Levobupivacaine 0.5% versus ropivacaine 0.75% for ultrasound-guided costoclavicular block in upper limb surgery: A randomized controlled trial

Technical Summary: Levobupivacaine 0.5% versus Ropivacaine 0.75% for Ultrasound-Guided Costoclavicular Block

Problem Statement
Effective perioperative analgesia is critical for upper limb surgeries to facilitate recovery and reduce systemic stress. While the costoclavicular brachial plexus block (CCB) has emerged as a reliable, superficial, and safe technique for upper limb anesthesia, comparative data regarding the optimal local anesthetic agent for this specific approach remain limited. Although levobupivacaine and ropivacaine are standard long-acting amide local anesthetics used in regional anesthesia, their efficacy profiles—specifically onset time, duration of analgesia, and recovery characteristics—have not been directly compared in the context of ultrasound-guided CCB. The study aimed to determine if 0.5% levobupivacaine offers superior duration of analgesia or motor blockade compared to 0.75% ropivacaine, or if ropivacaine provides a better sensory-motor differential for earlier mobilization.

Methodology
This was a prospective, randomized, double-blind controlled trial conducted at Kasturba Medical College, India, involving 60 adult patients (ASA I–III) scheduled for upper limb surgeries below the mid-shaft of the humerus.

• Intervention: Participants were randomly allocated into two groups (n=30 each). Group L received 20 mL of 0.5% levobupivacaine, and Group R received 20 mL of 0.75% ropivacaine for ultrasound-guided CCB.
• Procedure: Blocks were performed with the patient in a supine position, arm abducted to 90 degrees, using a high-frequency linear transducer to visualize the costoclavicular space and brachial plexus cords lateral to the axillary artery.
• Assessments:
  • Intraoperative: Sensory and motor blockade were assessed every 5 minutes for 30 minutes post-injection. Sensory block was graded on a 3-point scale (0: normal, 1: analgesia, 2: anesthesia) using cold and touch testing. Motor block was graded using a modified Bromage scale (0: no block, 1: paresis, 2: complete paralysis).
  • Postoperative: Pain was assessed using the Numerical Rating Scale (NRS) at 2-hour intervals for 12 hours. Recovery of sensory and motor function was recorded. Rescue analgesia (IV paracetamol) was administered if NRS > 4.
• Analysis: Data were analyzed using parametric and non-parametric tests, with statistical significance set at p < 0.05.

Key Results

• Demographics: Baseline characteristics (age, gender, BMI) were comparable between groups.
• Onset of Action:
  • Sensory Block: Group L (levobupivacaine) demonstrated a significantly faster onset of sensory block at the 5-minute mark (p=0.036). However, the mean overall onset time for sensory block was similar between groups (18.6 ± 5.5 min vs. 19 ± 4.5 min; p=0.75).
  • Motor Block: Group L showed significantly faster progression of motor block at 10 minutes (p=0.04). Mean onset times for motor block were comparable (22.8 ± 5.8 min vs. 23.5 ± 5.5 min; p=0.633).
• Postoperative Analgesia: NRS pain scores were statistically comparable between both groups at all time points from 2 to 12 hours.
• Recovery Characteristics:
  • Sensory Recovery: Group R (ropivacaine) exhibited significantly slower sensory recovery at 2 hours (p=0.001), though recovery profiles converged by 4 hours.
  • Motor Recovery: Group R demonstrated significantly slower motor recovery at 6 hours (p=0.005).
• Safety and Efficacy: Block failure rates were low and comparable (1 failure in Group R vs. 2 in Group L; p=1.00). Rescue analgesic requirements were similar (3 patients in Group L vs. 1 in Group R; p=0.61). No significant adverse events (e.g., local anesthetic toxicity, pneumothorax, nerve injury) were observed in either group.

Significance and Claims
The study concludes that both 0.5% levobupivacaine and 0.75% ropivacaine provide effective, safe, and clinically comparable anesthesia for ultrasound-guided costoclavicular blocks in upper limb surgery.

While levobupivacaine demonstrated a modest advantage in the early onset of sensory and motor blockade (specifically at 5 and 10 minutes, respectively), and ropivacaine showed slightly prolonged sensory and motor recovery at specific intervals (2 and 6 hours), these differences did not translate into significant variations in overall duration of analgesia, block failure rates, or safety profiles.

The authors assert that the choice between these agents for CCB should be guided by institutional preference, drug availability, and specific desired onset or recovery characteristics rather than major differences in efficacy. The study reinforces the clinical interchangeability of these two agents in this specific anatomical approach, noting that the compact nature of the costoclavicular space does not alter the established pharmacodynamic profiles of these long-acting local anesthetics.