British journal of anaesthesia
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Comparative Study
Determination of moderate-to-severe postoperative pain on the numeric rating scale: a cut-off point analysis applying four different methods.
Cut-off points (CPs) of the numeric rating scale (NRS 0-10) are regularly used in postoperative pain treatment. However, there is insufficient evidence to identify the optimal CP between mild and moderate pain. ⋯ Three of the four methods identified a treatment threshold of average pain of NRS≥4. This was considered to identify patients with pain of moderate-to-severe intensity. This cut-off was indentified as the tolerable pain threshold.
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End-tidal P(CO(2)) (Pe'(CO(2))) is routinely used in the clinical assessment of the adequacy of ventilation because it provides an estimate of Pa(CO(2)). How well Pe'(CO(2)) reflects Pa(CO(2)) depends on the gradient between them, expressed as ΔPa-e'(CO(2)). The major determinant of ΔPa-e'(CO(2)) is alveolar dead space (Vd(alv)). The fraction of inspired O(2) (Fi(O(2))) is not thought to substantially affect ΔPa-e'(CO(2)) in anaesthetized patients. We hypothesized that a high Fi(O(2)) may indeed increase ΔPa-e'(CO(2)) by preferentially vasodilating well-perfused alveoli, resulting in the redistribution of blood flow to these alveoli from poorly perfused alveoli and an increase in Vd(alv). We therefore investigated the effects of changes in Fi(O(2)) on ΔPa-e'(CO(2)) and Vd(alv). ⋯ These data demonstrate that ΔPa-e'(CO(2)), in anaesthetized patients depends on Fi(O(2)).
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The bispectral index (BIS) and the spectral entropy (state entropy, SE, and response entropy, RE) are depth-of-anaesthesia monitors derived from EEG and have been developed to measure the effects of anaesthetics on the cerebral cortex. We studied whether they can differentiate consciousness from unconsciousness during increasing doses of three different anaesthetic agents. ⋯ Because of wide inter-individual variability, BIS and entropy were not able to reliably differentiate consciousness from unconsciousness during and after stepwise increasing concentrations of dexmedetomidine, propofol, and sevoflurane.
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The ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') is an indicator of diastolic function that correlates well with left ventricular (LV) filling pressure and is relatively independent of systolic function and rhythm abnormalities. We prospectively evaluated the predictive value of E/e' for postoperative outcome in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB). ⋯ E/e' ratio >15 was a significant predictor of composite endpoints of postoperative morbidity. We suggest that E/e' ratio should be included in the routine preoperative assessment of patients presenting for OPCAB.
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Desflurane triggers post-conditioning in the diabetic human myocardium. We determined whether protein kinase C (PKC), mitochondrial adenosine triphosphate-sensitive potassium (mitoK(ATP)) channels, Akt, and glycogen synthase kinase-3β (GSK-3β) were involved in the in vitro desflurane-induced post-conditioning of human myocardium from patients with type 2 diabetes. ⋯ Desflurane-induced post-conditioning in human myocardium from patients with type 2 diabetes was mediated by the activation of PKC, the opening of the mitoK(ATP) channels, and the phosphorylation of Akt and GSK-3β.