Heart rate fluctuation after birth predicts subsequent cardiorespiratory stability in preterm infants

Abstract

BACKGROUND: Cardiorespiratory stability of preterm infants is a prerequisite for discharge from the neonatal intensive care unit (NICU) but very difficult to predict. We aimed to assess whether characterizing heart rate fluctuation (HRF) within the first days of life has prognostic utility. METHODS: We conducted a prospective cohort study in 90 preterm infants using a previously validated surface diaphragmatic electromyography (sEMG) method to derive interbeat intervals. We characterized HRF by time series parameters including sample entropy (SampEn) and scaling exponent alpha (ScalExp) obtained from daily 3-h measurements. Data were analyzed by multivariable, multilevel linear regression. RESULTS: We obtained acceptable raw data from 309/330 sEMG measurements in 76/90 infants born at a mean (range) of 30.2 (24.7-34.0) weeks gestation. We found a significant negative association of SampEn with duration of respiratory support (R 2 = 0.53, p < 0.001) and corrected age at discontinuation of caffeine therapy (R 2 = 0.35, p < 0.001) after adjusting for sex, gestational age, birth weight z-score, and sepsis. CONCLUSIONS: Baseline SampEn calculated over the first 5 days of life carries prognostic utility for an estimation of subsequent respiratory support and pre-discharge cardiorespiratory stability in preterm infants, both important for planning of treatment and utilization of health care resources.

Caffeine preserves quiet sleep in preterm neonates

“…The study was approved by the local ethical committee (EKBB‐Nr: 37/12), and conducted according to the principles of the Declaration of Helsinki. A detailed description of the study setting can be found in previous reports 22‐25 . Enrolled preterm neonates met the following inclusion criteria: written informed consent of their parents; very preterm birth (GA < 32 weeks), or very low birthweight (<1500 g).…”

“…A detailed description of the study setting can be found in previous reports. [22][23][24][25] Enrolled preterm neonates met the following inclusion criteria: written informed consent of their parents; very preterm birth (GA < 32 weeks), or very low birthweight (<1500 g). Exclusion criteria were perinatal asphyxia (either arterial cord blood pH < 7.0, base deficit > 12 mmol/l, or serum lactate > 5 mmol/l during first hour of life) or major congenital malformations.…”

Weight a minute: The smaller and more immature, the more predictable the autonomic regulation?

“…Notably, the VLBW infants did not exhibit a catch‐up of their lower HRV during their initial hospitalisation in the NICU, when reaching the same weight or PCA as their non‐VLBW peers. It has been shown that HRV does not significantly change, in relation to PNA, during the first 5 days of life in very preterm infants 2 . In contrast to this, data from term infants, indicate that HRV changes significantly during the first day of life, particularly during the first 6 h 3 .…”

“…Immediately after birth the body starts to adapt to extra‐uterine life, with major physiological respiratory and hemodynamic changes taking place 1 . In recent years, the interest in neonatal heart rate variability (HRV) and its postnatal development has increased 2–5 . HRV is influenced by multiple factors, such as delivery mode, 4 degree of prematurity and postnatal age 6 .…”

Comparison of oxygen supplementation in very preterm infants: Variations of oxygen saturation features and their application to hypoxemic episode based risk stratification

“…For each subject, the estimated measures were averaged over all available windows to give the estimate over 24 h. In addition, signal measures were averaged over 4 h to give measures at 6 time points spread over the 24 h. Signal behavior related to the histogram, variability, irregularity, and complexity was examined using the sample moments, extended Poincare plot, sample entropy and generalized multiscale entropy measures respectively. These indices have been applied to a variety of physiological and biomedical signals to assess numerous developmental as well as pathology related conditions in infants such as neurodevelopment (20), adverse outcome risk prediction (21,22), sleep stage classification (23), heart rate variability (24)(25)(26), cardiorespiratory dynamics (27), and regulation (28,29). A brief description of the measures is given next and a schematic of the signal indices is presented in Figure 1.…”