Impacts of Adding Dexmedetomidine to Bupivacaine In Ultrasound-Guided Supraclavicular Brachial Plexus Block in Forearm Surgeries
Dr. Mubina Begum Bijapur1 Dr. Nazeer Ahmed K2, Dr. Sanjeev B3 Dr. Rajendra Kumar B4,
Al-ameen Medical College Vijayapur
Dr. Mubina Begum Bijapur
Department of Anesthesia
Al-ameen Medical College Vijayapur
Background and Aims: Many drugs have been used with local anesthetics to enhance the analgesic duration of brachial plexus block. Our study aimed to evaluate the effect of Dexmedetomidine as an adjuvant to lidocaine in USG-guided supraclavicular BPB.
Methods: A randomized double-blinded study carried on 60 patients with ASA classes I and II, undergoing forearm surgeries. In group B, Bupivacaine 0.5% 2mg/kg administered and in group BD, patients were administered 2mg/kg of Bupivacaine 0.5% with Dexmedetomidine 1 µg/kg under ultrasound-guided supraclavicular Brachial plexus block. The onset of sensory and motor blocks was evaluated with pin prick test and modified Bromage scale respectively and recorded as onset of block. The first rescue analgesic time, total analgesic consumption, side effect, and hemodynamic variables were recorded. A VAS scale was used to evaluate the pain in terms of severity.
RESULT: Dexmedetomidine group showed fast onset, prolong analgesia , delayed time for first rescue analgesic demand and statistically significant less analgesic consumption in first 24 hours post- surgery compared to control group. No hemodynamic variations have been seen in both groups.
CONCLUSION: Current study showed that Dexmedetomidine has a greater impact as an adjuvant to Bupivacaine, in terms of enhance effectiveness of Supraclavicular Brachial plexus block and prolonged postoperative analgesia.
Keywords: Dexmedetomidine, Bupivacaine, Intra and Post-operatve Pain, Ultrasound-Guided; Brachial Plexus Block
Regional blocks are safe and effective techniques in several upper limb surgical procedures 1. This technique has several benefits over general anesthesia such as no of pain during operation, attenuation postoperative pain and analgesic dose, without any hemodynamic variations, and better patient’s comfort2. Supraclavicular brachial plexus block is a commonly perform in upper limb surgeries 3. A one dose of local anesthetic agent encompasses a restricted extend of block ,So various adjuvants like opioids are added to enhance their analgesic effect, however, due to the various side effects of these drugs, such as respiratory depression, apnoea and hypoxia efforts to seek out best choices continue 4.
Dexmedetomidine is highly selective alpha-2 adrenergic receptor agonists as a short-term sedation and analgesia agent in intensive care units (ICUs) and in operation theaters. Bupivacaine is long acting local anesthetic used in epidural anesthesia and subarchnoid block and in various peripheral nerve blocks 5. Addition of adjuvants like Dexmeditomidine to local anesthetic enhances the efficacy of various blocks and better control of postoperative pain thus aid in early ambulation of patients6,7.
So that our study aimed to evaluate the impact of adding Dexmedetomidine to Bupivacaine in Ultrasound guided Supraclavicular brachial plexus block in patients posted for forearm surgeries in terms of onset , duration of block, the first rescue analgesic time, and total analgesic consumption in first 24 hours as well as hemodynamic parameters and the side effects .
After approval from the Institute’s Ethics Committee and informed consent 60 patients with ASA class I and II, aged 18-50 years undergoing forearm surgery were enrolled for this study. Patients with cardiovascular and liver disorders, sensitivity to study drugs, opioids and need for general anesthesia during surgery were excluded from the study.
After explaining the block procedure and VAS pain scoring system to the patient, premedications Injection midazolam (0.05 mg/kg) and injection fentanyl (1µg/kg) were administered intravenously. The 60 patients were randomly allocated into two groups, B or D. The group B patients 2 mg/kg of Bupivacaine 0.5%% and the D group received 2 mg/kg of Bupivacaine 0.5% with Dexmedetomidine (1 µg/kg) administered in total volume of 30 ml. Supraclavicular block was performed using the HITACHI ALOKA F37 ultrasound machine with linear high frequency transducer the brachial plexus is visualize at the level between trunks and divisions by anesthesiologist who is blind of groupings and syringe contents. After local infiltration at the site of needle insertion by, a 50 mm, 22G sterile needle (Stimuplex®, B. Braun, Germany),was inserted under real time ultrasound guidance and after confirmation of tip of needle near the brachial plexus, the solution was injected and spread of drug was noted. In order to avoid intravascular injection frequent aspiration and injection technique was used. The research assistant, who was not aware of these aspects, completed the form including sensory and motor block and pain evaluation. The sensory block was confirmed with pin prick test in sensory dermatomes related to median, ulnar, radial nerves, and musculocutaneous nerves using 3-point scale. Modified Bromage scale was used to confirm the onset of motor blocked. After the onset, sensory and motor blocked recorded every 5 minutes during the first 30 minutes, then every 10 minutes until the next 30 minutes and there after every 15 minutes. The end of the motor block was determined with full movement of the limb and the end of sensory block was determined with pain in pin prick test. Also, the interval between the onset of sensory and motor block and the end of the block was recorded as duration of sensory and motor block. After the completion of surgical procedure the patient is shifted to the recovery room, where research questionnaire was completed and further assessment of the duration of sensory and motor block was continued in the recovery room.
Modified Bromage Scale
Score 0: Lack of movement,
Score 1: Discrete movements (trembling) of muscle groups,
Score 2: Ability to move against gravity, but not against resistance,
Score 3: Reduced strength, but able to move against resistance,
Score 4: Full muscle strength in relevant muscle groups.
To evaluate the severity of pain, a visual analog scale (VAS) was used (0: no pain and 10: the worst pain). The VAS was recorded before block, immediately after block, and every 5 minutes until the first 20 minutes and then, every 30 minutes during surgery. If the patient was experiencing pain with VAS higher than 3, 1µg/kg Fentanyl was injected and if VAS was higher than 5 with unsuccessful block, he or she would be under general anesthesia and was excluded from the study. During surgery, heart rate, systolic and diastolic blood pressure, and oxygen saturation was recorded every 15 minutes.
The first rescue analgesic request time and total analgesic consumption during 24 hours post-operative period were recorded. Patients were observed for any side effects during and after operation for first 24 hours.
The quantitative variables were reported as mean, standard deviation, and qualitative variables as number (percentage). In this study, to investigate gender, Chi-square was used, for quantitative demographic variables, two-sample independent t-test was used, and for variables over time, two groups of repeated measures were used. The significance level of these tests was considered smaller than 0.05. P > 0.05 statistically insignificant, p < 0 .001 statistically significant Data analysis was performed using SPSS 19 version.
A 60 patients undergoing forearm surgery equally allocated into two groups Group B (Bupivacaine), Group D(Bupivacaine with Dexmedetomidine). None of patients required immediate intervention such as bradycardia and hypotension.
Comparisons of demographic data between two groups are indicated in Table 1. No significant difference was observed between research groups (P-value < 0.05).
Table 1.Comparison of Demographic Status between Two Groups
Parameter Group B (n = 30) Group D (n = 30) P-Value
Sex (male: female) 20:10 24:6 0.592
Age 32.87 ± 10 34.11 ± 13.9 0.712
Weight 72.39 ± 6.98 69.62 ± 8.78 0.174
Height 172.88 ± 8.52 172.89 ± 8.25 0.810
Values are mean ± SD,and NO.
According to Table 2 in terms of block characteristics, there was a significant difference between the two groups.
Table 2.Comparisons the Block and Analgesia Characteristics between the Two Groups
Parameter Group B Group D P-Value
Onset of sensory block (min) 15.66 ± 4.11 13.35 ± 2.22 < 0.001
Duration of sensory block (min) 110.73 ± 12.38 154.03 ± 20.26 < 0.001
Onset of motor block (min) 19.61 ± 5.33 16.82 ± 1.77 < 0.001
Duration of motor block (min) 90.55 ± 16.20 140.27 ± 19.45 < 0.001
First analgesic request time (min) 45.16 ± 10.44 128.32 ± 15.50 < 0.001
Total analgesic consumption (mg) 76.94 ± 20.55 35.20 ± 19.35 < 0.001
Values are mean ± SD.
Statistically significant difference was observed between two groups in the VAS pain scores following post-surgery (P < 0.001) (Figure 1).
Figure 1.Comparison of VAS between two groups,Group B, Bupivacaine(blue line); Group D, Bupivacaine with Dexmeditomidine(red line)
Patient’s hemodynamic parameters (heart rate, SpO2, systolic and diastolic blood pressures) in each group were stable over time and the two groups showed no significant difference in the average variations of these parameters. Patients were controlled for adverse effects. Only two patients in the control group showed dizziness.