Anaesthesia
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Randomized Controlled Trial Comparative Study
The effects of intrathecal levobupivacaine and bupivacaine in the elderly.
The objective of this study was to compare the block durations and haemodynamic effects associated with intrathecal levobupivacaine or bupivacaine in elderly patients undergoing transurethral prostate surgery. Eighty patients were prospectively randomised to receive plain 1.5 ml levobupivacaine 0.5% (group levobupivacaine) or 1.5 ml plain bupivacaine 0.5% (group bupivacaine) in combination with fentanyl 0.3 ml (15 microg) for spinal anaesthesia. The time to reach T10 and peak sensory block level, and to maximum motor block were significantly shorter in group bupivacaine compared to group levobupivacaine (p < 0.05). ⋯ In group bupivacaine, mean arterial pressure was significantly lower than group levobupivacaine, starting from 10 min until 30 min after injection (p < 0.05). Hypotension and nausea were less common in group levobupivacaine than group bupivacaine (p < 0.05). Because of the better haemodynamic stability and fewer side-effects associated with levobupivacaine, it may be preferred for spinal anaesthesia in elderly patients.
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Review
The impact of intra-operative transoesophageal echocardiography on cardiac surgical practice.
The use of transoesophageal echocardiography during cardiac surgery has increased dramatically and it is now widely accepted as a routine monitoring and diagnostic tool. A prospective study was carried out between September 2004 and September 2007, and included all patients in whom intra-operative echocardiography was performed, 2 473 (44%) out of a total of 5 591 cases. Changes to surgery were subdivided into predictable (where echocardiographic examination was planned specifically to guide surgery) and unpredictable (new pathology not diagnosed pre-operatively). ⋯ The number of predictable changes increased between 2004-5 and 2006-7 (8% vs 13%, p = 0.025). In these cases, intra-operative echocardiography was specifically requested by the surgeon to help determine the operative intervention. This has implications for consent and operative risk, which have yet to be fully determined.
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To assess the utility of a relatively simple bedside method of estimating cardiac index during major surgery or in the intensive care unit, we conducted a prospective study in patients undergoing elective cardiac bypass surgery where a pulmonary artery catheter was inserted as part of routine monitoring. The cardiac index was estimated using standard techniques and compared with estimates from continuous cardiac dynamic monitoring using HEARTSMART software. ⋯ The mean bias (95% limits of agreement), for the pre-bypass cardiac index was -0.09 (-1.26 to 1.08) l x min(-1) x m(-2), and post-bypass was 0.12 l x min(-1) x m(-2) (-1.32 to 1.56). These results suggest that continuous cardiac dynamic monitoring using HEARTSMART is sufficiently accurate for assessment of haemodynamic variables in critically ill patients, facilitating goal-directed therapies.
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Comparative Study
A comparison of stroke volume variation measured by the LiDCOplus and FloTrac-Vigileo system.
The aim of this study was to compare the accuracy of stroke volume variation (SVV) as measured by the LiDCOplus system (SVVli) and by the FloTrac-Vigileo system (SVVed). We measured SVVli and SVVed in 15 postoperative cardiac surgical patients following five study interventions; a 50% increase in tidal volume, an increase of PEEP by 10 cm H2O, passive leg raising, a head-up tilt procedure and fluid loading. Between each intervention, baseline measurements were performed. 136 data pairs were obtained. ⋯ The LiDCOplus and FloTrac-Vigileo system are not interchangeable. Furthermore, the determination of SVVli and SVVed are too ambiguous, as can be concluded from the high values of the coefficient of variation for repeated measures. These findings underline Pinsky's warning of caution in the clinical use of SVV by pulse contour techniques.
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We conducted a pilot study of the effects of simulation as a tool for teaching doctor-paramedic teams to deliver pre-hospital anaesthesia safely. Participants undertook a course including 43 full immersion, high-fidelity simulations. Twenty videos taken from day 4 and days 9/10 of the course were reviewed by a panel of experienced pre-hospital practitioners. ⋯ The total time from arrival to inflation of the tracheal tube cuff was longer on days 9/10 than on day 4 (mean (SD) 14 min 52 s (2 min 6 s) vs 11 min 28 s (1 min 54 s), respectively; p = 0.005), while the number of safety critical events per simulation were fewer (median (IQR [range]) 1.0 (0-1.8 [0-2]) vs 3.5 (1.5-4.8 [0-8], respectively; p = 0.011). Crew resource management behaviours also improved in later simulations. On a personal training needs analysis, participants reported increased confidence after the course.