European Journal of Cardiovascular Medicine

Regional anesthesia techniques are essential in modern anesthetic practice, offering effective anesthesia and analgesia while avoiding the adverse effects associated with general anesthesia. Among these, brachial plexus blocks are widely practiced for upper limb surgeries as they provide reliable sensory and motor blockade, superior postoperative analgesia, reduced opioid consumption, and earlier recovery compared to general anesthesia1,2.

Bupivacaine has long been considered the gold standard for brachial plexus blocks due to its prolonged duration of action and dense anesthesia. However, concerns regarding its cardiotoxicity following inadvertent intravascular injection have prompted the search for safer alternatives3. Ropivacaine, an S-enantiomer of propivacaine, was developed with a superior safety profile. It demonstrates reduced cardiotoxicity, less motor blockade, and faster recovery, making it favorable in outpatient and ambulatory settings4,5.

To further improve block efficacy, adjuvants are often combined with local anesthetics. Commonly studied agents include epinephrine, opioids, clonidine, magnesium, and dexmedetomidine. Dexmedetomidine, a highly selective α2-adrenergic agonist, exhibits sedative, anxiolytic, and analgesic properties without significant respiratory depression6,7. When used as an adjuvant in peripheral nerve blocks, it shortens onset time, prolongs duration of sensory and motor blockade, improves block quality, and provides stable hemodynamics8,9.

Several studies have compared ropivacaine and bupivacaine in brachial plexus blocks, with variable results regarding onset and duration10–12. Dexmedetomidine has consistently shown block-prolonging effects with both agents13–15. However, limited literature directly compares ropivacaine–dexmedetomidine and bupivacaine–dexmedetomidine combinations in supraclavicular brachial plexus block.

Thus, the present study was designed to compare these two combinations, evaluating onset, duration, quality of block, and safety profile in patients undergoing elective upper limb surgeries.

This prospective, randomized, comparative study was conducted at ACSR Government Medical College and Hospital, Nellore, after approval from the Institutional Scientific and Ethics Committee. Written informed consent was obtained from all participants.

Inclusion criteria:

• Age 18–70 years
• ASA physical status I–II
• Scheduled for elective elbow, forearm, or hand surgery under supraclavicular brachial plexus block

Exclusion criteria:

• Refusal to participate
• History of bleeding disorders or anticoagulant therapy
• Peripheral neuropathy
• Local infection at the injection site
• Chronic respiratory disease
• Known hypersensitivity to study drugs

Randomization and Groups

Sixty patients were randomized using a computer-generated table into two groups (n=30 each):

• Group BD: 30 ml of 0.25% bupivacaine + dexmedetomidine 1 mcg/kg
• Group RD: 30 ml of 0.375% ropivacaine + dexmedetomidine 1 mcg/kg

Procedure

All patients underwent routine pre-anesthetic evaluation. Standard monitoring (ECG, SpO₂, NIBP) was applied. The supraclavicular approach was performed under aseptic precautions. After eliciting paresthesia, drug solutions were injected incrementally with negative aspiration to prevent intravascular injection.

Outcome Measures

1. Onset of sensory block: time from drug injection to loss of pinprick sensation in C4–T2 dermatomes.
2. Onset of motor block: time from injection to complete inability to move elbow, wrist, and fingers.
3. Duration of sensory block: time from onset to return of pinprick sensation.
4. Duration of motor block: time from onset to recovery of motor function.
5. Quality of block: graded as satisfactory (no need for supplemental analgesics) or unsatisfactory (intraoperative fentanyl required).
6. Hemodynamic parameters: HR, MAP, SpO₂ recorded at regular intervals.
7. Adverse effects: bradycardia, hypotension, respiratory depression, or neurological complications.

Statistical Analysis

Data were analyzed using SPSS software. Continuous variables were expressed as mean ± SD and compared using Student’s t-test. Categorical variables were analyzed using Chi-square test. p < 0.05 was considered statistically significant. A p-value of <0.01 as statistically highly significant. A p-value of <0.001 as statistically very highly significant.

Table 1: Age Distribution of Patients

Table 2: Gender Distribution

Table 3: Onset of Block

Table 4: Duration of Block

Table 5: Quality of Block

Table 6: Hemodynamic Changes

Interpretation:

• Ropivacaine–dexmedetomidine had faster onset of sensory and motor blockade.
• Bupivacaine–dexmedetomidine provided longer duration of analgesia.
• Block quality and hemodynamic stability were comparable.

The present study demonstrates the clinical differences between ropivacaine–dexmedetomidine and bupivacaine–dexmedetomidine in supraclavicular brachial plexus blocks. While both groups achieved effective anesthesia, notable differences were observed in onset and duration.

Ropivacaine, due to its lower lipid solubility and pure S-enantiomer structure, exhibited a faster onset of action. Similar findings were reported by Anupreet Kaur et al.16 and Kooloth et al.17, where ropivacaine produced earlier sensory and motor blockade compared to bupivacaine. However, consistent with our results, the duration of blockade was longer with bupivacaine, as shown in trials by McGlade et al.18 and Bertini et al.19.

Dexmedetomidine as an adjuvant significantly enhanced block quality in both groups. Its α2-adrenergic agonist action not only prolonged block duration but also provided sedation and stable hemodynamics. Agarwal et al.20 observed that addition of dexmedetomidine to bupivacaine prolonged analgesia significantly without major adverse effects. Similarly, Das et al.21 demonstrated that ropivacaine–dexmedetomidine combinations shortened onset and extended block duration compared to ropivacaine alone.

A meta-analysis by Abdallah and Brull22 confirmed that dexmedetomidine is an effective adjunct in peripheral nerve blocks, prolonging analgesia by approximately 4–6 hours. Importantly, none of our patients developed significant bradycardia, hypotension, or neurotoxicity, aligning with safety profiles reported in previous studies23–25.

Clinically, the choice of drug may be tailored according to surgical requirements. Ropivacaine–dexmedetomidine is advantageous in day-care surgeries requiring rapid onset and early motor recovery. In contrast, bupivacaine–dexmedetomidine is better suited for longer surgeries and when prolonged postoperative analgesia is desirable.

Overall, this study reinforces the complementary roles of ropivacaine and bupivacaine when combined with dexmedetomidine, offering anesthesiologists flexibility in optimizing anesthesia care.

Both ropivacaine–dexmedetomidine and bupivacaine–dexmedetomidine combinations are safe and effective for supraclavicular brachial plexus block. Ropivacaine ensures rapid onset and early recovery, while bupivacaine provides longer postoperative analgesia. Clinical selection should be individualized based on surgery duration and recovery requirements.

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2. Kooloth R, George GM, Manissery JJ. Comparison of clinical characteristics of ropivacaine and bupivacaine in supraclavicular brachial plexus block. Anaesth Essays Res. 2015;9(1):5-9. doi:10.4103/0259-1162.150165
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    16–25.