PhD Scientific Days 2021

CL_IV_L: Clinical Medicine IV. Lectures

Continuous non-invasive hemodynamic monitoring of neonates undergoing hypothermia

Text of the abstract

Introduction: Hemodynamic instability is common in neonates undergoing hypothermia due to hypoxic-ischemic encephalopathy (HIE). Rewarming is a critical period and non-invasive circulatory monitoring may be helpful in guiding cardiovascular suppotive therapy.
Aims: To provide a comprehensive analysis of cardiovascular changes during rewarming.
Methods: In a prospective, observational study, we examined 26 HIE neonates born between 2016 and 2019, who were treated with hypothermia in the 1st Department of Pediatrics, Semmelweis University. A hemodynamic monitor called ICON manufactured by Osypka Medical GmbH was used. We analyzed the data recorded by the monitor in every minute Heart rate (HR), stroke volume (SV), cardiac output (CO) data was recorded continuously with a minute frequency. Neurological outcome was assessed at 2 years using the BSID II. Scale. Good outcome was defined as >70 points on both the psychomotor and mental scale. We examined the cardiovascular changes separately in patients with good and poor outcomes.
Results: The mean (SD) gestational age was was 39 ± 1.3 weeks and birth weight was 3200 ± 600 g. Based on the neurological examination, 14 (54%) patients had good and 12 (46%) had poor outcome. The data collection lasted from median [IQR] of 11.8. [7.0; 24.3] hours of life (h) to 84.0. [81.8; 87.0] h. During hypothermia, the HR of the good outcome group tended to be lower than that of the poor group (90 ± 19 / min vs. 104 ± 18 / min, p = 0.07), during rewarming, the HR increased significantly in both groups, and the difference between the two groups disappeared (140 ± 15 /min vs. 143 ± 20 /min, p = 0.46). Interestingly, the SV did not change in the whole population during rewarming (1.45 ± 0.32 ml / kg before and 1.46 ml ± 0.34 ml / kg p= 0.98 after rewarming). Accordingly, a significant, 25% increase in CO was observed in both groups during rewarming (150 ± 34.9 ml/kg/min vs 190 ± 45.1 ml/kg/min, p=0.03) and there was no difference between outcome groups.
Conclusion: Based on continuous hemodynamic monitoring, the increase in cardiac output observed during rewarming in asphyxic neonates is primarily due to an increase in heart rate and not in stroke volume.
Funding: OTKA FK_20 135222.

University and Doctoral School

Semmelweis University, Károly Rácz Doctoral School of Clinical Medicine