La pléthysmographie de l'oxymètre de pouls : un ancien tracé plein d'avenir ? Principes et applications cliniques

Pulse oximeter allows us to monitor “Plethysmographic” oxygen saturation (SpO2), an approximate value of the arterial saturation (SaO2). A second parameter is issued from this technic: the plethysmographic curve. This study highlights the interest of plethysmography as a new hemodynamic parameter. Indeed, plethysmography oximetry curve can be useful to analyse the distal vascularisation by peripheric perfusion indices. The similarity between the arterial and plethysmographic curve, give us the possibility to transpose and to create new equivalent “plethysmographic” indices. The respiratory variation of the peak plethysmographic curve and the equivalent of the ΔDDown Plethysmographic curve allow to evaluate volume status. The equivalent of the Pulse Pressure respiratory variation (ΔPPleth) and the Pre-ejection period (ΔPEPPleh) are new fluid responsiveness parameters. Therefore, plethysmographic curve obtained from pulse oximetry, is an hemodynamic tool really non invasive, accurate, easy to use and instantaneously available.