Background and Goal of Study: Stroke volume variation (SVV) is of diagnostic value for fluid responsiveness in patients monitored with the FloTrac/Vigileo system, whereas central venous pressure (CVP) is considered not very useful for predicting fluid responsiveness; however, few studies investigated the relationship between intraoperative respiratory variation in CVP and fluid responsiveness. We hypothesized that respiratory variation in CVP could be a surrogate for SVV in mechanically ventilated patients under general anesthesia and analyzed the correlation between respiratory variation in CVP and SVV.
Materials and Methods: The study sample included 5 patients with normal heart function and normal sinus rhythm undergoing abdominal aorta replacement between June and November 2017, in whom hemodynamic changes including those before and after aortic clamping/declamping were captured on the vital signs monitor and invasive hemodynamic monitoring data including CVP and SVV were recorded every minute. Respiratory variation in the CVP waveform over a single respiratory cycle was calculated as follows: [(maximum CVP–minimum CVP)/maximum CVP]×100 (%). Respiratory variation in CVP was compared by dividing SVV values into two groups: SVV ≥16% (high SVV group) and SVV ≤10% (low SVV group). Statistical analysis was performed using Spearman’s correlation and the Mann-Whitney U test. Differences were considered statistically significant when p<0.05.
Results and Discussion: Hemodynamic changes were captured 64 times in total. Respiratory variation in CVP was significantly correlated with SVV (r=0.567, p<0.001) and was significantly greater in the high SVV group than in the low SVV group (p<0.001, Figure). Invasive hemodynamic monitoring data were recorded 1203 times in total. The median CVP was 9 mmHg (interquartile range [IQR] 7−11) and the median SVV was 10% (IQR 8−15). The absolute value of CVP was only slightly correlated with SVV (r=−0.283).
Conclusion: Respiratory variation in CVP can be a surrogate for SVV for predicting fluid responsiveness in mechanically ventilated patients under general anesthesia during noncardiac surgery, but the absolute value of CVP was not.

08 / Respiratory variation in central venous pressure as a surrogate for stroke volume variation for predicting fluid responsiveness during noncardiac surgery