Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 2018
Determination of respiratory system compliance during pressure support ventilation by small variations of pressure support.
In mechanically ventilated patients, measurement of respiratory system compliance (Crs) is of high clinical interest. Spontaneous breathing activity during pressure support ventilation (PSV) can impede the correct assessment of Crs and also alter the true Crs by inducing lung recruitment. We describe a method for determination of Crs during PSV and assess its accuracy in a study on 20 mechanically ventilated patients. ⋯ Comparison with Crs,VCV20 resulted in a negligible bias (- 1.3 ml/cmH2O, 95% limits of agreement - 13.9 to + 11.3) and r2 of 0.81. We conclude that the novel method provides an estimate of end-inspiratory Crs during PSV. Despite its limited accuracy, it might be useful for non-invasive monitoring of Crs in patients undergoing pressure support ventilation.
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J Clin Monit Comput · Aug 2018
Ventilation inhomogeneity in obstructive lung diseases measured by electrical impedance tomography: a simulation study.
Electrical impedance tomography (EIT) has mostly been used in the Intensive Care Unit (ICU) to monitor ventilation distribution but is also promising for the diagnosis in spontaneously breathing patients with obstructive lung diseases. Beside tomographic images, several numerical measures have been proposed to quantitatively assess the lung state. ⋯ Simulations revealed that minor obstructions are not adequately recognized in the reconstructed images and that obstruction above and below the electrode plane may result in misleading values of inhomogeneity measures. EIT measurements on several electrode planes are necessary to apply these measures in patients with obstructive lung diseases in a promising manner.
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J Clin Monit Comput · Aug 2018
Review Comparative Study Historical ArticleEfficient application of volatile anaesthetics: total rebreathing or specific reflection?
The circle system has been in use for more than a 100 years, whereas the first clinical application of an anaesthetic reflector was reported just 15 years ago. Its functional basis relies on molecular sieves such as zeolite crystals or activated carbon. In a circle system, the breathing gas is rebreathed after carbon dioxide absorption; a reflector on the other hand specifically retains the anaesthetic during expiration and resupplies it during the next inspiration. ⋯ The AnaConDa consists only of a reflector which is connected to a syringe pump for infusion of liquid sevoflurane or isoflurane. The Mirus represents a technical advancement; its control unit includes a gas and ventilation monitor as well as a gas dispensing unit. The functionality, specific features, advantages and disadvantages of both systems are discussed in the text.
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J Clin Monit Comput · Aug 2018
K-band Doppler radar for contact-less overnight sleep marker assessment: a pilot validation study.
An estimated 45 million persons in Europe are annually subjected to sleep-wake disorders. State-of-the-art polysomnography provides sophisticated insights into sleep (patho)physiology. A drawback of the method, however, is the obtrusive setting dependent on a clinical-based sleep laboratory with high operational costs. ⋯ The prototype has successfully classified limb movements, with a sensitivity and specificity of 88.9 and 76.8% respectively, and has achieved accurate respiratory and heart rate measurement performance with overall absolute errors of 1 breath per minute for respiration and 3 beats per minute for heart rate. This pilot study shows that K-band Doppler radar and wavelet transform MRA seem to be valid for overnight sleep marker assessment. The contact-less approach might offer a promising solution for home-based sleep monitoring and assessment.
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J Clin Monit Comput · Aug 2018
Case ReportsA "NIRS" death experience: a reduction in cortical oxygenation by time-resolved near-infrared spectroscopy preceding cardiac arrest.
Near-infrared spectroscopy (NIRS) has been used effectively post-cardiac-arrest to gauge adequacy of resuscitation and predict the likelihood of achieving a return of spontaneous circulation. However, preempting hemodynamic collapse is preferable to achieving ROSC through advanced cardiac life support. Minimizing "time down" without end-organ perfusion has always been a central pillar of ACLS. ⋯ Here we report a young man who suffered a pulseless electrical activity (PEA) arrest while cortical oxygenation was monitored using time-resolved near-infrared spectroscopy. The onset of cortical deoxygenation preceded the loss of palpable pulses by 15 min, suggesting that TRS-NIRS monitoring might provide a means of preempting PEA arrest. Our experience with this patient represents a promising new direction for continuous NIRS monitoring and has the potential to not only predict clinical outcomes, but affect them to the patient's benefit as well.