Journal of clinical monitoring and computing
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J Clin Monit Comput · Oct 2015
Hemodynamic volumetry using transpulmonary ultrasound dilution (TPUD) technology in a neonatal animal model.
To analyze changes in cardiac output and hemodynamic volumes using transpulmonary ultrasound dilution (TPUD) in a neonatal animal model under different hemodynamic conditions. 7 lambs (3.5-8.3 kg) under general anesthesia received arterial and central venous catheters. A Gore-Tex(®) shunt was surgically inserted between the descending aorta and the left pulmonary artery to mimic a patent ductus arteriosus. After shunt opening and closure, induced hemorrhagic hypotension (by repetitive blood withdrawals) and repetitive volume challenges, the following parameters were assessed using TPUD: cardiac output, active circulating volume index (ACVI), central blood volume index (CBVI) and total end-diastolic volume index (TEDVI). 27 measurement sessions were analyzed. ⋯ Correlations between changes in COufp and changes in hemodynamic volumes (ACVI 0.83; CBVI 0.84 and TEDVI 0.78 respectively) were (slightly) better than between changes in COufp and changes in heart rate (0.44) and central venous pressure (0.7). Changes in hemodynamic volumes using TPUD were as expected under different conditions. Hemodynamic volumetry using TPUD might be a promising technique that has the potential to improve the assessment and interpretation of the hemodynamic status in critically ill newborns and children.
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J Clin Monit Comput · Oct 2015
Radial artery cannulation decreases the distal arterial blood flow measured by power Doppler ultrasound.
Radial arterial cannulation is a popular technique for continuous hemodynamic monitoring in an area of anesthesia and intensive care. Although the risk for invasive monitoring is considerable, there is scarce information about the change in blood flow of cannulated vessel after the catheterization. In the current investigation, we evaluated the change in the cannulated arterial blood flow. ⋯ Study 2: There was no difference between the diameters of right and left RA, however, the UA was larger [3.4 (0.60) vs. 2.8 (0.83) mm] and the DBRA was narrower [1.4 (0.43) vs. 2.0 (0.47) mm] in the cannulated side. The diameters of DBRA were different between the intact and cannulated side in the patients. Although there is no information of relationships between cause of severe complication and decreased flow, significant reduction of blood flow should be concerned.
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J Clin Monit Comput · Oct 2015
Clinical Trial Observational StudyContinuous measurement of cardiac output with the electrical velocimetry method in patients under spinal anesthesia for cesarean delivery.
In this study, we aimed to continuously measure cardiac output (CO) with the electrical velocimetry (EV) method and characterize the hemodynamic profile of patients undergoing spinal anesthesia for elective cesarean delivery (CD), and to discuss the potential benefit of using real time CO monitoring to guide patient management. Forty-two patients scheduled for elective CD under spinal anesthesia were enrolled in this observational study. A non-invasive CO monitor incorporating the electrical velocimetry algorithm, ICON(®) (Cardiotronic(®), La Jolla, California, USA), was used to measure CO and stroke volume (SV) continuously. ⋯ Continuous CO monitoring with EV enables clinicians to determine CO and SV changes prior to onset of hypotension and to better understand patients' hemodynamics. It is an important addition to the current monitoring. The benefit of routinely using this technique remains to be determined in term of the patient outcomes.
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J Clin Monit Comput · Oct 2015
Clinical TrialEffect of propofol and remifentanil on a somatosensory evoked potential indicator of pain perception intensity in volunteers.
Somatosensory evoked potentials (SEPs) have been linked to noxious activation and stimulus intensity. In this exploratory study we investigated the impact of anaesthetic drugs on SEPs and pain ratings, to assess their applicability as an objective measure of the nociception/anti-nociception balance. Following institutional approval and written informed consent, 10 healthy adult volunteers were enrolled (29.5 ± 9.1 years, 63.0 ± 8.9 kg and 171.4 ± 7.2). ⋯ An individually adjusted/normalized ratio based on cortical SEPs amplitude and interpeak latency is proposed([Formula: see text]): [Formula: see text] and NSR were significantly correlated in three out of nine subjects, and [Formula: see text] and remifentanil Ce were significantly correlated in two (low number of evaluation points). [Formula: see text] was shown to decrease with increasing doses of propofol and remifentanil (P < 0.05). The proposed metric was depressed by anaesthetics and reflected pain evaluations. Further research is necessary to increase the number of volunteers and drugs' combination, to assess its applicability during surgically adequate anesthetic leves.
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J Clin Monit Comput · Oct 2015
Comparative StudyEvaluation of filtering methods for acquiring radial intra-artery blood pressure waveforms.
The methods for evaluating noninvasive blood pressure (NIBP) monitors using an intra-arterial reference are detailed in the ANSI/AAMI/ISO 81060-2:2009 standard. In a recent study, GE Healthcare obtained invasive radial arterial blood pressure waveforms. The work presented here describes the development of filtering strategies for obtaining high fidelity intra-arterial pressure waveforms for NIBP accuracy testing using the 81060-2 standard. ⋯ Clinicians need to understand that resonance artifacts potentially exist in intra-arterial waveforms and that the adjustments of monitoring systems may not be adequate. Optimal filters for obtaining intra-arterial waveforms should take into account the damping factor and natural frequency of the measuring system. In research and device evaluation studies it is necessary that optimal filtering be done to minimize the effects of under-damping.