British journal of anaesthesia
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Randomized Controlled Trial
Combined use of Bispectral Index and A-Line Autoregressive Index to assess anti-nociceptive component of balanced anaesthesia during lumbar arthrodesis.
This study evaluated the A-Line Autoregressive Index (AAI) response to surgical stimulation during lumbar arthrodesis, as an estimate of the anti-nociceptive component of a Bispectral Index (BIS) guided anaesthesia combined with epidural analgesia. ⋯ During a BIS-guided constant level of hypnosis, AAI response to the onset of surgical stimulation significantly differs according to the analgesic regimen. Further studies are needed to refine the estimation of sensitivity and specificity of this variable in assessing the balance between nociception and anti-nociception during general anaesthesia.
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Multicenter Study
Relationship between perioperative troponin elevation and other indicators of myocardial injury in vascular surgery patients.
In 2000 the European Society of Cardiology and the American College of Cardiology published a consensus document revising the definition of myocardial infarction. The usefulness of this revised definition has been challenged. It has been suggested that, rather than any release of cardiac troponin being potentially diagnostic of myocardial infarction, a diagnostic threshold consistent with significant myocardial injury should be defined. ⋯ These data suggest that further studies are required to define the optimal cardiac troponin diagnostic threshold for the diagnosis of myocardial infarction in the non-cardiac surgery population.
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Randomized Controlled Trial
Large volume N2O uptake alone does not explain the second gas effect of N2O on sevoflurane during constant inspired ventilation.
The second gas effect (SGE) is considered to be significant only during periods of large volume N(2)O uptake (VN(2)O); however, the SGE of small VN(2)O has not been studied. We hypothesized that the SGE of N(2)O on sevoflurane would become less pronounced when sevoflurane administration is started 60 min after the start of N(2)O administration when VN(2)O has decreased to approximately 125 ml min(-1), and that the kinetics of sevoflurane under these circumstances would become indistinguishable from those when sevoflurane is administered in O(2). ⋯ We confirmed the existence of a SGE of N(2)O. Surprisingly, when using an Fa of 65% N(2)O, the magnitude of the SGE was the same with large or small VN(2)O. The classical model and the graphical representation of the SGE alone should not be used to explain the magnitude of the SGE. We speculate that changes in ventilation/perfusion inhomogeneity in the lungs during general anaesthesia result in a SGE at levels of VN(2)O previously considered by most to be too small to exert a SGE.
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Many publications, including the instructions accompanying central venous catheters, state that it is negligent to site the catheter tip in the right atrium. If the catheter tip is above the carina on a post-procedure radiograph then it is generally accepted that the catheter lies outside the right atrium. It is also recommended that the catheter tip should lie in the long axis of the superior vena cava without acute abutment to the vein wall. We performed a retrospective audit of the position of central venous catheter tips on routine post-procedure chest radiographs in intensive care unit patients, to see if these potentially conflicting requirements had been met. ⋯ We suggest that for left-sided catheters placement of the tip below the carina is more likely to result in a satisfactory placement.
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We describe the anaesthetic management of a pair of thoracopagus twins of 14 months of age undergoing complex cardiac evaluation. Synchronous ventilation of the twins, needed for the ECG-gated magnetic resonance imaging-angiography, was achieved through a Carlens (Y) adaptor during procedures and transport. The complex logistical implications are obvious. We also describe the first use of bispectral index monitor for detection of cross-circulation in conjoint twins.