Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2018
Correction to: Changes in transcranial motor evoked potentials during hemorrhage are associated with increased serum propofol concentrations.
In the original publication of the article, the corresponding author inadvertently omitted one of the co-authors in the author group. The corrected author group is given in this erratum.
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J Clin Monit Comput · Jun 2018
Photoplethysmography for blood volumes and oxygenation changes during intermittent vascular occlusions.
Photoplethysmography (PPG) is an optical technique that measures blood volume variations. The main application of dual-wavelength PPG is pulse oximetry, in which the arterial oxygen saturation (SpO[Formula: see text]) is calculated noninvasively. However, the PPG waveform contains other significant physiological information that can be used in conjunction to SpO[Formula: see text] for the assessment of oxygenation and blood volumes changes. ⋯ A[Formula: see text] indicated significant changes for occlusion pressures exceeding 20 mmHg (p < 0.05) and correlation with tissue oxygenation changes measured by NIRS, while SpO[Formula: see text] had significant changes after 40 mmHg (p < 0.05). Relative changes in haemoglobin concentrations can be estimated from PPG signals and they showed a good level of accuracy in the detection of perfusion and oxygenation changes induced by different degrees of intermittent vascular occlusions. These results can open up to new applications of the PPG waveform in the detection of blood volumes and oxygenation changes.
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J Clin Monit Comput · Apr 2018
Letter Case ReportsAn abrupt reduction in end tidal carbon di oxide concentration in a mechanically ventilated patient in neurocritical care ward: a capnogram artifact.
In patients with normal lung and reasonable cardiac function such as head injury patients, the PETCo2 can be used as a surrogate for partial pressure of Carbon dioxide (PaCO2) in mechanically ventilated patients. Thus early interpretation and accurate assessment of capnogram is crucial in neurocritical care patients. Here we present and discuss a scenario where in connection of a jet nebulizer to the ventilator lead to abrupt decrease in end tidal carbon dioxide leading to a diagnostic dilemma. Also this report highlights and discusses the importance of the proper placement of breathing circuit components to ensure accurate CO2 readings in particular the use of a jet nebulizer.
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J Clin Monit Comput · Apr 2018
Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia.
The capnodynamic method is a minimally invasive method continuously calculating effective pulmonary blood flow (COEPBF), equivalent to cardiac output when intra pulmonary shunt flow is low. The capnodynamic equation joined with a ventilator pattern containing cyclic reoccurring expiratory holds, provides breath to breath hemodynamic monitoring in the anesthetized patient. Its performance however, might be affected by changes in the mixed venous content of carbon dioxide (CvCO2). ⋯ During prolonged hypercapnia, agreement remained good during changes in CO. The mean polar angle was -4.19° (-8.8° to 0.42°). Capnodynamic COEPBF is affected but recovers rapidly after transient large changes in PvCO2 and preserves good agreement and trending ability during states of prolonged hypercapnia at different levels of CO.