Articles: function.
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There is a growing interest in measuring cerebral autoregulation in patients with acute brain injury. Non-invasive finger photo-plethysmography (Finapres) is the method of choice to relate arterial blood pressure to changes in cerebral blood flow. Among acutely ill patients, however, peripheral vasoconstriction often limits the use of Finapres requiring direct intravascular blood pressure measurement. We evaluated how these two different forms of blood pressure monitoring affect the parameters of dynamic cerebral autoregulation (DCA). ⋯ Overall, both methods yield similar results and can be used for the assessment of DCA. However, there was a small but significant difference for both mean Mx and phase shift, which would need to be adjusted for during monitoring of patients when using both methods. When available, invasive arterial blood pressure monitoring may improve accuracy and thus should be the preferred method for DCA assessment in the ICU.
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Beyond being a substitute for X-ray, computed tomography, and scintigraphy, magnetic resonance imaging (MRI) inherently combines morphologic and functional information more than any other technology. Lung perfusion: The most established method is first-pass contrast-enhanced imaging with bolus injection of gadolinium chelates and time-resolved gradient-echo (GRE) sequences covering the whole lung (1 volume/s). Images are evaluated visually or semiquantitatively, while absolute quantification remains challenging due to the nonlinear relation of T1-shortening and contrast material concentration. ⋯ Respiratory mechanics: Time-resolved series with high background signal such as GRE or steady-state free precession visualize the movement of chest wall, diaphragm, mediastinum, lung tissue, tracheal wall, and tumor. The assessment of volume changes allows drawing conclusions on regional ventilation. With this arsenal of functional imaging capabilities at high spatial and temporal resolution but without radiation burden, MRI will find its role in regional functional lung analysis and will therefore overcome the sensitivity of global lung function analysis for repeated short-term treatment monitoring.
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Critical care nurse · Feb 2014
The importance of tracheostomy progression in the intensive care unit.
A plan to progress a tracheostomy toward decannulation should be initiated unless the tracheostomy has been placed for irreversible conditions. In most cases, tracheostomy progression can begin once a patient is free from ventilator dependence. ⋯ A systematic approach to tracheostomy progression involves assessing (1) hemodynamic stability, (2) whether the patient has been free from ventilator support for at least 24 hours, (3) swallowing, cough strength, and aspiration risk, (4) management of secretions, and (5) toleration of cuff deflation, followed by (6) changing to a cuffless tube, (7) capping trials, (8) functional decannulation trials, (9) measuring cough strength, and (10) decannulation. Critical care nurses can facilitate the process and avoid unnecessary delays and complications.
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Critical care medicine · Feb 2014
Inhibiting the Toll-Like Receptor 4 Toll/Interleukin-1 Receptor Domain Protects Against Hepatic Warm Ischemia and Reperfusion Injury in Mice.
During Toll-like receptor 4 signaling, the Toll/interleukin-1 receptor domain is essential for interactions with downstream Toll/interleukin-1 receptor domain-containing adaptor proteins. The aim of this study is to investigate the role of the Toll/interleukin-1 receptor domain in the Toll-like receptor 4 signaling pathway during hepatic ischemia and reperfusion injury. ⋯ Toll/interleukin-1 receptor domain inhibition disrupts the interaction of Toll-like receptor 4 with its adaptor proteins, which abrogates downstream signaling pathways and prevents the activation of nuclear factor-κB and Jun N-terminal kinase/p38. This reduction in signaling consequently reduces hepatic inflammation, cell apoptosis, and hepatic damage. Toll/interleukin-1 receptor domain-targeted therapy thus represents a new approach to inhibit the intracellular Toll-like receptor 4 signaling pathway and reveals novel therapeutic target sites, which will facilitate the development of specific therapeutic agents.