Anaesthesia
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Randomized Controlled Trial
Continuous patient-controlled epidural infusion of levobupivacaine plus sufentanil in labouring primiparous women: effects of concentration.
The effects of two different concentrations of epidural levobupivacaine were compared when used to provide analgesia for labour. Primiparous women in spontaneous uncomplicated labour were enrolled in a prospective, randomised and partially double-blinded study. The study solutions were either 0.568 mg x ml(-1) levobupivacaine (low concentration group) or 1.136 mg x ml(-1) levobupivacaine (high concentration group), with sufentanil 0.45 microg x ml(-1) added to both solutions. ⋯ The dose of levobupivacaine administered was higher and sometimes overstepping recommended limits in the high concentration group, but with no observed increase in side-effects. The choice between these two concentrations may still be made according to the patient's and the practitioner's preferences. The effects of an intermediate concentration should be studied in the future.
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Randomized Controlled Trial
Effect of midazolam on memory: a study of process dissociation procedure and functional magnetic resonance imaging.
To assess the effects of midazolam on explicit and implicit memories, 12 volunteers were randomly divided into the two groups: one with an Observer's Assessment of Alertness/Sedation score of 3 (mild sedation) and one with a score of 1 (deep sedation). Blood oxygen-level-dependent functional magnetic resonance imaging was measured before and during an auditory stimulus, then with midazolam sedation, and then during a second auditory stimulus with continuous midazolam sedation. After 4 h, explicit and implicit memories were assessed. ⋯ However, a deep level of midazolam sedation depressed activation of the superior temporal gyrus by auditory stimulus. We conclude that midazolam does not abolish implicit memory at a mild sedation level, but can abolish both explicit and implicit memories at a deep sedation level. The superior temporal gyrus may be one of the target areas.
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Randomized Controlled Trial
Effect-site concentration of remifentanil attenuating surgical stress index responses to intubation of the trachea.
Surgical Stress Index has been proposed for assessment of surgical stress and analgesia. It is a numeric index based on the normalised pulse beat interval and photoplethysmographic pulse wave amplitude. We determined the effect-site concentration of remifentanil for attenuation of Surgical Stress Index responses to intubation of the trachea. ⋯ Mean (SD) effect-site concentrations of remifentanil attenuating responses in 50% of patients were 2.13 (0.25) ng x ml(-1) and 3.05 (0.27) ng x ml(-1) in deep and normal groups, respectively (p = 0.034). From probit analysis, EC(50) and EC(95) of remifentanil (95% CI) were 2.34 (1.97-2.71) ng x ml(-1) and 3.19 (2.69-3.69) ng x ml(-1) in deep group and 3.17 (2.67-3.67) ng x ml(-1) and 3.79 (3.21-4.37) ng x ml(-1) in the normal group, respectively. The values from probit analysis and up-and-down method did not differ significantly.
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Claims notified to the NHS Litigation Authority in England between 1995 and 2007 and filed under anaesthesia were analysed to explore patterns of injury and cost related to airway or respiratory events. Of 841 interpretable claims the final dataset contained 96 claims of dental damage, 67 airway-related claims and 24 respiratory claims. Claims of dental damage contributed a numerically important (11%), but financially modest (0.5%) proportion of claims. ⋯ Among respiratory claims, ventilation problems, combined with hypoxia, were an important source of claims. Although limited clinical details hamper analysis, the data suggest that most airway and respiratory-related claims arise from sentinel events. The absence of clinical detail and denominators limit opportunities to learn from such events; much more could be learnt from a closed claim or sentinel event analysis scheme.
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If surgical 'capacity' always matched or exceeded 'demand' then there should be no waiting lists for surgery. However, understanding what is meant by 'demand', 'capacity' and 'matched' requires some mathematical concepts that we outline in this paper. 'Time' is the relevant measure: 'demand' for a surgical team is best understood as the total min required for the surgery booked from outpatient clinics every week; and 'capacity' is the weekly operating time available. We explain how the variation in demand (not just the mean demand) influences the analysis of optimum capacity. ⋯ Thus the question of how to balance demand and capacity is intimately related to the question of how to balance utilisation and waste. These mathematical considerations enable us to consider objectively how to manage the waiting list. They also enable us critically to analyse the extent to which philosophies adopted by the National Health Service (such as 'Lean' or 'Six Sigma') will be successful in matching surgical capacity to demand.