Concomitant infraclavicular plus distal median, radial, and ulnar nerve blockade accelerates upper extremity anaesthesia and improves block consistency compared with infraclavicular block alone.

Background: This prospective, randomized, observer-blinded study tested the hypothesis that a combined ultrasound-guided block of the infraclavicular brachial plexus plus distal median, radial, and ulnar nerves would accelerate upper extremity anaesthesia compared with infraclavicular block alone.

Methods: Elective wrist and hand surgery patients were randomly assigned to receive 42 ml infraclavicular lidocaine 1.5% with epinephrine 1/200,000 ('infraclavicular only'; n=30) or 30 ml lidocaine 1.5% with epinephrine 1/200,000 followed by a distal median, radial, and ulnar nerve block using 12 ml 50:50 lidocaine 2%+ropivacaine 0.75% ('combined'; n=31). A blinded observer assessed pinprick sensory and motor block in the four distal nerve territories at 10 and 15 min (each nerve/parameter: no block, 3, to complete block, 0).

Results: Total aggregate block score (sensory+motor) was reduced in the combined group at 15 min [mean (95% confidence interval)=6.7 (5.3-8.1) vs. 9.9 (7.9-11.9), mean difference (95% confidence interval)=3.2 (0.81-5.6), P=0.01], and corresponded to an estimated onset effect time benefit of 6 min (∼40% treatment effect). The combined group also demonstrated reduced variance about the mean (sd=3.7 vs. 5.4, P=0.046). Mean (sd) total block score (sensory+motor) was significantly reduced at 15 min in the combined group for each individual nerve [median, radial, ulnar, respectively: 1.4 (1.1) vs. 2.4 (1.5), P=0.005; 1.2 (1.1) vs. 2.0 (1.5), P=0.03; 1.6 (1.3) vs. 2.5 (1.6), P=0.03].

Conclusions: At an approximately equivalent total local anaesthetic dose, a combined infraclavicular block plus distal median, radial, and ulnar nerve blockade accelerates anaesthesia onset time and improves block consistency compared with an infraclavicular block alone. Background: ANZCTR: ACTRN12610000155099. https://www.anzctr.org.au/registry/trial_review.aspx?ID=335162.