Exploring the Additive or Synergistic Effects of the Systemic and Perineural Routes of Dexamethasone as Adjuncts to Supraclavicular Block: A Randomized Controlled Trial.

Summary

Among 104 patients, IV dexamethasone prolonged sensory block versus control by 4.5 h (95% CI, 1.3–7.7) and reduced 24-h pain and opioid use. Adding perineural dexamethasone to IV conferred no incremental benefits across all outcomes, indicating IV dexamethasone alone is sufficient as an adjunct.

Key Findings

• Sensory block duration: IV 21.3±7.3 h; IV+perineural 20.6±6.1 h; control 16.8±6.8 h.
• IV vs control prolonged sensory block by 4.5 h (95% CI, 1.3–7.7; P=0.006); IV+perineural vs control by 3.8 h (95% CI, 0.8–6.8; P=0.015).
• No differences between IV and IV+perineural in any outcomes, including pain, opioid consumption, or rebound pain.

Clinical Implications

Prefer IV dexamethasone as an adjunct to supraclavicular block; avoid routine perineural dexamethasone given lack of additive benefit.

Limitations

• Single block type (supraclavicular) and upper extremity procedures may limit generalizability
• Sample size powered for sensory duration; rarer adverse events may be underdetected

Future Directions

Evaluate dosing strategies and applicability across other peripheral nerve blocks; assess long-term safety and neuropathy risks comparing routes.