Predictive Value of Heart Rate Variability on Cardiorespiratory Events

Study Overview
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Brief Summary
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The aim of this study are to investigate whether heart rate variability (HRV) parameters derived from nonlinear time series analysis at five different time points have prognostic utility for assessing the risk of postimmunisation AOP in very preterm/very low birth weight infants immunised in the hospital.

Official Title
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Predictive Value of Heart Rate Variability on Cardiorespiratory Events of Preterm Infants Routinely Immunised in the Hospital

Conditions
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Post-immunisation Apnoea and Bradycardia of Prematurity (AOP)

Intervention / Treatment
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* Biological: immunisation


Participation Criteria
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Eligibility Criteria
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Inclusion criteria for preterm infants: Gestational Age (GA) 22+0 to 31+6 weeks and/or birth weight 400 g to 1500 g Chronological age > 7 days Written informed parental consent Inclusion criteria for term healthy control infants: GA 37 to 42 weeks, chronological age 3 to 28 days (beyond initial transition after birth) Hospitalised in the neonatal rooming-in unit of the University Children's Hospital Basel as healthy co-twin or healthy sibling, or neonate ready to be discharged home after reconvalescence from minor illness such as hyperbilirubinaemia Written informed parental consent Exclusion Criteria: Major congenital malformations including neuromuscular disorders, thoracic malformations, major cardiac malformation Lack of written informed parental consent

Ages Eligible for Study
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Minimum Age: 3 Days
Maximum Age: 28 Days

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental1<br>preterm infants will be routinely immunised during primary hospitalisation | Biological: immunisation<br>* combined diphtheria, tetanus, acellular pertussis, poliomyelitis, hepatitis B, ± Haemophilus influenzae type B and simultaneous pneumococcus (PCV13) vaccination<br>|
| Experimental2<br>preterm infants discharged and readmitted for immunisation during the 3-year period | Biological: immunisation<br>* combined diphtheria, tetanus, acellular pertussis, poliomyelitis, hepatitis B, ± Haemophilus influenzae type B and simultaneous pneumococcus (PCV13) vaccination<br>|
| Control<br>healthy control infants | Biological: immunisation<br>* combined diphtheria, tetanus, acellular pertussis, poliomyelitis, hepatitis B, ± Haemophilus influenzae type B and simultaneous pneumococcus (PCV13) vaccination<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in AOP | Difference in AOP events within 24 hours after - 24 hours before immunisation | record the sum of AOP events from 48 hours windows of raw data, within 24 hours after - 24 hours before immunisation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in prolonged hypoxaemic episodes | Difference in prolonged hypoxaemic episodes (SpO2 < 80% for at least 1 min) within 24 hours after - 24 hours before immunisation (CAP-trial definition). | record SpO2 from 48 hours windows of raw data, within 24 hours after - 24 hours before immunisation | 
| Difference in number of manual stimulations | Difference in number of manual stimulations within 24 hours after - 24 hours before immunisation | number of manual stimulations within 24 hours after - 24 hours before immunisation | 
| Difference in number increases in oxygen concentration | Difference in number increases in oxygen concentration within 24 hours after - 24 hours before immunisation | record oxygen concentration from 48 hours windows of raw data, within 24 hours after - 24 hours before immunisation | 
| Difference in number of increases in continuous positive airway pressure (CPAP) | Difference in number of increases in continuous positive airway pressure (CPAP) within 24 hours after - 24 hours before immunisation | within 24 hours after - 24 hours before immunisation | 
| Difference in number of reinstallations in continuous positive airway pressure (CPAP) | Difference in number of reinstallations in continuous positive airway pressure (CPAP) within 24 hours after - 24 hours before immunisation | within 24 hours after - 24 hours before immunisation | 
| Difference in number of endotracheal intubation | Difference in number of endotracheal intubation for AOP events within 24 hours after - 24 hours before immunisation | within 24 hours after - 24 hours before immunisation | 
| Difference in sample entropy (SampEn) of interbeat interval of heart rate (IBI) | Difference in SampEn of IBI 24 hours after - immediately prior to immunisation | 24 hours after - immediately prior to immunisation | 
| Difference in SampEn of IBI | Difference in SampEn of IBI in preterm infants measured at 37 to 42 weeks postconceptional age vs. SampEn of IBI in term healthy control infants | preterm infants measured at 37 to 42 weeks |