Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2010
Carina as a useful and reliable radiological landmark for detection of accidental arterial placement of central venous catheters.
Central venous catheters are commonly used in the management of critically ill patients. Their insertion can be challenging in hemodynamically unstable patients and in those with altered thoracic anatomy. Although ultrasound guided insertion can reduce this problem, this facility may not be available in all locations and in all institutions. ⋯ Other recognized measures used to identify arterial puncture would be blood gas analysis of the returning blood, use of pressure transducer to identify waveform pattern and the pressures. In this article, we propose that trachea and carina can be used as a reliable radiological landmark to identify accidental arterial placement of central venous catheters. We further conclude that this information could be useful especially when dealing with post-resuscitation victims and hemodynamically unstable critically ill patients.
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J Clin Monit Comput · Dec 2010
How do changes in exhaled CO₂ measure changes in cardiac output? A numerical analysis model.
In a previous study in anesthetized animals, the slope of percent decreases in exhaled CO₂ versus percent decreases in cardiac output (Q(T) inflation of vena cava balloons) was 0.73. To examine the mechanisms underlying this exhaled CO₂-Q(T) relationship, an iterative numerical analysis computer model of non-steady state CO(2) kinetics was developed. ⋯ The numerical analysis computer model helps to delineate the mechanisms underlying how decreased Q(T) resulted in decreased exhaled CO₂. The model permitted deconvolution of the effects of simultaneous variables and the interrogation of parameters that would be difficult to measure in actual experiments.
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J Clin Monit Comput · Dec 2010
Clinical TrialThe influence of basic ventilation strategies on cerebral oxygenation in anesthetized patients without vascular disease.
Optimizing cerebral oxygenation is of paramount importance in certain intraoperative situations. There is, however, a paucity of published data pertaining to changes in cerebral oxygenation seen with increases in the inspired fraction of oxygen (FIO2) or end-tidal carbon dioxide (PETCO2) in anesthetized patients without vascular disease. Here we tested the hypothesis that changes in FIO2 or PETCO2 correlate to a significant change in regional cerebral oxygenation (rSO2) in anesthetized patients without vascular disease. ⋯ Modulating oxygenation and ventilation in anesthetized patients without vascular disease leads to measurable changes in rSO2.
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J Clin Monit Comput · Dec 2010
Case ReportsPulmonary fluid status monitoring with intrathoracic impedance.
Various pacemakers can now track diverse hemodynamic parameters that are useful in the management of patients with heart failure. Among these indicators, pulmonary fluid status can be monitored. To the best of our knowledge, this is the first case describing an agreement between a simultaneous detection of an increase in lung water by transthoracic impedance monitoring (OptiVol™ (Medtronic, Inc., Minneapolis, MN), and the transpulmonary thermodilution method (PiCCO™, Pulsion Medical Systems, Munich, Germany) in a patient with acute pulmonary oedema. The present case suggests that transthoracic impedance monitoring could be a useful tool to guide therapy in critically ill patients with implanted devices and lung fluid congestion.
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J Clin Monit Comput · Oct 2010
Assessment of the effect of rapid crystalloid infusion on stroke volume variation and pleth variability index after a preoperative fast.
Stroke volume variation (SVV) during controlled mechanical ventilation is a useful predictor in response to volume expansion, and pleth variability index (PVI), a novel algorithm allowing for automated and continuous calculation of the respiratory variations in the pulse oximeter waveform amplitude, can also predict fluid responsiveness non-invasively in mechanically ventilated patients. The aim of this study was (1) to determine whether acute fluid infusion affects SVV and PVI, and (2) to compare the two values in the case of acute fluid infusion after a preoperative fast following general anesthesia induction. ⋯ A rapid infusion of 250-500 ml of a crystalloid in nearly healthy subjects who had fasted overnight returned their SVV to within the normal range. In such cases, SVV is a more sensitive predictor of fluid responsiveness than is PVI, and the infusion gradually increased SVI.