Minute-by-minute systemic hemodynamic responses to packed red blood cell transfusion in extremely low gestational age...

Packed red blood cell transfusion (PRBCT) is a common intervention for neonatal anemia, primarily guided by hemoglobin thresholds. Electrical velocimetry (EV) portable, non-invasive impedance cardiography tool, provides continuous systemic hemodynamics (SH) parameter measurements, offering valuable insights into the physiological effects of transfusions.

This prospective, observational cohort study, conducted between May 2021 and October 2023, included 30 extremely low gestational age neonates requiring elective PRBCT during their neonatal intensive care unit stay. Using EV, 11 SH parameters were continuously recorded over 31 hours: 4 hours before, 3 hours during, and 24 hours after transfusion. The effect of transfusion on these parameters was assessed using ARIMA, paired t-tests and mixed linear models.

Of the 30 infants, 20 were <26 weeks gestation, and 10 were 26 + 0 to 27 + 6 weeks gestation. Index of cardiac contractility, stroke volume, and cardiac output decreased significantly post-transfusion (p < 0.01). Systemic vascular resistance increased significantly after transfusion compared to before transfusion (p < 0.01).

This pilot study detected significant hemodynamic changes in response to PRBCT, which, while notable, remained within normal physiological range. These findings underscore the need to better understand the physiological impact of PRBCT and the highlight role of non-invasive SH monitoring in optimizing neonatal care.

This study is the first to apply Electrical Velocimetry (EV) for continuous, high-resolution monitoring of systemic hemodynamic (SH) parameters before, during, and after packed red blood cell transfusion (PRBCT) in extremely low-gestational-age neonates (ELGANs). The findings demonstrate measurable minute-by-minute fluctuations in cardiac contractility, stroke volume, cardiac output and vascular resistance temporally associated with transfusion. These fluctuations occurred even in infants who were hemodynamically stable at baseline, suggesting that EV may detect transfusion-related physiological variability not captured by routine monitoring, without implying a direct causal effect. Advanced monitoring technologies, such as EV, may enable more accurate and individualized neonatal care. To optimize outcomes for this vulnerable population and refine transfusion guidelines, further research including larger prospective studies and randomized controlled trials are needed.