Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2023
Observational StudyPreoperative cerebral oxygenation in high-risk noncardiac surgical patients: an observational study on postoperative mortality and complications.
Near Infrared Spectroscopy (NIRS) has become widely accepted to evaluate regional cerebral oxygen saturation (rScO2), potentially acting as a surrogate parameter of reduced cerebral oxygen delivery or increased consumption. Low preoperative rScO2 is associated with increased postoperative complications after cardiac surgery. However, its universal potential in pre-anesthesia risk assessment remains unclear. ⋯ No significant association between rScO2 values and NYHA, LVEF, or MET classes were observed. Preoperative rScO2 is not associated with postoperative complications in patients undergoing high-risk noncardiac surgery. We speculate that the discriminatory power of NIRS is insufficient due to individual variability of rScO2 values and confounding factors.
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J Clin Monit Comput · Jun 2023
Controlled Clinical TrialAgreement of somatic and renal near-infrared spectroscopy with reference blood samples during a controlled hypoxia sequence: a healthy volunteer study.
O3® Regional Oximetry (Masimo Corporation, California, USA) is validated for cerebral oximetry. We aimed to assess agreement of somatic and renal near-infrared spectroscopy with reference blood samples. ⋯ O3 regional oximetry can be used on the quadriceps and flank to monitor somatic saturation, yet has a saturation-level dependent bias. O3-derived values obtained at the flank underestimated renal reference values. Additionally, it is unlikely that the flank sensors did directly measure renal tissue.
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J Clin Monit Comput · Jun 2023
Automated electrocardiogram signal quality assessment based on Fourier analysis and template matching.
We developed and tested a novel template matching approach for signal quality assessment on electrocardiogram (ECG) data. A computational method was developed that uses a sinusoidal approximation to the QRS complex to generate a correlation value at every point of an ECG. The strength of this correlation can be numerically adapted into a 'score' for each segment of an ECG, which can be used to stratify signal quality. ⋯ The routine performs in linear O(n) time and occupies O(1) heap space in runtime. This approach can be used to lower the burden of pre-processing in ECG signal analysis. Given its runtime (O(n)) and memory (O(1)) complexity, there are potential applications for signal quality stratification and arrhythmia detection in wearable devices or smartphones.
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J Clin Monit Comput · Jun 2023
Comparative StudyA comparison of the NeurOs® and the INVOS 5100C® cerebral oximeter during variations of the partial pressure of carbon dioxide and fractional inspiratory concentration of oxygen.
This prospective method comparison study compared cerebral oxygen saturation (ScO2) measurement performance of the new cerebral oximeter (NeurOs®, Mespere LifeSciences, Ontario, Canada) in comparison to the established INVOS 5100C® (Medtronic, Boulder, USA) cerebral oximeter. We performed measurements during different levels of carbon dioxide pressure (PaCO2) during hyper- and hypoventilation and different levels of arterial oxygen saturation (SaO2) induced by variation of the inspiratory fraction of oxygen (FiO2). 59 anesthetized cardiac and vascular surgical patients were studied during hemodynamically stable conditions. Two versions of the NeurOs® oximeter were used in 39 and 20 patients, respectively: an older version with one bi-hemispherical sensor attached to the midline of the forehead and a newer version with two sensors that were attached to the left and right forehead. ⋯ The ScO2 measurement performance of the NeurOs® cerebral oximeter is not interchangeable with the INVOS® cerebral oximeter during variations of ventilation and oxygenation in elective cardiac or vascular surgical patients. The lack of reactivity to changes in ventilation (by variation of PaCO2) and oxygen delivery (by variation of FiO2) question the reliability of NeurOs® measurements to reflect changes in cerebral blood flow and cerebral oxygen balance. This holds true not only for different sensor positions at the forehead but also for different modes of penetration.
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J Clin Monit Comput · Jun 2023
Scalp blocks do not affect the accuracy of neuronavigation facial recognition registration.
Scalp block is a regional anesthesia technique to reduce the sympathetic response to skull pin application and postoperative pain in patients undergoing craniotomy. These blocks are often performed prior to surgical incision, however, the effect that these blocks have on neuronavigation facial tracing recognition accuracy is unclear because they may distort facial anatomy. ⋯ Scalp block does not interfere with neuronavigation facial recognition accuracy during neurosurgical procedures.