A comparison of systolic and diastolic time variation with pulse pressure variation as a predictor of fluid responsiveness during pediatric liver transplantation

ABSTRACT

BACKGROUND: In pediatric patients, dynamic preload indices to predict fluid responsiveness remain controversial. Because each beat of blood pressure (BP) - waveform - contains evidence of a systolic and diastolic time interval (STI, DTI), we compared pulse pressure variation (PPV) with respiratory STI and DTI variation (STV, DTV) as predictors of fluid responsiveness during pediatric liver transplantation. METHODS: A total of 61 datasets from 16 pediatric liver transplant patients (age range one month to seven years), before and after an inferior vena cava clamp was applied, were retrospectively evaluated from electronically archived BP and central venous pressure (CVP) waveforms. STI and DTI were separated by a beat-to-beat blood pressure waveform. STV, DTV and PPV were calculated by averaging three consecutive respiratory cycles. Averaged CVP was used as a static preload index. A PPV threshold of > or =16%, a known cutoff value in pediatric surgery, was used to discriminate fluid responsiveness in the receiver operating characteristic (ROC) curve analysis. RESULTS: PPV showed correlations with STV and DTV (r = 0.65 and 0.57, P < 0.001, respectively), but not with CVP (r = -0.30, P = 0.079). The area under the ROC curves (AUC) of STV, DTV and CVP were 0.834, 0.872, and 0.613, respectively. Cut-off values of STV and DTV were 7.7% (sensitivity/specificity, 0.80/0.83) and 7.7% (sensitivity/specificity, 0.70/0.88), respectively. CONCLUSIONS: This study demonstrates that STV and DTV from a BP waveform showed the potential to predict fluid responsiveness as a surrogate of PPV during pediatric surgery.