%0 Journal Article %T Pulse oximetry wave variation as a noninvasive tool to assess volume status in cardiac surgery %A Westphal %A Glauco A %A Silva %A Eliezer %A Gon£¿alves %A Anderson Roman %A Caldeira Filho %A Milton %A Poli-de-Figueiredo %A Lu¨ªz F %J Clinics %D 2009 %I Faculdade de Medicina / USP %R 10.1590/S1807-59322009000400012 %X objective: to compare variations of plethysmographic wave amplitude (¦Äppleth) and to determine the percent difference between inspiratory and expiratory pulse pressure (¦Äpp) cutoff values for volume responsiveness in a homogenous population of postoperative cardiac surgery patients. introduction: intra-thoracic pressure variations interfere with stroke volume variation. pulse pressure variations through arterial lines during mechanical ventilation have been recommended for the estimation of fluid responsiveness. pulse oximetry may offer a non-invasive plethysmographic method to evaluate pulse pressure; this may be useful for guiding fluid replacement. methods: controlled, prospective study in cardiac surgery patients under controlled ventilation. simultaneous digital recordings of arterial pressure and plethysmographic waves were performed. ¦Äpp, systolic pressure (¦Äps), dppleth, and systolic component (¦Äspleth) were calculated. a dpp > 13% identified fluid-responsive patients. volume expansion was performed in responsive subjects. systolic and amplitude components of pressure and plethysmographic waves were compared. results: in 50 measurements from 43 patients, ¦Äpp was correlated with (ppleth (r=0.90, p<0.001), (ps (r=0.90, p<0.001), and (spleth (r=0.73, p<0.001). an aarea under roc curve (auc) identified the fluid responsiveness thresholds: (ppleth of 11% (auc = 0.95¡À0.04), (ps of 8% (auc=0.93¡À0.05), and (spleth of 32% (auc=0.82¡À0.07). a (ppleth value > 11% predicted (pp > 13% with 100% specificity and 91% sensitivity. volume expansion, performed in 20 patients, changed (pp, (ppleth, (ps and (spleth significantly (p<0.008). conclusions: ¦Äppleth is well correlated with dpp and constitutes a simple and non-invasive method for assessing fluid responsiveness in patients following cardiac surgery. %K volume replacement %K hemodynamics %K postoperative care %K cardiac function %K cardiac catheterization [intervention]. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1807-59322009000400012&lng=en&nrm=iso&tlng=en