Comparison between the trapezius and adductor pollicis muscles as an acceleromyography monitoring site for moderate neuromuscular blockade during lumbar surgery

Acceleromyography at the adductor pollicis located in a distal part of the body may not reflect the degree of neuromuscular blockade (NMB) at the proximally located muscles manipulated during lumbar surgery. We investigated the usefulness and characteristics of acceleromyographic monitoring at the trapezius for providing moderate NMB during lumbar surgery. Fifty patients were randomized to maintain a train-of-four count 1–3 using acceleromyography at the adductor pollicis (group A; n = 25) or the trapezius (group T; n = 25). Total rocuronium dose administered intraoperatively [mean ± SD, 106.4 ± 31.3 vs. 74.1 ± 17.6 mg; P P P = 0.003) and lumbar muscle tone in group T were significantly lower than group A. Time to maximum block with an intubating dose was significantly shorter in group T than group A (44 [37–54] vs. 60 [55–65] sec; P