Respiratory variations in pulse oximetry plethysmographic waveform amplitude to predict fluid responsiveness in the operating room.
BACKGROUND
Respiratory variations in pulse oximetry plethysmographic waveform amplitude (DeltaPOP) are related to respiratory variations in pulse pressure (DeltaPP) and are sensitive to changes in preload. The authors hypothesized that DeltaPOP can predict fluid responsiveness in mechanically ventilated patients during general anesthesia.


METHODS
Twenty-five patients referred for cardiac surgery were studied after induction of general anesthesia. Hemodynamic data (cardiac index, central venous pressure, pulmonary capillary wedge pressure, DeltaPP, and DeltaPOP) were recorded before and after volume expansion (500 ml hetastarch, 6%). Fluid responsiveness was defined as an increase in cardiac index of 15% or greater.


RESULTS
Volume expansion induced changes in cardiac index (2.0+/-0.4 to 2.3+/-0.5 mmHg; P<0.05), DeltaPP (11+/-7 to 6+/-5%; P<0.05), and DeltaPOP (12+/-9 to 7+/-5%; P<0.05). DeltaPOP and DeltaPP were higher in responders than in nonresponders (17+/-8 vs. 6+/-4 and 14+/-7 vs. 6+/-4%, respectively; P<0.05 for both). A DeltaPOP greater than 13% before volume expansion allowed discrimination between responders and nonresponders with 80% sensitivity and 90% specificity. There was a significant relation between DeltaPOP before volume expansion and percent change in cardiac index after volume expansion (r=0.62; P<0.05).


CONCLUSIONS
DeltaPOP can predict fluid responsiveness noninvasively in mechanically ventilated patients during general anesthesia. This index has potential clinical applications.
Cannesson
Maxime
M
Hospices Civils de Lyon, Department of Anesthesiology and Intensive Care, Louis Pradel Hospital, Claude Bernard Lyon I University, France. maxime_cannesson@hotmail.com
Attof
Yassin
Y
Rosamel
Pascal
P
Desebbe
Olivier
O
Joseph
Pierre
P
Metton
Olivier
O
Bastien
Olivier
O
Lehot
Jean-Jacques
JJ
D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General; D001794:Blood Pressure / Q000187:drug effects*; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010952:Plasma Substitutes / Q000494:pharmacology*; D010991:Plethysmography; D012119:Respiration / Q000187:drug effects*; D012121:Respiration, Artificial
D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes