11 research outputs found
Prise de dĂ©cision dâĂ©vacuation des populations protĂ©gĂ©espar une digue lors dâune crue majeure de la Loire â exemple du Val dâOrlĂ©ans
Early Detection and Correction of Cerebral Desaturation With Noninvasive Oxy-Hemoglobin, Deoxy-Hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series.
Regional cerebral oxygen saturation (rS o2 ) obtained from near-infrared spectroscopy (NIRS) provides valuable information during cardiac surgery. The rS o2 is calculated from the proportion of oxygenated to total hemoglobin in the cerebral vasculature. Root O3 cerebral oximetry (Masimo) allows for individual identification of changes in total (ÎcHbi), oxygenated (Î o2 Hbi), and deoxygenated (ÎHHbi) hemoglobin spectral absorptions. Variations in these parameters from baseline help identify the underlying mechanisms of cerebral desaturation. This case series represents the first preliminary description of Î o2 Hbi, ÎHHbi, and ÎcHbi variations in 10 cardiac surgical settings. Hemoglobin spectral absorption changes can be classified according to 3 distinct variations of cerebral desaturation. Reduced cerebral oxygen content or increased cerebral metabolism without major blood flow changes is reflected by decreased Î o2 Hbi, unchanged ÎcHbi, and increased ÎHHbi Reduced cerebral arterial blood flow is suggested by decreased Î o2 Hbi and ÎcHbi, with variable ÎHHbi. Finally, acute cerebral congestion may be suspected with increased ÎHHbi and ÎcHbi with unchanged Î o2 Hbi. Cerebral desaturation can also result from mixed mechanisms reflected by variable combination of those 3 patterns. Normal cerebral saturation can occur, where reduced cerebral oxygen content such as anemia is balanced by a reduction in cerebral oxygen consumption such as during hypothermia. A summative algorithm using rS o2 , Î o2 Hbi, ÎHHbi, and ÎcHbi is proposed. Further explorations involving more patients should be performed to establish the potential role and limitations of monitoring hemoglobin spectral absorption signals