Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of computer-controlled administration of propofol with two manually controlled infusion techniques.
Ninety women were studied in order to compare dose requirements and quality of anaesthesia between target-controlled infusion and two manually controlled infusion schemes for propofol administration: group I received target-controlled infusion for induction (4 micrograms.ml-1 target blood concentration, increased by 2 micrograms.ml-1 after 3 min of consciousness not lost), groups II and III received an induction bolus of propofol at infusion rates of 1200 or 600 ml.h-1, respectively, until loss of consciousness. Anaesthesia was maintained with propofol target-controlled infusion in group 1 or by constant rate infusion in the other two groups. Computer simulations were used to calculate blood and effect-site propofol concentrations. ⋯ There was a lower incidence of apnoea in group I than in groups II and III. There were no significant differences between the groups in other objective parameters of anaesthetic quality studied. Computer simulations showed an "overshoot' in propofol blood and effect-site concentration with manual induction and significantly higher maintenance levels with target-controlled infusion.
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Antiphospholipid syndrome is a paradoxical disease state with in vitro prolongation of activated partial thromboplastin time and a strong predilection for in vivo thrombosis. The syndrome can be associated with systemic lupus erythematosus or lupus-like diseases or may be primary, presenting with thrombotic phenomena in young patients with no risk factors for thrombosis. We present two cases seen in two different settings in the hospital.
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Randomized Controlled Trial Clinical Trial
The minimum effective doses of pethidine and doxapram in the treatment of post-anaesthetic shivering.
This study was designed to find the minimum effective doses of doxapram and pethidine to stop post-anaesthetic shivering. Two hundred and twenty healthy patients who shivered following routine surgery were allocated randomly to receive one of 10 doses of doxapram (0.18, 0.23, 0.29, 0.35, 0.41, 0.47, 0.7, 0.93, 1.17 and 1.4 mg.kg-1), one of five doses of pethidine (0.12, 0.18, 0.23, 0.29 and 0.35 mg.kg-1) or saline. Probit analysis demonstrated that the number of patients who stopped shivering with doxapram was independent of the amount of drug given in this dose range. ⋯ We conclude that 0.35 mg.kg-1 of pethidine is the minimum dose required to treat post-anaesthetic shivering effectively. We also conclude that 0.18 mg.kg-1 of doxapram is as effective as 1.4 mg.kg-1 in the treatment of post-anaesthetic shivering. Further study is required to find the minimum effective dose of doxapram.
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We have sought to define a way in which nitrous oxide can be safely and universally used at minimal to low flows by utilising a circle system with a controlled leak provided by a standard gas analyser sampling line and a fresh gas supply of 50% nitrous oxide in oxygen, entering from a trunk interposed between the ventilator and the circle system. Although preliminary calculations suggested that this arrangement was likely to work, it was found that 13 of 23 patients studied prospectively developed an inspired oxygen fraction below 0.3. We conclude that, although this arrangement provides a new means of introducing nitrous oxide into the circle breathing system, it does not appear inherently safer or more convenient than the conventional route.
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A postal survey was performed to investigate whether the National Confidential Enquiry into Perioperative Deaths (NCEPOD) had influenced clinical practice. A short questionnaire was sent to 100 consultant anaesthetists from England, Wales and Northern Ireland. There was a 72% response rate. ⋯ Some individuals had tried and failed to establish improvements. Nearly 80% perceived current threats to standards of care that NCEPOD might investigate in the future. The replies indicated that NCEPOD is perceived by clinicians as influencing clinical practice and standards of care.