Perineural versus intravenous dexmedetomidine as an adjuvant for ilioinguinal/iliohypogastric nerve block in open inguinal hernia repair: a randomised controlled trial.

In 30 seconds

This single-centre, triple-blind randomised controlled trial compared perineural, intravenous and placebo dexmedetomidine as adjuncts to an ilioinguinal/iliohypogastric nerve block in 90 adults undergoing elective open inguinal hernia repair. At 6 hours, movement-evoked pain was lower with perineural dexmedetomidine than placebo: mean VAS scores were 10.3 ± 10.3 versus 22.0 ± 20.6, a difference of -11.7 (95% CI - 21.9 to - 1.4; p = 0.022). Intravenous dexmedetomidine did not reduce pain versus placebo and was associated with more bradycardia than perineural administration.

Key findings

• At 6 hours, movement VAS was 10.3 ± 10.3 with perineural dexmedetomidine versus 22.0 ± 20.6 with placebo; difference -11.7 (95% CI - 21.9 to - 1.4; p = 0.022).
• Intravenous dexmedetomidine did not differ from placebo for 6-hour movement pain (p = 0.888).
• Bradycardia occurred in 20.0% with intravenous dexmedetomidine, 3.3% with perineural dexmedetomidine and 6.7% with placebo (DexIV vs DexLA p = 0.040).
• Time to first opioid was similar across groups (p = 0.723); hypotension rates were 43.3%, 40.0% and 20.0%, respectively (p = 0.151).

Why it matters

The trial suggests that the route of dexmedetomidine administration may affect both early analgesia and haemodynamic effects when used with this nerve block. The perineural group had a reduction in movement-evoked pain that the authors considered clinically relevant, while intravenous administration offered no demonstrated analgesic benefit and had more bradycardia. Pain was low overall, so the size and practical importance of benefit should be interpreted in that context.

What to keep in mind

The trial was single-centre and included 90 adults; follow-up outcomes reported here focus on early pain and opioid timing.