Fifteen years of ultrasound guidance in regional anaesthesia: Part 2-recent developments in block techniques

Liposomal Bupivacaine for Peripheral Nerve Blockade: A Randomized, Controlled, Crossover, Triple-blinded Pharmacodynamic Study in Volunteers

BACKGROUND

Little is known about the pharmacodynamic characteristics of liposomal bupivacaine. Hypothesizing that they would not identify pharmacodynamic differences from plain bupivacaine during the initial period after administration, but would find better long-term pharmacodynamic characteristics, the authors designed a randomized, controlled, triple-blinded, single-center study in volunteers.

METHODS

Volunteers aged 18 to 55 yr (body mass index, 18 to 35 kg/m2) received two ulnar nerve blocks under ultrasound guidance. Using a crossover design with a washout phase of 36 days or more, one block was performed with liposomal and one with plain bupivacaine. Which came first was determined by randomization. Sensory data were collected by pinprick testing and motor data by thumb adduction, either way in comparison with the contralateral arm. Endpoints included success, time to onset, and duration of blockade. Residual efficacy was assessed by the volunteers keeping a diary. Statistical analysis included Wilcoxon signed-rank and exact McNemar's tests, as well as a generalized estimation equation model.

RESULTS

Successful sensory blockade was noted in 8 of 25 volunteers (32%) after liposomal and in 25 of 25 (100%) after plain bupivacaine (P < 0.0001). Significant differences emerged for time to onset, defined as 0% response to pinpricking in four of five hypothenar supply areas (P < 0.0001), and for time from onset to 80% or 20% in one of five areas (P < 0.001; P < 0.001). Carryover effects due to the randomized sequencing were unlikely (estimate, -0.6286; sequence effect, 0.8772; P = 0.474). Self-assessment greater than 3.5 days did reveal, for liposomal bupivacaine only, intermittent but unpredictable episodes of residual sensory blockade.

CONCLUSIONS

The results show that liposomal bupivacaine is not a suitable "sole" drug for intraoperative regional anesthesia. Findings of its limited long-term efficacy add to existing evidence that a moderate effect, at best, should be expected on postoperative pain therapy.

EDITOR’S PERSPECTIVE

Use of Peripheral Nerve Blocks for Total hip Arthroplasty

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent literature regarding regional anesthesia (RA) techniques and outcomes for total hip arthroplasty (THA) in the face of changing surgical techniques and perioperative considerations.

RECENT FINDINGS

Based on large meta-analyses, peripheral nerve blocks are indicated for THA. Each block has its own risks and benefits and data for outcomes for particular techniques are limited. New surgical techniques, improved use of multimodal analgesia, and improved ultrasound guided regional anesthetics lead to better pain control for patients undergoing THA with less associated risks. Block selection continues to be influenced by provider comfort, surgical approach, patient anatomy, and postoperative goals. Head-to-head studies of particular nerve blocks are warranted.

The impact of biological sex in peripheral nerve blockade: A prospective pharmacodynamic, pharmacokinetic and morphometric study in volunteers

STUDY OBJECTIVE

The impact of biological sex in peripheral regional anaesthesia is largely unknown. We therefore designed a prospective study in volunteers to investigate the impact of biological sex on pharmacodynamic, pharmacokinetic and morphometric characteristics for peripheral nerve blockade.

METHODS

The initial study plan was powered to include 90 volunteers to find a difference of 35 min in duration of sensory block (primary outcome variable) with 80% power and alpha error at 5%. After discussions in ethical review, a pilot study of 2 x 12 volunteers from each sex were studied. Female and male volunteers received ultrasound guided nerve blockade with 3.0 mL ropivacaine 7.5 mg mL-1. Sensory duration of blockade, as the primary outcome, was evaluated by pinprick testing. Secondary outcomes were sensory onset time of blockade, pharmacokinetic characteristics and the visibility of ulnar nerves using ultrasound. Analyses included Mann-Whitney U-statistics with P<0.05 (two-sided) as significant.

RESULTS

After 24 participants, the median (IQR) duration of sensory blockade was 450 (420; 503) min in women and 480 (450; 510) min in men (P = 0.49). Sensory onset time of blockade, and ultrasound visibility of nerves were also similar between the study groups. The total drug exposure across time (AUC0-infinity) was significantly higher in women (P = 0.017). After a the planned power re-analysis after these 24 study paticipants, which suggested that > 400 subjects would be required with 80% power and alpha error of 5% to find significance for the primary outcome parameter for marginal differences, we terminated the study at this point.

CONCLUSIONS

We did not detect significant differences between female and male study participants in terms of pharmacodynamic and morphometric characteristics after ultrasound guided ulnar nerve blocks. Women did show significantly greater pharmacokinetic ropivacaine exposures. The results of this study indicate that peripheral regional block pharmacodynamic characteristics are independent of the biological sex, whereas pharmacokinetic parameters are sex-dependent.

Brachial plexus block using only 1% lidocaine to reduce pain during the endovascular treatment of dysfunctional arteriovenous access

BACKGROUND

Interventional endovascular treatments of dysfunctional arteriovenous (AV) access for hemodialysis can cause pain and discomfort to the patients. Ultrasound-guided brachial plexus block (BPB) is an alternative regional anesthesia method, but conventional BPB using ropivacaine or bupivacaine may cause long-lasting motor power loss, significantly reducing patient satisfaction. This study aimed to introduce BPB using only 1% lidocaine, which induces sensory loss while minimizing motor block, and evaluate the efficacy and safety of this procedure.

METHODS

This retrospective study was conducted on 277 consecutive patients with dysfunctional AV access requiring percutaneous transluminal angioplasty (PTA). Of these, 174 patients underwent the BPB procedure using 1% lidocaine. Time data were recorded, and the motor strength grade (MRC scale, grade 0-5) was evaluated. Numeric rating pain score (NRPS, grade 0-10) was asked during every PTA, and overall NRPS and satisfaction scores (scale 1-3) were asked after the procedure was completed.

RESULTS

Of the 174 patients who received BPB, the success rate was 100%, and there were no significant complications related to BPB. The MRC scale measured at the time when the complete sensory loss was achieved was 1.99 ± 0.63, and that at the point of sensory recovery when the block effect expired was 3.93 ± 0.62, indicating a good grade of motor strength. The average NRPS during PTA in the BPB group was significantly lower than that of the control group without BPB (1.04 ± 2.04vs 6.30 ± 2.71, p < 0.001). The overall satisfaction score was significantly higher in the BPB group than in the control group (2.79 ± 0.50vs 2.00 ± 0.81, p < 0.001).

CONCLUSIONS

BPB using only 1% lidocaine can induce a sensory block while minimizing the effect on motor function. It can be applied safely in an outpatient clinic setting with relatively higher satisfaction.

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

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

Augmented reality in ultrasound-guided regional anaesthesia: useful tool or expensive toy?

Use of augmented reality is increasingly applied in medical education and practice. The main advantage of this technology is the display of relevant information in the visual field of multiple operators. Here we provide a critical analysis of the potential application of augmented reality in regional anaesthesia.

Perioperative costs of local or regional anesthesia versus general anesthesia in the outpatient setting: a systematic review of recent literature

BACKGROUND AND OBJECTIVES

In this systematic review, we carried out an assessment of perioperative costs of local or regional anesthesia versus general anesthesia in the ambulatory setting.

METHODS

A systematic literature search was conducted to find relevant data on costs and cost-effectiveness analyses of anesthesia regimens in outpatients, regardless of the medical procedure they underwent. The hypothesis was that local or regional anesthesia has a lower economic impact on hospital costs in the outpatient setting. The primary outcome was the average total cost of anesthesia calculated on perioperative costs (drugs, staff, resources used).

RESULTS

One-thousand-six-hundred-ninety-eight records were retrieved, and 28 articles including 27,581 patients were selected after reviewing the articles. Data on the average total costs of anesthesia and other secondary outcomes (anesthesia time, recovery time, time to home readiness, hospital stay time, complications) were retrieved. Taken together, these findings indicated that local or regional anesthesia is associated with lower average total hospital costs than general anesthesia when performed in the ambulatory setting. Reductions in operating room time and postanesthesia recovery time and a lower hospital stay time may account for this result.

CONCLUSIONS

Despite the limitations of this systematic review, mainly the heterogeneity of the studies and the lack of cost-effectiveness analysis, the economic impact of the anesthesia regimes on healthcare costs appears to be relevant and should be further evaluated.

Magnetic resonance imaging study of the sciatic nerve variation in the pediatric gluteal region: Implications for the posterior approach of the sciatic nerve blockade

INTRODUCTION

In pediatric patients, the sciatic nerve is one of the most commonly blocked peripheral nerves during orthopedic procedures of the lower limb. Ultrasound guidance is the current standard for a successful localization of the sciatic nerve in the gluteal region. Relevant anatomical landmarks are also used to determine the nerve location when ultrasound is not available or inadequate. However, reports have demonstrated paucity of information regarding the sciatic nerve location and variation in the hip throughout pediatric development. This imaging study aimed to document and analyze the relative morphometric relationship of the sciatic nerve in the pediatric gluteal region throughout development.

METHODS

The location of the sciatic nerve in relation to bony landmarks was measured in 84 pediatric magnetic resonance imaging of patients aged 0.7-15.8 years.

RESULTS

The sciatic nerve was identified medial to the most lateral point of greater trochanter at the level of ischial spine and the tip of coccyx. The strong positive correlation between sciatic nerve to landmark distances and age and stature demonstrated linear variation between sciatic nerve location with age and growth of children. To predict the nerve location in the gluteal region, regression equations using patient age were created, having implications for the posterior approach of the sciatic nerve blockade in children. Clinically significant differences were found between sexes, specifically in the older age group.

CONCLUSION

Despite the small sample size of younger age group, this study is the first to document the morphometric changes of the sciatic nerve in the gluteal region across pediatric development and may be useful for providing confirmatory guidelines for nerve location when ultrasound is not accessible or cannot be utilized for practice.

Artificial intelligence using deep neural network learning for automatic location of the interscalene brachial plexus in ultrasound images

BACKGROUND

Identifying the interscalene brachial plexus can be challenging during ultrasound-guided interscalene block.

OBJECTIVE

We hypothesised that an algorithm based on deep learning could locate the interscalene brachial plexus in ultrasound images better than a nonexpert anaesthesiologist, thus possessing the potential to aid anaesthesiologists.

DESIGN

Observational study.

SETTING

A tertiary hospital in Shanghai, China.

PATIENTS

Patients undergoing elective surgery.

INTERVENTIONS

Ultrasound images at the interscalene level were collected from patients. Two independent image datasets were prepared to train and evaluate the deep learning model. Three senior anaesthesiologists who were experts in regional anaesthesia annotated the images. A deep convolutional neural network was developed, trained and optimised to locate the interscalene brachial plexus in the ultrasound images. Expert annotations on the datasets were regarded as an accurate baseline (ground truth). The test dataset was also annotated by five nonexpert anaesthesiologists.

MAIN OUTCOME MEASURES

The primary outcome of the research was the distance between the lateral midpoints of the nerve sheath contours of the model predictions and ground truth.

RESULTS

The data set was obtained from 1126 patients. The training dataset comprised 11 392 images from 1076 patients. The test dataset constituted 100 images from 50 patients. In the test dataset, the median [IQR] distance between the lateral midpoints of the nerve sheath contours of the model predictions and ground truth was 0.8 [0.4 to 2.9] mm: this was significantly shorter than that between nonexpert predictions and ground truth (3.4 mm [2.1 to 4.5] mm; P < 0.001).

CONCLUSION

The proposed model was able to locate the interscalene brachial plexus in ultrasound images more accurately than nonexperts.

TRIAL REGISTRATION

ClinicalTrials.gov (https://clinicaltrials.gov) identifier: NCT04183972.

The median effective analgesic concentration of ropivacaine in ultrasound-guided interscalene brachial plexus block after arthroscopic rotator cuff repair

Background: The median effective analgesic concentration (MEAC) of ropivacaine in interscalene brachial plexus block (ISBPB) for postoperative analgesia after arthroscopic rotator cuff repair (ARCR) has not been determined. Therefore, this study aimed to evaluate the MEAC after ARCR using 10 ml ropivacaine.

Method: This study was conducted on 40 patients with American Society of Anesthesiologists grade I or II who had selective ARCR. The 10 ml ropivacaine was administered for determined, with an initial concentration of 0.3% using up-and-down sequential allocation. After successful or unsuccessful postoperative analgesia, the concentration of ropivacaine was decreased or increased by 0.05% in the next patient. We defined successful postoperative analgesia as a visual analog scale score of <4 at rest within the initial 8 h after ISBPB. The analytic techniques of linear, linear-logarithmic, exponential regressions and centered isotonic regression were used for calculating MEAC. The secondary outcomes was sufentanil consumption, time to 1st rescue analgesic, onset time of sensory block and motor block.

Results: The concentration of ropivacaine administered ranged from 0.1% to 0.35%. The MEAC from the four different methods (linear, linear-logarithmic, exponential regressions and centered isotonic regression) were 0.207% (95% CI, 0.168–0.355%), 0.182% (95% CI, 0.165–0.353%), 0.196% (95% CI, 0.154–0.356%), and 0.163%, respectively. Of the four models, exponential regression had the least residual standard error (0.0990).

Conclusion: The MEAC derived from the four statistical models for 10 ml ropivacaine in ultrasound-guided ISBPB for postoperative analgesia was distributed within a narrow range of 0.163%–0.207%. The exponential regression model calculated by the goodness-of-fit test at a concentration of 0.196% best fits the study data.

Clinical Trial Registration:http://www.chictr.org.cn/showproj.aspx?proj=127449, identifier ChiCTR2100047978

Quadratus lumborum blocks for abdominal transplant surgeries at UPMC Children's Hospital of Pittsburgh-A five year experience

BACKGROUND

Adequate perioperative analgesia for pediatric abdominal transplant surgery is essential for patient recovery. However, the risks of commonly used medications such as hepatotoxicity, nephrotoxicity, bleeding concerns, and poor graft results with opioids limit pain management in this population. Thoracic epidural, continuous erector spinae plane, and type-1 quadratus lumborum blocks (QLBs) have been described and utilized in the adult population in this setting. The safety and benefits of regional anesthetic techniques in pediatrics have been widely documented for different types of procedures except pediatric abdominal transplantation, where data remains scarce. Our primary goal was to determine if QLBs provided adequate perioperative analgesia when part of a multimodal approach. Secondary objectives were to examine complications and effects on the intensive care unit (ICU) and hospital stay.

METHODS

We performed a retrospective, observational study of pediatric patients who underwent abdominal transplant surgeries at the University of Pittsburgh Medical Center Children's Hospital of Pittsburgh from January 2015 to July 2021 and received a single injection QLB for pain control. Data collected included: demographics, nerve block characteristics, perioperative opioid consumption, use of non-opioid analgesia, daily pain scores, and hospital and ICU stay.

RESULTS

Forty-two patients met the inclusion criteria for our study. Our results suggest that QLBs decrease opioid consumption, facilitate early extubation, prevent reintubation in the ICU, and reduce ICU and hospital stay.

CONCLUSIONS

QLB is feasible and can be used as a multimodal approach for postoperative pain control in pediatric solid organ transplantation.

The Amplitude of Diaphragm Compound Muscle Action Potential Correlates With Diaphragmatic Excursion on Ultrasound and Pulmonary Function After Supraclavicular Brachial Plexus Block

Objective

This prospective, double-blind, randomized study assessed (1) the associations between diaphragm compound muscle action potential (CMAP), hemidiaphragmatic excursion, and pulmonary function after supraclavicular brachial plexus block (SCBPB) and (2) diagnostic efficacy of pulmonary function for hemidiaphragmatic paralysis evidenced by diaphragm CMAP as an assessment of diaphragm strength was evaluated.

Methods

Eighty-six patients were scheduled for the removal of hardware after healing of a right upper limb fracture distal to the shoulder who were randomly assigned in a 1:1 ratio to two groups: Group A (diaphragmatic excursion), or Group B (pulmonary function). Phrenic nerve conduction studies (PNCSs), M-mode ultrasonography of the diaphragm, and pulmonary function tests (PFTs) were performed before and 30 min after SCBPB. PNCSs were used to determine the latency and amplitude of diaphragm CMAP. Ultrasonography of the diaphragm was performed with patients in a supine position using a low-frequency probe over the subcostal space at the midclavicular line. The diaphragmatic excursion was measured during quiet breathing and deep breathing. Pulmonary function, i.e., forced vital capacity (FVC), predicted value of FVC, and forced expiratory flow in the first second (FEV1), was measured with spirometry. Receiver Operating Characteristic (ROC) curve analysis was used to assess the diagnostic efficacy of pulmonary function for hemidiaphragmatic paralysis evidenced by diaphragm CMAP as an assessment of diaphragm strength.

Results

There were significant associations between the reduction in amplitude of diaphragm CMAP and reductions in diaphragmatic excursion during quiet breathing (r = 0.70, p < 0.01) and deep breathing (r = 0.63, p < 0.01) when expressed as a percentage of baseline values. There were significant associations between the reduction in amplitude of diaphragm CMAP and reductions in FVC (r = 0.67, p < 0.01), FVC% (r = 0.67, p < 0.01), and FEV1 (r = 0.62, p < 0.01), when expressed as percentage of baseline values. The area under the ROC curve for FVC was 0.86. A decrease of >8.4% in FVC compared to pre-block predicted hemidiaphragmatic paralysis (determined by diaphragm CMAP) with sensitivity and specificity of 79.2 and 100%, respectively.

Conclusions

The relative reduction in diaphragm CMAP amplitude after SCBPB was correlated with relative reductions in diaphragmatic excursion and pulmonary function. FVC has potential as a useful diagnostic indicator of hemidiaphragmatic paralysis, evidenced by diaphragm CMAP, after SCBPB. These data establish diaphragm CMAP as a direct and objective index of diaphragmatic paralysis after SCBPB.

Comparing Blind and Ultrasound-Guided Retrobulbar Nerve Blocks in Equine Cadavers: The Training Effect

Simple Summary

Standing ophthalmic surgeries have become more and more common in horses. For these standing surgeries, the blind retrobulbar block is often used for anesthesia and akinesia of the eye. However, placing a retrobulbar block using this blind technique can lead to complications, for example, penetration of the globe, nerve injury or chemosis due to spreading of the local anesthetic in the region of the globe. For this reason, it might be better to perform the retrobulbar block using guidance by ultrasound. Ultrasound-guided retrobulbar block has only been described twice in the literature using equine cadavers. Comparison of the ultrasound-guided peribulbar technique to the blind technique has only been carried out once. Furthermore, the learning curve of ultrasound-guided retrobulbar nerve block placement has not been evaluated. Our study aimed to compare the blind and ultrasound-guided approaches to retrobulbar block placement in horses and to evaluate the success and complication rates, analyzing the effect of training on ultrasound guidance. A trend towards a significant improvement in accuracy was seen for ultrasound guidance, and larger scale follow-up studies might show a significant training effect on the use of ultrasound in retrobulbar nerve block placement and that the use of ultrasound guidance could be promising.

Abstract

In standing ophthalmic surgery in horses, a retrobulbar nerve block (RNB) is often placed blindly for anesthesia and akinesia. The ultrasound (US)-guided RNB may have fewer complications, but the two techniques have only been compared once in equine cadavers. This study compares the techniques for success and complication rates and analyzes the effect of training on US guidance. Twenty-two equine cadavers were divided into three groups: blind RNBs were performed bilaterally in eight cadavers, US-guided RNBs were performed bilaterally in seven cadavers, and after US-guided training, blind RNBs were performed bilaterally in seven cadavers. All RNBs were performed by the same two inexperienced operators, and a combination of contrast medium (CM; 1.25 mL) and methylene blue dye (1.25 mL) were injected (2.5 mL total volume). Needle positioning in the periorbita and the distance of the CM to the optic foramen were assessed using computerized tomography (CT). Dye spreading was evaluated by dissection. In group 1, 37.5% of the injections were in the optimal central position in the periorbita; in group 2, 75% and in group 3, 71.4%. There was no significant difference between the groups regarding needle position (groups 1 and 2 p = 0.056; groups 1 and 3 p = 0.069, groups 2 and 3 p = 0.8). The mean CM distribution distance was not significantly different between all groups. Group 1 had 18.75% intraocular injections versus 0% in group 2 and 7.1% in group 3 (not significant). US guidance showed no significant increases in accuracy nor decreases in complications. However, the effects on accuracy showed a trend towards significant improvement, and larger scale follow-up studies might show significant training effects on US guidance.

Effect of Different Modes of Administration of Dexmedetomidine Combined with Nerve Block on Postoperative Analgesia in Total Knee Arthroplasty

INTRODUCTION

Dexmedetomidine (DEX) as a nerve block adjuvant can significantly prolong analgesia. However, whether perineural or systemic administration of DEX is more beneficial in patients undergoing total knee arthroplasty (TKA) has not been thoroughly investigated. To this end, we evaluated the effects of perineural and systemic DEX administration on postoperative analgesia in patients undergoing TKA surgery.

METHODS

We randomly assigned patients undergoing TKA under general anesthesia combined with femoral nerve block and sciatic nerve block to one of three groups: (1) ropivacaine plus perineural dexmedetomidine (DP): 0.25% ropivacaine 40 mL plus 0.5 μg/kg dexmedetomidine; (2) ropivacaine plus systemic dexmedetomidine (DS): 0.25% ropivacaine 40 mL plus systemic 0.5 μg/kg dexmedetomidine; (3) control group (C): 0.25% ropivacaine 40 mL.

RESULTS

The average length of time until patients first experienced postoperative pain was significantly longer in the DP group (26.0 h [22.0-30.0 h]) than in the DS group (22.4 h [18-26.8 h]) and the control group (22.9 h [19.5-26.3 h], P = 0.001). For this result there was no significant difference between the DS and the control group. Compared with the DS and control groups, patients in the DP group had lower resting visual analogue scale (VAS) scores at 24, 48, and 72 h after surgery (P < 0.05). VAS activity scores at 12, 24, and 48 h after surgery in the DP group were lower than those in the DS and control groups, with a statistically significant difference (P < 0.05). Compared with the DS and control groups, the amount of postoperative opioids in the DP group was also significantly reduced, and the number of people needing postoperative rescue analgesia was significantly lower, with a statistical difference (P < 0.05). Meanwhile, the sleep satisfaction of patients in the DP group on the first night after surgery and the satisfaction with pain control at 72 h after surgery were both higher than those in the DS group and control group (P < 0.05).

CONCLUSIONS

Perineural administration of DEX can significantly prolong the interval until patients report pain for the first time after TKA, relieve postoperative pain, reduce postoperative opioid dosage, and improve postoperative sleep quality and satisfaction with pain control.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trial Registry, identifier ChiCTR1900025808.

What Is the Minimum Effective Volume of Local Anaesthetic Applied in Brachial Plexus Blockage With an Axillary Approach Under Ultrasonography Guidance?

Peripheral nerve blocks with the use of ultrasonography (USG) allow visualisation of both the structures and nerves and make the block administrations safe, quick, and comfortable. However, few publications concerning the minimum local anesthetic (LA) volume are capable of providing blocks. This study aimed to find the minimum effective LA volume in brachial plexus blockage administrations with an axillary approach accompanied by ultrasonography in hand, elbow, and forehand operations. Materials and Method The study included a total of 55 patients (classified as American Society of Anesthesiologists (ASA) I-II) who underwent hand surgery by administering USG-guided axillary brachial plexus blockage. The ulnar, median, and radial nerves were located, and the minimum effective LA volume was investigated starting with a total of 21 ml of bupivacaine 0.5%. After accomplishing the blockage, the volume was decreased by 0.5 ml for each nerve. Block administration time, block onset times, anesthesia times, and time to first analgesic requirement were recorded. Results The minimum effective LA volume for each nerve was 2.5 ml for a total of 7.5 ml. In comparing block administration times, there were no differences between high or low volume groups. It was found that sensory block onset time was 17 minutes for 7.5 ml and 11 minutes for 21 ml; sensory block regression time was six hours for 7.5 ml and 10.4 hours for 21 ml, respectively. This regression was statistically significant. The first analgesic requirement was 5.8 - 16.6 hours, respectively, for each group. Conclusion In the administration of an USG-guided axillary block, sufficient anesthesia can be achieved by administering 2.5 ml of bupivacaine 0.5% for each nerve. However, it might be kept in mind that motor and sensory block onset time will be extended and regression time and time to the first analgesic requirement will be shorter with this volume. In addition, more advanced studies must be done for the determination of the optimum volume which can be used.

A randomised, non-inferiority study of chloroprocaine 2% and ropivacaine 0.75% in ultrasound-guided axillary block

Chloroprocaine is a short-acting local anaesthetic with a rapid onset of action and an anaesthesia duration up to 60 min. In this pivotal study success rates, onset and remission of motor and sensory block and safety of chloroprocaine 2% was compared to ropivacaine 0.75% for short-duration distal upper limb surgery with successful block rates as primary outcome. The study was designed as a prospective, randomised, multi-centre, active-controlled, double-blind, parallel-group, non-inferiority study, performed in 4 European hospitals with 211 patients scheduled for short duration distal upper limb surgery under axillary plexus block anaesthesia. Patients received either ultrasound guided axillary block with 20 ml chloroprocaine 2%, or with 20 ml ropivacaine 0.75%. Successful block was defined as block without any supplementation in the first 45 min calculated from the time of readiness for surgery. 90.8% patients achieved a successful block with chloroprocaine 2% and 92.9% patients with Ropivacaine 0.75%, thus non-inferiority was demonstrated (10% non inferiority margin; 95% CI − 0.097, 0.039; p = 0.02). Time to onset of block was not significantly different between the groups. Median time to motor and sensory block regression was significantly shorter as was time to home discharge (164 [155–170] min for chloroprocaine versus 380 [209–450] for the ropivacaine group, p < 0.001). For short-duration surgical procedures, the short-acting Chloroprocaine 2% may be used, with success rates non-inferior to ropivacaine and a favourable safety profile.

Trial registration: The trial was registered at Clinicaltrials.gov with registration number NCT02385097 (March 11th, 2015) and European Clinical Trial Database with the EudraCT number 2014-002519-40 (July 7th, 2015, Austria—BASG).

Effects of Different Local Analgesic Techniques on Postoperative Quality of Life and Pain in Patients Undergoing Total Hip Arthroplasty Under General Anesthesia: A Randomized Controlled Trial

Background

Both lumbosacral plexus block (LSPB) and local infiltration analgesia (LIA) can provide postoperative analgesia for patients undergoing total hip arthroplasty (THA). The current study aimed to compare the differences between LSPB and LIA on postoperative pain and quality of life (QoL) in THA patients.

Methods

A total of 117 patients aged 40–80 years, ASA I-III, were prospectively randomized into two groups: a general anesthesia plus LSPB (Group LSPB) and a general anesthesia plus LIA (Group LIA). Pain intensity and opioid consumption were recorded Within 72 hours after surgery. QoL was measured by EQ-5D and EQ-VAS questionnaires, and the incidence of postoperative pain was measured as part of the EQ-5D on day 1, day 3, day 7, and month 1, month 3, and month 6 after surgery.

Results

EQ-5D scores: Mobility, Self-Care, Usual Activities, Pain/Discomfort, and Anxiety/Depression were higher in Group LSPB versus Group LIA throughout six-month follow-ups (p = 0.039). The pain intensity was lower in Group LSPB than in Group LIA 0–12 h after surgery (2.41 vs 2.79, p = 0.01), but was higher in Group LSPB than in Group LIA 12–24 h (2.59 vs 2.05, p = 0.02) and 24–48 h (2.18 vs 1.73, p = 0.02) after surgery. There were no differences in opioid consumption between the groups during the first 72 postoperative hours. In the first month after surgery, more patients in Group LSPB than in Group LIA had no pain (52 vs 40, p = 0.04).

Conclusion

Both LSPB and LIA can provide satisfactory postoperative analgesia. The LSPB is better than LIA for long-term QoL in THA patients undergoing general anesthesia.

Clinical Trial Registration Number

The Chinese Clinical Trial Registry (ChiCTR-INR-17012545).

Comparison of Sevoflurane and Propofol on the Incidence of Postoperative Pain and Quality of Life in Patients Undergoing Total Knee Arthroplasty With Chronic Pain Before Surgery

BACKGROUND

Propofol and sevoflurane as frequently used general anesthetics can affect postoperative pain. Our study explored whether the incidence of postoperative pain differed among patients with chronic pain undergoing total knee arthroplasty (TKA) anesthetized with sevoflurane or propofol.

METHODS

Patients were randomly assigned to groups receiving either sevoflurane (Group S, n = 50) or propofol (Group P, n = 47) for anesthesia maintenance during TKA. The incidences of postoperative pain and quality of life (QoL) were measured using the EuroQol 5-Dimension (EQ-5D) scale at 1, 3, and 7 days post-operation (DPO), and 1 and 3 months post-operation (MPO).

RESULTS

At 3 DPO, fewer patients reported moderate pain (P = 0.001) and more patients reported no pain (P = 0.003) in Group S than that in Group P. At 3 MPO, more patients reported no pain (P = 0.04) and fewer patients reported moderate pain (P = 0.04) in Group S than in Group P. No significant differences were found in the incidence of postoperative pain between the 2 groups of patients at the other time points. The EQ-5D scores were higher in Group S than in Group P (P = 0.022), and the difference was 0.15 at most, which was not optimal. The EQ-5D clinical results might be not very significant.

CONCLUSIONS

Sevoflurane anesthesia may have potential advantages in reducing postoperative pain in patients undergoing TKA with a preoperative VAS score > 4.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Ultrasound-Guided Subclavian Perivascular Brachial Plexus Block Using 0.5% Bupivacaine with Dexmedetomidine as an Adjuvant: A Prospective Randomized Controlled Trial

Background:

Ultrasound guidance has dramatically improved the accuracy of nerve localization, and various adjuvants prolong the block and extend analgesia.

Aims:

This study aimed to evaluate the effects of dexmedetomidine added to 0.5% bupivacaine on the onset and duration of motor and sensory blockade and the duration of analgesia.

Settings and Design:

This is a prospective, randomized double-blind, study.

Materials and Methods:

Sixty adult patients aged 20–60 years of either sex undergoing orthopedic procedures on the forearm were randomly allocated into two groups of thirty each: Group BS (bupivacaine + saline) and Group BD (bupivacaine + dexmedetomidine). All patients were administered subclavian perivascular brachial plexus block under ultrasound guidance. Group BS: Patients in this group were administered 20-mL 0.5% bupivacaine + 0.75-mL saline. Group BD: Patients in this group were administered 20-mL 0.5% bupivacaine + 0.75-mL dexmedetomidine (75 μg).

Statistical Analysis:

Statistical analysis was performed with IBM SPSS software Version 21.0. Quantitative data were expressed as mean ± standard deviation. Independent sample t-test was used for comparisons between the two groups. P < 0.05 was considered statistically significant.

Results:

Demographic data and surgical characteristics were similar in both groups. The onset times for sensory and motor blocks were statistically significantly shorter in Group BD compared to Group BS (P < 0.01), whereas the duration of blocks and analgesia were statistically significantly longer (P < 0.01) in Group BD.

Conclusion:

The addition of dexmedetomidine to 0.5% bupivacaine for supraclavicular brachial plexus block shortens the onset time and prolongs both the duration of the block and analgesia.

Effect of local anesthetic volume (20 mL vs 30 mL ropivacaine) on electromyography of the diaphragm and pulmonary function after ultrasound-guided supraclavicular brachial plexus block: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Diaphragmatic paralysis following supraclavicular brachial plexus block (SCBPB) is ascribed to phrenic nerve palsy. This study investigated the effect of 2 volumes of 0.375% ropivacaine on efficacy of block as a surgical anesthetic and as an analgesic and examined diaphragm compound muscle action potentials (CMAPs) and pulmonary function before and after SCBPB.

METHODS

Eighty patients scheduled for removal of hardware for internal fixation after healing of an upper limb fracture distal to the shoulder were randomized to receive ultrasound-guided SCBPC for surgical anesthesia with 20 mL (Group A) or 30 mL (Group B) 0.375% ropivacaine. The latency and amplitude of diaphragm CMAPs and forced vital capacity (FVC), FVC% predicted, and forced expiratory volume in 1 s (FEV1) were measured before and 30 min after SCBPB.

RESULTS

Block success as primary anesthetic in addition to analgesia was 81% in Group A and 91% in Group B. There were no obvious differences in the effectiveness of analgesia between the two groups. The mean time to onset of motor block was significantly longer in Group A (8.1±2.7 min) than in Group B (5.4 ± 2.8 min; p<0.05). The mean amplitude of the diaphragm CMAP was significantly lower in Group B than in Group A (p=0.03). The changes in FVC (Group A, - 8.1% vs Group B, -16.5%), FVC% (Group A, -8.0% vs Group B, -17.1%), and FEV1 (Group A, -9.5% vs Group B, -15.2%) from pre-SCBPB to post-SCBPB were significantly less in Group A than in Group B (all p=0.03).

CONCLUSIONS

The incidence rates of phrenic nerve palsy and diaphragm paralysis were reduced, and lung function was less impaired in patients who received 20 mL vs 30 mL of 0.375% ropivacaine without any differences in block success. Selecting a lower volume of anesthetic for nerve block may be especially beneficial in obese patients or patients with cardiopulmonary disease.

TRIAL REGISTRATION NUMBER

ChiCTR-IND-17012166.

[Regional anesthesia in daily clinical practice: an economic analysis based on case vignettes]

BACKGROUND

The economic effect is a crucial aspect of every medical procedure. This article analyzes the economic implications of various methods in anesthesia based on three case vignettes.

METHODS

The management of anesthesia of a forearm fracture with sufficient brachial plexus blockade, general anesthesia and insufficient brachial plexus blockade with subsequent general anesthesia was analyzed with respect to the relevant cost factors (personnel costs, durables, consumables, fixed assets costs, anesthesia-related overhead costs).

RESULTS

Sufficient regional anesthesia was the least expensive method for a forearm fracture with 324.26 €, followed by general anesthesia with 399.18 € (+23% compared with regional anesthesia). Insufficient regional anesthesia was most the expensive method, which necessitated an additional general anesthesia (482.55 €, +49% compared with sufficient regional anesthesia).

CONCLUSION

Even considering that this cost analysis was calculated based on data from only one medical institution (General Hospital of Vienna, Medical University of Vienna), regional anesthesia appeared to be cost efficient compared with other anesthesia procedures. Main cost drivers in this example were personnel costs.

A computed tomography and magnetic resonance imaging study of the variations of the sciatic nerve branches of the pediatric knee: Implications for peripheral nerve blockade

In pediatric patients, peripheral anesthetic blockade of the sciatic nerve is useful for postoperative pain relief after orthopedic procedures of the lower limb. The identification of the sciatic and its branches relative to the surrounding anatomical structures of the knee significantly contribute to the successful nerve blockade. However, reports have demonstrated complications arising from the inadequate and inconsistent understanding of the anatomy of the nerves in the knee region. In addition, the paucity of information regarding the location of the nerves of the knee throughout the pediatric development needs to be addressed in order for peripheral nerve blockades to become more readily used among the pediatric population. This clinical imaging study therefore aimed to document and analyze the relative morphometric relationship of the nerves in the knee region throughout the different stages of pediatric development. The locations of the sciatic, tibial, and common fibular nerves were measured in relation to relevant anatomical structures in 142 pediatric magnetic resonance imaging and computed tomography. A strong correlation was found between age and the distance from the common fibular nerve to the semitendinosus muscle, and thus can be used to predict stature. Significant differences were found between males and females, specifically after puberty, suggesting that sexual dimorphism emerges more distinctively at puberty. In order to predict the location of the nerves at the popliteal fossa, a regression formula using the patient's age and bicondylar width was created. These finding may have significant implications for popliteal approach of the sciatic nerve blockade in pediatric patients. Clin. Anat. 32:836-850, 2019. © 2019 Wiley Periodicals, Inc.

[C5-6 nerve root block technique for postoperative analgesia of shoulder arthroscope: a randomized controlled trial]

OBJECTIVE

To compare the effects of ultrasound-guided interscalene brachial plexus block and C5-6 nerve root block for analgesia after shoulder arthroscopy.

METHODS

In the study, 40 patients of ASA I-II were selected for elective general anesthesia to repair the shoulder ligament rupture in Peking University Third Hospital, who were randomly divided into two groups, respectively for the intermuscular brachial plexus block group (group I) and C5-6 nerve root block group (group C), n=20. The forty patients underwent ultrasound-guided brachial plexus block or C5-6 nerve root block before general anesthesia. Group I: 0.2% ropivacaine 10 mL was injected into brachial plexus intermuscular approach; Group C: 0.2% ropivacaine 10 mL was injected around the nerve roots of C5 and C6, and the ultrasound images showed that the liquid wrapped nerve roots. The time of sensory and motor block after puncture, operation time, the time of postoperative analgesia, numerical rating scale (NRS) scores at 1, 6, 12, and 24 h postoperatively and the finger movements were recorded. The adverse drug reactions and the patient satisfaction were recorded. The primary end point was the study of shoulder rest and movement pain in the patients with postoperative nerve blockage; the secondary end point was the patient's limb movements and thepatient satisfaction.

RESULTS

The duration of analgesia was (571.50±70.11) min in group I and (615.60±112.15) min in group C, and there was no difference between the two groups (P>0.05). The static and dynamic NRS scores at 1, 6, and 12 h in group C were lower than those in group I (P<0.05). There was no difference in static and dynamic NRS scores between the two groups during 24 hours (P>0.05). There was a significant difference in grade of muscle strength between group C [5(4,5)] and group I [4(2,4)] in the patients with nerve block hind limb (P<0.01), and there were significant differences between the two groups' sensation in the radial nerve group C [1(0,2)] and group I [2(1,2)], the median nerve group C [0(0,2)] and group I [2(1,2)], and the ulnar nerves group C [0(0,1)] and group I [1(1,2)] (P<0.01). There was no statistical difference between the two groups in the sencation of the shoulder, group C 2(1,2) and group I 2(1,2) , P>0.05. Compared with group I 8(6,9), group C 9(8,10) was a significant difference in satisfaction (P<0.01).

CONCLUSION

Interscalene brachial plexus block and C5-6 nerve root block could satisfy the needs of analgesia after shoulder arthroscopy, but C5-6 nerve root blockage does not limit the limb activity, the numbness is less, and the patient's satisfaction is higher.

[Ultrasound-guided interventions on the peripheral nervous system]

CLINICAL/METHODICAL ISSUE

Up to the advent of high-resolution ultrasound, interventions on the peripheral nervous system, including local anesthesia and pain treatment were performed without visual guidance, which in some cases led to treatment failure or local tissue and nerve damage.

METHODICAL INNOVATIONS

Progress in the field of ultrasound has enabled the functional visualization, anesthesia and anti-inflammatory or neurolytic treatment of many peripheral nerves, such as the brachial plexus, nerves of the upper and lower extremities and various nerves of the trunk. Contrast medium-guided biopsies have also become feasible.

ACHIEVEMENTS

This article discusses the general prerequisites for such interventions and details the visualization and the interventional algorithms for interventions on the brachial plexus, on large nerves often affected by compression neuropathies, such as the median, ulnar, sciatic and femoral nerves and small nerves, such as the lateral cutaneous nerves of the thigh. Furthermore, contrast medium-aided biopsies of intraneural and perineural masses are discussed. Finally, the treatment of stump neuromas via phenol instillation is described.

PRACTICAL RECOMMENDATIONS

Innovations in high-resolution ultrasound allow the reliable and safe diagnosis and treatment of various pathologies of the peripheral nervous system with few side effects. Compared to older methods, which did not use visual guidance ultrasound provides higher success rates and lower adverse event rates in many instances.

Superior perioperative analgesia with combined femoral-obturator-sciatic nerve block in comparison with posterior lumbar plexus and sciatic nerve block for ACL reconstructive surgery

PURPOSE

The purpose of this randomized controlled study is to compare and evaluate the intraoperative and post-operative outcome of PLPS nerve block and that of femoral, obturator and sciatic (FOS) nerve block as a method of anaesthesia, in performing ACL reconstruction.

METHODS

Patients referred for elective arthroscopic ACL reconstruction using hamstring autograft were divided in two groups. The first group received combined femoral-obturator-sciatic nerve block (FOS Group) under dual guidance, whereas the second group received posterior lumbar plexus block under neurostimulation and sciatic nerve block (PLPS Group) under dual guidance.

RESULTS

The two groups were comparable in terms of age, sex, BMI and athletic activity. The time needed to perform the nerve blocks was significantly shorter for the FOS group (p < 0.005). Similarly, VAS scores during tourniquet inflation and autograft harvesting were significantly higher (p < 0.005) in the PLPS group and this is also reflected in the intraoperative fentanyl consumption and conversion to general anaesthesia. Finally, patients in this group also reported higher post-operative VAS scores and consumed more morphine.

CONCLUSIONS

Peripheral nerve blockade of FOS nerve block under dual guidance for arthroscopic ACL reconstructive surgery is a safe and tempting anaesthetic choice. The success rate of this technique is higher in comparison with PLPS and results in less peri- and post-operative pain with less opioid consumption. This study provides support for the use of peripheral nerve blocks as an exclusive method for ACL reconstructive surgery in an ambulatory setting with almost no complications.

LEVEL OF EVIDENCE

I.

Periarticular injections with continuous perfusion of local anaesthetics provide better pain relief and better function compared to femoral and sciatic blocks after TKA: a randomized clinical trial

PURPOSE

Combined femoral and sciatic nerve blocks for post-operative pain management following total knee arthroplasty (TKA) improve patient satisfaction, decrease narcotic consumption and improve pain. However, accompanying motoric weakness can cause falls and related complications. We wonder whether peri-capsular injections in combination with intra-articular perfusion of local anaesthetics would result in equal or less pain without the related complications of nerve blocks. The objective of the study was to verify these aspects in a prospective randomized trial comparing both treatments.

METHODS

Fifty TKA patients randomly received either a femoral (continuous) and a sciatic (single-shot) nerve block (CFNB group, 25 knees) or periarticular infiltrations and a continuous post-operative intra-articular infusion (PIAC group, 25 knees). VAS for pain, pain medication consumption, functional assessment, straight leg raising as well as KSS were recorded post-operatively for 6 days.

RESULTS

VAS (p < 0.001) and KSS (p = 0.05) were significantly better for PIAC. There was increased pain following CFNB compared to PIAC. Catheters stayed for 4 days, a pain 'rebound' occurred after removing in CFNB but not after PIAC. There was no difference in regard to knee function (n.s.), but straight leg raising was significant better following PIAC. There were two falls in patients with CFNB.

CONCLUSION

Peri-capsular injections combined with an intra-articular catheter provide better pain control, no rebound pain with better function and might decrease the risk of complications related to motor weakness.

LEVEL OF EVIDENCE

I.

Ultrasound-triggered local anaesthesia

On-demand relief of local pain would allow patients to control the timing, intensity and duration of nerve block in a safe and non-invasive manner. Ultrasound would be a suitable trigger for such a system, as it is in common clinical use and can penetrate deeply into the body. Here, we demonstrate that ultrasound-triggered delivery of an anaesthetic from liposomes allows the timing, intensity and duration of nerve block to be controlled by ultrasound parameters. On insonation, the encapsulated sonosensitizer protoporphyrin IX produces reactive oxygen species that react with the liposomal membrane, leading to the release of the potent local anaesthetic tetrodotoxin. We also show repeatable ultrasound-triggered nerve blocks in vivo, with nerve-block duration depending on the extent and intensity of insonation. We did not detect any systemic toxicity, and tissue reaction was benign in all groups. On-demand, personalized local anaesthesia could be beneficial for the managing of relatively localized pain states, and potentially minimize opioid use.

An electronic surgical order, undertaking patient education, and obtaining informed consent for regional analgesia before the day of surgery reduce block-related delays

Background

Obtaining patient informed consent for a regional analgesia block on the day of surgery can result in surgical case delays. We hypothesized that implementing a preoperative electronic surgical order, undertaking patient education, and obtaining informed consent for a regional block in our preoperative assessment clinic prior to the day of surgery would reduce surgical case delays attributed to our regional anesthesia pain service and increase the percentage of patients for whom our regional anesthesia pain service was requested to provide a block.

Methods

A prospective two-group time-series design, with a nonrandomized, pre- and post-intervention data collection strategy, was applied. Based upon the surgeons’ newly implemented preoperative electronic outpatient orders, patients were identified by our preoperative assessment clinic staff to receive educational materials. The attending anesthesiologist in the preoperative assessment clinic then obtained written informed consent. Block-related delay and utilization data were analyzed with conventional inferential statistics.

Results

We observed a 14.8% (95% CI: 9.4%, 20.1%; P<0.001) decrease in surgical case delays, attributed to the regional nerve block, in the post- vs pre-intervention group. In addition, there was a 9.9% (95% CI: 4.7%, 15.1%); P<0.001) increase in the proportion of patients for whom a regional nerve block was ordered by our three high-volume orthopedic surgeons in the post- vs pre-intervention time periods.

Conclusion

When performed before the day of surgery, a surgeon’s electronic order, patient education, and informed consent for regional postoperative analgesia can improve patient throughput, thereby reducing block-related operating room delays. The preoperative assessment clinic can serve as a venue to achieve this goal, thereby adding value by decreasing downstream delays on the day of surgery.

New technique targeting the C5 nerve root proximal to the traditional interscalene sonoanatomical approach is analgesic for outpatient arthroscopic shoulder surgery

STUDY OBJECTIVE

Regional anesthesia and analgesia for shoulder surgery is most commonly performed via interscalene nerve block. We developed an ultrasound-guided technique that specifically targets the C5 nerve root proximal to the traditional interscalene block and assessed its efficacy for shoulder analgesia.

DESIGN

Prospective case series.

SETTING

Vanderbilt Bone and Joint Surgery Center.

PATIENTS

Patients undergoing shoulder arthroscopy at an ambulatory surgery center.

INTERVENTIONS

Thirty-five outpatient shoulder arthroscopy patients underwent an analgesic nerve block using a new technique where ultrasound visualization of the C5 nerve root served as the primary target at a level proximal to the traditional interscalene approach. The block was performed with 15mL of 0.5% plain ropivicaine.

MEASUREMENTS

Post anesthesia care unit pain scores, opioid consumption, hand strength, and duration of block were recorded. Cadaver dissection after injection with methylene blue confirmed that the primary target under ultrasound visualization was the C5 nerve root.

MAIN RESULTS

Pain scores revealed 97% patients had 0/10 pain at arrival to PACU, with 91% having a pain score of 3/10 or less at discharge from PACU. Medical Research Council (MRC) hand strength mean (SD) score was 4.17 (0.92) on a scale of 1-5. The mean (SD) duration of the block was 13.9 (3.5) hours.

CONCLUSIONS

A new technique for ultrasound-guided blockade at the level of the C5 nerve root proximal to the level of the traditional interscalene block is efficacious for shoulder post-operative pain control.

Holistic ultrasound in trauma: An update

Holistic ultrasound is a total body examination using an ultrasound device aiming to achieve immediate patient care and decision making. In the setting of trauma, it is one of the most fundamental components of care of the injured patients. Ground-breaking imaging software allows physicians to examine various organs thoroughly, recognize imaging signs early, and potentially foresee the onset or the possible outcome of certain types of injuries. Holistic ultrasound can be performed on a routine basis at the bedside of the patients, at admission and during the perioperative period. Trauma care physicians should be aware of the diagnostic and guidance benefits of ultrasound and should receive appropriate training for the optimal management of their patients. In this paper, the findings of holistic ultrasound in trauma patients are presented, with emphasis on the lungs, heart, cerebral circulation, abdomen, and airway. Additionally, the benefits of ultrasound imaging in interventional anaesthesia techniques such as ultrasound-guided peripheral nerve blocks and central vein catheterization are described.

Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection

Background

Interscalene brachial plexus (ISB) block is often associated with phrenic nerve block and diaphragmatic paresis. The goal of our study was to test if the anterior or the posterior ultrasound guided approach of the ISB is associated with a lower incidence of phrenic nerve blocks and impaired lung function.

Methods

This was a prospective, randomized and single-blinded study of 84 patients scheduled for elective shoulder surgery who fullfilled the inclusion and exclusion critereria. Patients were randomized in two groups to receive either the anterior (n = 42) or the posterior (n = 42) approach for ISB. Clinical data were recorded. In both groups patients received ISB with a total injection volume of 15 ml of ropivacaine 1 %. Spirometry was conducted at baseline (T₀) and 30 min (T₃₀) after accomplishing the block.

Changes in spirometrical variables between T₀ and T₃₀ were investigated by Wilcoxon signed-rank test for each puncture approach. The temporal difference between the posterior and the anterior puncture approach groups were again analyzed by the Wilcoxon-Mann-Whitney test.

Results

The spirometric results showed a significant decrease in vital capacity, forced expiratory volume per second, and maximum nasal inspiratory breathing after the Interscalene brachial plexus block; indicating a phrenic nerve block (p <0.001, Wilcoxon signed-rank). A significant difference in the development of the spirometric parameters between the anterior and the posterior group could not be identified (Wilcoxon-Mann-Whitney test). Despite the changes in spirometry, no cases of dyspnea were reported.

Conclusion

A different site of injection (anterior or posterior) did not show an effect in reducing the cervical block spread of the local anesthetic and the incidence of phrenic nerve blocks during during ultrasound guided Interscalene brachial plexus block. Clinical breathing effects of phrenic nerve blocks are, however, usually well compensated, and subjective dyspnea did not occur in our patients.

Trial registration

German Clinical Trials Register (DRKS number 00009908, registered 26 January 2016).

Perineural Dexmedetomidine as an Adjuvant Reduces the Median Effective Concentration of Lidocaine for Obturator Nerve Blocking: A Double-Blinded Randomized Controlled Trial

Research suggests that the addition of dexmedetomidine to local anesthetics can prolong peripheral nerve blocks; however, it is not known whether dexmedetomidine can reduce the quantity of local anesthetic needed. We hypothesized that adding dexmedetomidine as an adjuvant to an obturator nerve block could reduce the median effective concentration of lidocaine. In this double-blinded randomized trial, 60 patients scheduled for elective transurethral resection of bladder tumors on the lateral wall were randomly divided into two groups: the control group (C group, n = 30) and the dexmedetomidine group (D group, n = 30). Two main branches of the obturator nerve (i.e., anterior and posterior) were identified using neural stimulation at the inguinal level, with only lidocaine used for the C group and 1 μg/kg dexmedetomidine combined with lidocaine used for the D group. The median effective concentration was determined by an up-and-down sequential trial. The ratio of two consecutive concentrations was 1.2. The median effective concentration (95% confidence interval) of lidocaine was 0.57% (0.54%-0.62%) in the C group and 0.29% (0.28%-0.38%) in the D group. The median effective concentration of lidocaine was significantly lower in the D group than in the C group (p < 0.05). These results indicate that dexmedetomidine (1 μg/kg) in combination with lidocaine for obturator nerve block decreases the median effective concentration of lidocaine.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02066727.

Assessment of variation in depth of brachial plexus using ultrasound for supraclavicular brachial plexus block in patients undergoing elective upper limb surgery

Background and Aims:

Supraclavicular approach to the brachial plexus may be associated with complications such as pneumothorax, inadvertent vascular puncture, inter-scalene block and neurovascular injuries. The present study was conceived to find out the variation in depth of brachial plexus to suggest the minimum length of needle required to effectively perform the block, thus preventing possible complications.

Methods:

After approval from our Institutional Ethical Committee, informed and written consent was obtained from each of the ninety American Society of Anesthesiologists Physical Status I and II patients recruited, of either sex in the age group of 20–50 years. Supraclavicular fossa was scanned using a high-frequency linear probe, and the distances (shortest distance [SD] from skin to the most superficial neural element and longest distance [LD] from skin to the most deep neural element) were measured using on-screen callipers on optimal frozen image. Pearson correlation was used to find out the relation between these two distances and demographic parameters.

Results:

Mean SD was 0.60 ± 0.262 cm, and mean LD was found to be 1.34 ± 0.385 cm. We observed significant correlation between these two distances with weight and body mass index (BMI).

Conclusion:

Significant correlation was observed between SD and LD with weight and BMI. We suggest that a needle with a shaft length of 3 cm will be sufficient to reach the sheath of the brachial plexus during performance of the block.

Real-time ultrasound-guided comparison of adductor canal block and psoas compartment block combined with sciatic nerve block in laparoscopic knee surgeries

Background:

Lumbar plexus block, combined with a sciatic nerve block, is an effective locoregional anesthetic technique for analgesia and anesthesia of the lower extremity. The aim of this study was to compare the clinical results outcome of the adductor canal block versus the psoas compartment block combined with sciatic nerve block using real time ultrasound guidance in patients undergoing elective laparoscopic knee surgeries.

Patients and Methods:

Ninety patients who were undergoing elective laparoscopic knee surgeries were randomly allocated to receive a sciatic nerve block in addition to lumbar plexus block using either an adductor canal block (ACB) or a posterior psoas compartment approach (PCB) using 25 ml of bupivacine 0.5% with adrenaline 1:400,000 injection over 2-3 minutes while observing the distribution of the local anesthetic in real time. Successful nerve block was defined as a complete loss of pinprick sensation in the region that is supplied by the three nerves along with adequate motor block, 30 minutes after injection. The degree of motor block was evaluated 30 minutes after the block procedure. The results of the present study showed that the real time ultrasound guidance of PCB is more effective than ACB approach. Although the sensory blockade of the femoral nerve achieved equally by both techniques, the LFC and OBT nerves were faster and more effectively blocked with PCB technique. Also PCB group showed significant complete sensory block without need for general anesthesia, significant decrease in the post-operative VAS and significant increase time of first analgesic requirement as compared to the ACB group.

Result and Conclusion:

The present study demonstrates that blockade of lumber plexus by psoas compartment block is more effective in complete sensory block without general anesthesia supplementation in addition to decrease post-operative analgesic requirement than adductor canal block.

[Hygiene aspects in ultrasound-guided regional anesthesia]

BACKGROUND

Sterile and clean working conditions are one of the keystones of medical practice and this is also true for ultrasound-guided regional anesthesia. The routine clinical practice in ultrasound-guided regional anesthesia does not always comply with the principles of sterile and clean working conditions in medicine: therefore, patients are exposed to potential hazards regarding the transmission of pathogens via the ultrasound equipment.

OBJECTIVE

This article deals with the question of whether sterile working conditions in ultrasound-guided regional anesthesia are a relevant topic with medical and economic implications. Is it possible to implement the general recommendations for sterile working conditions in ultrasonography for the specific application of ultrasound-guided regional anesthesia?

MATERIAL AND METHODS

A search of the available literature and published guidelines in the field of sterile working conditions with ultrasound was carried out.

RESULTS

The association between cross-infections and ultrasound equipment is undeniable. Many methods for cleansing and disinfection of ultrasound equipment have been published. All these methods are associated with advantages and disadvantages. The direct sterilization of ultrasound probes with high-percentage alcohol can damage ultrasound probes (especially linear). The use of self-adhesive sterile ultrasound probe covers is a practical method to achieve sterile working conditions in ultrasound-guided regional anesthesia.

CONCLUSION

The use of sterile ultrasound probe covers and sterile ultrasound contact media is an important prerequisite to avoid cross-infection between patients. An appropriate scientific evaluation should serve as evidence in this field.