Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2017
Effective evaluation of arterial pulse waveform analysis by two-dimensional stroke volume variation-stroke volume index plots.
Arterial pulse waveform analysis (APWA) with a semi-invasive cardiac output monitoring device is popular in perioperative hemodynamic and fluid management. However, in APWA, evaluation of hemodynamic data is not well discussed. In this study, we analyzed how we visually interpret hemodynamic data, including stroke volume variation (SVV) and stroke volume (SV) derived from APWA. ⋯ The plots approximately shifted on the rectangular hyperbolic curves, depending on blood loss and blood transfusion. Arithmetic estimation is close to real measurement of the SVV-SV interaction in hyperbolic curves. In APWA, using SVV as an index of preload and the cardiac index or SVI derived from arterial pressure-based cardiac output as an index of cardiac function, is likely to be appropriate for categorizing hemodynamic stages as a substitute for Forrester subsets.
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J Clin Monit Comput · Oct 2017
Transcutaneous near-infrared spectroscopy for monitoring spinal cord ischemia: an experimental study in swine.
We aimed to assess the ability of near-infrared spectroscopy (NIRS) to detect spinal cord ischemia, and to evaluate changes in regional oxygen saturation (rSO2) following recovery of spinal cord circulation and cerebrospinal fluid drainage. Four 12-month-old female swine weighing 28.7-29.5 kg were acquired for this study. NIRS probes were placed along the midline of the upper (T6/7) and lower (T9/T10) thoracic vertebrae. ⋯ Histological analysis revealed that ischemic changes had occurred in all spinal levels. NIRS may be used to detect decreases in and recovery of spinal cord circulation following aortic clamping and de-clamping, whereas it may not reflect minor changes in spinal cord circulation due to cerebrospinal fluid drainage. Further clinical studies are required to investigate the potential for NIRS as an index of spinal cord circulation.
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J Clin Monit Comput · Oct 2017
Efficacy and safety of novel high-frequency multi-train stimulation for recording transcranial motor evoked potentials in a rat model.
Recently, low-frequency multi-train stimulation (MTS) was shown to effectively enhance transcranial motor-evoked potentials (TcMEPs). In contrast, high- frequency double-train stimulation was reported to elicit a marked facilitation. The aim of this study was to evaluate the efficacy of high-frequency MTS in the augmentation of potentials. ⋯ The aversion index was >0.8 in all animals after they received 100 high-frequency MTSs. Histologically, no pathological changes were evident in the rat brains. High-frequency MTS shows potential to effectively enhance TcMEP responses, and to be used safely in transcranial brain stimulation.