Comparison of intermediate vs subcutaneous cervical plexus block for carotid endarterectomy

Evaluating the Analgesic Efficacy of Superficial Cervical Plexus Block for Head and Neck Surgeries: A Comparative Randomized Control Study

INTRODUCTION

In the present study, the advantages of superficial cervical plexus block (SCPB) were evaluated using a landmark-guided method. Our primary aim was to evaluate the analgesic efficacy of SCPB in various head and neck surgeries by observing intra- and postoperative requirements of the total dose of the systemic analgesic, visual analog scale (VAS) score, and the total duration of analgesia; vital parameters and associated perioperative complications were also observed.

MATERIALS AND METHODS

Sample size was calculated using reference by taking the parameter pain score at 12 hours using MedCalc software v. 19.5.1 (MedCalc Software, Ostend, Belgium) with a mean difference of score 3±3.5 between two groups, 80% power, and 95% confidence interval (CI); the sample size for each group was 21. There were 30 patients in each group of ASA I, II, and III who were posted for mandibular, tympanomastoid and clavicular surgeries. Group A received general anaesthesia with systemic analgesia and Group B received general anaesthesia followed by SCPB with an injection of bupivacaine 0.25% 10ml on each side according to the site of surgery. VAS score, intra and postoperative analgesic requirement in 24 hours, time of first demand bolus, and peri-operative complications were noted.

RESULTS

Intraoperative fentanyl requirement for group A was 97.5±13.75 µg as compared to group B (70.16±13.09 µg), postoperative injection paracetamol requirement was also significantly higher in group A (2566.66±504 mg) as compared to group B (833.33±874.28 mg). The total duration of analgesia was significantly higher in Group B (1191.33±375.36 min) as compared to Group A (122.0±50.88 min) with a p-value <0.0001. No significant complications were noted in any patient.

CONCLUSION

SCPB provides better perioperative analgesia by decreasing intraoperative as well as postoperative systemic analgesic requirements and their associated side effects, with no significant perioperative complications in various head and neck region surgeries.

Regional Anesthesia for Vascular Surgery and Pain Management

Patients undergoing vascular surgery tend to have significant systemic comorbidities. Vascular surgery itself is also associated with greater cardiac morbidity and overall mortality than other types of noncardiac surgery. Regional anesthesia is amenable as the primary anesthetic technique for vascular surgery or as an adjunct to general anesthesia. When used as the primary anesthetic, regional anesthesia techniques avoid complications associated with general anesthesia in this challenging patient population. In this article, the authors describe regional anesthetic techniques for carotid endarterectomy, arteriovenous fistula creation, lower extremity bypass surgery, and amputation.

Aphonia Following Bilateral Cervical Plexus Blocks for an Awake Hemithyroidectomy: A Case Report

A 35-year-old female patient was scheduled for a left hemithyroidectomy. We performed bilateral cervical plexus blocks with ultrasound guidance for an awake thyroidectomy. Soon after the blocks, she developed a weak voice, which gradually progressed to complete aphonia. Due to her apprehension, general anesthesia was administered. After an uneventful surgery, the patient spontaneously regained her normal voice in the postoperative period. The case report describes a previously unreported complication of aphonia presumably due to bilateral recurrent laryngeal nerve blocks, which might have occurred from the infiltrated local anesthetic extravasating to the deeper planes through the cervical fascia.

Regional Anesthetic and Analgesic Techniques for Clavicle Fractures and Clavicle Surgeries: Part 2-A Retrospective Study

Objective. Clavicle fracture fixation is commonly performed under general anesthesia due to the complex sensory innervation in this region which poses a challenge for anesthesiologists applying regional anesthetic (RA) techniques. In part 1 of this two-part study, we summarized the current literature describing various RA approaches in clavicle fractures and surgery. In our earlier scoping review, we surmised that a superficial or intermediate cervical plexus block (CPB) may provide analgesia for this procedure and, when combined with an interscalene brachial plexus block (ISB), can provide anesthesia to the clavicular region for surgical fixation. We performed a retrospective study, consolidating assumptions that were based on the results of our earlier scoping review. Methods. A retrospective study was conducted on 168 consecutive patients who underwent clavicle fixation surgery at a tertiary healthcare system in Singapore. We used a standardized pro forma to collate perioperative data from the electronic health records of both hospitals, including anesthetic technique, analgesic requirements, pain scores, and adverse events, up to the second postoperative day or up until discharge. Results. In our study, patients who received RA had significantly reduced pain scores and opioid requirements, compared to general anesthesia (GA) alone. Through subgroup analysis, differences were found in postoperative pain scores and opioid requirements in the following order: GA alone > GA with local infiltration analgesia > CPB > CPB plus ISB. All patients who received combined CPB and ISB had upper limb weakness in recovery, compared to none with CPB alone (p < 0.001). Of those who received an ISB either in isolation or combined with a CPB, four (9.3%) were reported to have dyspnea (within 24 h) and motor weakness that persisted beyond 12 h, compared to none for patients that received CPB alone. Conclusions. Addition of a CPB to GA for clavicle fracture fixation surgery is associated with reduced pain scores in the early postoperative period, with a lower opioid requirement compared to GA alone. In patients undergoing GA, the combination of a CPB with an ISB was associated with a small, although statistically significant, reduction in pain scores and opioid requirements compared to a CPB alone.

Regional Anesthetic and Analgesic Techniques for Clavicle Fractures and Clavicle Surgeries: Part 1—A Scoping Review

Objective. Clavicle fractures are common injuries potentially associated with significant perioperative pain. However, this region’s complex sensory innervation poses a challenge for regional anesthetic or analgesic (RA) techniques. We conducted this scoping review to summarize the current literature, particularly with regards to motor-sparing techniques. Methods. A scoping review was carried out in accordance with the Joanna Briggs Institute’s framework. All articles describing the use of RA for clavicle fractures or surgery were included. PubMed^®, Ovid MEDLINE^®, EMBASE^®, Scopus^®, CINAHL^®, and the Cochrane database were searched without language restrictions. Results. Database searches identified 845 articles, 44 of which were included in this review, with a combined patient total of 3161. We included all peer-reviewed publications containing clinical data and summarized the findings. Conclusions. Current evidence of RA techniques in clavicle surgery is heterogeneous, with different approaches used to overcome the overlapping sensory innervation. The literature largely comprises case reports/series, with several randomized controlled trials. Intermediate cervical plexus block is the regional technique of choice for clavicle surgery, and can provide reliable surgical anesthesia when combined with an interscalene block. Cervical plexus block can provide motor-sparing analgesia following clavicle surgery. Promising alternatives include the clavipectoral block, which is a novel motor-sparing regional technique. Further studies are required to determine the efficacy and safety of various techniques.

Evaluation of analgesic efficacy of superficial cervical plexus block in patients undergoing modified radical mastoidectomy: A randomised controlled trial

Background and Aims:

Intravenous analgesics and local infiltration are used for postoperative analgesia in patients undergoing mastoidectomy. No randomised controlled trial (RCT) has so far determined response rates of pain reduction after ultrasound-guided superficial cervical plexus block (SCPB) in adult patients undergoing modified radical mastoidectomy.

Methods:

This double-blind RCT was conducted in 30 adult patients of the American Society of Anesthesiologists (ASA) grade I/II undergoing modified radical mastoidectomy. The primary outcome was a reduction in the visual analogue scale (VAS) score. Secondary outcomes were postoperative diclofenac consumption, haemodynamics, and occurrence of any adverse events. All patients received general anaesthesia. At the end of the surgery, patients were randomised to either Group ‘Block’ (n = 15) ultrasound guided SCPB with 5 mL ropivacaine 0.5% or Group ‘No block’ (n = 15). All patients received intravenous (IV) paracetamol 1 g every 6 hourly and rescue analgesic IV diclofenac 75 mg if VAS score >4.

Results:

Patients in Group ‘Block’ reported lower VAS score at rest versus Group ‘No block’ at 1 h postoperatively (P = 0.012). VAS score on movement was lower in patients of Group ‘Block’ compared to Group ‘No block’ at 1 h (P = 0.010), 4 h (P = 0.035), 8 h (P = 0.027), and 12 h (*P = 0.003) postoperatively. Diclofenac consumption was lower in patients of Group ‘Block’ (P = 0.041). No adverse effects were reported.

Conclusion:

Postoperative ultrasound-guided SCPB produced higher response rates in terms of reduction in VAS score in patients undergoing modified radical mastoidectomy.

Anastomoses (Superficial Cervical Ansa) Between the Cervical Plexus and Peripheral Facial Nerve Branches: Implications for Regional Anesthesia in Carotid Endarterectomies - Anatomical Study

Purpose

Sensory innervation in the carotid triangle involves the cervical plexus, cranial nerves, and the sympathetic trunk. This innervation also applies to skin incision, including various anatomical structures with potentially different innervation, such as the skin (dermatomes), the platysma (myotomes), and the superficial layer of the cervical fascia (fasciotomes), as well as retromandibular retractor insertion (co-innervation: V, VII). The aim of this anatomical study was to develop an injection technique for carotid endarterectomies to additionally block anastomoses between the transverse cervical nerve (TCN), the cervical branch VII (CB VII), and the marginal mandibular branch VII (MMB VII). These anastomoses are also termed superficial cervical ansa (SCA).

Materials and Methods

Preparations (n=16) were performed on unembalmed donor cadavers (n=8). Subplatysmal injections (each using 5 mL of Alcian blue) were performed cranially within the carotid triangle between the anterior margin of the sternocleidomastoid muscle and the submandibular gland.

Results

Anastomoses between the TCN, CB VII, and MMB VII were stained in all preparations (n=16).

Conclusion

This anatomical study presents an ultrasound-guided subplatysmal SCA block to optimize, in addition to a cervical plexus block, the quality of anesthesia for carotid endarterectomies.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy may significantly reduce the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks that may be minimised by performing the operation under local rather than general anaesthetics. This is an update of a Cochrane Review first published in 1996, and previously updated in 2004, 2008, and 2013.

OBJECTIVES

To determine whether carotid endarterectomy under local anaesthetic: 1) reduces the risk of perioperative stroke and death compared with general anaesthetic; 2) reduces the complication rate (other than stroke) following carotid endarterectomy; and 3) is acceptable to individuals and surgeons.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trials registers (to February 2021). We also reviewed reference lists of articles identified.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the use of local anaesthetics to general anaesthetics for people having carotid endarterectomy were eligible.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data, assessed risk of bias, and evaluated quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) tool. We calculated a pooled Peto odds ratio (OR) and corresponding 95% confidence interval (CI) for the following outcomes that occurred within 30 days of surgery: stroke, death, ipsilateral stroke, stroke or death, myocardial infarction, local haemorrhage, and arteries shunted.

MAIN RESULTS

We included 16 RCTs involving 4839 participants, of which 3526 were obtained from the single largest trial (GALA). The main findings from our meta-analysis showed that, within 30 days of operation, neither incidence of stroke nor death were significantly different between local and general anaesthesia. Of these, the incidence of stroke in the local and general anaesthesia groups was 3.2% and 3.5%, respectively (Peto odds ratio (OR) 0.91, 95% confidence interval (CI) 0.66 to 1.26; P = 0.58; 13 studies, 4663 participants; low-quality evidence). The rate of ipsilateral stroke under both types of anaesthesia was 3.1% (Peto OR 1.03, 95% CI 0.71 to 1.48; P = 0.89; 2 studies, 3733 participants; low-quality evidence). The incidence of stroke or death in the local anaesthesia group was 3.5%, while stroke or death incidence was 4.1% in the general anaesthesia group (Peto OR 0.85, 95% CI 0.62 to 1.16; P = 0.31; 11 studies, 4391 participants; low-quality evidence). A lower rate of death was observed in the local anaesthetic group but evidence was of low quality (Peto OR 0.61, 95% CI 0.35 to 1.06; P = 0.08; 12 studies, 4421 participants).

AUTHORS' CONCLUSIONS

The incidence of stroke and death were not convincingly different between local and general anaesthesia for people undergoing carotid endarterectomy. The current evidence supports the choice of either approach. Further high-quality studies are still needed as the evidence is of limited reliability.

Efficacy of Ultrasound-Guided Intermediate Cervical Plexus Block by Anterior Route for Perioperative Analgesia in Robotic Thyroidectomy by Retroauricular Approach: A Case Series

Retroauricular or facelift approach for robotic thyroidectomy involves a long incision with extensive subcutaneous dissection causing severe pain and discomfort. Multimodal analgesic regimen with inclusion of intermediate cervical plexus block by anterior route provided excellent perioperative analgesia without affecting recurrent laryngeal nerve monitoring in 10 cases. All the patients were monitored with bispectral index (maintained 40-60) and extubated on table. Median numeric pain rating scale score in 24 hours postoperatively was 3. None of the cases had any significant complications on follow-up.

Ultrasound-guided interscalene block combined with intermediate or superficial cervical plexus block for clavicle surgery: A randomised double blind study

BACKGROUND

The complex innervation of the clavicle makes general anaesthesia a preferred technique for clavicular surgeries in current practice. The role and approach of regional anaesthesia remains unanswered.

OBJECTIVES

This study aims to delineate the relative effectiveness between interscalene brachial plexus block with either intermediate cervical plexus or superficial cervical plexus block (CPB) as the anaesthetics for clavicular surgery.

DESIGN

A randomised, double-blind prospective study.

SETTING

Single-centre, tertiary care medical college and research institute.

PATIENTS

Fifty patients with American Society of Anesthesiologist's (ASA) grade I to III, aged 18 to 70 years, scheduled for clavicular surgery, during May 2018 to April 2019 were enrolled in this study.

INTERVENTION

All patients received interscalene block with 10 ml of 0.5% bupivacaine. Patients were randomised to undergo additional ultrasound-guided intermediate CPB (Group-1) or superficial CPB (Group-2) with 10 ml of 0.5% bupivacaine.

MAIN OUTCOME MEASURES

The block success rate, sensory block onset time, haemodynamic parameters, duration of postoperative analgesia and complications were noted. Categorical data were analysed using the chi-square test and Fisher's exact test. Continuous data were analysed using Student's t-test.

RESULT

In Group 1, block success was 100%. In Group 2, five patients failed to achieve adequate surgical anaesthesia (P = 0.02). The average sensory block onset time in Group 1 was 2.5 ± 0.4 min and was longer in Group 2, 4.3 ± 0.5 min (P < 0.001). There was no difference between the groups with respect to haemodynamic parameters and complications. The mean duration of postoperative analgesia was longer in Group 1 (7.5 ± 0.8 h) as compared with Group 2 (5.7 ± 0.4 h, P < 0.001).

CONCLUSION

Ultrasound-guided combined interscalene and intermediate CPB had a better success rate, with faster sensory block onset time and prolonged postoperative analgesia as compared with interscalene and superficial CPB in patients undergoing clavicle surgery.

TRIAL REGISTRATION

Clinical trial registry of India (www.ctri.nic.in) - CTRI/2018/05/013785.

Incidence of hemi-diaphragmatic paresis after ultrasound-guided intermediate cervical plexus block: a prospective observational study

PURPOSE

An intermediate cervical plexus block (CPB) targets the posterior cervical space between the sternocleidomastoid muscle and the prevertebral fascia. The phrenic nerve descends obliquely on the surface of the anterior scalene muscle beneath the prevertebral fascia after originating from the C3-C5 ventral rami. Therefore, the phrenic nerve can be affected by a local anesthetic during an intermediate CPB, depending on the permeability characteristics of the prevertebral fascia. This study investigated whether an intermediate CPB affects the phrenic nerve, inducing hemidiaphragmatic paresis.

METHODS

In this prospective observational study, 20 patients undergoing single-incision transaxillary robot-assisted right thyroidectomy were enrolled. The intermediate CPB (0.25% ropivacaine 0.2 ml/kg) was performed at the C4-5 intervertebral level carefully, without penetrating the prevertebral fascia, before the patient emerged from general anesthesia. Diaphragmatic motions of the block side were measured by M-mode ultrasonography at three time points: before anesthesia (baseline) and at 30 and 60 min after the intermediate CPB. Hemidiaphragmatic paresis was divided into three grades, depending on the percentage of diaphragm movement compared to the baseline: none (> 75%), partial paresis (25-75%), and complete paresis (< 25%).

RESULTS

No patient showed any partial or complete ipsilateral hemidiaphragmatic paresis within 60 min after the intermediate CPB.

CONCLUSION

Intermediate CPB using 0.2 ml/kg of 0.25% ropivacaine at the C4-5 intervertebral level did not cause ipsilateral hemidiaphragmatic paresis. This may imply that the effect of the intermediate CPB on the phrenic nerve is not significant.

Comparison of ultrasound-guided intermediate vs subcutaneous cervical plexus block for postoperative analgesia in patients undergoing total thyroidectomy: A randomised double-blind trial

Background and Aims:

Intermediate cervical plexus block (CPB) is a new procedure whose analgesic efficacy compared to superficial cervical plexus block is yet to be established. We compared the analgesic efficacy of superficial vs intermediate CPB for post-operative analgesia after thyroid surgery.

Methods:

Forty-five patients with American Society of Anaesthesiologists' physical status 1 or 2 undergoing total thyroidectomy were recruited. Forty-four patients in superficial/subcutaneous CPB group (n = 22) and intermediate CPB (n = 22) received 20 mL 0.25% bupivacaine with adrenaline 100 μg bilaterally in ultrasound-guided superficial and intermediate cervical plexus block before induction of general anaesthesia., respectively. The primary outcome measure was the postoperative visual analogue scale (VAS) scores at 0, 2, 4, 6, 12 and 24. Secondary outcome measures included the total dose of rescue analgesic required, duration of postoperative analgesia and patient's satisfaction score. Statistical analysis was with the Mann-Whitney U test and independent t-test.

Results:

The post-operative VAS scores were lower in intermediate CPB group compared to superficial CPB group at 2, 4, 6, 12, 18 and 24 h [P < 0.05]. Time tofirst rescue analgesic demand was prolonged 10.06 ± 3.62 h in intermediate group compared to 7.94 ± 3.62 h in superficial group [P = 0.017] and total analgesic consumption were lower in intermediate group (71.25 ± 16.70 μg) than the superficial group (101.25 ± 50.31 μg) [P = 0.011].

Conclusion:

Ultrasound-guided intermediate CPB reduces post-operative pain scores, prolongs duration of analgesia and decreases demands for rescue analgesia compared to superficial CPB.

Cervical plexus block

Cervical plexus blocks (CPBs) have been used in various head and neck surgeries to provide adequate anesthesia and/or analgesia; however, the block is performed in a narrow space in the region of the neck that contains many sensitive structures, multiple fascial layers, and complicated innervation. Since the intermediate CPB was introduced in addition to superficial and deep CPBs in 2004, there has been some confusion regarding the nomenclature and definition of CPBs, particularly the intermediate CPB. Additionally, as the role of ultrasound in the head and neck region has expanded, CPBs can be performed more safely and accurately under ultrasound guidance. In this review, the authors will describe the methods, including ultrasound-guided techniques, and clinical applications of conventional deep and superficial CPBs; in addition, the authors will discuss the controversial issues regarding intermediate CPBs, including nomenclature and associated potential adverse effects that may often be neglected, focusing on the anatomy of the cervical fascial layers and cervical plexus. Finally, the authors will attempt to refine the classification of CPB methods based on the target compartments, which can be easily identified under ultrasound guidance, with consideration of the effects of each method of CPB.

Ultrasound-guided bilateral superficial cervical plexus block for thyroid surgery: The effect of dexmedetomidine addition to bupivacaine-epinephrine

Background:

The thyroid gland surgery is a common and painful procedure demanding analgesia. Many regional techniques are applied for anterior neck surgeries mostly assigned in relation to the involved cervical fascia. Dexmedetomidine (Precedex) is a selective alpha 2 adrenoceptor agonist which prolongs the sensory blockade duration of local anesthetics. Our study hypothesis is that ultrasound (US)-guided bilateral superficial cervical plexus block (BSCPB) may provide longer analgesia when adding dexmedetomidine to bupivacaine-epinephrine.

Purpose:

The aim of this study is to evaluate the analgesic efficacy and possible side effects of US-guided BSCPB and the effect of dexmedetomidine addition to bupivacaine-epinephrine in patients undergoing thyroid surgery.

Methods:

This prospective, double-blind, randomized study was performed on 42 patients randomized into two equal groups each of 21; bupivacaine Group B and dexmedetomidine Group D. Patients with contraindications to regional anesthesia or uncontrolled comorbidities were excluded from the study. Total pethidine consumption in 24 h is the primary outcome. The visual analog scale, timing of the first opioid request, and hemodynamics are the secondary outcomes.

Results:

In Group D, there was a longer time to the first request of opioid postoperatively, a lower total pethidine consumption and pain score postoperatively, and lower fentanyl requirements intraoperatively.

Conclusions:

Sonographic-guided bilateral SCPB using a combination of bupivacaine, dexmedetomidine, and epinephrine was superior to bupivacaine for prolonged analgesia with less intra- and postoperative opioid consumption and lower side effect profile during thyroid surgery.

[Regional anesthesia for carotid surgery : An overview of anatomy, techniques and their clinical relevance]

BACKGROUND

Perioperative care for patients undergoing carotid endarterectomy (CEA) often presents a challenge to the anesthesia provider, as this patient group commonly suffers from a wide range of comorbidities. Although clinical trials could not demonstrate a significant benefit associated with regional anesthesia for outcomes such as insult, cardiac infarction or mortality, many authors concur that regional anesthetic techniques might be preferential in specific patient populations for this type of surgery.

OBJECTIVES

This article aims to present an overview of the currently used techniques for regional anesthesia in CEA, as well as discussing their influence on the perioperative outcome.

MATERIALS AND METHODS

After performing an extensive search of medical databases (Pubmed/Medline) the authors present a narrative analysis and interpretation of recent literature.

RESULTS

Currently there is a clear trend towards ultrasound guided regional anesthesia and away from classic landmark based techniques. The literature seems to support the notion that superior and intermediate cervical blocks are safer and less invasive than deep blocks.

CONCLUSIONS

With regional anesthetic techniques evolving to be more and more complex, the use of ultrasound is becoming increasingly indispensable in the operating theatre. For anesthesiologists with sufficient training and a profound knowledge of the respective anatomy, regional anesthesia seems to be a veritable alternative to general anesthesia for CEA.

Ropivacaine 0.375% vs. 0.75% with prilocaine for intermediate cervical plexus block for carotid endarterectomy: A randomised trial

BACKGROUND

Carotid endarterectomy is widely performed under regional anaesthesia. Ultrasound guidance is increasingly used in many regional anaesthetic procedures to improve safety and efficacy, and because it can reduce the amount of local anaesthetic required. Despite this, an ideal approach and dosing regimen for cervical plexus block remain elusive.

OBJECTIVE

The aim of this study was to compare two different concentrations of ropivacaine in terms of analgesic adequacy, haemodynamic effects and plasma concentration using an ultrasound-guided triple approach for intermediate cervical plexus blockade.

DESIGN

A randomised, placebo-controlled, blinded study.

SETTING

University Clinic Salzburg, Department of Anaesthesiology, Perioperative Medicine and Intensive Care, Paracelsus Medical University, Salzburg, Austria, from 16 November 2012 to 17 September 2013.

PATIENTS

Forty-six patients prospectively randomised to receive ultrasound-guided intermediate cervical block with either 20 ml ropivacaine 0.75% or 20 ml ropivacaine 0.375% each with 20 ml prilocaine 1%.

INTERVENTION

After subcutaneous infiltration, blocks were performed using ultrasound-guided infiltration below the sternocleidomastoid muscle, and ultrasound-guided infiltration of the carotid sheath. Ropivacaine and prilocaine plasma concentrations were measured at intervals.

MAIN OUTCOME

The primary study endpoint was the volume of supplementary lidocaine 1% required to achieve adequate surgical anaesthesia. Perioperative haemodynamic variables and pain scores were recorded.

RESULTS

There was no statistical difference in the volume of supplementary lidocaine given: 5.0 (±3.63) ml in the ropivacaine 0.375% group and 5.17 (±2.76) ml in the ropivacaine 0.75% group (P = 0.846). Pain scores were similarly low across both groups. Measured concentrations of ropivacaine and prilocaine did not reach toxic levels in either group. Levels of ropivacaine were approximately two-fold higher in the 0.75% group [mean area under the curve (AUC) 10 531.11 (±2912.84) vs. 5264.34 ng (±1594.69), P < 0.0001]. Perioperative cardiovascular stability was excellent in both groups. There were no serious block-related complications.

CONCLUSION

An ultrasound-guided intermediate block provides adequate anaesthesia for carotid thrombendarterectomy with a little need for supplementary local anaesthetic. Use of 0.375% ropivacaine provided similarly effective analgesia as 0.75%, but resulted in significantly lower plasma concentrations.

TRIAL REGISTRATION

The study was registered at the European Clinical Trial Database (Eudra CT No.: 2012-002769) as well as at ClinicalTrials.gov (NCT01759940).

[Ultrasound-guided intermediate cervical plexus block. Anatomical study]

BACKGROUND AND OBJECTIVES

The innervation of the human cervical region is complex and subject to relevant anatomical variability involving sections of the cervical plexus, brachial plexus and cranial nerves.

AIM

The objective was to demonstrate the dissemination of injected dye solution by anatomical preparation and to define a suitable target compartment for an ultrasound-guided block technique.

MATERIAL AND METHODS

Own anatomical preparations are compared to recent review articles on the subject. The focus is on clinically relevant conclusions for performing cervical plexus blocks. In three non-embalmed cadavers six intermediate ultrasound-guided blocks of the cervical plexus were carried out, each with 20 ml methylene blue. Following preparation of the cervical plexus photographic documentation of the spread of the injected marker was performed.

RESULTS

In five cases the target compartment was correctly identified. In these cases, a cranio-caudal spread of the injectate within the double layer of the cervical fascia was observed. In addition, the superficial layer was permeable to the injected methylene blue. The injection solution disseminated with the sensitive terminal branches of the cervical plexus below the platysma. In all cases an anastomosis (superficial cervical ansa) between the facial nerve (ramus colli) and the cervical plexus (transverse cervical nerve) could be demonstrated. The prevertebral lamina proved to be impermeable to injected methylene blue and no evidence of a porous structure of the prevertebral lamina was found.

CONCLUSION

The compartment between the superficial and the prevertebral layer of the cervical fascia is a suitable target for cervical plexus blocks. This injection site describes an intermediate cervical plexus block. As the compartment contains the sensory terminal branches of the spinal nerves C2-4, it may be referred to as C2-C4 compartment. The cranio-caudal spread of the injectate allows lateromedial needle guidance in the horizontal plane. As the superficial lamina is not a barrier to the injectate an additional subcutaneous infiltration of the nerve area appears dispensable. The prevertebral lamina proved to be impermeable to injected methylene blue. Whether phrenic nerve blocks are preventable with more distal intermediate cervical plexus blocks (selective block of the supraclavicular nerves, e.g. for surgery of the clavicle) must be investigated in clinical trials. The permanent anastomosis (superficial cervical ansa) between the cervical plexus and the ramus colli of the facial nerve provides an anatomically reasonable explanation for inadequate cervical plexus blocks.

Feasibility of ultrasound-guided capsule-sheath space block combined with anterior cervical cutaneous nerves block for thyroidectomy: an observational pilot study

Background

We evaluated the efficacy of a new anesthetic technique termed ultrasound-guided capsule-sheath space block (CSSB) combined with anterior cervical cutaneous nerve block (CCNB) for thyroidectomy.

Methods

The study included two parts: Part one was an imaging study to determine technique feasibility. The CSSB was performed on five healthy volunteers by introducing the needle 0.5 cm lateral to the probe under in-plane needle ultrasound guidance. After puncture of the false capsule and its subsequent contraction with the true capsule of thyroid, 10 mL of contrast medium was deposited slowly in the capsule-sheath space. The CCNB was performed bilaterally as follows: Under ultrasound guidance, a subcutaneous injection was made along the sternocleidomastoid using 10 mL of contrast medium which was followed by a girdle-shaped picchu raised from the cricoid cartilage to supraclavicular region. The spreading pattern of contrast medium was imaged using computed tomographic scanning. In part two (a clinical case series) the technique efficacy was evaluated. Seventy-eight patients undergoing thyroidectomy had ultrasound-guided CSSB and CCNB with local anesthetics. The sensory onset of CCNB, intraoperative hemodynamic parameters, and analgesic effect were assessed and complications were noted.

Results

The distribution of contrast medium was well defined. In part two the onset time of CCNB was 2.2 ± 0.7 min, and the hemodynamic parameters remained stable intraoperatively. The recall of visual analogue scale scores during surgery was 2 [1–4] for median (range). The patients’ and surgeons’ satisfaction scores were 2 [1–4] and 1 [1–3] for median (range). No serious complications occurred.

Conclusions

Combining ultrasound-guided CSSB and CCNB is a feasible, effective and safe technique for thyroidectomy.

Trial registration

Current Controlled Trials ChiCTR-ONC-12002025. Registered 19 March 2012.

Regional anesthesia for vascular surgery

Patients presenting for vascular surgery present a challenge to anesthesiologists because of their severe systemic comorbidities. Regional anesthesia has been used as a primary anesthetic technique for many vascular procedures to avoid the cardiovascular and pulmonary perturbations associated with general anesthesia. In this article the use of regional anesthesia for carotid endarterectomy, open and endovascular abdominal aortic aneurysm repair, infrainguinal arterial bypass, lower extremity amputation, and arteriovenous fistula formation is described. A focus is placed on reviewing the literature comparing anesthetic techniques, with brief descriptions of the techniques themselves.

Regional anaesthesia for carotid endarterectomy

Summary Regional anaesthesia is a popular choice for patients undergoing carotid endarterectomy (CEA). Neurological function is easily assessed during carotid cross-clamping; haemodynamic control is predictable; and hospital stay is consistently shorter compared with general anaesthesia (GA). Despite these purported benefits, mortality and stroke rates associated with CEA remain around 5% for both regional anaesthesia and GA. Regional anaesthetic techniques for CEA have improved with improved methods of location of peripheral nerves including nerve stimulators and ultrasound together with a modification in the classification of cervical plexus blocks. There have also been improvements in local anaesthetic, sedative, and arterial pressure-controlling drugs in patients undergoing CEA, together with advances in the management of patients who develop neurological deficit after carotid cross-clamping. In the UK, published national guidelines now require the time between the patient's presenting neurological event and definitive treatment to 1 week or less. This has implications for the ability of vascular centres to provide specialized vascular anaesthetists familiar with regional anaesthetic techniques for CEA. Providing effective regional anaesthesia for CEA is an important component in the armamentarium of techniques for the vascular anaesthetist in 2014.

Regional anesthesia for vascular surgery

Vascular surgical patients are a diverse group of patients who tend to be elderly, with multiple comorbidities, while vascular procedures may involve significant blood loss and ischemia of tissues beyond the arterial obstruction. Regional anesthesia techniques may offer benefits to patients undergoing vascular surgery because of their cardiorespiratory comorbidities. However, this group of patients is commonly receiving multiple medications, including anticoagulants, so regional techniques are not without risks. This review will discuss this topic based around 3 fundamental revascularization procedures, carotid, abdominal aortic aneurysm repair, and infrainguinal surgery, discussing the clinical applications of regional techniques relevant to each key area.