Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2016
Randomized Controlled TrialThe effect of anesthesia depth on the oculocardiac reflex in strabismus surgery.
The aim of this study was to investigate the effect of the bispectral index (BIS) guided depth of anesthesia to inhibition of the oculocardiac reflex (OCR) during pediatric strabismus surgery. Patients between the ages of 3 and 16 years who were scheduled for elective strabismus surgery were randomly assigned to two groups. In Group 1 (n: 32), the BIS values of the patients were maintained at <50; in Group 2 (n: 28), the BIS values of the patients were maintained at levels greater than or equal to 50 with 4-7 % desflurane in a 50 % O2-air mixture by titrating the concentration during the surgery. ⋯ Moreover, the incidence of OCR in group 2 was higher in medial rectus (MR) traction (78.9 %) than in lateral rectus (LR) traction (33.3 %) (p = 0.035), with no significant difference in Group 1 between MR (21.1 %) and LR (26.7 %) tractions (p = 0.83). We found that the lower BIS values are associated with the lower incidence of OCR in pediatric patients undergoing strabismus surgery. And our findings confirmed that the deeper anesthesia has a protective effect against the OCR.
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J Clin Monit Comput · Dec 2016
Prediction of fluid responsiveness in the beach chair position using dynamic preload indices.
Hemodynamic instability in the beach chair position (BCP) may lead to adverse outcomes. Cardiac preload optimization is a prerequisite to improve hemodynamics. We evaluated the clinical usefulness of dynamic indices for the prediction of fluid responsiveness in BCP patients under general anesthesia. ⋯ Patients were considered responders to volume expansion if the stroke volume index increased by ≥15 %. The areas under receiver operating characteristic curves for SVV, PPV and PVI were 0.83, 0.81 and 0.74, respectively (p < 0.05), with the corresponding optimal cut-off values of 12, 15 and 10 %. SVV, PPV and PVI can be used to predict fluid responsiveness in the BCP under mechanical ventilation.
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J Clin Monit Comput · Dec 2016
Comparative StudyPerformance of computer simulated inhalational anesthetic uptake model in comparison with real time isoflurane concentration.
Gas Man software was developed to enhance our understanding of the pharmacokinetics of inhalational anaesthetics. To date the Gas Man software has not been validated in humans. In this study we compared the Gas Man software with real time measured end tidal isoflurane concentrations while using a semi closed circle system in anesthetised patients. ⋯ The end-tidal concentration values of isoflurane in real patients are very close to those predicted by Gas Man software. The pharmocokinetics of inhalational anesthetic administration in patients can be taught accurately using Gas Man technology. This technology may also help in developing different kinetic models of inhalational agents in the body.
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J Clin Monit Comput · Dec 2016
Sensor fusion methods for reducing false alarms in heart rate monitoring.
Automatic patient monitoring is an essential resource in hospitals for good health care management. While alarms caused by abnormal physiological conditions are important for the delivery of fast treatment, they can be also a source of unnecessary noise because of false alarms caused by electromagnetic interference or motion artifacts. One significant source of false alarms is related to heart rate, which is triggered when the heart rhythm of the patient is too fast or too slow. ⋯ Twenty recordings selected from the MIMIC database were used to validate the system. The results showed that neural networks fusion had the best false alarm reduction of 92.5 %, while the Bayesian technique had a reduction of 84.3 %, fuzzy logic 80.6 %, majority voter 72.5 % and the heart rate variability index 67.5 %. Therefore, the proposed algorithms showed good performance and could be useful in bedside monitors.
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J Clin Monit Comput · Dec 2016
Utility of the bispectral index for assessing natural physiological sleep stages in children and young adults.
Polysomnography (PSG) is the gold standard for the analysis of sleep architecture but is not always available in routine practice, as it is time consuming and cumbersome for patients. Bispectral index (BIS), developed to quantify the deepness of general anesthesia, may be used as a simplified tool to evaluate natural sleep depth. We objectively recorded sleep architecture in young patients using the latest BIS Vista monitor and correlated BIS values with PSG sleep stages in order to determine BIS thresholds. ⋯ BIS threshold that identified stage N3 was <55 (AUC = 0.964, p < 0.001) with an 87 %-sensitivity and a 93 %-specificity. BIS identified stage N3 with satisfactory sensitivity and specificity but is limited by its inability to distinguish REM sleep from wake. Further studies combining BIS with chin electromyogram and/or electrooculogram could be of interest.