Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2017
A feasability study of color flow doppler vectorization for automated blood flow monitoring.
An ongoing issue in vascular medicine is the measure of the blood flow. Catheterization remains the gold standard measurement method, although non-invasive techniques are an area of intense research. We hereby present a computational method for real-time measurement of the blood flow from color flow Doppler data, with a focus on simplicity and monitoring instead of diagnostics. ⋯ Errors on synthetic images ranged from nonexistent to substantial depending on experimental conditions. Mean errors on measurements from our phantom flow simulation ranged from 1.2 to 40.2% for angle estimation, and from 3.2 to 25.3% for real-time flow estimation. This study is a proof of concept showing that accurate measurement can be done from automated color flow Doppler signal extraction, providing the industry the opportunity for further optimization using raw ultrasound data.
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J Clin Monit Comput · Dec 2017
Phenylephrine increases near-infrared spectroscopy determined muscle oxygenation in men.
Phenylephrine increases mean arterial pressure (MAP) by enhanced total peripheral resistance (TPR) but near-infrared spectroscopy (NIRS) determined muscle oxygenation (SmO2) increases. We addressed that apparent paradox during supine rest and head-up tilt (HUT). Variables were determined ± phenylephrine in males during supine rest (n = 17) and 40° HUT (n = 7). ⋯ Brachial artery blood flow tended to decrease while SskinO2 together with StibialO2 decreased by 11% (P = 0.026) and 20% (P < 0.001), respectively. Conversely, phenylephrine increased SmO2 (9%) and restored the HUT elicited decrease in SmO2 (by 19%) along with SV (P = 0.02). Phenylephrine reduces skin and bone oxygenation and tends to reduce arm blood flow, suggesting that the increase in SmO2 reflects veno-constriction with consequent centralization of the blood volume.
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J Clin Monit Comput · Dec 2017
A nurses' alarm fatigue questionnaire: development and psychometric properties.
Alarm fatigue can adversely affect nurses' efficiency and concentration on their tasks, which is a threat to patients' safety. The purpose of the present study was to develop and test the psychometric accuracy of an alarm fatigue questionnaire for nurses. This study was conducted in two stages: in stage one, in order to establish the different aspects of the concept of alarm fatigue, the researchers reviewed the available literature-articles and books-on alarm fatigue, and then consulted several experts in a meeting to define alarm fatigue and develop statements for the questionnaire. ⋯ The test of the reliability of nurses' alarm fatigue questionnaire based on the internal homogeneity and retest methods yielded the following results: test-retest correlation coefficient = 0.99; Guttman split-half correlation coefficient = 0.79; Cronbach's alpha = 0.91. Regarding the importance of recognizing alarm fatigue in nurses, there is need for an instrument to measure the phenomenon. The results of the study show that the developed questionnaire is valid and reliable enough for measuring alarm fatigue in nurses.
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J Clin Monit Comput · Dec 2017
Ventilation/perfusion ratio and right to left shunt in healthy newborn infants.
Oxygenation impairment can be assessed non-invasively by determining the degree of right-to-left shunt and ventilation/perfusion (VA/Q) inequality. These indices have been used in sick newborn infants, but normative values have not been reported which are essential to determine the magnitude of the abnormality. We, therefore, aimed to measure the shunt and VA/Q in infants with no history of respiratory conditions and determine if there was any effect of supine or prone position and the reproducibility of the data. ⋯ No significant differences were found in VA/Q in the supine compared to the prone position. The intraclass correlation coefficient of VA/Q between two independent raters was 0.968 (95% CI 0.947-0.980), p < 0.001. Right-to-left shunt and VA/Q ratio in healthy newborn infants were similar in the prone compared to the supine position.
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J Clin Monit Comput · Dec 2017
Influence of continuously evolving transcatheter aortic valve implantation technology on cerebral oxygenation.
This study assessed the influence of the evolution in Transcatheter Aortic Valve Implantation technology on cerebral oxygenation. Cerebral oxygenation was measured continuously with Near-Infrared Spectroscopy and compared retrospectively between balloon-expandable, self-expandable and differential deployment valves which were implanted in 12 (34%), 17 (49%) and 6 patients (17%), respectively. Left and right SctO2 values were averaged at four time points and used for analysis (i.e. at baseline, balloon-aortic valvuloplasty, valve deployment, and at the end of the procedure). ⋯ Furthermore, both the incidence and duration below a cerebral oxygenation of 55% was significantly different between balloon and self-expandable valves (p = 0.038 and p = 0.018, respectively). This study demonstrated that Transcatheter Aortic Valve Implantation procedures are associated with significant cerebral desaturations, especially during balloon-aortic valvuloplasty and valve deployment. Moreover, our results showed that latest innovations in Transcatheter Aortic Valve Implantation technology beneficially influenced the adequacy of cerebral perfusion.