Hemodynamic Patterns Determined By Non-Invasive Cw-Doppler Ultrasound Cardiac Monitoring (USCOM) in Preterm Neonates with Respiratory Distress Syndrome During Non-Invasive Respiratory Support

Aim: To determine the hemodynamic patterns in preterm neonates with respiratory distress syndrome (RDS) using the USCOM-1A technology.

Materials and Methods: The USCOM device is a bedside method of evaluating cardiac output (CO) based on continuous-wave Doppler ultrasound. Hemodynamic parameters were measured daily for 7 days in 32 preterm neonates 32 ± 1 weeks of gestation (1688 ± 111 g) with RDS requiring noninvasive respiratory support (NCPAP, NIPPV, HFNC) and no catecholamine support in comparison with 28 healthy term neonates (3100 ± 690 g).

Results: At day 1, preterm neonates had lower SVI (18 ± 5 vs 28 ± 8 ml m−2, p = 0.043) and higher SVRI (1585 ± 245 vs 1035 ± 358 dyn s cm−5 m2, p = 0.013) with a tendency for lower cardiac index (2.6 ± 0.8 vs 4.0 ± 1.3 l min−1 m−2, p = 0.089). Together with no difference in SMII, it indicates the presence of diastolic dysfunction with low preload. It is noted that all parameters had not changed by day 7 in preterm neonates, whereas term neonates demonstrated significantly increased SMII reflecting postnatal cardiovascular adaptation. Compared with preterm neonates with RDS requiring NCPAP/NIPPV, preterm neonates requiring HFNC had higher levels of FTc (330 ± 59 vs 388 ± 41 ms, р = 0.045), SVI (13 ± 3 vs 18 ± 4, ml/m2, р = 0.007), SMII (0.41 ± 0.09 vs 0.57 ± 0.21, р = 0.02), and CI (2.2 ± 0.6 vs 4.5 ± 0.9 l/min/m2, р = 0.006).

Conclusions:Noninvasive respiratory support in preterm neonates with RDS may lead to diastolic dysfunction that is less prominent in neonates with HFNC.