Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2017
Effective evaluation of arterial pulse waveform analysis by two-dimensional stroke volume variation-stroke volume index plots.
Arterial pulse waveform analysis (APWA) with a semi-invasive cardiac output monitoring device is popular in perioperative hemodynamic and fluid management. However, in APWA, evaluation of hemodynamic data is not well discussed. In this study, we analyzed how we visually interpret hemodynamic data, including stroke volume variation (SVV) and stroke volume (SV) derived from APWA. ⋯ The plots approximately shifted on the rectangular hyperbolic curves, depending on blood loss and blood transfusion. Arithmetic estimation is close to real measurement of the SVV-SV interaction in hyperbolic curves. In APWA, using SVV as an index of preload and the cardiac index or SVI derived from arterial pressure-based cardiac output as an index of cardiac function, is likely to be appropriate for categorizing hemodynamic stages as a substitute for Forrester subsets.
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J Clin Monit Comput · Oct 2017
Intraoperative TTE inferior vena cava monitoring in elderly orthopaedic patients with cardiac disease and spinal-induced hypotension.
Objective To address the role of transthoracic echocardiography in inferior vena cava (IVC) monitoring in the management of haemodynamically unstable elderly patients subjected to lower limb orthopaedic surgery under spinal anesthesia. Possible implications in the postoperative care unit (PACU) length of stay (LOS) are investigated. Methods 41 elderly patients with cardiac diseases were recruited. ⋯ The primary risk factor for a prolonged stay in PACU, as determined by multiple regression analysis was RAP. Conclusions Patients with high dynamic collapsibility of the IVC may require aggressive treatment to restore their haemodynamic status. Additionally, intraoperative levels of RAP, as measured by IVCCI, can act as a predictor for increased LOS in the PACU.
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J Clin Monit Comput · Aug 2017
A modified breathing pattern improves the performance of a continuous capnodynamic method for estimation of effective pulmonary blood flow.
In a previous study a new capnodynamic method for estimation of effective pulmonary blood flow (COEPBF) presented a good trending ability but a poor agreement with a reference cardiac output (CO) measurement at high levels of PEEP. In this study we aimed at evaluating the agreement and trending ability of a modified COEPBF algorithm that uses expiratory instead of inspiratory holds during CO and ventilatory manipulations. COEPBF was evaluated in a porcine model at different PEEP levels, tidal volumes and CO manipulations (N = 8). ⋯ The overall trending ability as assessed by the four-quadrant and the polar plot methodology was high with a concordance rate of 93 and 94 % respectively. The mean polar angle was 0.4 (95 % CI -3.7 to 4.5)°. A ventilatory pattern recurrently introducing end-expiratory pauses maintains a good agreement between COEPBF and the reference CO method while preserving its trending ability during CO and ventilatory alterations.
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J Clin Monit Comput · Aug 2017
Randomized Controlled TrialA novel multivariate STeady-state index during general ANesthesia (STAN).
The assessment of the adequacy of general anesthesia for surgery, namely the nociception/anti-nociception balance, has received wide attention from the scientific community. Monitoring systems based on the frontal EEG/EMG, or autonomic state reactions (e.g. heart rate and blood pressure) have been developed aiming to objectively assess this balance. In this study a new multivariate indicator of patients' steady-state during anesthesia (STAN) is proposed, based on wavelet analysis of signals linked to noxious activation. ⋯ These variables were used in the construction of the combined index STAN; STAN responded adequately to noxious stimuli, with a more pronounced response to laryngoscopy/intubation (18.5-43.1 %, [Formula: see text]), and the attenuation provided by the analgesic, detecting steady-state periods in the different physiological signals analyzed (approximately 50 % of the total study time). A new multivariate approach for the assessment of the patient steady-state during general anesthesia was developed. The proposed wavelet based multivariate index responds adequately to different noxious stimuli, and attenuation provided by the analgesic in a dose-dependent manner for each stimulus analyzed in this study.
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J Clin Monit Comput · Aug 2017
Observational StudyUsing extra systoles to predict fluid responsiveness in cardiothoracic critical care patients.
Fluid responsiveness prediction is an unsettled matter for most critical care patients and new methods relying only on the continuous basic monitoring are desired. It was hypothesized that the post-ectopic beat, which is associated with increased preload, could be analyzed in relation to preceding sinus beats and that the change in cardiac performance (e.g. systolic blood pressure) at the post-ectopic beat could predict fluid responsiveness. Cardiothoracic critical care patients scheduled for a 500 ml volume expansion were observed. ⋯ The change in pre-ejection period predicted fluid responsiveness in 22 patients correctly with 67 % specificity and 83 % sensitivity (optimal threshold: 19 ms pre-ejection period decrease), ROC area: 0.81 (CI [0.66;0.96]). Pulse pressure variation had ROC area of 0.57 (CI [0.39;0.75]). Based on standard critical care monitoring, analysis of the extra systolic post-ectopic beat predicts fluid responsiveness in cardiothoracic critical care patients with good accuracy.