British journal of anaesthesia
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Randomized Controlled Trial
Haemodynamic effects from aortocaval compression at different angles of lateral tilt in non-labouring term pregnant women.
Aortocaval compression (ACC) can result in haemodynamic disturbances and uteroplacental hypoperfusion in parturients. Its detection is difficult because in most patients, sympathetic compensation results in no signs or symptoms. However, profound hypotension may develop after sympathectomy during regional anaesthesia. In this prospective observational study, we aimed to detect ACC by analysing haemodynamic changes in term parturients who were positioned sequentially at different angles of lateral tilt. ⋯ Patients with ACC can be identified by the CO changes from serial measurements between supine, 15°, or full lateral tilt. Our findings suggest that in non-labouring parturients, ACC is asymptomatic and can be effectively minimized by the use of a left lateral tilt of 15° or greater.
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Randomized Controlled Trial Comparative Study
Deltoid, triceps, or both responses improve the success rate of the interscalene catheter surgical block compared with the biceps response.
The influence of the muscular response elicited by neurostimulation on the success rate of interscalene block using a catheter (ISC) is unknown. In this investigation, we compared the success rate of ISC placement as indicated by biceps or deltoid, triceps, or both twitches. ⋯ Eliciting deltoid, triceps, or both twitches was associated with a higher success rate compared with eliciting biceps twitches during continuous interscalene block.
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Randomized Controlled Trial
Magnetic resonance imaging study of the in vivo position of the extraglottic airway devices i-gel™ and LMA-Supreme™ in anaesthetized human volunteers.
Exact information on the anatomical in situ position of extraglottic airway (EGA) devices is lacking. We used magnetic resonance imaging (MRI) to visualize the positions of the i-gel™ and the LMA-Supreme™ (LMA-S) relative to skeletal and soft-tissue structures. ⋯ The LMA-S and i-gel™ differ significantly with regard to in situ position and spatial relationship with adjacent structures assessed by MRI, despite similar clinical and fibreoptical findings. This could be relevant with regard to risk of aspiration, glottic narrowing, and airway resistance and soft-tissue morbidity.