The hemodynamic effects of neonatal patent ductus arteriosus shunting on superior mesenteric artery blood flow.

OBJECTIVE

To determine if the ratio of the pulsatility index (PI) of the left pulmonary artery to the PI of the descending aorta, the Rp/Rs index, correlates with the degree of ductal steal from the intestine in neonates with a patent ductus arteriosus (PDA).

STUDY

DESIGN

Echocardiograms and Doppler studies of the superior mesenteric artery (SMA) were performed in 41 neonates less than 35 weeks gestational age with a hemodynamically significant PDA (hsPDA).

RESULTS

There was a significant negative correlation between the Rp/Rs index and the SMA PI after controlling for ductal size (r=-0.476, p<0.008).

CONCLUSIONS

The Rp/Rs index can be used as an indicator of ductal steal on intestinal blood flow. The Rp/Rs index may be a useful adjunct to existing and new techniques for improving early assessment and treatment of hsPDA, and for evaluating the effects of hsPDA on systemic organs.