Ventilation-induced plethysmographic variations predict fluid responsiveness in ventilated postoperative cardiac surgery patients.
BACKGROUND
It has been shown that ventilation-induced pulse pressure variation (PPV) is a better variable than central venous pressure (CVP) or pulmonary artery occlusion pressure (PAOP) for predicting cardiac output changes after fluid administration. The plethysmographic wave form measured with a fingertip pulse is very similar to the arterial blood pressure curve.


METHODS
We investigated whether this widely used, noninvasive instrument could predict fluid responsiveness by conducting an observational study in 32 patients who had undergone cardiac surgery. We compared PPV, CVP, PAOP, diastolic pulmonary artery pressure, and ventilation-induced plethysmographic variation (VPV) for predicting the cardiac output change after the administration of 500 mL 6% hydroxyethylstarch.


RESULTS
We found a good correlation between cardiac output changes and both PPV and VPV (P < 0.05). Receiver operating characteristic analysis revealed an area under the curve of 0.937 for PPV and 0.892 for VPV. The optimal thresholds were a variation of 11.3% for both PPV and VPV in predicting a 15% increase in cardiac output.


CONCLUSIONS
This study shows that VPV, like PPV, is a more reliable predictor of fluid responsiveness than CVP and PAOP.
Wyffels
Piet A H
PA
Department of Anaesthesiology, UZ Gasthuisberg, Leuven, Belgium. pietwyffels@hotmail.com
Durnez
Pieter-Jan
PJ
Helderweirt
Johan
J
Stockman
Willem M A
WM
De Kegel
Dirk
D
D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D013504:Cardiovascular Surgical Procedures / Q000379:methods; D005260:Female; D005440:Fluid Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods*; D011182:Postoperative Care / Q000379:methods*; D011237:Predictive Value of Tests; D012121:Respiration, Artificial / Q000379:methods*