Right ventricular stroke volume variation: a tool to assess right ventricular volume responsiveness.

BACKGROUND

So far, only left ventricular functional preload indices are used as a routine to assess volume responsiveness. Right ventricular (RV) functional preload indices have been described, but offer no continuous monitoring.

METHODS

Following ethical approval, a pressure-induced right ventricular failure (RVF) was induced with continuous infusion of a thromboxane-A2-analogue (U46619) in 15 anesthetized and ventilated pigs. Before and after increasing mean pulmonary artery pressure (MPAP) by 50%, right ventricular stroke volume variation (RVSVV) was assessed with an ultrasonic pulmonary artery flow probe. Measurements were repeated following volume depletion (- 300 mL) and stepwise retransfusion (200 mL of whole blood and 200 mL of a colloid solution).

RESULTS

A significant and systematic increase in RVSVV during induction of RVF was observed. Volume depletion led to an increase in RVSVV and re-transfusion led to a decrease in RVSVV. RVSVV was higher and a significant decrease in RVSVV was present in all animals experiencing an increase in CO by more than 5% during retransfusion.

CONCLUSION

RVSVV seems to reflect volume requirement of the right ventricle and it might prove a reliable parameter to assess volume responsiveness in RVF.