Prediction of hyperdynamic circulation by arterial diastolic reflected waveform analysis in patients undergoing liver transplantation.

OBJECTIVES: In cirrhotic patients with hyperdynamic circulation characterized by a decrease in systemic vascular resistance (SVR) and an increase in cardiac output, cardiac and vascular properties are expressed in peripheral arterial pressure waveforms. We attempted to assess whether the variables derived from the radial artery waveform can predict hyperdynamic circulation in liver transplant recipients.

MATERIALS AND METHODS: Before surgical incision, we obtained the simultaneous cardiac index (CI) and SVR determined by a pulmonary artery catheter in 30 liver transplant recipients. We analyzed the diastolic reflected waveform characteristics by calculating the diastolic augmentation index (DAIx, %), which was defined as 100×[peak pressure of diastolic reflected wave-diastolic arterial pressure]/pulse pressure. The time from diastolic arterial pressure to the peak of the diastolic reflected wave, corrected by RR intervals (tDA), was also determined.

RESULTS: CI and SVR were correlated with DAIx (r=-0.553, P=0.002 and r=0.617, P<0.001) and tDA (r=0.504, P=0.004 and r=-0.692, P<0.001). The areas under the receiver operating characteristic curves were 0.900 [95% confidence interval: 0.713-0.978 for both DAIx and tDA to predict hyperdynamic circulation (CI>4.0 l/min/m and SVR<800 dynes·s/cm, n=13)]. DAIx less than 35% and tDA more than 484 ms were the best cutoff values for differentiation of hyperdynamic circulation (sensitivity/specificity 92.3%/76.5% and 100%/70.6%, respectively).

CONCLUSION: Diastolic reflected waveform characteristics can be used to predict high CI and low SVR in liver transplant recipients. This study suggests that these minimally invasive indicators may also be valuable when pulmonary artery catheterization is not available in patients with a hyperdynamic condition.