[Veno-venous extracorporeal oxygenation and veno-arterial extracorporeal oxygenation. Questions, answers]. / Assistance respiratoire veino-veineuse et assistance circulatoire veino-artérielle avec oxygénation extracorporelle. Questions, réponses.

A round table, organized by the French Society of Perfusion (Sofraperf) at the French national congress on extracorporeal circulations (Perfusion 2013), was attended by perfusionists, anaesthesiologists, intensivists and surgeons around the theme of respiratory veno-venous support and veno-arterial circulatory support with extracorporeal oxygenation in intensive care units. The debate was conducted in a participatory manner by bi-directional questions-answers session between moderators and assistance. The authors report management of this type of therapy that is not perfectly homogeneous, supported on literature data. Cannulae, cannulation, circuit, oxygenator, anticoagulation, control, surveillance, weaning are subject to paragraphs with defined entry whose contents are mutually enriching.

[Vasomotor tone and CBP : monitoring components, pratical and therapeutic approaches]. / Tonus vasomoteur et CEC : éléments de surveillance, attitudes pratique et thérapeutique.

The vasomotor tone is an essential determinant of blood pressure. Vascular resistance is the result of a calculation including vasomotor tone, blood flow and blood viscosity. The vascular tone is modulated by the sympathetic system and the direct actions of drugs (patient's pathology, anaesthesia). The pressure and flow allow the vascular tone apprehension. A decrease in vasomotor tone lowers the mean arterial pressure and may cause an intense vasoplegia with arterial vascular resistance below than 800 dyn/s/cm(5) leading to a lack of tissue oxygenation. Vasomotor paralysis can be caused by the patient medications or an intense inflammatory reaction starting at the extracorporeal circulation onset. Monitoring parameters of extracorporeal circulation such as pressure, flow, arterial and venous oxygen saturation, blood level in the venous reservoir, and extensively blood gases, haemoglobin, CO(2) partial pressure level of the oxygenator vent, bispectral index, and oxygen saturation of cerebral tissue are reviewed. They will know the vasoplegia consequences and bear an indication of adequate tissue oxygenation. It may be obtained by using vasopressors (ephedrine, norepinephrine, terbutalin and vasopressin) methylene blue, increasing blood viscosity (erythrocytes) and blood flow, even by inducing hypothermia.

Statistical methods of estimation and inference for functional MR image analysis.

Two questions arising in the analysis of functional magnetic resonance imaging (fMRI) data acquired during periodic sensory stimulation are: i) how to measure the experimentally determined effect in fMRI time series; and ii) how to decide whether an apparent effect is significant. Our approach is first to fit a time series regression model, including sine and cosine terms at the (fundamental) frequency of experimental stimulation, by pseudogeneralized least squares (PGLS) at each pixel of an image. Sinusoidal modeling takes account of locally variable hemodynamic delay and dispersion, and PGLS fitting corrects for residual or endogenous autocorrelation in fMRI time series, to yield best unbiased estimates of the amplitudes of the sine and cosine terms at fundamental frequency; from these parameters the authors derive estimates of experimentally determined power and its standard error. Randomization testing is then used to create inferential brain activation maps (BAMs) of pixels significantly activated by the experimental stimulus. The methods are illustrated by application to data acquired from normal human subjects during periodic visual and auditory stimulation.