616 research outputs found
Partial liquid ventilation and inhaled nitric oxide have a cumulative effect in improving arterial oxygenation in experimental ards
No full textNouvelle méthode syntagmatique de vectorisation appliquée au self-organizing map des textes vietnamiens
No full text@inproceedings{CN-NGUYEN-2004, author = {Nguyen D.T.}, title = {Nouvelle méthode syntagmatique de vectorisation appliquée au self-organizing map des textes vietnamiens}, booktitle = {RECIRAL'04}, year = {2004}, address = {Fès, Maroc}, month = {avril} }National audienc
Exogenous surfactant and nitric oxide have a synergistic effect in improving gas exchange in experimental ards
No full textPartial liquid ventilation and inhaled nitric oxide have a cumulative effect in improving arterial oxygenation in experimental ards
No full text
Exogenous surfactant and nitric oxide have a synergistic effect in improving gas exchange in experimental ards
No full text
Theoretical investigation of measuring cerebral blood flow in the adult human head using bolus indocyanine green injection and near-infrared spectroscopy
No full textTo investigate the accuracy of measuring cerebral blood flow (CBF) using a bolus injection of indocyanine green (ICG) detected by near infrared spectroscopy in adult human heads, simulations were performed using a two layered model, representing the extracerebral and intracerebral layers. Modelled optical data were converted into tissue ICG concentration using either the one detector modified Beer Lambert law (MBLL) method, or the two detector partial pathlength (PPL) method. CBFs were estimated using deconvolution and blood flow index techniques respectively. Using the MBLL method, CBFs were significantly underestimated but the PPL method improved their accuracy and robustness, especially when used as relative measures. Dispersion of the arterial input function also affected the CBF estimates
Investigation of in vivo measurement of cerebral cytochrome-c-oxidase redox changes using near-infrared spectroscopy in patients with orthostatic hypotension
No full textWe have previously used a continuous four wavelength near infrared spectrometer to measure changes in the cerebral concentrations of oxy- (Δ[HbO2] and deoxy- haemoglobin (Δ[HHb]) during head-up tilt in patients with primary autonomic failure. The measured changes in light attenuation also allow calculation of changes in the concentration of oxidised cytochrome c oxidase (Δ[oxCCO]), and this paper analyses the Δ[oxCCO] during the severe episodes of orthostatic hypotension produced by this experimental protocol. We studied 12 patients during a passive change in position from supine to a 60º head-up tilt. The challenge caused a reduction in mean blood pressure of 59.93 (±26.12) mmHg (Mean (±SD), p<0.0001), which was associated with a reduction in the total concentration of haemoglobin (Δ[HbT]= Δ[HbO2]+Δ[HHb]) of 5.02 (±3.81) μM (p<0.0001) and a reduction in the haemoglobin difference concentration (Δ[Hbdiff]= Δ[HbO2]-Δ[HHb]) of 14.4 (±6.73) μM (p<0.0001). We observed a wide range of responses in Δ[oxCCO]. 6 patients demonstrated a drop in Δ[oxCCO] (0.17 ±0.15μM ); 4 patients demonstrated no change (0.01 ±0.12 μM ) and 2 patients showed an increase in Δ[oxCCO] (0.21 ±0.01 μM ). Investigation of the association between the changes in concentrations of haemoglobin species and the Δ[oxCCO] for each patient show a range of relationships. This suggests that a simple mechanism for crosstalk, which might produce artefactual changes in [oxCCO], is not present between the haemoglobin and the oxCCO NIRS signals. Further investigation is required to determine the clinical significance of the changes in [oxCCO]
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