Ultrasound-guided Locoregional Anaesthesia for Carotid Endarterectomy: A Prospective Observational Study

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.

Effects of Unilateral Intermediate Cervical Plexus Block on the Diaphragmatic Function in Patients Undergoing Unilateral Thyroidectomy: A Randomized Controlled Study

Background and Purpose

Although unilateral intermediate cervical plexus block (ICPB) can be used for perioperative analgesia in neck surgery, its effect on diaphragm function remains controversial. This prospective study aimed to examine whether unilateral ICPB with different concentrations of ropivacaine resulted in the diaphragmatic dysfunction in unilateral thyroidectomy.

Methods

A total of 54 patients scheduled to undergo unilateral thyroidectomy under general anesthesia were randomly allocated to receive either 10 mL of 0.3% (Group L) or 0.5% (Group H) ropivacaine for ICPB. General anesthesia was then administered for surgery. The diaphragm thickness and diaphragmatic excursion were measured at three different times: before the ICPB, at 40 min and 4 h after the block. The primary outcome was the incidence of diaphragmatic dysfunction of the block side at 40 min and 4 h after ICPB. Secondary outcomes included the maximum pain score within 24 h after the surgery, rescue analgesics within 24 h after the surgery, and time to first ambulation.

Results

The incidence of diaphragmatic dysfunction on the block side of Group H was higher than that of Group L at 40 min after block (58% vs 29%, P = 0.01). However, the incidence of diaphragmatic dysfunction was comparable between Group H and Group L (65% vs 46%) at 4 h after block placement. Within 24 h after the operation, the maximum VAS pain score of Group H was significantly lower than Group L (P = 0.04), and fewer patients in Group H required rescue analgesics (P < 0.01).

Conclusion

The ICPB with different concentrations of ropivacaine can induce the ipsilateral diaphragmatic dysfunction. The high concentration of ropivacaine results in higher incidence of diaphragmatic dysfunction at 40 min, but comparable incidence at 4 h after block compared with lower concentration of ropivacaine.

Chinese Clinical Trial Registry

ChiCTR2000029348.

Understanding fascial anatomy and interfascial communication: implications in regional anesthesia

With the extensive application of ultrasound in regional anesthesia, there has been rapid development of interfascial plane block techniques recently. Compared with neuraxial anesthesia or nerve plexus blocks, the interfascial plane blocks have many advantages, such as technical simplicity, fewer complications and comparable or better analgesia. The concept of fascial interconnectivity is fundamental in understanding the effects and complications of interfascial plane blocks. Many fascial planes are continuous and communicate with each other without a clear anatomical boundary. The prevertebral fascia of the neck, endothoracic fascia of the chest, transversalis fascia of the abdomen, and the fascia iliaca of the pelvic cavity form a natural fascial continuation. This anatomical feature suggests that the space beneath the cervical prevertebral fascia, the thoracic paravertebral space, the space between transversalis fascia and psoas muscles (psoas major and quadratus lumborum), and the fascia iliaca compartment are a confluent potential cavity. Additionally, the permeability of the fascia at different anatomical locations to local anesthetics is different, which can also influence the block effect and the incidence of complications. This article summarizes the anatomical characteristics and communication relationships of the major fascia which are related to regional anesthesia, and their relationships with block effects and complications.

Efficacy of superficial cervical plexus block versus cervical retrolaminar block both combined with auriculotemporal nerve block in parotid surgeries

Background

Regional techniques in parotid surgeries include superficial cervical plexus block (SCPB) and auriculotemporal nerve (ATN) block, which can be used as an anesthetic technique for awake parotidectomy. This study aimed to evaluate the efficacy of cervical retrolaminar block (RLB) as an alternative to SCPB both, used in combination with auriculotemporal nerve (ATN) block, in parotid surgery.

Material and methods

A total of 40 patients undergoing parotid surgery were prospectively randomized into either the SCPB group (n = 20) or the cervical RLB group (n = 20) using 20 ml of 0.25% bupivacaine plus 5 mcg\mL epinephrine. Both were combined with ATN block using 5 ml of 0.25% bupivacaine plus 5 mcg\mL epinephrine.

Results

The time to first request for analgesia was longer in the RLB group than the SCPB group. Total intra operative fentanyl consumption and post-operative pethidine consumption in the first 24h were lower in group RLB. All patients (n = 20) in the SCPB group required rescue analgesia using pethidine, while only 40% of patients required pethidine in the RLB group. Visual analog scale was lower in the RLB group from 2 to 24-h post-operatively, but it was associated with hypotension and longer block technique time occurred with RLB than SCPB. There was no significant difference in side effects except for 20% Horner's syndrome in the SCPB group.

Conclusion

Cervical RLB is more effective analgesic technique than SCPB, as the cervical RLB showed longer time to first analgesic request, lower intraoperative anesthetic consumption, lower total post-operative pethidine consumption and lower VAS.

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A study on 40 patient undergoing elective parotid surgery of 2 groups; Cervical retrolaminar block or SCPB.

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Cervical retrolaminar block more effective than SCBP.

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Cervical retrolaminar block is alternative Technique to paravertebral block.

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No significant difference between the two study groups according to complications.

Can Ultrasound-Guided Regional Anesthesia Techniques For Tracheostomy Be An Alternative To General Anesthesia?

Introduction The cervical plexus block (CPB) has been used for a long time for both analgesia and anesthesia in carotid endarterectomy and thyroid operations. To be unfamiliar with the technique and its perceived difficulty, potential risks, and possible adverse effects such as intravascular injection has limited broader use before the practical use of ultrasound. We hypothesize that the cervical plexus block can provide adequate anesthesia in tracheostomy cases and provide excellent anesthesia comfort when combined with a translaryngeal block. Methods This double-blinded, randomized 29 patients undergoing primary tracheostomy operation to receive either CPB (Group S) or CPB with translaryngeal block (Group ST). The primary outcome was cumulated analgesic consumption during the first 24 postoperative hours. Secondary outcomes were as follows: pain related to incision, patient tolerance as assessed by tracheostomy cannula comfort score, cough and gag, pain at rest, nausea and vomiting, and time to first analgesic demand. Results The patient tolerance for tracheostomy was higher in Group ST than Group S. The median tracheostomy cannula comfort score was 4.0 in Group S. In contrast, the median score was significantly lower in group ST (P<.001). The cough and gag reflex scores were significantly lower in Group ST than Group S (1.0 vs 4.0, P<.001). Conclusion This trial supported the hypothesis that the CPB combined with the translaryngeal block yields excellent anesthesia for tracheostomies. The technique we briefly described, in a way, is the equivalent of awake fiberoptic intubation to awake tracheostomy with minimal sedation adjusted according to airway patency.

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.

Cardiac output and cerebral blood flow during carotid surgery in regional versus general anesthesia: A prospective randomized controlled study

OBJECTIVE

Carotid endarterectomy (CEA) is a preventive procedure aimed at decreasing the subsequent risk of fatal or disabling stroke in patients with significant carotid stenosis. It is well-known that carotid surgery under ultrasound-guided regional anesthesia (US-RA) causes a significant increase in blood pressure, heart rate and stress hormone levels owing to increased sympathetic activity. However, little is known about the effects on cardiac output (CO), cardiac index (CI), and cerebral blood flow (CBF) under US-RA as compared with general anesthesia (GA).

METHODS

Patients scheduled for CEA were randomized prospectively to receive US-RA (n = 37) or GA (n = 41). The primary end point was the change in CI after induction of anesthesia and the change from baseline over time at four different times during the entire procedure in the respective randomized US-RA and GA groups. In addition to systolic blood pressure and heart rate, we also recorded peak systolic velocity, end-diastolic velocity, and minimum diastolic velocity as seen from transcranial Doppler ultrasound examination, as well as regional cerebral oxygenation (rSO₂) as seen from near-infrared refracted spectroscopy to evaluate cerebral blood flow.

RESULTS

In the US-RA group, the CI increased after induction of anesthesia (3.7 ± 0.8 L/min/m²) and remained constant until the end of the procedure. In the GA group CI was significantly lower (2.4 ± 0.6 L/min/m²; P < .001). After induction of anesthesia, the rSO₂ remained constant in the GA group on both the ipsilateral (63 ± 9 rSO₂) and the contralateral (65 ± 7 rSO₂) sides; in contrast, it significantly increased in the US-RA group (ipsilateral 72 ± 8 rSO₂; P < .001; contralateral 72 ± 6 rSO₂; P < .001). The transcranial Doppler ultrasound parameters (peak systolic velocity, end-diastolic velocity, and minimum diastolic velocity) did not differ between the US-RA and the GA group. The clinical outcome was similarly favorable for both groups.

CONCLUSIONS

CI was maintained near baseline values throughout the procedure during US-RA, whereas a significant decrease in CI values was observed during CEA under GA. Near-infrared refracted spectroscopy values, reflecting blood flow in small vessels, were higher in US-RA patients than in those with GA. These differences did not influence clinical outcome.

Ultrasound-guided supraclavicular nerve block for implantable port catheters: Does it show a significant difference in pain control?

BACKGROUND

Nerve blocks have been used for decades at head and neck region interventions and recently introduced as an alternative option for subcutaneous port implantation. This study aimed to compare two different local anesthesia techniques used during subcutaneous port implantation.

METHODS

This retrospective study was conducted with 107 patients who were categorized into two groups according to the local anesthesia techniques used during port implantations. Group 1 underwent local infiltration anesthesia and Group 2 received an ultrasound-guided supraclavicular nerve block. In both groups, prilocaine 2% was used for skin anesthesia and no other systemic anesthetic drugs or additional local anesthetics were administered during port implantation. Local anesthetic doses were 400 mg in Group 1 and 200 mg in Group 2. The time required for adequate cutaneous anesthesia, procedure time, complication rate and visual analog scale (VAS) score were recorded for each patient.

RESULTS

Groups 1 and 2 contained 58 and 49 patients respectively. Both groups showed similar demographic distributions of patients (p > 0.05). Mean procedure times and the time required for adequate cutaneous anesthesia were longer in Group 2 (p < 0.05). Group 2 also showed 12 immediate complications, although they were temporary and recovered without any intervention under surveillance. Mean VAS scores during port implantation were similar in both groups [Group 1: 1.17(±0.60), Group 2: 1.1(±0.62)] (p > 0.05).

CONCLUSIONS

The VAS scores did not differ significantly between groups. Although a supraclavicular nerve block may require lower local anesthetic doses for similar cutaneous anesthesia, it is associated with higher immediate complication rates due to unintended blockade of the peripheral nerves. Thus, if the nerve block is preferred over local infiltration anesthesia during port implantation, to prevent life-threatening complications, caution needed especially for the patients with contralateral vocal cord or diaphragm paralysis.

Peripheral nerve blocks in the cervical region: from anatomy to ultrasound-guided techniques

Cervical plexus nerve blocks have been employed in various head and neck operations. Both adequate anaesthesia and analgesia are attained in clinical practice. Nowadays, ultrasound imaging in regional anaesthesia is driven towards a certain objective that dictates high accuracy and safety during the implementation of peripheral nerve blocks. In the cervical region, ultrasound-guided nerve blocks have routinely been conducted only for the past few years and thus only a small number of publications pervade the current literature. Moreover, the sonoanatomy of the neck, the foundation stone of interventional techniques, is very challenging; multiple muscles and fascial layers compose a complex of compartments in a narrow anatomic region, in which local anaesthetics are injected. Therefore, this review intends to deliver new insights into ultrasound-guided peripheral nerve block techniques in the neck. The sonoanatomy of the cervical region, in addition to the cervical plexus, cervical ganglia, superior and recurrent laryngeal nerve blocks are comprehensively discussed.

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.

Anesthetic and Analgesic Efficient of Regional Nerve Blockade in Otoplasty

AIM

The prominent ear is the most common congenital deformity of the external ear. Otoplasty is performed to correct the appearance of the prominent ear. This study was planned to compare the analgesic and anesthetic effects of local nerve blockade and local infiltration anesthesia in the otoplasties.

METHOD

Thirty-two patients who underwent otoplasty in both ears between February 2018 and March 2019 were included in the study. Three patients were excluded because they refused regional anesthesia. In the patients included in the study, only local infiltration anesthesia was applied to 1 ear and regional nerve blockade was applied to the other ear. Regional nerve blockade was applied to the study group; local infiltration anesthesia was applied to the control group. Surgical and anesthetic complications were recorded. The onset time, duration and severity of pain were followed. Numerical evaluation scale scores were used to evaluate pain levels.

RESULTS

It was observed that the first pain of the patients On the side where regional nerve block (RNB) anesthesia was applied after an average of 10.5 hours. On the other hand on the side where local infiltration anesthesia was applied; the pain was observed to start after an average of 3.5 hours. At the 6th and 12th hours postoperatively, the scores of the numerical evaluation scale were significantly lower in the study group than the control group (P < 0.05). At the 24th-hour pain score, the values were lower in the study group, but the difference was not significant between the groups (P > 0.05). In the regional anesthesia group, can develop such as difficulty in swallowing, weakness in the neck, weakness in the upper extremity, nausea, Horner syndrome; but all side effects resolve spontaneously within 6 to 12 hours.

CONCLUSION

The application of regional anesthesia in prominent ear surgical procedures can be considered as an alternative method to provide better quality preoperative anesthesia and better quality postoperative analgesia in patients.

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.

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 superficial cervical plexus block under dexmedetomidine sedation versus general anesthesia for carotid endarterectomy: a retrospective pilot study

Background

Carotid endarterectomy (CEA) has been performed under regional and general anesthesia (GA). The general anesthesia versus local anesthesia for carotid surgery study compared the two techniques and concluded that there was no difference in perioperative outcomes. However, since this trial, new sedative agents have been introduced and devices that improve the delivery of regional anesthesia (RA) have been developed. The primary purpose of this pilot study was to compare intraoperative hemodynamic stability and postoperative outcomes between GA and ultrasound-guided superficial cervical plexus block (UGSCPB) under dexmedetomidine sedation for CEA.

Methods

Medical records from 43 adult patients who underwent CEA were retrospectively reviewed, including 16 in the GA group and 27 in the RA group. GA was induced with propofol and maintained with sevoflurane. The UGSCPB was performed with ropivacaine under dexmedetomidine sedation. We compared the intraoperative requirement for vasoactive drugs, postoperative complications, pain scores using the numerical rating scale, and the duration of hospital stay.

Results

There was no difference between groups in the use of intraoperative antihypertensive drugs. However, intraoperative inotropic and vasopressor agents were more frequently required in the GA group (p<0.0001). In the GA group, pain scores were significantly higher during the first 24 h after surgery (p<0.0001 between 0-6 h, p<0.004 between 6-12 h, and p<0.001 between 12-24 h). The duration of hospital stay was significantly more in the GA group (13.3±4.6 days in the GA group vs. 8.5±2.4 days in the RA group, p<0.001).

Conclusion

In this pilot study, intraoperative hemodynamic stability and postoperative outcomes were better in the RA compared to the GA group.

Use of Ultrasound-Guided Superficial Cervical Plexus Block for Pain Management in the Emergency Department

BACKGROUND

Although use of the superficial cervical plexus block (SCPB) by anesthesia for perioperative indications is well described, there is a paucity of research on use of SCPB in the emergency department (ED).

OBJECTIVE

This prospective observational study aims to prospectively characterize the feasibility, potential for efficacy, and safety of ultrasound-guided SCPB in a convenience sample of ED patients presenting with painful conditions of the "cape" distribution of the neck and shoulder.

METHODS

Data were gathered prospectively on a convenience sample of 27 patients presenting to a community ED with painful conditions involving the distribution of the SCPB: para-cervical muscle spasm/pain (n = 8), clavicle fractures (n = 7), acromioclavicular joint injuries (n = 3), radicular pain (n = 3), and rotator cuff disorders (n = 6). Pre- and post-block 11-point verbal numeric pain scores (VNPS) were recorded, as was the incidence of any immediate complications. A retrospective chart review looked for delayed complications in the 14-day post-block period.

RESULTS

The mean 11-point VNPS reduction was 5.4 points (62%). There were no early serious complications and one case each of self-limiting vocal hoarseness and asymptomatic hemi-diaphragmatic paresis. No delayed block-related complications were found.

CONCLUSIONS

While limited by the fact that this was a nonrandomized observational experience with no control group, our findings suggest that SCBP may be safe and have potential for efficacy, and warrants further evaluation in a randomized controlled trial.

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.

A Randomized Controlled Trial Examining the Effect of the Addition of the Mandibular Block to Cervical Plexus Block for Carotid Endarterectomy

OBJECTIVES

Although the cervical plexus block generally provides adequate analgesia for carotid endarterectomy, pain caused by metal retractors on the inferior surface of the mandible is not prevented by the cervical block. Different pain relief methods can be performed for patients who experience discomfort in these areas. In this study, the authors evaluated the effect of mandibular block in addition to cervical plexus block on pain scores in carotid endarterectomy.

DESIGN

A prospective, randomized, controlled trial.

SETTING

Training and research hospital.

PARTICIPANTS

Patients who underwent a carotid endarterectomy.

INTERVENTIONS

Patients scheduled for carotid endarterectomy under cervical plexus block were randomized into 2 groups: group 1 (those who did not receive a mandibular block) and group 2 (those who received a mandibular block). The main purpose of the study was to evaluate the mandibular block in addition to cervical plexus block in terms of intraoperative pain scores.

MEASUREMENTS AND MAIN RESULTS

Intraoperative visual analog scale scores were significantly higher in group 1 (p = 0.001). The amounts of supplemental 1% lidocaine and intraoperative intravenous analgesic used were significantly higher in group 1 (p = 0.001 and p = 0.035, respectively). Patient satisfaction scores were significantly lower in group 1 (p = 0.044). The amount of postoperative analgesic used, time to first analgesic requirement, postoperative visual analog scale scores, and surgeon satisfaction scores were similar in both groups. There was no significant difference between the groups with respect to complications. No major neurologic deficits or perioperative mortality were observed.

CONCLUSIONS

Mandibular block in addition to cervical plexus block provides better intraoperative pain control and greater patient satisfaction than cervical plexus block alone.

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.

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 techniques for carotid surgery: the state of art

PURPOSE

This review will analyse some aspects of regional anaesthesia (RA) for carotid endarterectomy (CEA), a surgical procedure which requires a strict monitoring of patient's status. RA remains an important tool for the anaesthesiologist. Some debates remain about type and definition of regional anaesthesia, efficacy and safety of the different cervical block techniques, the right dose, concentration and volume of local anaesthetic, the use of adjuvants, the new perspectives: ultrasonography, the future directions.

METHODS

A literature search was performed for journal articles in English language in the PubMed Embase and in The Cochrane Library database, from January 2000 to December 2013. The electronic search strategy contained the following medical subject headings and free text terms: local anaesthesia versus general anaesthesia for endarterectomy, superficial and deep cervical block, complications of cervical nerve block, ultrasound guidance of superficial and deep cervical plexus block.

CONCLUSIONS

The gold standard for RA will be achieved after overcoming a number of limitations by a more extensive use of ultrasonography, by combining general and regional anaesthesia, including conscious anaesthesia, by defining the appropriate volume, concentration and dosage of local agents and by addition of adjuvants.