Does targeted neonatal echocardiography affect hemodynamics and cerebral oxygenation in extremely preterm infants?

To investigate the effect of targeted neonatal echocardiography (TnEcho) on heart rate, arterial oxygen saturation (SPO2), cerebral regional oxygen saturation (CrSO2) and cerebral fractional oxygen extraction (CFOE) in extremely preterm infants during the first 3 postnatal days.

s a nested study in a prospective observational study, we acquired continuous data on heart rate, SPO2, CrSO2 and CFOE. Data averaged for the duration of TnEcho study were compared with the data collected during a baseline period immediately before the start of echocardiography. The duration of the baseline and study periods was the same. TnEcho evaluation included assessment of preload, afterload, contractility, left and right ventricular output, patent ductus arteriosus and foramen ovale.

We analyzed 138 data pairs before and during TnEcho in 22 extremely preterm infants (gestational age 25.9 ± 1.2 weeks; range 23 to 27). There was no significant difference in heart rate between baseline and TnEcho period. There was a statistical, but clinically negligible, difference between baseline and TnEcho in SPO2 (median (quartile) 91.4% (88.9, 94.2) vs 91.3% (88.9, 94), P = 0.048), CrSO2 (76.8% (70.7, 81.5) vs 74.9% (69.5, 80.1), P<0.0001) and CFOE (15.8% (9.8, 23.6) vs 17.5% (11.3, 24.7), P<0.0001). The changes in the parameters monitored were similar in preterm infants who developed peri/intraventricular hemorrhage and in those who did not.

Although there were statistically significant changes in SPO2, CrSO2 and CFOE, the alterations were minimal and unlikely of clinical relevance. Thus, cerebral hemodynamics and systemic and cerebral oxygenation are not perturbed during TnEcho and the procedure is well tolerated by the extremely preterm infants during the postnatal transitional period.