A.H. van Kaam

Pneumothorax in a preterm infant monitored by electrical impedance tomography: a case report.

Electrical impedance tomography (EIT) is a noninvasive bedside tool for monitoring regional changes in ventilation. We report, for the first time, the EIT images of a ventilated preterm infant with a unilateral pneumothorax, showing a loss of regional ventilation in the affected lung during both high-frequency oscillation and spontaneous ventilation.

Central blood flow measurements in stable preterm infants after the transitional period

Background Central blood flow measurements can provide detailed information on the hemodynamic condition of the preterm infant. However, reference values for right and left ventricular output (RVO and LVO) and superior vena cava flow (SVC flow) are only available for infants in the transitional period. The aim of this study was to determine RVO, LVO and SVC after the transitional period in stable preterm infants. Methods RVO, LVO and SVC flow were measured with functional echocardiography on days 7 and 14 of life in stable preterm infants less than 32 weeks gestation, with minimal respiratory support and no cardiovascular support. Infants with a clinical suspicion of an infection within 48 h after data collection or a ductal diameter >1.4 mm were excluded from analysis. Results We performed 111 measurements in 62 preterm infants with a median (range) gestational age of 28 (25–31) weeks and birth weight of 1105 (650–2370) g. 57 measurements were analysed on day 7 and 47 on day 14. The mean (SD) RVO, LVO and SVC flow were 429 (116), 296 (74) and 89 (33) ml/kg/min on day 7 and 433 (81), 300 (79) and 86 (26) ml/kg/min on day 14. There were no significant differences in flows between days 7 and 14 in the paired measurements. Conclusion This study provides central blood flow values in stable preterm infants after the transitional period. The flow variables were shown to remain stable between days 7 and 14.

An economic analysis of immediate delivery and expectant monitoring in women with hypertensive disorders of pregnancy, between 34 and 37 weeks of gestation (HYPITAT-II)

To assess the economic consequences of immediate delivery compared with expectant monitoring in women with preterm non‐severe hypertensive disorders of pregnancy.

Population Pharmacokinetics of Amoxicillin in Term Neonates Undergoing Moderate Hypothermia

The pharmacokinetics (PK) of amoxicillin in asphyxiated newborns undergoing moderate hypothermia were quantified using prospective data (N = 125). The population PK was described by a 2‐compartment model with a priori birthweight (BW) based allometric scaling. Significant correlations were observed between clearance (Cl) and postnatal age (PNA), gestational age (GA), body temperature (TEMP), and urine output (UO). For a typical patient with GA 40 weeks, BW 3,000 g, 2 days PNA (i.e., TEMP 33.5°C), and normal UO, Cl was 0.26 L/h (interindividual variability (IIV) 41.9%) and volume of distribution of the central compartment was 0.34 L/kg (IIV of 114.6%). For this patient, Cl increased to 0.41 L/h at PNA 5 days and TEMP 37.0°C. The respective contributions of both covariates were 23% and 27%. Based on Monte Carlo simulations we recommend 50 and 75 mg/kg/24h amoxicillin in three doses for patients with GA 36–37 and 38–42 weeks, respectively.

Electrical activity of the diaphragm during nCPAP and high flow nasal cannula

Objective To determine if the electrical activity of the diaphragm, as measure of neural respiratory drive and breathing effort, changes over time in preterm infants transitioned from nasal continuous positive airway pressure (nCPAP) to high flow nasal cannula (HFNC). Design Prospective observational study. Setting Neonatal intensive care unit. Patients Stable preterm infants transitioned from nCPAP to HFNC using a 1:1 pressure to flow ratio. Interventions The electrical activity of the diaphragm was measured by transcutaneous electromyography (dEMG) from 30 min before until 3 hours after the transition. Main outcome measures At eight time points after the transition to HFNC, diaphragmatic activity was compared with the baseline on nCPAP. Percentage change in amplitudedEMG, peakdEMG and tonicdEMG were calculated. Furthermore, changes in respiratory rate, heart rate and fraction of inspired oxygen (FiO2) were analysed. Results Thirty-two preterm infants (mean gestational age: 28.1±2.2 weeks, mean birth weight: 1118±368 g) were included. Compared with nCPAP, the electrical activity of the diaphragm did not change during the first 3 hours on HFNC (median (IQR) change in amplitudedEMG at t=180 min: 2.81% (−21.51–14.10)). The respiratory rate, heart rate and FiO2 remained stable during the 3-hour measurement. Conclusions Neural respiratory drive and breathing effort assessed by electrical activity of the diaphragm is similar in the first 3 hours after transitioning stable preterm infants from nCPAP to HFNC with a 1:1 pressure-to-flow ratio.

Very preterm born children at early school age: Healthcare therapies and educational provisions

AIM To explore changes in motor and cognitive outcomes in very preterm (VP; gestational age<30weeks) born children between ages five and six years, and to determine whether changes in these outcomes were associated with the use of healthcare therapies and educational provisions. STUDY DESIGN Single-center observational cohort study. Five-year-old VP born children of a one-year-cohort of our neonatal follow-up program (N=90) were invited for re-assessments at age six. Use of healthcare therapies and educational provisions was registered at ages five and six years. Motor function (Movement Assessment Battery for Children-2 [M-ABC-2]; higher scores indicate better functioning) and IQ (Wechsler Preschool and Primary Scale for Intelligence [WPPSI-III-NL]) were assessed at both ages. RESULTS Sixty-four VP born children were seen at ages five and at six years. In this year, 61% received healthcare therapies and/or educational provisions. M-ABC-2 scores of VP born children who received healthcare therapy and/or educational provisions were significantly higher (M=8.9 [SD=3.2]) at age six years than at age five years (M=7.5 [SD=3.3]); p<0.00). M-ABC-2 scores remained stable in the average range in VP born children without any support. IQ scores remained stable irrespective of received support. CONCLUSIONS Improvements in motor outcomes are associated with the use of healthcare therapies and/or educational support between ages five and six years in VP born children. Future studies need to determine the efficacy of existing interventions, and to develop tailored interventions to support VP born children in the transfer period from preschool to primary education.

Optimized breath detection algorithm in electrical impedance tomography

OBJECTIVE This paper defines a method for optimizing the breath delineation algorithms used in electrical impedance tomography (EIT). In lung EIT the identification of the breath phases is central for generating tidal impedance variation images, subsequent data analysis and clinical evaluation. The optimisation of these algorithms is particularly important in neonatal care since the existing breath detectors developed for adults may give insufficient reliability in neonates due to their very irregular breathing pattern. APPROACH Our approach is generic in the sense that it relies on the definition of a gold standard and the associated definition of detector sensitivity and specificity, an optimisation criterion and a set of detector parameters to be investigated. The gold standard has been defined by 11 clinicians with previous experience with EIT and the performance of our approach is described and validated using a neonatal EIT dataset acquired within the EU-funded CRADL project. MAIN RESULTS Three different algorithms are proposed that improve the breath detector performance by adding conditions on (1) maximum tidal breath rate obtained from zero-crossings of the EIT breathing signal, (2) minimum tidal impedance amplitude and (3) minimum tidal breath rate obtained from time-frequency analysis. As a baseline a zero-crossing algorithm has been used with some default parameters based on the Swisstom EIT device. SIGNIFICANCE Based on the gold standard, the most crucial parameters of the proposed algorithms are optimised by using a simple exhaustive search and a weighted metric defined in connection with the receiver operating characterics. This provides a practical way to achieve any desirable trade-off between the sensitivity and the specificity of the detectors.

Clinical performance of a novel textile interface for neonatal chest electrical impedance tomography

OBJECTIVE Critically ill neonates and infants might particularly benefit from continuous chest electrical impedance tomography (EIT) monitoring at the bedside. In this study a textile 32-electrode interface for neonatal EIT examination has been developed and tested to validate its clinical performance. The objectives were to assess ease of use in a clinical setting, stability of contact impedance at the electrode-skin interface and possible adverse effects. APPROACH Thirty preterm infants (gestational age: 30.3  ±  3.9 week (mean  ±  SD), postnatal age: 13.8  ±  28.2 d, body weight at inclusion: 1727  ±  869 g) were included in this multicentre study. The electrode-skin contact impedances were measured continuously for up to 3 d and analysed during the initial 20-min phase after fastening the belt and during a 10 h measurement interval without any clinical interventions. The skin condition was assessed by attending clinicians. MAIN RESULTS Our findings imply that the textile electrode interface is suitable for long-term neonatal chest EIT imaging. It does not cause any distress for the preterm infants or discomfort. Stable contact impedance of about 300 Ohm was observed immediately after fastening the electrode belt and during the subsequent 20 min period. A slight increase in contact impedance was observed over time. Tidal variation of contact impedance was less than 5 Ohm. SIGNIFICANCE The availability of a textile 32-electrode belt for neonatal EIT imaging with simple, fast, accurate and reproducible placement on the chest strengthens the potential of EIT to be used for regional lung monitoring in critically ill neonates and infants.

PS-278 Automated Versus Manual Fio2 Control At Different Saturation Targets In Preterm Infants

Background Preterm infants spend only 50% of time within the target oxygen saturation (SpO2) during manual FiO2 control (M-FiO2). Automated FiO2 control (A-FiO2) improves SpO2 targeting but it is uncertain if this applies to different SpO2 target ranges and during non-invasive support (NIVS) and mechanical ventilation (MV). Objective To compare the efficacy of A-FiO2 vs M-FiO2 in keeping two different SpO2 targets during NIVS or MV. Design/methods Preterm infants on FiO2 >0.21 receiving NIVS or MV were randomised to SpO2 targets 89–93% or 91–95% and underwent M-FiO2 and A-FiO2 for 24 h each, in random sequence. Results 80 infants (GA:26 w, age:18 d) were included (NIVS = 48, MV = 32). Time within target increased and below target decreased during A-FiO2 compared with M-FiO2, especially in the lower target range. There was a reduction in time and hypoxemia episodes with SpO2 < 80% during A-FiO2. Outcomes did not differ between NIVS or MV. Conclusions Automated FiO2 control improved SpO2 targeting across different SpO2 ranges and reduced hypoxemia with less workload during both NIVS and MV. Abstract PS-278 Table 1 Target 89–93% Target 91–95% A-FiO2 M-FiO2 A-FiO2 M-FiO2 %-time in target 62 (17) 54 (16)* 62 (17) 58 (15)* %-time >target 21 (13) 25 (10)* 22 (13) 19 (8) %-time < target 17 (11) 21 (8)* 17 (10) 23 (9)* %-time SpO2 >98% 0.2 (0.0–0.8) 0.7 (0.1–1.6)* 0.7 (0.2–2.1) 1.7 (0.7–4.3) %-time SpO2 < 80% 1.2 (0.2–2.2) 2.6 (1.0–4.3)* 0.8 (0.3–2.1) 2.0 (0.9–5.0)* Episodes < 80%, >1 min/24 h 4 (1–12) 15 (5–24)* 4 (1–11) 13 (3–24)* Manual FiO2 adjustments/24h 1 (0–3) 102 (72–173)* 1 (0–3) 109 (79–156)* * p < 0.05

O-218 The Effect Of Caffeine On Diaphragmatic Activity In Preterm Infants

Background Preterm infants born with a GA <32 weeks are at high risk of developing central apnea of prematurity (AOP). Treatment with caffeine reduces central AOP by stimulating the breathing centre. Animal studies suggest that caffeine improves contractility of the diaphragm. We have determined the effect of caffeine on diaphragmatic activity in preterm infants. Methods Spontaneously breathing preterm infants <32 weeks treated with an intravenous loading dose (10 mg/kg) of caffeine base for central AOP were eligible for the study. Diaphragmatic activity was continuously measured by transcutaneous electromyography (dEMG) starting 30-min before (baseline) until 1-hour after caffeine administration. Diaphragmatic inspiratory activity per breath, expressed as the relative amplitude change of dEMG (logEMGAR), area under the curve (AUC), respiratory rate (RR), as well as tidal volume (Vt ) measured by respiratory inductive plethysmography, were calculated at 4 fixed time points after caffeine administration (5,15,30 and 60-min) using the average of all breaths in a 30-sec recording and compared to baseline. Results 30 preterm infants (mean GA 29.1 ± 1.3 wk; birth weight 1237 ± 370 g) were included. 5-min after caffeine administration, diaphragmatic activity significantly increased (median, IQR) compared to baseline; logEMGAR (0.13, 0.09–0.17), corresponding with an amplitude increase of 35% (22–49%). AUC (19%, 11–34%) and Vt (30%, 7–48) also increased significantly. Caffeine did not impact RR. The increased activity was observed at all subsequent time points. Conclusions This is the first study showing that caffeine treatment, besides stimulating respiratory drive, results in a rapid (within 5-min) and sustained increase in diaphragmatic contractility in preterm infants.