Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2016
Clinical TrialUltrasound evaluation of the radial artery for arterial catheterization in healthy anesthetized patients.
The purpose of this study was to assess the anatomy of the radial artery using ultrasound in anesthetized patients, and to correlate its anatomical data with patients' characteristics. The success rate of radial artery cannulation using ultrasound was also evaluated to analyze the relationship between the anatomical data and the success rate. Study 1 One hundred ninety-five patients scheduled for general anesthesia were enrolled. ⋯ Study 2 The first attempt success rate of arterial catheterization using ultrasound was 92.5 % using long-axis in-plane technique, regardless of patient's characteristics. For small sized adult patients, a 22G angio-catheter should be used during radial artery cannulation, because the radial artery diameter significantly correlated with BSA in healthy anesthetized patients. In addition, ultrasound-guided catheterization is recommended in elderly patients because the incidence of abnormal angle between the radial artery and skin surface was high.
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Low flow anesthesia increases the use of CO2 absorbents, but independent data that compare canister life of the newest CO2 absorbents are scarce. Seven different pre-packed CO2 canisters were tested in vitro: Amsorb Plus, Spherasorb, LoFloSorb, Medisorb, Medisorb EF, LithoLyme, and SpiraLith. CO2 (160 mL min(-1)) flowed into the tip of a 2 L breathing bag that was ventilated with a tidal volume of 500 mL, a respiratory rate of 10/min, and an I:E ratio of 1:1 using the controlled mechanical ventilation mode of the Aisys (®) (GE, Madison, WI, USA). ⋯ The most important factors that determine canister life of prepacks in a circle breathing system are the chemical composition of the canister, the absolute amount of absorbent present in the canister, and the FICO2 replacement threshold. The use of the fractional canister usage allows cost comparisons among different prepacks. Results should not be extrapolated to prepacks that fit onto other anesthesia machines.
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J Clin Monit Comput · Apr 2016
Case ReportsEndovascular coil detachment causing EMG artefact in BIS: a mechanistic exploration.
Deployment of endovascular coils used in interventional neuroradiology commonly involves electrolytic detachment of the coil from the pusher catheter. This report describes a case of artefactual increase in electromyography (EMG) values of bispectral index (BIS) monitor during coil detachment. An explanation of this event is provided connecting mechanism of coil detachment and derivation of EMG values in a BIS monitor. While rising EMG values are thought to arise from frontalis contraction, they may as well be an unrecognized electrical artefact, especially in context of undistorted electroencephalography waveform.
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J Clin Monit Comput · Apr 2016
Bioelectrical impedance spectroscopy to estimate fluid balance in critically ill patients.
Fluid management is a crucial issue in intensive-care medicine. This study evaluated the feasibility and reproducibility of bioimpedance spectroscopy to measure body-water composition in critically ill patients, and compared fluid balance and daily changes in total body water (TBW) measured by bioimpedance. This observational study included 25 patients under mechanical ventilation. ⋯ Regardless of the technique used to estimate volume status, important limits of agreement were observed. Non-invasive determination of body-water composition using bioimpedance spectroscopy is feasible in critically ill patients but requires knowledge of the patient's weight. The best method to assess volume status after fluid resuscitation and the value gained from information about body composition provided by bioimpedance techniques needs further evaluation.
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J Clin Monit Comput · Apr 2016
Comparative StudyCardiac output method comparison studies: the relation of the precision of agreement and the precision of method.
Cardiac output (CO) plays a crucial role in the hemodynamic management of critically ill patients treated in the intensive care unit and in surgical patients undergoing major surgery. In the field of cardiovascular dynamics, innovative techniques for CO determination are increasingly available. Therefore, the number of studies comparing these techniques with a reference, such as pulmonary artery thermodilution, is rapidly growing. ⋯ But as the actual CO of a subject changes from assessment to assessment, there is no real repetition of a measurement. This situation equals a scenario in which single measurements are given for multiple true values per subject. In such a case it is not possible to assess the precision of method.