Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2017
Randomized Controlled TrialPerformance of a closed-loop feedback computer-controlled infusion system for maintaining blood pressure during spinal anaesthesia for caesarean section: a randomized controlled comparison of norepinephrine versus phenylephrine.
Closed-loop feedback computer-controlled vasopressor infusion has been previously described for maintaining blood pressure during spinal anaesthesia for caesarean section but there are limited data available comparing the relative performance of different vasopressors. The aim of this study was to compare the performance of norepinephrine versus phenylephrine in this system. Data from a randomized, two-arm parallel group, double-blinded controlled trial were reanalyzed. 104 patients scheduled for elective caesarean section under spinal anaesthesia were randomized to receive computer-controlled closed-loop infusion of either norepinephrine 5 µg ml-1 or phenylephrine 100 µg ml-1. ⋯ In addition, median performance error was smaller (0.75 [-1.56-2.52] %) versus 2.61 [0.83-4.57] %, P = 0.002) and wobble was smaller (2.85 [2.07-5.17] %) versus 3.39 [2.62-4.90] %, P = 0.028) in the norepinephrine group versus the phenylephrine group. Divergence was similar between groups. The precision of the control of blood pressure was greater with norepinephrine compared with phenylephrine at the drug concentrations used.
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J Clin Monit Comput · Jun 2017
Comparative Study Observational StudyEffect of patent ductus arteriosus and patent foramen ovale on left ventricular stroke volume measurement by electrical velocimetry in comparison to transthoracic echocardiography in neonates.
This prospective single-center observational study compared impedance cardiography [electrical velocimetry (EV)] with transthoracic echocardiography (TTE, based on trans-aortic flow) and analyzed the influence of physiological shunts, such as patent ductus arteriosus (PDA) or patent foramen ovale (PFO), on measurement accuracy. Two hundred and ninety-one triplicate simultaneous paired left ventricular stroke volume (LVSV) measurements by EV (LVSVEV) and TTE (LVSVTTE) in 99 spontaneously breathing neonates (mean weight 3270 g; range 1227-4600 g) were included. For the whole cohort, the mean absolute LVSVEVwas 5.5 mL, mean LVSVTTEwas 4.9 mL, resulting in an absolute Bland-Altman bias of -0.7 mL (limits of agreement LOA -3.0 to 1.7 mL), relative bias -12.8 %; mean percentage error MPE 44.9 %; true precision TPEV33.4 % (n = 99 aggregated data points). ⋯ In neonates with shunts (PDA and/or PFO; n = 67): mean LVSVEV5.8 mL, mean LVSVTTE5.0 mL, bias -0.8 mL (LOA -3.1 to 1.5 mL), relative bias -14.8 %, MPE 41.9 %, TPEV29.3 %. Accuracy was affected by PDA and/or PFO, with a significant increase in the relative difference in LVSVEVversus LVSVTTE: Subjects without shunts -2.9 % (n = 91), PFO alone -9.6 % (n = 125), PDA alone -14.0 % (n = 12), and PDA and PFO -18.5 % (n = 63). Physiological shunts (PDA and/or PFO) in neonates affect measurement accuracy and cause overestimation of LVSVEVcompared with LVSVTTE.
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J Clin Monit Comput · Jun 2017
Analysis of central venous pressure (CVP) signals using mathematical methods.
Central venous pressure (CVP) is an important clinical parameter for physicians but only the absolute CVP value is typically monitored in the intensive care unit (ICU). In this study, we propose a novel mathematical method to present and analyze CVP signals. ⋯ The statistical features of time and frequency domain, wavelet, and empirical mode decomposition of these signals were extracted. We found no significant difference among the CVP signals regarding sex, smoking, coronary disease, and respiration mode of the samples.
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J Clin Monit Comput · Jun 2017
Clinical TrialEfficacy of bioelectrical impedance analysis during the perioperative period in children.
We evaluated the efficacy of bioelectrical impedance analysis (BIA) during the perioperative period by estimating the preoperative and postoperative body fluid status. After obtaining informed consent, we enrolled 100 children (3-12 years of age) scheduled for elective surgeries. All children had been fasted preoperatively. ⋯ The baseline and postoperative ICW showed a strong positive correlation (Pearson correlation coefficient = 0.992, P < 0.001), as did the baseline and postoperative ECW (Pearson correlation coefficient = 0.990, P < 0.001). Also there was no dehydration and irritability on medical recording preoperatively. BIA may be an alternative method for estimating the perioperative fluid status in children and determining details of fluid administration.
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J Clin Monit Comput · Jun 2017
Observational StudyConsistency of cardiac function index and global ejection fraction with global end-diastolic volume in patients with femoral central venous access for transpulmonary thermodilution: a prospective observational study.
Global ejection fraction (GEF) and cardiac function index (CFI) are transpulmonary thermodilution (TPTD)-derived indices of the systolic function. Their validity relies on an accurate determination of the global end-diastolic volume (GEDV). Due to an overestimation of GEDV using a femoral central venous catheter (CVC) a correction formula for indexed GEDV (GEDVI) has been implemented in the latest PiCCO™-algorithm. ⋯ By contrast, GEFcalculated (23.1 ± 8.7 %) was not substantially different from GEFdisplayed (22.4 ± 8.6 %). Although GEDV and GEF are corrected for femoral CVC site, this does not apply to CFI. However, all indices derived from GEDV should be calculated consistently.