Introduction : In pediatric patients, dynamic preload indices to predict fluid responsiveness have conflicting results in comparison with adults. A recent study demonstrated that pulse pressure variation (PPV) ≥16% has provided an accurate method for predicting fluid responsiveness in pediatric congenital heart surgery. The present study was designed to compare PPV and respiratory systolic, diastolic and pulse transit time interval variation (STV, DTV and PTTV, respectively) as predictors of fluid responsiveness during pediatric liver transplantation.
Methods : A total of 61 data from 16 pediatric patients, median age 8.5 months (range 0.1 - 7 yr), were retrospectively evaluated from electrically recorded radial arterial and central venous pressure (CVP) waveform. The time from the onset of systolic upstroke to the dicrotic notch was defined as the systolic time interval (STI), and the time from dicrotic notch to the beginning of systolic upstroke was defined as the diastolic time interval (DTI). The time from peak R wave on electrocardiography to the onset of systolic upstroke was defined as the pulse transit time (PTT) interval. STV was calculated by averaging of three consecutive respiratory cycles with the following: (STImaximum - STIminimum) / STImean. Same method was used for calculating DTV, PTTV and PPV. STV, DTV and PTTV were corrected by cardiac period. Averaged CVP was used as a static preload index. PPV threshold of ≥16% was used to discriminate fluid responsiveness. Receiver operating characteristic (ROC) curves and Pearson’s correlation analysis were used for the comparison.
Results : PPV showed correlations with STV, DTV and PTTV (r = 0.65, 0.57 and 0.60, respectively), but less with CVP (r = - 0.30). Area under ROC curves (AUC) of STV, DTV, PTTV and CVP were 0.834, 0.872, 0.832 and 0.613, respectively. Cut-off values of STV, DTV and PTTV were 7.7% (sensitivity/specificity, 0.80/0.83), 7.7% (sensitivity/specificity, 0.70/0.88) and 8.7% (sensitivity/specificity 0.67/1.0), respectively.
Conclusion : This study shows that STV, DTV and PTTV showed correlation with PPV, suggesting that this novel method may have a potential to predict hemodynamic response during pediatric surgery.