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| ORIGINAL ARTICLE |
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| Year : 2017 | Volume
: 18
| Issue : 2 | Page : 56-62 |
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Comparative study of supraclavicular brachial plexus block with or without dexamethasone
Nilesh M Solanki, Ankur Garg, Shradha D Kavad, Ajay Rathod
Department of Anaesthesia, B. J. Medical College and Civil Hospital, Ahmedabad, Gujarat, India
| Date of Submission | 02-Sep-2017 |
| Date of Acceptance | 04-Oct-2017 |
| Date of Web Publication | 12-Dec-2017 |
Correspondence Address:
Dr. Nilesh M Solanki
44-Devshrusti Bungalows-II, B/H Kena Bungalows, Motera Stadium Road, Motera, Sabarmati, Ahmedabad - 380 005, Gujarat
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/TheIAForum.TheIAForum_29_17
Background: Local anesthetics with various adjuvants are used to increase the duration of postoperative analgesia in supraclavicular brachial plexus block. Perineural injection of steroid is known to influence postoperative analgesia.
Materials and Methods: A total of fifty patients of the American Society of Anaesthesiologist Grade I–II undergoing various upper limb surgeries under supraclavicular brachial plexus block were randomly divided into two groups. In Group C, patients received 32 ml of mixture of 1.5% lignocaine–adrenaline 10 ml, 0.5% bupivacaine 20 ml and normal saline 2 ml, whereas in Group D, patients received the same amount of local anesthetics with dexamethasone 2 ml (8 mg). Sensory and motor block were recorded at the regular intervals. Postoperative analgesia was assessed using visual analog scale (VAS) score. Statistical analysis was performed using Student's unpaired t-test.
Results: The mean onset time of sensory and motor block was 3.24 ± 1.09 min and 6.2 ± 1.44 min in Group D and 4.24 ± 1.42 min and 7.52 ± 1.50 min in Group C, respectively. There was markedly prolonged duration of analgesia in Group D (12–16 h) compared to Group C (4–5 h). The mean VAS score was 4.16 ± 1.39 at the end of 6 h in Group C, whereas it was 0 (zero) in Group D at the same time. The difference was statistically significant (P < 0.05).
Conclusion: Addition of dexamethasone as an adjuvant to local anesthetics in brachial plexus block provides in significantly early-onset and markedly prolonged duration of analgesia without hemodynamic disturbances.
Keywords: Analgesia, dexamethasone, local anesthetics, supraclavicular block
How to cite this article:
Solanki NM, Garg A, Kavad SD, Rathod A. Comparative study of supraclavicular brachial plexus block with or without dexamethasone. Indian Anaesth Forum 2017;18:56-62 |
How to cite this URL:
Solanki NM, Garg A, Kavad SD, Rathod A. Comparative study of supraclavicular brachial plexus block with or without dexamethasone. Indian Anaesth Forum [serial online] 2017 [cited 2023 Jun 4];18:56-62. Available from: http://www.theiaforum.org/text.asp?2017/18/2/56/220556 |
| Introduction | |  |
Brachial plexus block is good alternative to general anesthesia for upper limb surgery. This avoids the unwanted effect of anesthetic drugs used during general anesthesia and the stress of upper airway instrumentation.[1]
Various additives such as opioids, clonidine, and verapamil were added to local anesthetics to achieve quick, dense, and prolonged block, but the results are either inconclusive or associated with side effects.[2],[3],[4]
Steroids have powerful anti-inflammatory as well as analgesic property. They relieve pain by reducing inflammation and blocking transmission of nociceptive C-fibers and by suppressing ectopic neural discharge.[5]
With this background data, we evaluated the effect of dexamethasone as an adjuvant to mixture of local anesthetics in supraclavicular brachial plexus block in patients undergoing upper limb surgery. The duration of postoperative analgesia, onset as well as duration of sensory and motor block, perioperative hemodynamic changes and any side effect were recorded.
| Materials and Methods | | |
After obtaining institutional ethical committee approval and written informed consent from patients, this study was conducted in the orthopedic operation theater in our institute, between August 2015 to September 2016, a total of 50 American Society of Anaesthesiologist physical status I or II patients of either sex, aged 18–70 years scheduled for elective or emergency orthopedic surgeries of upper limb under supraclavicular brachial plexus block were included in this study. Patients with history of uncontrolled diabetes, renal and liver diseases, pregnant women, peptic ulcer disease, and bleeding disorder, allergy to local anesthetic drugs and on long-term steroid therapy were excluded from the study.
The research methodology was prospectively randomized with the help of computer generated coded envelopes and the patients were divided into two groups as follows: Group C and Group D.
In the operation room after establishing 18 gauge intravenous (IV) access in the contralateral hand, the baseline parameters were observed and recorded, which included heart rate, noninvasive blood pressure, electrocardiogram, and pulse oximetry. All patients were premedicated with injection glycopyrrolate 0.2 mg and injection ondansetron 4 mg intravenously. Patients in Group C received 32 ml of mixture of 1.5% lignocaine–adrenaline 10 ml, 0.5% bupivacaine 20 ml, and normal saline 2 ml, whereas in Group D, patients received the same amount of local anesthetics with dexamethasone 2 ml (8 mg).
Supraclavicular brachial plexus block was performed under strict aseptic and antiseptic precautions with the patient in supine position and head turned slightly to the opposite side. A small pillow was placed in between the shoulders. The arm to be anesthetized is adducted and hand extended along the side toward the ipsilateral knee as far as possible. Landmarks such as midclavicular point, external jugular vein, and subclavian artery pulsation were identified. About 2 cm above the midclavicular point just lateral to subclavian artery pulsation, a 23 gauge 1.5 inch needle was introduced and directed caudally and medially until paresthesia was encountered, then 32 ml of local anesthetics with or without dexamethasone was injected slowly and aspiration done every 5 ml, during injection to prevent vascular injection. Block was given either by blind technique or by the peripheral nerve stimulator (PNS). In PNS-guided block 22-gauge, 5 cm insulated needle was introduced and directed in the same manner as above. The stimulation frequency was set at 3 Hz, the duration of stimulation at 0.1 m, and the intensity of the stimulating current was initially set to deliver 3 mA and was then gradually decreased. The position of the needle was considered to be acceptable when an output current <0.7 mA still elicited a slight distal motor response in each of the nerve distributions.
Sensory and motor block were recorded at the regular intervals after drug injection. Sensory block was assessed by pin prick and compared with the same stimulation on the contra lateral hand. Sensory block was graded as:
- Grade-0: No sensation felt
- Grade-1: Dull sensation felt
- Grade-2: Sharp pain felt.
Onset time was defined as from end of injection to first dull sensation felt.
Motor block was evaluated by thumb abduction (radial nerve), thumb adduction (ulnar nerve), thumb apposition (median nerve), and flexion of elbow (musculocutaneous nerve). Motor block was graded as follows:
- Grade-0: Complete paralysis
- Grade-1: Paresis
- Grade-2: Normal muscle force.
Onset time was considered when patient felt heaviness on abduction of arm at shoulder.
Block was considered complete, when all the segments supplied by the nerves had anesthesia. In case of unsatisfactory effect, patients were supplemented with general anesthesia and these cases were excluded from the study. Injection midazolam 1 mg was given intravenously 20 min after the procedure when assessment of block was complete. Patients were monitored for vital parameters at regular intervals and any untoward side effects were also noted. Assessment of blood loss was done and crystalloids and colloids were administered accordingly.
At the end of surgery vital parameters, consciousness, response to verbal commands and duration of surgery were noted. Postoperatively, vital parameters were monitored every 2 hourly and analgesia was assessed using visual analog scale (VAS) score. VAS score 0 and 8–10 were taken as no pain and worst pain perceived, respectively. If the VAS score >4, rescue analgesia was given in the form of injection diclofenac sodium 1.5 mg/kg intramuscularly.
If any side effects related to the technique or drug such as nausea, vomiting, respiratory depression, pneumothorax occurred they were recorded.
The duration of the sensory block was defined as the time interval between complete sensory block and return of normal sensation. The duration of motor block was defined as the time interval between the complete paralysis and complete recovery of motor function.
The duration of analgesia was defined as the time from injection of drug in brachial plexus to rescue analgesia was given. All results were expressed in mean ± standard deviation or number as applicable.
Statistical analysis
In this study, sample size was calculated using formula n = 4pq/E 2 which is based on Hardy-Weinberg principle. In this formula, P is the prevalence of upper limb surgery at our institute.
Statistical analysis was carried out using Microsoft Office Excel 2010 and Graph Pad Prism 6.05 (QuickCalc) software (Graph Pad software Inc., La Jolla CA, USA). The data were analyzed using Chi-square test with Yates's correction and Fisher's exact test (two-tailed) for qualitative and Student's unpaired t test for quantitative data. P < 0.05 was considered to be statistically significant, P < 0.001 was taken as highly statistically significant, and P > 0.05 was considered to be nonsignificant.
| Results | | |
There was no significant difference among the groups with regard to demographic variables (P > 0.05) [Table 1]. There were more male patients than female and duration of surgery was similar in both the groups. The difference was not statistically significant (P > 0.05).
Primary outcome of study
Onset of sensory and motor block
The mean onset time of sensory block was 4.24 ± 1.42 min in Group C and 3.24 ± 1.09 min in Group D. The mean onset time of motor block was 7.52 ± 1.50 min in Group C and 6.2 ± 1.44 min in Group D. The difference was statistically significant (P< 0.05) [Figure 1]. | Figure 1: Time of onset of sensory and motor block in both the groups. There was statistically significant difference in onset of sensory and motor block in Group D as compared to Group C (P < 0.05). Data presented as mean
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Duration of analgesia
There was markedly prolonged duration of analgesia in Group D, 12–16 h (mean 855.6 ± 83.81 min) compared to Group C, 4–5 h (mean 276.16 ± 20.44 min). The results were statistically highly significant (P< 0.001) [Figure 2]. | Figure 2: Duration of sensory block, motor block and postoperative analgesia in both the groups. There was statistically significant difference in duration of sensory block, motor block and postoperative analgesia in Group D as compared to Group C (P < 0.001). Data presented as mean
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Duration of sensory and motor block
There was significant difference in duration of sensory block in Group D (636.4 ± 26.12 min) as compared to Group C (262.04 ± 17.6 min). Similarly, the duration of motor block was prolonged in Group D (463.2 ± 35.20 min) as compared to Group C (251.4 ± 18.68 min) [Figure 2].
Visual analog scale score
The mean VAS score was 4.16 ± 1.39 at the end of 6 h in Group C, while it was 0 (zero) in Group D at the same time. The difference was statistically highly significant (P< 0.001) [Figure 3]. | Figure 3: Comparison of visual analog scale score in both the groups. The mean visual analog scale score was >4 in Group D (end of 14 hours) as compared to Group C (end of 6 hours). The difference was statistically significant (P < 0.001). Data presented as number
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Secondary outcomes of the study
There was no statistically significant difference in heart rate and systolic blood pressure on addition of dexamethasone to mixture of local anesthetic drugs [Figure 4] and [Figure 5]. | Figure 4: Comparison of heart rate at different time intervals in both the groups. There was no statistically significant difference between two groups of patients in terms of heart rate. Data presented as mean
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 | Figure 5: Comparison of systolic blood pressure at different time intervals in both the groups. There was no statistically significant difference between two groups of patients in terms of systolic blood pressure. Data presented as mean
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There was no significant complication observe during our study.
| Discussion | | |
A regional technique should always be considered whenever general condition of the patient is poor, or the patients is not adequately prepared or in the presence of associated condition like uncontrolled diabetes, hypertension, cardiovascular, or respiratory diseases. It is also useful when the patients prefers to retain his consciousness during surgery and when it is important for the patient to remain ambulatory.
Various approaches to brachial plexus block have been described, but supraclavicular brachial plexus block is widely employed peripheral nerve block to provide anesthesia and analgesia for upper limb surgeries. It avoids the unwanted effect of the anesthetic drugs used during general anesthesia and the stress response of laryngoscope and tracheal intubation. We had selected supraclavicular approach to brachial plexus block.
In this study, we aimed to find the effect of dexamethasone with local anesthetics mixture for early onset and prolongation of postoperative analgesia in patients undergoing upper limb surgery under supraclavicular brachial plexus block.
Any method of postoperative pain relief must meet three basic criteria. It should be effective, safe and feasible. Local anesthetics alone provide better operating condition with shorter duration of analgesia. To extend the analgesia period beyond the operating rooms, various methods have been tried with the aim of prolonging the local anesthetic action, like continuous infusion of local anesthetics via indwelling catheters or use of different additives in local anesthetics.
In our study, dexamethasone was used as an adjuvant in local anesthetics. The present study was a randomized, prospective, double-blinded, and controlled study. The assessment of onset and duration of block was carried out by the principal investigator who was blinded to the drugs administered in the block.
Calcium ions have an important role in analgesia mediated by local anesthetics. Local anesthetis reduce calcium permeability and various studies have shown that verapamil can potentiate the analgesic effects of local anesthetics.[4]
Epidural steroids were used for pain relief agent in backache and sciatica.[5] A study done by Elhakim et al.[6] suggest that oral and IV route of dexamethasone reduces overall pain scores and analgesic requirements in the postoperative period without any adverse effects in pediatric tonsillectomy patients. Dexamethasone is also known to reduce postoperative nausea and vomiting.[7] Dexamethasone has been used successfully for postoperative pain relief and reduces swelling following extraction of third molar teeth.[8] The possible mechanism of analgesic and antiemetic actions are due to anti-inflammatory property of dexamethasone.[7],[8]
Steroids are very potent anti-inflammatory and immunosuppressive agents. Perineural injection was found to be safe, devoid of potential side effects and may affect postoperative analgesia. Among the various steroids, dexamethasone a 9α-derivative synthetic glucocorticoid is preferred because it is highly potent anti-inflammatory, about 30 times as potent as hydrocortisone and without any mineralocorticoid activity.[9]
Kopacz et al.[10] reported that intercostals injection of dexamethasone containing bupivacaine microcapsules produces prolonged duration of anesthesia and analgesia in healthy human volunteers. They also concluded that there is a causative relationship between the suppression of inflammation and the remarkably longer duration action.
The mechanism of action is not clearly understood when corticosteroids as an adjuvant to local anesthetics for peripheral nerve blocks. The block prolonging effect may be due to its local action of nerve fibers and not a systemic one.[10] However, Baxender et al.[8] concludes that analgesic properties of corticosteroids are the result of their systemic effect. According to the traditional theory of steroid action, steroids bind to intracellular receptors and modulate nuclear transcription.
In one study by Shrestha et al.[11] onset of action was 10–30 min in local anesthetic group (mean 18.15 ± 4.25) and 10–20 min (mean 14.5 ± 2.10 min) in the local anesthetic plus steroid group. Another study by Islam et al.[12] found that the mean onset time of sensory and motor block was 11.64 ± 2.19 min and 13.32 ± 0.98 min in control group (Group A) and 9.89 ± 1.97 min and 11.09 ± 1.28 min in dexamethasone group (Group B).
In our study, significantly early-onset of sensory (3.24 ± 1.09) and motor block (6.2 ± 1.44) was noticed in Group D, whereas in Group C, onset of sensory (4.24 ± 1.42) and motor block (7.52 ± 1.50) was noticed. Our observation in terms of time taken for onset of sensory (mean 196.33 ± 26.45 s) and motor block (mean 225.66 ± 26.86 s) concur with studies done by Golwala et al.[9]
However, another study by Movafegh et al.[13] found that the onset time of sensory and motor blockade was similar in both the groups. Dexamethasone did not produce significant difference in the onset time of sensory and motor block.
Some authors believe that addition 4–8 mg of dexamethasone as an adjuvant to mixture of local anesthetics in supraclavicular brachial plexus block, markedly prolonged duration of post-operative analgesia.[9],[11],[12],[14]
In our study mean duration of analgesia in Group C was (mean 276.16 ± 20.44 min), whereas in Group D, it was (mean 855.6 ± 83.81 min). We assessed the duration of analgesia among the study groups by using VAS score every 2 hourly. The VAS score in both the groups were similar in the first 3 h after ignition of block. There was markedly prolonged duration of analgesia in Group D, 12–16 h, whereas in Group C, it was 4–5 h. The mean duration of analgesia was 3 times more prolonged in the dexamethasone group compared to the control group.
Arish et al.[15] concluded that when dexamethasone used as an adjuvant along with local anesthetic in brachial plexus block, it effectively prolongs the duration of both sensory (mean 1075.20 ± 144.831 min) and motor blockade (mean 475.20 ± 114.787 min) with no side effects.
In our study, the duration of sensory block in Group D (mean 636.4 ± 26.12 min) as compared to Group C (mean 262.04 ± 17.6 min). Similarly, the duration of motor block was prolonged in Group D (mean 463.2 ± 35.20 min) as compared to Group C (mean 251.4 ± 18.68 min). All data were highly significant statistically which showed that the sensory and motor block was significantly prolonged compared to the control group.
In comparison with epinephrine and midazolam addition of dexamethasone to bupivacaine had rapid onset of block and longer time to first analgesic request with fewer side effects.[16]
Baloda et al.[17] concluded, the addition of 8 mg of dexamethasone to 0.5% isobaric levobupivacaine effectively and safely shortens the onset of sensory and motor blockade, increases the duration of sensory and motor blockade and increases the duration of postoperative analgesia without any hemodynamic disturbances.
Albrecht et al.[18] did not show an interaction between dose of perineural dexamethasone (4-10 mg) and duration of analgesia. Dexamethasone increased the mean (95% CI) duration of analgesia by 233 (172–295) min when injected with short or medium term action local anesthetics and by 488 (419–557) min when injected with long term action local anesthetics P < 0.00001 for both.
Fourteen studies consisting of a total of 1022 patients in systematic review done by Knezevic et al.[19] have identified a significant beneficial postoperative effect of adding perineural dexamethasone to local anesthetics for brachial plexus block in several regards: duration of analgesia, pain scores, and opioid consumption. Both low (4–5 mg) and high doses (8–10 mg) of dexamethasone used in perineural adjunctive application comparably prolonged the duration of brachial plexus analgesia, regardless of different local anesthetic types and brachial plexus approaches.
Choi et al.[20] in their systematic review of 9 studies and 801 patients demonstrate that perineural administration of dexamethasone with local anesthetic prolongs brachial plexus block effects with no observed adverse events. The effect of systemic administration of dexamethasone on brachial plexus block must be investigated.
Some authors used the nerve stimulator [13],[17] or ultrasound transducer [16] to aid the location of brachial plexus. In our study, we used blind technique and nerve stimulator for supraclavicular block.
Dexamethasone is not known to have any imminent effect on heart rate. Complications with a single dose of dexamethasone are rare and previous studies have determined that short term use of dexamethasone was safe.
Limitation of our study is we did not use ultrasound guided block because of unavailability in our institute during the study period.
Multiple studies have shown that perineural dexamethasone improves postoperative analgesia. However, some studies have shown minimal benefit, and have raised concerns regarding adverse physio-chemical effects of perineural dexamethasone.
More studies are required to evaluate the practical benefits and clinical safety of perineural dexamethasone as a local anesthetics adjunct. Furthermore, direct comparisons between perineural and IV dexamethasone administration would also provide information regarding the optimal route of administration and a possible clarification of the mechanism of action of this adjuvant.
| Conclusion | | |
The addition of 8 mg of dexamethasone as an adjuvant to mixture of local anesthetics in supraclavicular brachial plexus block effectively and safety shortens the onset of sensory and motor block, increases the duration of sensory and motor block and markedly prolonged duration of postoperative analgesia without hemodynamic disturbances.
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Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
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| 3. | Iohom G, Machmachi A, Diarra DP, Khatouf M, Boileau S, Dap F, et al. The effects of clonidine added to mepivacaine for paronychia surgery under axillary brachial plexus block. Anesth Analg 2005;100:1179-83. [ PUBMED] |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1]
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