Anaesthesia
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Comparative Study
A comparison of a prototype electromyograph vs. a mechanomyograph and an acceleromyograph for assessment of neuromuscular blockade.
The extent of neuromuscular blockade during anaesthesia is frequently measured using a train-of-four stimulus. Various monitors have been used to quantify the train-of-four, including mechanomyography, acceleromyography and electromyography. Mechanomyography is often considered to be the laboratory gold standard of measurement, but is not commercially available and has rarely been used in clinical practice. ⋯ The mean difference (95% limits of agreement) in train-of-four ratios between opposite arms when using electromyography was -0.7 (-20.7 to 19.3). There were significantly more acceleromyography train-of-four values > 1.0 (23%) compared with electromyography or mechanomography (2-4%; p < 0.0001). Electromyography most closely resembled mechanomyographic assessment of neuromuscular blockade, whereas acceleromyography frequently produced train-of-four ratio values > 1.0, complicating the interpretation of acceleromyography results in the clinical setting.
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Randomized Controlled Trial Comparative Study
Differential frontal alpha oscillations and mechanisms underlying loss of consciousness: a comparison between slow and fast propofol infusion rates.
Mechanisms underlying loss of consciousness following propofol administration remain incompletely understood. The objective of this study was to compare frontal lobe electroencephalography activity and brainstem reflexes during intravenous induction of general anaesthesia, in patients receiving a typical bolus dose (fast infusion) of propofol compared with a slower infusion rate. We sought to determine whether brainstem suppression ('bottom-up') predominates over loss of cortical function ('top-down'). ⋯ Alpha band power emerged several minutes after the loss of consciousness in participants allocated to the fast infusion group. Our results show a predominance of 'bottom-up' mechanisms during fast infusion rates and 'top-down' mechanisms during slow infusion rates. The underlying mechanisms by which propofol induces loss of consciousness are potentially influenced by the speed of infusion.
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Pilot and feasibility studies are preliminary investigations undertaken before a larger study. We hypothesised that only a small proportion of pilot or feasibility studies published in anaesthesia journals were correctly labelled as such. We searched for papers published between 2007 and 2017 in six anaesthesia journals using the text words 'pilot' OR 'feasibility' and included 266 original articles with 26,682 human participants. ⋯ These results have important consequences for patients, trialists, researchers and funders. We argue that correctly labelled pilot studies enhance the quality of scientific research by encouraging methodological rigour, ensuring scientific validity and reducing research waste. Authors, reviewers, editors and publishers should ensure they adhere to the contents of the 2016 CONSORT extension for pilot and feasibility studies.