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Year : 2020  |  Volume : 14  |  Issue : 2  |  Page : 248-252  

Articaine and dexmedetomidine – Supplemented articaine for arteriovenous fistula creation under ultrasound-guided supraclavicular block

Department of Anesthesia, Faculty of Medicine, Ain Shams University, Cairo, Egypt

Date of Submission17-Dec-2019
Date of Acceptance09-May-2020
Date of Web Publication12-Oct-2020

Correspondence Address:
Dr. Simon Halim Armanious
Department of Anesthesia, Faculty of Medicine, Ain Shams University, Cairo
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/aer.AER_147_19

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Background: Articaine has emerged as a local anesthetic (LA) that produces sensory and motor blockade shorter than bupivacaine and lower in neurotoxicity than lidocaine. Studies have shown that adding dexmedetomidine to LA produces prolongation of sensory and motor bock duration. Early regain of motor power with adequate analgesia is needed in hemodialysis fistula creation surgery, for early start of physiotherapy. We designed this study to test efficacy of adding dexmedetomidine to articaine on the duration of sensory and motor block. Methods: After university review board approval, written informed consent to participate in the study was obtained. Patients with chronic renal failure undergoing radiocephalic hemodialysis fistula creation were eligible for enrollment in this double-blind, randomized trial. Patients receive either 40 ml of 2% articaine hydrochloride or 40 ml of articaine 2% mixed with dexmedetomidine (1 μ− 1). Sensory block duration in minutes is assessed by pinprick test and motor block duration in minutes is tested by Bromage scale; both are recorded as a primary outcome. Secondary outcomes, including onset of sensory and motor block, time for rescue analgesia, hemodynamic changes, oversedation, and possible side effect, were recorded. Results: Fifty patients were enrolled in the study (25 in the articaine Group A and 25 in the articaine and dexmedetomidine group [AD]). Longer sensory block duration was in Group AD (230–260 min) than in Group A (172–185 min) with P < 0.001. In addition, motor block duration was significantly longer in Group AD than in Group A, (220 ± 110 min), (165 ± 45 min), respectively. The duration of effective analgesia was significantly longer in Group AD (363 ± 134 min) versus in Group A (244 ± 84 min). The onset of block was short and similar between groups. Conclusion: Addition of dexmedetomidine to articaine during arteriovenous fistula creation provide prolongation of sensory and motor block duration and augment analgesia.
Trial registration: This trial was registered at Clinical with the identification number NCT04171349.

Keywords: Articaine, dexmedetomidine, hemodialysis fistula creation, supraclavicular block, ultrasound guided

How to cite this article:
Armanious SH, Abdelhameed GA. Articaine and dexmedetomidine – Supplemented articaine for arteriovenous fistula creation under ultrasound-guided supraclavicular block. Anesth Essays Res 2020;14:248-52

How to cite this URL:
Armanious SH, Abdelhameed GA. Articaine and dexmedetomidine – Supplemented articaine for arteriovenous fistula creation under ultrasound-guided supraclavicular block. Anesth Essays Res [serial online] 2020 [cited 2021 Jan 21];14:248-52. Available from:

   Introduction Top

The incidence of end-stage renal disease (ESRD) cases is going up worldwide. Ultrasound-guided nerve blockade has been shown to improve various surgical parameters in patients with ESRD undergoing arteriovenous fistula (AVF) creation. Blood flow was shown to be significantly increased in those patients having brachial plexus blockade; regional anesthesia improves venodilatation, increases postsurgical fistula blood flow, and possibly decreases time for AVFs maturation.[1]

The supraclavicular brachial plexus block is used successfully in AVF creation due to blockade of both ulnar and musculocutaneous nerves. These nerves can be missed during the interscalene and axillary approach, respectively.[2]

For early start of physiotherapy, motor function of upper limb muscle should recover after adequate anesthesia. Thus, an ideal local anesthetic (LA) drug used should have shorter motor blockade than sensorial blockade to facilitate earlier movement of upper extremity.[3]

Articaine is an amide LA produced in the 1960s and first used in clinical trials in 1974. Although it is an amide that is similar to prilocaine in chemical structure, it contains a thiophene ring rather than a benzene ring. Articaine is a rapid and short acting LA, which has low neurotoxicity and appears to diffuse through tissues more readily than other commonly used LA agents. It is metabolized by nonspecific plasma esterases both in blood and tissues, leading to its rapid clearance.[4]

α2 adrenergic receptor agonists have been the focus of interest for their sedative, analgesic, perioperative sympatholytic, and cardiovascular stabilizing effects along with providing reduction in anesthetic requirements.[5] Dexmedetomidine, an imidazole compound, dextroisomer of medetomidine, displays specific and selective α2-adrenoceptor agonist. Dexmedetomidine may act on supraspinal (locus coeruleus) or spinal level or peripheral α2-adrenoreceptor to reduce nociceptive transmission, leading to analgesia.[6]

Previous trials focused on adding dexmedetomidine to either levobupivacaine and bupivacaine, found augmentation of both sensory and motor block along with prolonged duration of effective analgesia.[6],[7] However, there remains limited knowledge of the analgesic efficacy and clinical utility of adding dexmedetomidine to articaine during peripheral nerve block in humans. Therefore, we compared the effect of articaine and dexmedetomidine added to articaine on duration sensory and motor block, analgesic requirement, and quality of block during (AVF) creation under ultrasound-guided (USG) supraclavicular plexus block.

   Methods Top

This study was conducted in Ain Shams University Hospital from June 2019 to October 2019. After university board approval, clinical trial registration at, with identification number NCT04171349, written and informed consent, fifty (NCT04171349). Fifty adult patients with chronic renal failure on hemodialysis (American Society of Anesthesiologists physical Status III, aged 25–75) scheduled for radiocephalic AVF creation under brachial plexus block were included in the study. Details of anesthetic technique and study protocol were fully explained at the preoperative visit; written consent was obtained from each patient before inclusion in the study. Patients were excluded if allergy to LAs, those having infection at the site of needle insertion, those having international normalized ratio more than 1.5, coagulopathy, neuromuscular, or severe hepatic or severe pulmonary disease, patients who refused to participate, and/or those having epilepsy were excluded from the study. Patients underwent dialysis early in the morning or the day before surgery. Patients were randomly allocated to two parallel groups based on a computer-generated sequence, which was kept in sealed envelopes. Just before the surgery, the envelope was opened by an attending pharmacist who had no other role in the data collection or analysis. All health-care providing team (patients, anesthetists, surgeons, and nurses) were blinded to the patients' allocation. The brachial plexus block was performed in both groups guided by ultrasound. The articaine group (Group A, n = 25) received 40 ml of articaine HCL 2% (articaine 20 − 1) and the articaine–dexmedetomidine (Group AD, n = 25) received 40 ml of articaine 2% mixed with dexmedetomidine (μ −1). The solution for block was prepared in similar-looking 40 ml syringes. Patients were monitored in the operation theater for electrocardiogram, heart rate (HR), respiratory rate (RR), noninvasive blood pressure (BP), and oxygen saturation (SpO2).

The patients underwent dialysis session one day before surgery and physiotherapy on the day of surgery. After explanation of anesthetic technique, base line HR, arterial BP, and SpO2 were recorded. An intravenous line was secured in the contralateral limb. The patient positioned to supine position, back elevated 30 degrees, head tilted to the contralateral side. Transportable ultrasound system (SonoSite M-Turbo; SonoSite Inc., Bothell, WA, USA) with 38 mm 8–13 MHz linear high-frequency transducer, was placed in supraclavicular fossa, to obtain clear images of brachial plexus. Skin was sterilized, anesthetized, and subclavian artery was identified. After careful aspiration 40 ml of LA solution (according to the study group), was injected in 5 ml increments around the brachial plexus, lateral and superior to the artery, through a 22-gauge 2-inch Stimuplex A needle; B. Braun Medical Inc., Melsungen, Germany.

Block assessment

Block was tested every 5 min, if it was adequate; surgery can be commenced after 30 min. Sensory block was assessed by the pinprick method [Table 1].
Table 1: Grade of sensory block

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It was performed in four nerve areas (musculocutaneous [lateral side of forearm], radial [radial dorsum of the hand], median [thenar eminence], and ulnar nerves [hypothenar eminence]) and compared on the contralateral arm. Motor block was assessed with modified Bromage scale for upper extremities on a three-point scale: 0 = normal motor function, 1 = decreased motor strength, and 2 = complete motor block; it was tested by thumb abduction (radial nerve), thumb adduction (ulnar nerve), thumb opposition (median nerve), and ability to flex elbow in pronation and supination (musculocutaneous nerve). The time between the end of the drug injection and the total abolition of pinprick sensation along the distribution of any of nerves - median, ulnar, radial, or musculocutaneous was considered as onset time of sensory block, and the time between the end of the drug injection and Grade 1 motor block was considered as onset time for motor block; both were recorded as secondary outcome.

Sensory block duration was the time between the onset of sensory block to the complete resolution of anesthesia on all nerves distribution, and motor duration block was the time interval between the onset time of motor block and the recovery of complete motor function of that limb; the duration of sensory and motor block was considered as a primary outcome.

Analgesia time (time interval between the administration of local anesthesia solution and onset of pain at surgical site) was recorded. Analgesia for the first pain consisted of 1 g paracetamol IV infusion, given for a pain visual analog scale score of ≥4. The time to first-dose rescue analgesia was also recorded as a secondary outcome.

The block was considered incomplete when any of the segments supplied by median, radial, ulnar, and musculocutaneous nerve had no analgesia even after 30 min of drug injection. These patients were supplemented with IV dexmedetomidine (1 μ −1) and surgeon infiltrate lidocaine (10 mg.mL − 1), as needed. When one or more nerve remains unblocked, it was considered a failed block. In this case, general anesthesia was started, and those patients with failed block were excluded from the study. Patients were monitored for hemodynamic variables such as HR, BP, RR, and SpO2 before block and 5, 10, 20, 30, 45, 60, 120, and 180 min after block. Sedation score using Ramsay Sedation Scale (1: awaken and alert, 2: sedated but responding to mild physical stimuli, 3: sedated but responding to moderate or strong physical stimuli, and 4: not arousable) was measured at the same time points. All patients were monitored for any side effects either intra- or postoperative such as anaphylaxis, urticarial rash, nausea, vomiting, dryness of mouth, agitation, fever, headache, circumoral numbness, tongue numbness, tinnitus, visual blurring, convulsion, respiratory affection, pneumothorax, accidental vascular puncture, hematoma, LA toxicity, phrenic nerve block and diaphragmatic paralysis, postblock neuropathy, and any hemodynamic instability.

Statistical method

Sample size calculation was done using Power Analysis and Sample Size 11 software program (NCSS, LLC. Kaysville, Utah, USA). The power analysis was carried out on the basis of the duration of motor block, which was the primary outcome. Group sample sizes of 22 patients per group would achieve an 80% power to detect a difference of 55 min in the duration of motor block with estimated means of 165 and 220 min and with estimated group standard deviations (SDs) of 3.0 and 5.3 and with a significance level (α) of 0.05000 using a two-sided two-sample t-test. Twenty-five patients per group were included to replace any missing data.

The statistical analysis was carried out using a standard Statistical Package for the Social Sciences (SPSS) software package (version 17; SPSS Inc., Chicago, Illinois, USA). Student's t-test was used to analyze parametric data that were expressed as mean ± SD values; discrete (categorical) variables were analyzed using the Chi–squared test and were expressed as numbers (%) median (25th–75th percentiles), or mean ± SD. P < 0.05 was considered statistically significant.

   Results Top

The study has been carried out in Ain shams University Hospitals on 50 adult patients with chronic renal failure scheduled for elective arteriovenous shunt creation surgery.

There was no statistically significant difference among the patients in the two groups with respect to age, weight, and sex ratio [Table 2]. The onset of sensory and motor block among different nerve distribution was similar; it was fast in both groups [Table 3].
Table 2: Demographic data

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Table 3: Onset time of sensory and motor blocks of each nerve

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The mean duration of sensory block ranged from 172 to 185 min in group A, whereas it ranged from 230 to 260 min in group AD, according to each nerve distribution. On the other hand, the duration of motor lock ranged from 161 to 211 min in group A, whereas it ranged from 220 to 250 min in group AD for each nerve [Table 4].
Table 4: Duration time of sensory and motor blocks of each nerve

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The first rescue analgesia was 244 ± 84 min in Group A and 363 ± 134 min in Group AD (P = 0.001). One patient in Group AD did not need analgesic in the postoperative 24 h period. There was no episode of hypoxemia or respiratory depression or hemodynamic side effects, such as hypotension or bradycardia, in either group during 24 h period postoperatively. In Group A, only one patient had a Ramsay Score of 2 and other patient had a score of 3. In Group AD, four patients had sedation scores of 3 and one patient had a score of 4. No statistically significant differences in sedation scores were found between the two groups (P = 0.274). Major complications (e.g. unintentional intravascular injection and persistent neurological deficit) did not occur. There was no episode of nausea and vomiting. No resuscitation or other treatment was required. No patient required readmission to the hospital after home discharge.

   Discussion Top

High failure rate of AVF at an early stage (one-third) may be influenced by anesthesia technique which determines pre- and postoperative vascular diameter and flow through the AVF; regional anesthesia such as supraclavicular brachial plexus block is a well-acceptable anesthetic techniques for AVF creation;[4] peripheral nerve block is associated with sympathetic block, which results in an increased intraoperative vascular diameter and blood flow, both intraoperatively and for several hours postoperatively. Maintenance of high flow through the fistula postoperatively can prevent thrombosis and fistula failure and is important for fistula maturation.

Articaine was introduced into UK clinical practice in 1988 as an amide LA. That unlike other LAs contains a thiophene instead of benzene ring, this increases its lipid solubility leading to a greater portion of the administered dose enters the neurons and hence increase drug potency Yopp et al.[8] Articaine also possesses an ester link that allows hydrolysis by plasma esterases as well as liver; thus, it can be considered less nephrotoxic.[9] Rapid breakdown of articaine to inactive metabolite articaine acid is related to a very low systemic toxicity and short duration of action. To date, there has been an increasing use of adjuncts (e.g. opioids and α2-adrenoreceptor agonists) to LA drugs to improve the block quality and extend duration.[10] Dexmedetomidine is a selective alpha-2 adrenoreceptor agonist. It provides dose-dependent sedation and analgesia without relevant respiratory depression; now, dexmedetomidine is used as an adjuvant to LA drugs in peripheral nerve blockade.

From our research, we found a lack of previous data concerning use of articaine in supraclavicular block. Simon et al.[11] studied both lidocaine and articaine in axillary block; they found that both drugs share similar pharmacodynamics properties, but differ in pharmacokinetic behavior.

In this randomized double-blind study, we evaluated the effect of adding dexmedetomidine (1 μ −1). As an adjuvant to articaine 2% in USG supraclavicular block for the patients with ESRD undergoing AVF creation and we found an increase in duration of sensory, motor block, and duration of effective postoperative analgesia. But it is neither affects onset time of the block nor modify the rate of successful blocks. Adding dexmedetomidine did not modify the rate of successful blocks.

Articaine is used safely as an LA for outpatient dental surgery.[12] Although evidence demonstrates safe discharge to home with insensate limb,[13] hospital discharge without protective reflexes remains point of controversy because of the possibility of accidental injury.[14] Lack of prolonged analgesia is a disadvantage. Hence, α2-adrenoreceptor agonists are added to limit side effects of LA. and prolong duration of effective analgesia and improve intensity of motor block, Addition of dexmedetomidine in brachial plexus is reported to improve success rate and postoperative analgesia in some studies.[6],[15]

The rapid onset of sensory and motor blockade was similar in both the study groups (7 ± 2 min) with the use of articaine, while in a previous study Marhofer et al.[16] added dexmedetomidine as an adjuvant to ropivacaine in a USG-guided ulnar nerve block and showed that the time for the onset of motor block is decreased without effect on time to the onset of sensory block. Also, Das et al.[17] studied 84 patients posted for elective forearm and hand surgeries to evaluate the effect of adding dexmedetomidine to ropivacaine for supraclavicular brachial plexus blockade. They found that the onset of the block is earlier in the dexmedetomidine group (13.95 ± 1.34 min).

The duration of sensory bock was longer in group AD versus Group A (230–260 min vs. 172–185 min); Das et al.[17] also found that sensory block duration was longer in the dexmedetomidine group (379.4 ± 55.59 min). Longer motor block duration in Group AD versus Group A (220 ± 110 min vs. 165 ± 45 min) also goes with longer motor block in Das's study (312 ± 49.91 min). Longer block duration in Das study may be attributed to their usage of ropivacaine which is a known long-acting LA drug.

We recorded significantly increased duration of effective analgesia in AD group (250 ± 130 min). A similar result was found by Gandhi et al.[18] who observed increased duration of analgesia in Group D (732.4 ± 95.1 min), compared to 194.8 ± 60.4 min in the control group. Also, Swami et al.[15] observed a significant (P = 0.001) increase in the duration of analgesia in the dexmedetomidine group as compared with clonidine. Esmaoglu et al.[6] reported significant increased duration of analgesia when they added dexmedetomidine to levobupivacaine.

In our study, the duration of motor block was significantly prolonged in AD group (220 ± 200 min). Prolonged motor block was undesired in AVF operation as it increases incidence of trauma to the paralyzed limb. So usage of short acting LA like articaine is more favorable than levobupivacaine which results in excessive motor block (312.0 ± 49.91 min) in Das et al., study.[17]

In accordance with a study by Esmaoglu et al.[6] and Swami et al.,[15] our study showed no serious side effects except for mild bradycardia, hypotension and one patient experienced excessive somnolence, all were observed in dexmedetomidine group and managed conservatively.

   Conclusion Top

The addition of dexmedetomidine to articaine during supraclavicular block for chronic renal failure patients prolongs duration of motor block and analgesia; however, it does not affect onset of sensory and motor block. It allows early start of physiotherapy and hospital discharge. The action of dexmedetomidine is most probably peripheral rather than centrally mediated. However, further trials with larger sample size are needed to determine the exact dose and possible neurotoxicity of dexmedetomidine.


We acknowledge Prof. Hany El Dahaby, the Chairman of Department of Anesthesia, Ain Shams University.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Malinzak EB, Gan TJ. Regional anaesthesia for vascular access. Anesth Analg 2009;109:976-80.  Back to cited text no. 1
Vermeylen K, Engelen S, Sermeus L, Soetens F, van de Velde M. Supraclavicular brachial plexus blocks: Review and current practice. Acta Anaesthesiol Belg 2012;63:15-21.  Back to cited text no. 2
Shemesh D, Olsha O, Orkin D, Raveh D, Goldin I, Reichenstein Y, et al. Sympathectomy-like effects of brachial plexus block in arteriovenous access surgery. Ultrasound Med Biol 2006;32:817-22.  Back to cited text no. 3
Oertel R, Rahn R, Kirch W. Clinical pharmacokinetics of articaine. Clin Pharmacokinet 1997;33:417-25.  Back to cited text no. 4
Pöpping DM, Elia N, Marret E, Wenk M, Tramèr MR. Clonidine as an adjuvant to local anesthetics for peripheral nerve and plexus blocks: A meta-analysis of randomized trials. Anesthesiology 2009;111:406-15.  Back to cited text no. 5
Esmaoglu A, Yegenoglu F, Akin A, Turk CY. Dexmedetomidine added to levobupivacaine prolongs axillary brachial plexus block. Anesth Analg 2010;111:1548-51.  Back to cited text no. 6
Brummett CM, Norat MA, Palmisano JM, Lydic R. Perineural administration of dexmedetomidine in combination with bupivacaine enhances sensory and motor blockade in sciatic nerve block without inducing neurotoxicity in rat. Anesthesiology 2008;109:502-11.  Back to cited text no. 7
Yapp KE, Hopcraft MS, Parashos P. Articaine: A review of the literature. Br Dent J 2011;210:323-9.  Back to cited text no. 8
Ogle OE, Mahjoubi G. Local anesthesia: Agents, techniques, and complications. Dent Clin North Am 2012;56:133-48, i×.  Back to cited text no. 9
Choi S, Rodseth R, McCartney CJ. Effects of dexamethasone as a local anaesthetic adjuvant for brachial plexus block: A systematic review and meta-analysis of randomized trials. Br J Anaesth 2014;112:427-39.  Back to cited text no. 10
Simon MA, Vree TB, Gielen MJ, Booij LH, Lagerwerf AJ. Similar motor block effects with different disposition kinetics between lidocaine and (+ or -) articaine in patients undergoing axillary brachial plexus block during day case surgery. Int J Clin Pharmacol Ther 1999;37:598-607.  Back to cited text no. 11
Bartlett G, Mansoor J. Articaine buccal infiltration vs lidocaine inferior dental block-A review of the literature. Br Dent J 2016;220:117-20.  Back to cited text no. 12
Hutton, M, Brull R, McFarlane A. Regional anesthesia and outcomes. BJA Educ 2018;18:52-6.  Back to cited text no. 13
Vetter TR, Boudreaux AM, Jones KA, Hunter JM Jr., Pittet JF. The perioperative surgical home: How anesthesiology can collaboratively achieve and leverage the triple aim in health care. Anesth Analg 2014;118:1131-6.  Back to cited text no. 14
Swami SS, Keniya VM, Ladi SD Rao R. Comparison of dexmedetomidine and clonidine (α2 agonist drugs) as adjuvant to local anesthesia in supraclavicular brachial plexus block: A randomized double -blind prospective study. Indian J Anesthesia 2012;56:243-9.  Back to cited text no. 15
Marhofer D, Kettner SC, Marhofer P, Pils S, Weber M, Zeitlinger M. Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: A volunteer study. Br J Anaesth 2013;110:438-42.  Back to cited text no. 16
Das B, Lakshmegowda M, Sharma M, Mitra S, Chauhan R. Supraclavicular brachial plexus block using ropivacaine alone or combined with dexmedetomidine for upper limb surgery: A prospective, randomized, double-blinded, comparative study. Rev Esp Anestesiol Reanim 2016;63:135-40.  Back to cited text no. 17
Gandhi R, Shah A, Patel I. Use of dexmedetomidine alone with bupivacaine for brachial plexus block. Nat J Med Res 2012;2:67-9.  Back to cited text no. 18


  [Table 1], [Table 2], [Table 3], [Table 4]


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