Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2010
Assessment of the effect of rapid crystalloid infusion on stroke volume variation and pleth variability index after a preoperative fast.
Stroke volume variation (SVV) during controlled mechanical ventilation is a useful predictor in response to volume expansion, and pleth variability index (PVI), a novel algorithm allowing for automated and continuous calculation of the respiratory variations in the pulse oximeter waveform amplitude, can also predict fluid responsiveness non-invasively in mechanically ventilated patients. The aim of this study was (1) to determine whether acute fluid infusion affects SVV and PVI, and (2) to compare the two values in the case of acute fluid infusion after a preoperative fast following general anesthesia induction. ⋯ A rapid infusion of 250-500 ml of a crystalloid in nearly healthy subjects who had fasted overnight returned their SVV to within the normal range. In such cases, SVV is a more sensitive predictor of fluid responsiveness than is PVI, and the infusion gradually increased SVI.
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J Clin Monit Comput · Oct 2010
Novel automatic endotracheal position confirmation system: mannequin model algorithm evaluation.
A novel endotracheal intubation accurate positioning confirmation system based on image classification algorithm is introduced and evaluated using a mannequin model. ⋯ This fully automatic image recognition system was used successfully to discriminate airway carina and non-carina endotracheal tube positioning. The system had a 100% success rate using a mannequin model and therefore further investigation including live tissue model and human research should follow.
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J Clin Monit Comput · Aug 2010
Comparative StudySNAP II versus BIS VISTA monitor comparison during general anesthesia.
Effectively monitoring the level of consciousness during general anesthesia is clinically beneficial to both the patient and the physician. An electroencephalogram (EEG)-based level-of-consciousness monitor can help minimize intraoperative awareness as well as the effects of over-sedation. In this study, we compared the SNAP II (Stryker Instruments, Kalamazoo, MI USA) and BIS VISTA (Aspect Medical Systems, Newton, MA USA) monitors' primary metrics (SI and BIS, respectively) in terms of correlation, agreement and responsiveness to return to preoperative baseline in surgical cases involving general anesthesia. ⋯ Although the SI and BIS both can assess a patient's level of consciousness and are correlated, they are not in agreement with each other numerically and therefore are not interchangeable. It is difficult to assess each monitor's true responsiveness to acute changes in consciousness level from our study design. The differences between the metrics we observed in this study are most likely due to differences in signal processing methodologies, EEG frequencies employed and signal filtering utilized in the monitors.
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J Clin Monit Comput · Aug 2010
Masseter muscle oxygen saturation is associated with central venous oxygen saturation in patients with severe sepsis.
This monocentric prospective study was conducted to determine if tissue oxygen saturation measured non invasively over masseter muscle site (Masseter-StO2) can predict the central venous oxygen saturation (ScvO2) level in severe sepsis and septic shock. ⋯ In patients with severe sepsis or septic shock, non invasive recording of Masseter-StO2 was significantly associated with ScvO2 Further studies are required to determine the usefulness of Masseter-StO2 guided management of severe sepsis or septic shock.
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J Clin Monit Comput · Aug 2010
The effect of skin incision on the electroencephalogram during general anesthesia maintained with propofol or desflurane.
A variety of effects of surgical incision on the electroencephalogram (EEG) during modern general anesthesia have been previously described; including both increases and decreases in both high and low frequencies in the EEG. What are the patterns commonly seen during routine clinical anesthesia? ⋯ During anesthesia maintained with desflurane or propofol, surgical incision has modest effects on the EEG patterns. It does not cause an increase in high frequency power; the most consistent changes are a loss of EFA amplitude and burst suppression patterns. This effect is not strongly modified by the depth of anesthesia--as estimated by the BIS.