Anaesthesia
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Randomized Controlled Trial
Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks.
The extent of analgesia provided by transversus abdominis plane blocks depends upon the site of injection and pattern of spread within the plane. There are currently a number of ultrasound-guided approaches in use, including an anterior oblique-subcostal approach, a mid-axillary approach and a more recently proposed posterior approach. We wished to determine whether the site of injection of local anaesthetic into the transversus abdominis plane affects the spread of the local anaesthetic within that plane, by studying the spread of a local anaesthetic and contrast solution in four groups of volunteers. ⋯ In contrast, the posterior approaches, using both landmark and ultrasound identifications, resulted in predominantly posterior spread of contrast around the quadratus lumborum to the paravertebral space from T5 to L1 vertebral levels. We concluded that the pattern of spread of local anaesthetic differs depending on the site of injection into the transversus abdominis plane. This may have important implications for the extent of analgesia produced with each approach.
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Pressure infusion devices are used in clinical practice to apply large volumes of fluid over a short period of time. Although air infusion is a major complication, they have limited capability to detect and remove air during pressure infusion. In this investigation, we tested the air elimination capabilities of the Fluido(®) (The Surgical Company), Level 1(®) (Level 1 Technologies Inc.) and Ranger(®) (Augustine Medical GmbH) pressure infusion devices. ⋯ In our experimental setting, we found, during high flow, an increased amount of uneliminated air in all used devices compared with lower perfusion flows. All tested devices had a good air elimination capability. The use of ultrasonic air detection coupled with an automatic shutoff is a significant safety improvement and can reliably prevent accidental air embolism at rapid flows.
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Surgical aortic valve replacement is the conventional treatment for symptomatic aortic valve stenosis; however, the technique of transfemoral transcatheter aortic valve implantation has recently been developed for older patients at high risk for surgery. We assessed whether this procedure could be safely performed under sedation in 100 patients. Their predicted surgical mortality was 21.6% and mean (SD) age 80 (6.6) years. ⋯ All conversions to general anaesthesia occurred after successful valve implantation. Mean (SD) anaesthesia time was 31 (12) min and procedural time 107 (77) min; 30-day and 1-year all-cause mortality were 6% and 13%, respectively. In the majority of patients, transcatheter valve implantation can safely be facilitated by sedation, provided monitoring and drug administration are carried out by an experienced cardiac anaesthetist.