Anaesthesia
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Randomized Controlled Trial
Therapeutic doses of neostigmine, depolarising neuromuscular blockade and muscle weakness in awake volunteers: a double-blind, placebo-controlled, randomised volunteer study.
Neostigmine reverses non-depolarising neuromuscular blockade, but may cause muscle weakness when administered after full recovery of neuromuscular function. We hypothesised that neostigmine in therapeutic doses impairs muscle strength and respiratory function in awake healthy volunteers. Twenty-one volunteers were randomised to receive two doses of either intravenous (i.v.) neostigmine 2.5 mg with glycopyrrolate 450 μg (neostigmine group, n = 14) or normal saline 0.9% (placebo group, n = 7). ⋯ The second dose of neostigmine with glycopyrrolate further decreased grip strength mean (SD) -41 (23) % vs. +1.0 (15) %, p = 0.0004; single twitch height -25 (15) % vs. -2.5 (6.6) %, p = 0.0030; predicted forced expiratory volume in 1 s -23 (24) % vs. -0.7 (4.4) %, p = 0.0063; and predicted forced vital capacity, -27.1 (22.0) % vs. -0.66 (3.9) %, p = 0.0010. Train-of-four ratio remained unchanged (p = 0.22). In healthy volunteers, therapeutic doses of neostigmine induced significant and dose-dependent muscle weakness, demonstrated by a decrease in maximum voluntary hand grip strength and a restrictive spirometry pattern secondary to depolarising neuromuscular blockade.
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Randomized Controlled Trial
Effects of depth of neuromuscular block on surgical conditions during laparoscopic colorectal surgery: a randomised controlled trial.
There have been few objective evaluations of the effects of deep neuromuscular blockade on intra-operative conditions. In this prospective randomised controlled study, we evaluated the effects of deep neuromuscular block on surgical conditions during laparoscopic colorectal surgery. Patients were randomly allocated using a computer-generated randomisation code to either moderate (train-of-four count 1-2 maintained and antagonised with neostigmine) or deep (post-tetanic count 1-2 maintained and reversed with sugammadex) levels of neuromuscular blockade. ⋯ In total, we recruited 70 patients of whom 64 (32 in each group) were analysed. Increases in intra-abdominal pressure (14/32 vs. 6/32; p = 0.031), intra-operative restoration of spontaneous breathing (16/32 vs. 2/32; p < 0.001) and request for additional neuromuscular blockade (21/32 vs. 8/32; p = 0.001) were more frequent in the moderate compared with the deep group. In patients undergoing elective laparoscopic colorectal surgery, deep neuromuscular blockade provided better surgical conditions than moderate neuromuscular blockade, as measured by a reduction in the incidence of intra-abdominal pressure alarms.