Baseline cardiac output and its alterations during ibuprofen treatment for patent ductus arteriosus in preterm infants.

BACKGROUND

Infants with hemodynamically significant patent ductus arteriosus (PDA) may physiologically compensate with a supranormal cardiac output (CO). As such, a supranormal CO may be a surrogate marker for a significant PDA or indicate a failed response to PDA closure by ibuprofen. Electrical cardiometry (EC) is an impedance-based monitor that can continuously and non-invasively assess CO (COEC). We aimed to trend COEC through ibuprofen treatment for PDA in preterm infants.

METHODS

We reviewed our database of preterm infants receiving ibuprofen for PDA closure. Response to ibuprofen was defined as no ductal flow in echocardiography ≤24 h after treatment. Responders were compared with gestational age (GA) and postnatal age matched non-responders and their trends of COEC were compared. Both groups' baseline COEC were further compared to the reference infants without PDA.

RESULTS

Eighteen infants (9 responders and 9 non-responders) with median (interquatile range) GA 27.5 (26.6-28.6) weeks, birthweight 1038 (854-1218) g and age 3.5 (3.0-4.0) days were studied. There were positive correlations between COEC and ductal diameter and left atrium/ aortic root ratio (r = 0.521 and 0.374, p < 0.001, respectively). Both responders and non-responders had significantly higher baseline COEC than the reference. Although there was no significant within-subject alteration of COEC during ibuprofen treatment, there was a between-subject difference indicating non-responders had generally higher COEC.

CONCLUSIONS

The changes of COEC during pharmacological closure of PDA is less drastic compared to surgical closure. Infants with PDA had higher baseline COEC compared to those without PDA, and non-responders had higher COEC especially at baseline compared to responders.