Anaesthesia
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Comparative Study Clinical Trial
Introduction of an algorithm for ROTEM-guided fibrinogen concentrate administration in major obstetric haemorrhage.
We compared blood component requirements during major obstetric haemorrhage, following the introduction of fibrinogen concentrate. A prospective study of transfusion requirements and patient outcomes was performed for 12 months to evaluate the major obstetric haemorrhage pathway using shock packs (Shock Pack phase). The study was repeated after the pathway was amended to include fibrinogen concentrate (Fibrinogen phase). ⋯ The median (IQR [range]) quantity of fibrinogen administered was significantly greater in the Shock Pack phase, 3.2 (0-7.1 [0-20.4]) g, than in the Fibrinogen phase, 0 (0-3.0 [0-12.4]) g, p = 0.0005. Four (9.5%) of 42 patients in the Shock Pack phase developed transfusion associated circulatory overload compared with none of 51 patients in the Fibrinogen phase (p = 0.038). Fibrinogen concentrate allows prompt correction of coagulation deficits associated with major obstetric haemorrhage, reducing the requirement for blood component therapy and the attendant risks of complications.
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The risk of accidental over-dosing of obese children poses challenges to anaesthetists during dose calculations for drugs with serious side-effects, such as analgesics. For many drugs, dosing scalars such as ideal body weight and lean body mass are recommended instead of total body weight during weight-based dose calculations. However, the complex current methods of obtaining these dosing scalars are impractical in the peri-operative setting. ⋯ A nomogram was created and its performance compared with the standard calculation method by volunteers using measurements from 108 obese children. The nomogram was as accurate (bias 0.12 kg vs -0.41 kg, respectively, p = 0.4), faster (mean (SD) time taken 2.8 (1.0) min (vs 3.3 (0.9) min respectively, p = 0.003) and less likely to result in mistakes (significant errors 3% vs 19%, respectively, p = 0.001). We present a system that simplifies estimation of ideal body weight and lean body mass in obese children, providing foundations for safer drug dose calculation.
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We measured heating of isotonic saline by three fluid warmers in six experiments: saline at 5 °C or 20 °C delivered at 30, 50 or 100 ml.min(-1). At the three flow rates, the enFLOW(®) , buddy lite(™) and ThermoSens(®) systems heated 5 °C saline to mean (SD) temperatures of: 41.1 (0.5) °C, 37.7 (0.6) °C and 39.1 (0.6) °C; to 40.3 (0.8) °C, 33.9 (1.6) °C and 39.3 (0.7) °C; and to 37.1 (0.8) °C, 24.0 (1.3) °C and 37.6 (1.0) °C, respectively, p < 0.0001 for each experiment. ⋯ The results for saline at 20 °C were similar. The enFLOW system heated saline above 36 °C faster than the ThermoSens system, whereas the buddy lite often failed to achieve 36 °C.
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Although electroencephalogram reactivity (i.e. transient changes in electrical brain activity following external stimulus) might be useful in depth-of-anaesthesia monitoring, it has not been systematically examined with different anaesthetics at doses titrated to unresponsiveness. Three 10-subject groups of healthy volunteers received dexmedetomidine, propofol or sevoflurane in escalating pseudo-steady-state concentrations at 10-min intervals until they did not open their eyes to command. The electroencephalogram was continuously recorded and spectral variables were calculated with short-time Fourier transform and time-varying autoregressive modelling. ⋯ Dexmedetomidine, propofol and sevoflurane induced distinct suppression patterns on the electroencephalogram reactivity at the same clinical endpoint (unresponsiveness). Reactivity was best maintained with propofol, while only minimally preserved with dexmedetomidine and sevoflurane. Thus, it may be difficult to harness reactivity for depth-of-anaesthesia monitoring.
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Editorial Comment
Awareness in cardiothoracic anaesthetic practice - where now after NAP5?