Anaesthesia
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Thyromental distance (TMD) measurement is commonly used to predict difficult intubation. We surveyed anaesthetists to determine how this test was being performed. Comparative accuracy of ruler measurement and other forms of measurement were also assessed in a meta-analysis of published literature. ⋯ In terms of distance, the minimum acceptable TMD was felt to be 6.5 cm by 55% of respondents. However, the actual width of three fingers was (range) 4.6-7.0 cm (mean 5.9 cm), with significant differences between genders and between proximal and distal interphalangeal joints. The meta-analysis showed ruler measurement increased test sensitivity (48% (95% CI 43-53) vs 16% (95% CI 14-19) without a ruler), when predicting difficult intubation.
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Randomized Controlled Trial
Effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children.
We investigated the effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children without the use of neuromuscular blocking drugs. One hundred and thirty paediatric patients, aged 3-8 years, were randomly allocated to receive no remifentanil (group control) or remifentanil 0.1 microg kg(-1) min(-1) (group remi(0.1)), 0.2 microg kg(-1) min(-1) (group remi(0.2)), 0.3 microg kg(-1) min(-1) (group remi(0.3)). All patients were anaesthetised using 5% sevoflurane. ⋯ Successful intubation was defined as excellent or good intubating conditions. The end-tidal concentration (SD) of sevoflurane for successful tracheal intubation in 50% of children (ED(50)) were 5.16 (0.22)% in control, 3.27 (0.18)%, 1.81 (0.20)% and 1.01 (0.11)%, in remi(0.1), remi(0.2), and remi(0.3) groups, respectively. Using probit analysis, the 95% effective dose (ED(95)) of sevoflurane were 5.60% (95% CI 5.35-7.66), 3.77% (95% CI 3.45-7.74), 2.18% (95% CI 1.96-3.86), 1.19% (95% CI 1.06-1.82) in control, remi(0.1), remi(0.2), and remi(0.3) groups, respectively.
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This study reviews the predictive value of maximum oxygen consumption (VO2max) and anaerobic threshold, obtained through cardiopulmonary exercise testing, in calculating peri-operative morbidity and mortality in non-cardiopulmonary thoraco-abdominal surgery. A literature review provided nine studies that investigated either one or both of these two variables across a wide range of surgical procedures. ⋯ We conclude that peak oxygen consumption and possibly anaerobic threshold are valid predictors of peri-operative morbidity and mortality in non-cardiopulmonary thoraco-abdominal surgery. These indicators could potentially provide a means of allocating increased care to high-risk patients.
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Randomized Controlled Trial
Monitor position and the accuracy and speed of ultrasound-guided nerve blocks.
Ultrasound is rapidly becoming an essential skill for all anaesthetists with an interest in regional anaesthesia. Using a single-blinded cross-over trial design, we assessed the accuracy and speed of simulated ultrasound-guided nerve blockade with the monitor either in direct line-of-sight or perpendicular to the line-of-sight. ⋯ Needle placement was significantly more accurate when anaesthetists had the monitor in front of them (29 acceptable) than to the side (22 acceptable). For anaesthetists with limited ultrasound experience, the accuracy, but not speed, of ultrasound guided regional anaesthesia can be improved by aligning the monitor in the line of sight of the operator.