the nerve block are highlighted for an accurate diagnosis and effective treatment of PNIs. The aim is to guide healthcare professionals in navigating similar clinical scenarios, ultimately ensuring patient safety and optimizing outcomes.

The role of high-resolution ultrasound and MRI in the evaluation of peripheral nerves in the lower extremity

Lower extremity peripheral neuropathy is a commonly encountered neurologic disorder, which can lead to chronic pain, functional disability, and decreased quality of life for a patient. As diagnostic imaging modalities have improved, imaging has started to play an integral role in the detection and characterization of peripheral nerve abnormalities by non-invasively and accurately identifying abnormal nerves as well as potential causes of neuropathy, which ultimately leads to precise and timely treatment. Ultrasound, which has high spatial resolution and can quickly and comfortably characterize peripheral nerves in real time along with associated denervation muscle atrophy, and magnetic resonance neurography, which provides excellent contrast resolution between nerves and other tissues and between pathologic and normal segments of peripheral nerves, in addition to assessing reversible and irreversible muscle denervation changes, are the two mainstay imaging modalities used in peripheral nerve assessment. These two modalities are complimentary, and one may be more useful than the other depending on the nerve and location of pathology. Imaging must be interpreted in the context of available clinical information and other diagnostic studies, such as electrodiagnostic tests. Here, we offer a comprehensive overview of the role of high-resolution ultrasound and magnetic resonance neurography in the evaluation of the peripheral nerves of the lower extremity and their associated neuropathies.

Precision of Ultrasound-Guided versus Anatomical Palpation-Guided Needle Placement of the Ulnar Nerve at the Cubital Tunnel: A Cadaveric Study

Percutaneous electrical stimulation has been performed for years with only the assistance of anatomical landmarks. The development of real-time ultrasonography guidance has improved the precision and safety of these percutaneous interventions. Despite ultrasound-guided and palpation-guided procedures being performed routinely for targeting nerve tissues in the upper extremity, the precision and safety of these techniques are unknown. The aim of this cadaveric study was to determine and compare the precision and safety of ultrasound-guided versus palpation-guided needling procedure with and without the handpiece of the ulnar nerve on a cadaveric model. Five physical therapists performed a series of 20 needle insertion tasks each (n = 100), 10 palpation-guided (n = 50) and 10 ultrasound-guided (n = 50) on cryopreserved specimens. The purpose of the procedure was to place the needle in proximity to the ulnar nerve at the cubital tunnel. The distance to target, time performance, accurate rate, number of passes, and unintentional puncture of surrounding structures were compared. The ultrasound-guided procedure was associated with higher accuracy (66% vs. 96%), lower distance from needle to the target (0.48 ± 1.37 vs. 2.01 ± 2.41 mm), and a lower frequency of perineurium puncture (0% vs. 20%) when compared with the palpation-guided procedure. However, the ultrasound-guided procedure required more time (38.33 ± 23.19 vs. 24.57 ± 17.84 s) than the palpation-guided procedure (all, p < 0.001). Our results support the assumption that ultrasound guidance improves the accuracy of needling procedures on the ulnar nerve at the cubital tunnel when compared with palpation guidance.

Role of regional anesthesia in patients with acute sickle cell pain: A scoping review

Sickle cell disease is the most prevalent inherited blood disorder in the world, with significant morbidity and mortality. Patients often have recurrent painful vaso-occlusive episodes, and the American Society of Hematology gives a conditional recommendation for the use of regional anesthesia for acute sickle cell pain management. This scoping review summarizes the current evidence and identifies gaps for future research. Our screening process is outlined, and articles that mentioned the use of regional anesthesia for acute sickle cell crises were included. We present and interpret our results and highlight opportunities for future investigation.

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.

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

Correlates of post-dural puncture headache and efficacy of different treatment options: a monocentric retrospective study

Background:

Post-dural puncture headache (PDPH) is a severe positional headache that appears usually within 72 hours after inadvertent dural puncture, secondary to cerebrospinal fluid leakage. It is treated first by conservative treatment (including bed rest, hydration, caffeine and simple analgesia) and then by invasive procedures such as blood patch. This study aims to evaluate factors associated with PDPH among a sample of Lebanese patients and assess the rate of success of different treatment modalities administered in a specific sequence: conservative treatment first, then ultrasound-guided bilateral greater occipital nerve block (GONB) if failure of conservative treatment and finally epidural blood patch (EBP) if failure of GONB.

Methods:

A retrospective case–control study was conducted between January 2015 and December 2019 in the Notre-Dame des Secours University Hospital. Out of a total of 10,051 procedures, 18 cases were diagnosed with PDPH and were matched based on gender, age and procedure type to a control group of patients who did not develop PDPH randomly selected (72 patients).

Results:

Higher body mass index (adjusted odds ratio (ORa) = 0.77) was significantly associated with lower odds of PDPH, whereas the presence of previous chronic headache (ORa = 5.56) was significantly associated with higher odds of PDPH. Seven out of 18 (38.89%) had their pain symptoms/headache resolved on conservative treatment. Out of the remaining 11 patients, 6 (33.33%) had their symptoms resolved on GONB with a significant decrease in the pain score 48 hours after GONB compared to baseline (5.55 vs 9.73; p = 0.007). Five patients (27.78%) had their symptoms resolved using a blood patch, with a significant decrease in the pain score after blood patch compared to baseline (3.00 vs 9.80; p = 0.041).

Conclusion:

Our preliminary data suggest that ultrasound-guided GONB is a minimally risky and efficacious technique for those who fail to respond to conservative treatment.

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.

The use of intravenous lidocaine for postoperative pain and recovery: international consensus statement on efficacy and safety

Intravenous lidocaine is used widely for its effect on postoperative pain and recovery but it can be, and has been, fatal when used inappropriately and incorrectly. The risk-benefit ratio of i.v. lidocaine varies with type of surgery and with patient factors such as comorbidity (including pre-existing chronic pain). This consensus statement aims to address three questions. First, does i.v. lidocaine effectively reduce postoperative pain and facilitate recovery? Second, is i.v. lidocaine safe? Third, does the fact that i.v. lidocaine is not licensed for this indication affect its use? We suggest that i.v. lidocaine should be regarded as a 'high-risk' medicine. Individual anaesthetists may feel that, in selected patients, i.v. lidocaine may be beneficial as part of a multimodal peri-operative pain management strategy. This approach should be approved by hospital medication governance systems, and the individual clinical decision should be made with properly informed consent from the patient concerned. If i.v. lidocaine is used, we recommend an initial dose of no more than 1.5 mg.kg^-1 , calculated using the patient's ideal body weight and given as an infusion over 10 min. Thereafter, an infusion of no more than 1.5 mg.kg^-1 .h^-1 for no longer than 24 h is recommended, subject to review and re-assessment. Intravenous lidocaine should not be used at the same time as, or within the period of action of, other local anaesthetic interventions. This includes not starting i.v. lidocaine within 4 h after any nerve block, and not performing any nerve block until 4 h after discontinuing an i.v. lidocaine infusion.

Ultrasound-guided diagnostic deep peroneal nerve blocks prior to potential neurectomy: a retrospective review

OBJECTIVE

To describe our technical and preliminary clinical experience with ultrasound-guided diagnostic deep peroneal nerve (DPN) blocks for patients considering deep peroneal neurectomy.

MATERIALS AND METHODS

Retrospective analysis of ultrasound-guided diagnostic DPN blocks performed in the anterior lower leg in patients pursuing deep peroneal neurectomy for foot pain not directly attributable to the DPN. Patient age, sex, foot laterality, diagnosis, nerve block complications, location of the DPN with respect to vascular landmarks in the lower leg, pain relief from nerve block, and pain relief from neurectomy (if performed) were recorded.

RESULTS

Twenty-six DPN blocks were performed for 25 feet, of which a majority had pain attributable to midfoot osteoarthritis (22/25). Variable DPN locations with respect to vascular landmarks in the lower leg were observed, including lateral to the anterior tibial artery (12/25), anterior to the artery (5/25), medial to the artery (3/25), lateral to the lateral paired vein (4/25), and 1-cm lateral to the artery (1/25). After DPN blocks, patients reported pain relief in 22/25 feet. Of the eleven patients who proceeded to have a deep peroneal neurectomy, ten reported improved foot pain.

CONCLUSION

Diagnostic deep peroneal nerve blocks for patients considering deep peroneal neurectomy for denervation therapy should be performed in the anterior lower leg where the anterior tibial vessels serve as anatomic landmarks. Those who perform DPN blocks with ultrasound guidance should be aware of variable DPN position with respect to the vascular landmarks.

Pain Management for Orthopedic Injuries

Pain management in acute orthopedic injury needs to be tailored to the presentation and patient. Subjective and objective assessment, in conjunction with pathophysiology, should be used to provide symptom control. Ideally, treatment should be administered in an escalating fashion, attempting to manage pain with the lowest dose of the safest medication available. There are also adjunctive therapies, including those that are nonpharmacologic, that can provide additional relief.

Anesthesia during deployment of a military forward surgical unit in low income countries: A register study of 1547 anesthesia cases

BACKGROUND

Military anesthesia meets unique logistical, technical, tactical, and human constraints, but to date limited data have been published on anesthesia management during military operations.

OBJECTIVE

This study aimed to describe and analyze French anesthetic activity in a deployed military setting.

METHODS

Between October 2015 and February 2018, all patients managed by Sainte-Anne Military Hospital anesthesiologists deployed in mission were included. Anesthesia management was described and compared with the same surgical procedures in France performed by the same anesthesia team (hernia repair, lower and upper limb surgeries). Demographics, type of surgical procedure, and surgical activity were also described. The primary endpoint was to describe anesthesia management during the deployment of forward surgical teams (FST). The secondary endpoint was to compare anesthesia modalities during FST deployment with those usually used in a military teaching hospital.

RESULTS

During the study period, 1547 instances of anesthesia were performed by 11 anesthesiologists during 20 missions, totaling 1237 days of deployment in nine different theaters. The majority consisted of regional anesthesia, alone (43.5%) or associated with general anesthesia (21%). Compared with France, there was a statistically significant increase in the use of regional anesthesia in hernia repair, lower and upper limb surgeries during deployment. The majority of patients were civilians as part of medical support to populations.

CONCLUSION

In the context of an austere environment, the use of regional anesthesia techniques predominated when possible. These results show that the training of military anesthetists must be complete, including anesthesia, intensive care, pediatrics, and regional anesthesia.

Efficacy of bilateral greater occipital nerve block in postdural puncture headache: a narrative review

The Epidural blood patch is considered the gold standard for managing postdural puncture headache when supportive measures fail. However, it is a procedure which can lead to another inadvertent dural puncture. Other potential adverse events that could occur during a blood patch are meningitis, neurological deficits, and unconsciousness. The bilateral greater occipital nerve block has been used for treating chronic headaches in patients with PDPH with a single injection. This minimally invasive, simple procedure can be considered for patients early, along with other supportive treatment, and an epidural blood patch can be avoided.

Efficacy of two injection-site localisation techniques for botulinum toxin injections: a single-blind, crossover, randomised trial protocol among adults with hemiplegia due to stroke

INTRODUCTION

Botulinum toxin injections are an effective treatment for limb spasticity following stroke. Different tracking techniques are used for this purpose: palpation, electrostimulation, electromyography and ultrasound. Yet very few studies have compared these different techniques, and none has successfully proved the superior efficacy of ultrasound-guided injections compared to another tracking method. The primary objective of our study was therefore to compare the efficacy of botulinum toxin injections depending on the tracking technique used: ultrasound versus electrostimulation.

METHODS AND ANALYSIS

This is a clinical, single-centre, prospective, interventional, single-blind, crossover, randomised trial. In total, 30 patients aged between 18 and 80 years presenting with triceps surae spasticity (evaluated >1 on the modified Ashworth scale) associated with hemiplegia sequelae due to stroke will be included. The patients will be selected among those who attend for consultation the Physical Medicine and Rehabilitation Department of the Clermont-Ferrand University Hospital. One group will receive the abobotulinumtoxinA (BoNT-A) injection guided by electrostimulation then ultrasound, and the second group's botulinum toxin injections will be guided by ultrasound then electrostimulation. For each patient, the duration of study participation is 5 months. The primary end point is variation in passive ankle dorsiflexion range of motion at slow and high speeds (Tardieu scale) with the knee straight.

ETHICS AND DISSEMINATION

This study received ethics approval form the CPP of Rhônes-Alpes region. Results will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT01935544; pre-results.

Regional Anesthesia for Painful Injuries after Disasters (RAPID): study protocol for a randomized controlled trial

Background

Lower extremity trauma during earthquakes accounts for the largest burden of disaster-related injuries. Insufficient pain management is common in resource-limited disaster settings, and regional anesthesia (RA) may reduce pain in injured patients beyond current standards of care. To date, no controlled trials have been conducted to evaluate the use of RA for pain management in a disaster setting.

Methods/design

The Regional Anesthesia for Painful Injuries after Disasters (RAPID) study aims to evaluate whether regional anesthesia (RA), either with or without ultrasound (US) guidance, can reduce pain from earthquake-related lower limb injuries in a disaster setting. The proposed study is a blinded, randomized controlled equivalence trial among earthquake victims with serious lower extremity injuries in a resource-limited setting. After obtaining informed consent, study participants will be randomized in a 1:1:1 allocation to either: standard care (parenteral morphine at 0.1 mg/kg); standard care plus a landmark-guided fascia iliaca compartment block (FICB); or standard care plus an US-guided femoral nerve block. General practice humanitarian response providers who have undergone a focused training in RA will perform nerve blocks with 20 ml 0.5 % levobupivacaine. US sham activities will be used in the standard care and FICB arms and a normal saline injection will be given to the control group to blind both participants and nonresearch team providers. The primary outcome measure will be the summed pain intensity difference calculated using a standard 11-point Numerical Rating Scale reported by patients over 24 h of follow-up. Secondary outcome measures will include overall analgesic requirements, adverse events, and participant satisfaction.

Discussion

Given the high burden of lower extremity injuries in the aftermath of earthquakes and the currently limited treatment options, research into adjuvant interventions for pain management of these injuries is necessary. While anecdotal reports on the use of RA for patients injured during earthquakes exist, no controlled studies have been undertaken. If demonstrated to be effective in a disaster setting, RA has the potential to significantly assist in reducing both acute suffering and long-term complications for survivors of earthquake trauma.

Trial registration

ClinicalTrials.gov (NCT02698228), registered on 16 February 2016.

Ultrasound-guided alcohol neurolysis of lateral femoral cutaneous nerve for intractable meralgia paresthetica: a case series

Meralgia paresthetica is a rare sensory entrapment neuropathy which leads to burning, tingling and numbness in the antero-lateral aspect of thigh. Mostly it runs a benign course, and responds to conservative measures. We present a case series of six patients with intractable meralgia paresthetica with severe pain over antero-lateral thigh along the distribution of lateral cutaneous nerve of thigh which was further confirmed by nerve conduction study. These patients did not respond to the oral anti-neuropathic medications. The two successive diagnostic lateral femoral cutaneous nerve block not only had confirmed the diagnosis but also provided pain relief for a few days. Then the ultrasound-guided lateral femoral cutaneous nerve neurolysis was done using 50% alcohol. In all the patients, there were more than 50% decrease in pain intensity and improvement in quality of life after the procedure, and the relief and improvement were maintained for up to 12 weeks. This case series shows ultrasound-guided lateral femoral cutaneous nerve neurolysis is a safe and effective treatment for intractable meralgia paresthetica and also provides prolonged pain relief and is a good option in avoiding the surgery. Summary points The literature on neurolysis is rare, with only few case reports. This is the first case series on this topic, and it will greatly improve the evidence that ultrasound-guided neurolysis can also be used for intractable meralgia paresthetica patients who do not respond to conservative measures before proceeding to surgery.

Update in Musculoskeletal Ultrasound Research

CONTEXT

Musculoskeletal ultrasound (US) research is expanding due to increased clinical utility of sonography.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Ultrasound is widely applied in musculoskeletal imaging and sports medicine. The real-time capabilities and favorable cost profile of US make it ideal for use in diagnosis of musculoskeletal conditions. The enthusiasm for the use of US in musculoskeletal imaging has led to an increase in US research to broaden its applications.

CONCLUSION

Several recent advances have been made in conventional and novel US imaging techniques, quantitative US imaging, and US-guided interventions.

STRENGTH OF RECOMMENDATIONS TAXONOMY SORT

C.

The future of regional anesthesia education: lessons learned from the surgical specialty

PURPOSE

Application of ultrasound in regional anesthesia has now become the standard of care and its use has shown to reduce complications. Nevertheless, gaining expertise in ultrasound-guided regional anesthesia requires the acquisition of new cognitive and technical skills. In addition, due to a reduction in resident working hours and enforcement of labour laws and directives across various states and countries, trainees perform and witness fewer procedures. Together, these issues create challenges in the teaching and learning of ultrasound-guided regional anesthesia in the time-based model of learning.

PRINCIPAL FINDINGS

The challenges of teaching ultrasound-guided regional anesthesia are similar to those experienced by our surgical counterparts with the advent of minimally invasive surgery. In order to overcome these challenges, our surgical colleagues used theories of surgical skills training, simulation, and the concept of deliberate practice and feedback to shift the paradigm of learning from experience-based to competency-based learning.

CONCLUSION

In this narrative review, we describe the theory behind the evolution of surgical skills training. We also outline how we can apply these learning theories and simulation models to a competency-based curriculum for training in ultrasound-guided regional anesthesia.

The use of ultrasound guidance for perioperative neuraxial and peripheral nerve blocks in children

BACKGROUND

The use of ultrasound guidance for regional anaesthesia has become popular over the past two decades. However, it is not recognized by all experts as an essential tool. The cost of an ultrasound machine is substantially higher than the cost of other tools such as a nerve stimulator.

OBJECTIVES

To determine whether ultrasound guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of increasing the success rate or decreasing the rate of complications.

SEARCH METHODS

We searched the following databases to March 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), EMBASE (OvidSP) and Scopus (from inception to 27 January 2015).

SELECTION CRITERIA

We included all parallel randomized controlled trials (RCTs) that evaluated the effects of ultrasound guidance used when a regional blockade technique was performed in children, and that included any of our selected outcomes.

DATA COLLECTION AND ANALYSIS

We assessed selected studies for risk of bias by using the assessment tool of The Cochrane Collaboration. Two review authors independently extracted data. We graded the level of evidence for each outcome according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) Working Group scale.

MAIN RESULTS

We included 20 studies (1241 participants) for which the source of funding was a government organization (two studies), a charitable organization (one study), an institutional department (four studies) or an unspecified source (11 studies); two studies declared that they received help from the industry (equipment loan). In 14 studies (939 participants), ultrasound guidance increased the success rate by decreasing the occurrence of a failed block: risk difference (RD) -0.11 (95% confidence interval (CI) -0.17 to -0.05); I(2) = 64%; number needed for additional beneficial outcome for a peripheral nerve block (NNTB) 6 (95% CI 5 to 8). Blocks were performed under general anaesthesia (usual clinical practice in this population); therefore, haemodynamic changes to the surgical stimulus (rather than classic sensory/motor blockade evaluation) were used to define success. For peripheral nerve blocks, the younger the child, the greater was the benefit. In eight studies (414 participants), pain scores at one hour in the post-anaesthesia care unit were reduced when ultrasound guidance was used; however, the clinical relevance of the difference was unclear (equivalent to -0.2 on a scale from 0 to 10). In eight studies (358 participants), block duration was longer when ultrasound guidance was used: standardized mean difference (SMD) 1.21 (95% CI 0.76 to 1.65; I(2) = 73%; equivalent to 62 minutes). Here again, younger children benefited most from ultrasound guidance. Time to perform the procedure was reduced when ultrasound guidance was used for pre-scanning before a neuraxial block (SMD -1.97, 95% CI -2.41 to -1.54; I(2) = 0%; equivalent to 2.4 minutes; two studies with 122 participants) or as an out-of-plane technique (SMD -0.68, 95% CI -0.96 to -0.40; I(2) = 0%; equivalent to 94 seconds; two studies with 204 participants). In two studies (122 participants), ultrasound guidance reduced the number of needle passes required to perform the block (SMD -0.90, 95% CI -1.27 to -0.52; I(2) = 0%; equivalent to 0.6 needle pass per participant). For two studies (204 participants), we could not demonstrate a difference in the incidence of bloody puncture when ultrasound guidance was used for neuraxial blockade, but we found that the number of participants was well below the optimal information size (RD -0.07, 95% CI -0.19 to 0.04). No major complications were reported for any of the 1241 participants. We rated the quality of evidence as high for success, pain scores at one hour, block duration, time to perform the block and number of needle passes. We rated the quality of evidence as low for bloody punctures.

AUTHORS' CONCLUSIONS

Ultrasound guidance seems advantageous, particularly in young children, for whom it improves the success rate and increases the block duration. Additional data are required before conclusions can be drawn on the effect of ultrasound guidance in reducing the rate of bloody puncture.

Nerve detection with optical spectroscopy for regional anesthesia procedures

Background

Regional anesthesia has several advantages over general anesthesia but requires accurate needle placement to be effective. To achieve accurate placement, a needle equipped with optical fibers that allows tissue discrimination at the needle tip based on optical spectroscopy is proposed. This study investigates the sensitivity and specificity with which this optical needle can discriminate nerves from the surrounding tissues making use of different classification methods.

Methods

Diffuse reflectance spectra were acquired from 1563 different locations from 19 human cadavers in the wavelength range of 400–1710 nm; measured tissue types included fascicular tissue of the nerve, muscle, sliding fat and subcutaneous fat. Physiological parameters of the tissues were derived from the measured spectra and part of the data was directly compared to histology. Various classification methods were then applied to the derived parameter dataset to determine the accuracy with which fascicular tissue of the nerve can be discriminated from the surrounding tissues.

Results

From the parameters determined from the measured spectra of the various tissues surrounding the nerve, fat content, blood content, beta-carotene content and scattering were most distinctive when comparing fascicular and non-fascicular tissue. Support Vector Machine classification with a combination of feature selections performed best in discriminating fascicular nerve tissue from the surrounding tissues with a sensitivity and specificity around 90 %.

Conclusions

This study showed that spectral tissue sensing, based on diffuse reflectance spectroscopy at the needle tip, is a promising technique to discriminate fascicular tissue of the nerve from the surrounding tissues. The technique may therefore improve accurate needle placement near the nerve which is necessary for effective nerve blocks in regional anesthesia.

Ultrasound guidance for upper and lower limb blocks

BACKGROUND

Peripheral nerve blocks can be performed using ultrasound guidance. It is not yet clear whether this method of nerve location has benefits over other existing methods. This review was originally published in 2009 and was updated in 2014.

OBJECTIVES

The objective of this review was to assess whether the use of ultrasound to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. Specifically, we have asked whether the use of ultrasound guidance:1. improves success rates and effectiveness of regional anaesthetic blocks, by increasing the number of blocks that are assessed as adequate2. reduces the complications, such as cardiorespiratory arrest, pneumothorax or vascular puncture, associated with the performance of regional anaesthetic blocks

SEARCH METHODS

In the 2014 update we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (July 2008 to August 2014); EMBASE (July 2008 to August 2014); ISI Web of Science (2008 to April 2013); CINAHL (July 2014); and LILACS (July 2008 to August 2014). We completed forward and backward citation and clinical trials register searches.The original search was to July 2008. We reran the search in May 2015. We have added 11 potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate them into the formal review findings during future review updates.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing ultrasound-guided peripheral nerve block of the upper and lower limbs, alone or combined, with at least one other method of nerve location. In the 2014 update, we excluded studies that had given general anaesthetic, spinal, epidural or other nerve blocks to all participants, as well as those measuring the minimum effective dose of anaesthetic drug. This resulted in the exclusion of five studies from the original review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We used standard Cochrane methodological procedures, including an assessment of risk of bias and degree of practitioner experience for all studies.

MAIN RESULTS

We included 32 RCTs with 2844 adult participants. Twenty-six assessed upper-limb and six assessed lower-limb blocks. Seventeen compared ultrasound with peripheral nerve stimulation (PNS), and nine compared ultrasound combined with nerve stimulation (US + NS) against PNS alone. Two studies compared ultrasound with anatomical landmark technique, one with a transarterial approach, and three were three-arm designs that included US, US + PNS and PNS.There were variations in the quality of evidence, with a lack of detail in many of the studies to judge whether randomization, allocation concealment and blinding of outcome assessors was sufficient. It was not possible to blind practitioners and there was therefore a high risk of performance bias across all studies, leading us to downgrade the evidence for study limitations using GRADE. There was insufficient detail on the experience and expertise of practitioners and whether experience was equivalent between intervention and control.We performed meta-analysis for our main outcomes. We found that ultrasound guidance produces superior peripheral nerve block success rates, with more blocks being assessed as sufficient for surgery following sensory or motor testing (Mantel-Haenszel (M-H) odds ratio (OR), fixed-effect 2.94 (95% confidence interval (CI) 2.14 to 4.04); 1346 participants), and fewer blocks requiring supplementation or conversion to general anaesthetic (M-H OR, fixed-effect 0.28 (95% CI 0.20 to 0.39); 1807 participants) compared with the use of PNS, anatomical landmark techniques or a transarterial approach. We were not concerned by risks of indirectness, imprecision or inconsistency for these outcomes and used GRADE to assess these outcomes as being of moderate quality. Results were similarly advantageous for studies comparing US + PNS with NS alone for the above outcomes (M-H OR, fixed-effect 3.33 (95% CI 2.13 to 5.20); 719 participants, and M-H OR, fixed-effect 0.34 (95% CI 0.21 to 0.56); 712 participants respectively). There were lower incidences of paraesthesia in both the ultrasound comparison groups (M-H OR, fixed-effect 0.42 (95% CI 0.23 to 0.76); 471 participants, and M-H OR, fixed-effect 0.97 (95% CI 0.30 to 3.12); 178 participants respectively) and lower incidences of vascular puncture in both groups (M-H OR, fixed-effect 0.19 (95% CI 0.07 to 0.57); 387 participants, and M-H OR, fixed-effect 0.22 (95% CI 0.05 to 0.90); 143 participants). There were fewer studies for these outcomes and we therefore downgraded both for imprecision and paraesthesia for potential publication bias. This gave an overall GRADE assessment of very low and low for these two outcomes respectively. Our analysis showed that it took less time to perform nerve blocks in the ultrasound group (mean difference (MD), IV, fixed-effect -1.06 (95% CI -1.41 to -0.72); 690 participants) but more time to perform the block when ultrasound was combined with a PNS technique (MD, IV, fixed-effect 0.76 (95% CI 0.55 to 0.98); 587 participants). With high levels of unexplained statistical heterogeneity, we graded this outcome as very low quality. We did not combine data for other outcomes as study results had been reported using differing scales or with a combination of mean and median data, but our interpretation of individual study data favoured ultrasound for a reduction in other minor complications and reduction in onset time of block and number of attempts to perform block.

AUTHORS' CONCLUSIONS

There is evidence that peripheral nerve blocks performed by ultrasound guidance alone, or in combination with PNS, are superior in terms of improved sensory and motor block, reduced need for supplementation and fewer minor complications reported. Using ultrasound alone shortens performance time when compared with nerve stimulation, but when used in combination with PNS it increases performance time.We were unable to determine whether these findings reflect the use of ultrasound in experienced hands and it was beyond the scope of this review to consider the learning curve associated with peripheral nerve blocks by ultrasound technique compared with other methods.

Ultrasound guidance for upper and lower limb blocks

BACKGROUND

Peripheral nerve blocks can be performed using ultrasound guidance. It is not yet clear whether this method of nerve location has benefits over other existing methods. This review was originally published in 2009 and was updated in 2014.

OBJECTIVES

The objective of this review was to assess whether the use of ultrasound to guide peripheral nerve blockade has any advantages over other methods of peripheral nerve location. Specifically, we have asked whether the use of ultrasound guidance:1. improves success rates and effectiveness of regional anaesthetic blocks, by increasing the number of blocks that are assessed as adequate2. reduces the complications, such as cardiorespiratory arrest, pneumothorax or vascular puncture, associated with the performance of regional anaesthetic blocks

SEARCH METHODS

In the 2014 update we searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (July 2008 to August 2014); EMBASE (July 2008 to August 2014); ISI Web of Science (2008 to April 2013); CINAHL (July 2014); and LILACS (July 2008 to August 2014). We completed forward and backward citation and clinical trials register searches.The original search was to July 2008. We reran the search in May 2015. We have added 11 potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate them into the formal review findings during future review updates.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing ultrasound-guided peripheral nerve block of the upper and lower limbs, alone or combined, with at least one other method of nerve location. In the 2014 update, we excluded studies that had given general anaesthetic, spinal, epidural or other nerve blocks to all participants, as well as those measuring the minimum effective dose of anaesthetic drug. This resulted in the exclusion of five studies from the original review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We used standard Cochrane methodological procedures, including an assessment of risk of bias and degree of practitioner experience for all studies.

MAIN RESULTS

We included 32 RCTs with 2844 adult participants. Twenty-six assessed upper-limb and six assessed lower-limb blocks. Seventeen compared ultrasound with peripheral nerve stimulation (PNS), and nine compared ultrasound combined with nerve stimulation (US + NS) against PNS alone. Two studies compared ultrasound with anatomical landmark technique, one with a transarterial approach, and three were three-arm designs that included US, US + PNS and PNS.There were variations in the quality of evidence, with a lack of detail in many of the studies to judge whether randomization, allocation concealment and blinding of outcome assessors was sufficient. It was not possible to blind practitioners and there was therefore a high risk of performance bias across all studies, leading us to downgrade the evidence for study limitations using GRADE. There was insufficient detail on the experience and expertise of practitioners and whether experience was equivalent between intervention and control.We performed meta-analysis for our main outcomes. We found that ultrasound guidance produces superior peripheral nerve block success rates, with more blocks being assessed as sufficient for surgery following sensory or motor testing (Mantel-Haenszel (M-H) odds ratio (OR), fixed-effect 2.94 (95% confidence interval (CI) 2.14 to 4.04); 1346 participants), and fewer blocks requiring supplementation or conversion to general anaesthetic (M-H OR, fixed-effect 0.28 (95% CI 0.20 to 0.39); 1807 participants) compared with the use of PNS, anatomical landmark techniques or a transarterial approach. We were not concerned by risks of indirectness, imprecision or inconsistency for these outcomes and used GRADE to assess these outcomes as being of moderate quality. Results were similarly advantageous for studies comparing US + PNS with NS alone for the above outcomes (M-H OR, fixed-effect 3.33 (95% CI 2.13 to 5.20); 719 participants, and M-H OR, fixed-effect 0.34 (95% CI 0.21 to 0.56); 712 participants respectively). There were lower incidences of paraesthesia in both the ultrasound comparison groups (M-H OR, fixed-effect 0.42 (95% CI 0.23 to 0.76); 471 participants, and M-H OR, fixed-effect 0.97 (95% CI 0.30 to 3.12); 178 participants respectively) and lower incidences of vascular puncture in both groups (M-H OR, fixed-effect 0.19 (95% CI 0.07 to 0.57); 387 participants, and M-H OR, fixed-effect 0.22 (95% CI 0.05 to 0.90); 143 participants). There were fewer studies for these outcomes and we therefore downgraded both for imprecision and paraesthesia for potential publication bias. This gave an overall GRADE assessment of very low and low for these two outcomes respectively. Our analysis showed that it took less time to perform nerve blocks in the ultrasound group (mean difference (MD), IV, fixed-effect -1.06 (95% CI -1.41 to -0.72); 690 participants) but more time to perform the block when ultrasound was combined with a PNS technique (MD, IV, fixed-effect 0.76 (95% CI 0.55 to 0.98); 587 participants). With high levels of unexplained statistical heterogeneity, we graded this outcome as very low quality. We did not combine data for other outcomes as study results had been reported using differing scales or with a combination of mean and median data, but our interpretation of individual study data favoured ultrasound for a reduction in other minor complications and reduction in onset time of block and number of attempts to perform block.

AUTHORS' CONCLUSIONS

There is evidence that peripheral nerve blocks performed by ultrasound guidance alone, or in combination with PNS, are superior in terms of improved sensory and motor block, reduced need for supplementation and fewer minor complications reported. Using ultrasound alone shortens performance time when compared with nerve stimulation, but when used in combination with PNS it increases performance time.We were unable to determine whether these findings reflect the use of ultrasound in experienced hands and it was beyond the scope of this review to consider the learning curve associated with peripheral nerve blocks by ultrasound technique compared with other methods.

Advanced ultrasound procedures

Ultrasound guidance has become the standard of care for many bedside procedures, owing to its portability, ease of use, and significant reduction in complications. This article serves as an introduction to the use of ultrasonography in several advanced procedures, including pericardiocentesis, thoracentesis, paracentesis, lumbar puncture, regional anesthesia, and peritonsillar abscess drainage.

Starting with ultrasonography decreases popliteal block performance time in inexperienced hands: a prospective randomized study

Background

The widespread of hallux valgus surgery in a day care setting enhanced the role of regional anaesthesia in the last few years. Sciatic nerve block at popliteal fossa has been shown to provide safe and effective analgesia. Our purpose was to compare the success rate and performance time of popliteal block during resident’s training for regional anaesthesia by using nerve stimulation (NS) or combined nerve stimulation and ultrasound (NS + US).

Methods

70 adult patients undergoing hallux valgus surgery were randomly assigned to receive sciatic nerve block at popliteal fossa with US+NS or NS alone with a double injection technique for peroneal and tibial branches, respectively. Two residents experienced with nerve stimulator performed the procedures after a learning phase concerning ultrasonography. A local anaesthetic solution, containing 10 mL of 0.75% ropivacaine and 10 mL of 2% lidocaine was used: 12 mL were infiltrated close the tibial nerve, and 8mL were infiltrated close the common peroneal nerve. Block success rate, sensory block onset time, block performance time were evaluated. Recourse to general anaesthesia was considered as failure.

Results

No differences were detected in success rate and onset time of sensory block between the two groups (P > 0.05). The time to block tibial nerve and the overall block time were significantly faster in US+NS group (P < 0.05).

Conclusions

Ultrasound guidance for popliteal nerve block resulted in similar success rate with a faster procedure time when compared with nerve stimulator, thus providing a possible effect on resident education and operating room efficiency.

Dual guidance improves needle tip placement for peripheral nerve blocks in a porcine model

BACKGROUND

The objective of the study was to evaluate whether the use of ultrasound (US) together with nerve stimulation (USNST) provides a better needle tip position for performing peripheral regional anaesthesia than the use of US or nerve stimulation (NST) alone.

METHODS

Needle placements were applied at the brachial plexus and sciatic nerves in 32 anaesthetised pigs. Following needle placement near the target nerve, using either the USNST or the US or NST, a volume of 0.3 ml synthetic resin was injected mimicking a 'test-dose' injection. The primary outcome was the incidence of close needle-to-nerve placement assessed by injectate localisation in direct contact with the nerve epineurium. Secondary endpoints were the incidences of intraneural injection and haematoma formation in direct contact with the target nerve.

RESULTS

A total of 611 punctures were performed. The evaluation for the criterion 'close needle placement' revealed significant differences in favour of the USNST group (98.5%) compared with the NST (90.1%) and the US group (81.6%) (P = 0.001). Significant differences were observed regarding 'intraneural needle placement' between the groups as well (USNST, 0.5%; US, 4%; NST, 2.5%; P = 0.034). The incidence of haematoma formation was significantly higher in the NST group (10.8%) than in the US group (2.5%) and in the USNST group (1.5%) (P = 0.001).

CONCLUSION

These findings suggest that the USNST approach combines the benefits of the US and the NST techniques in terms of a higher rate of close needle tip placements and a lower incidence of haematoma formation.

Lipid emulsion for local anesthetic systemic toxicity

The accidental overdose of local anesthetics may prove fatal. The commonly used amide local anesthetics have varying adverse effects on the myocardium, and beyond a certain dose all are capable of causing death. Local anesthetics are the most frequently used drugs amongst anesthetists and although uncommon, local anaesthetic systemic toxicity accounts for a high proportion of mortality, with local anaesthetic-induced cardiac arrest particularly resistant to standard resuscitation methods. Over the last decade, there has been convincing evidence of intravenous lipid emulsions as a rescue in local anesthetic-cardiotoxicity, and anesthetic organisations, over the globe have developed guidelines on the use of this drug. Despite this, awareness amongst practitioners appears to be lacking. All who use local anesthetics in their practice should have an appreciation of patients at high risk of toxicity, early symptoms and signs of toxicity, preventative measures when using local anesthetics, and the initial management of systemic toxicity with intravenous lipid emulsion. In this paper we intend to discuss the pharmacology and pathophysiology of local anesthetics and toxicity, and the rationale for lipid emulsion therapy.

[Perioperative pain management in major reconstructive surgery in pediatric urology: a plea for continuous epidural anesthesia]

Regional analgesia is firmly established in modern pediatric anesthetic practice and its popularity continues to grow. In our department continuous epidural anesthesia (CEA) is a frequently used technique of pain management following major reconstructive procedures of the lower urinary tract. The aim of this study was to investigate the efficacy, safety, and potential benefits of CEA over standard analgesics.We retrospectively reviewed the records of 21 infants who underwent single-stage bladder exstrophy repair in our department. In 15 children an epidural catheter was placed preoperatively for CEA; 6 patients treated without CEA served as controls. Total doses of narcotics and analgesics, length of intensive care unit (ICU) stay and ventilatory assistance, time to first bowel activity, anticholinergic requirements, and CEA-related side effects were documented and compared for both groups.Children given epidural anesthesia required six- to tenfold lower doses of morphine intra- and postoperatively compared to those without CEA; ventilatory support upon completion of surgery was remarkably shorter (59 versus 210 min) in the CEA group as well as ICU stay (1.1 versus 1.8 days). The total consumption of anticholinergics was twice as high as in patients without CEA. There were no relevant CEA-related complications.Being a retrospective audit of practice in our institution with a small number of patients, our results are in line with previously published data on CEA in pediatric patients. CEA has been shown to significantly reduce the need for anesthetics and morphine and allows early extubation with all subsequent advantages for a speedy recovery post surgery. Thus, the technique is to be recommended as a safe and efficacious method for pain management following major reconstructive surgery in pediatric urology. Importantly, this type of anesthesia should be performed only by experienced anesthesiologists in institutions where appropriate equipment, staff, and monitoring are available.