Prematurely born neonates require, amongst others, pharmaceutical therapy. Dosing guidelines for these therapies are often based on data from term born neonates or older infants, while these are... Show morePrematurely born neonates require, amongst others, pharmaceutical therapy. Dosing guidelines for these therapies are often based on data from term born neonates or older infants, while these are not necessarily similar to prematurely born neonates. When suboptimal dosing guidelines are applied the neonates are at risk for under- or overdosing. In this thesis the pharmacokinetics and pharmacodynamics of a variety of drugs frequently used in preterm neonates were characterized, ultimately to optimize treatment. Specifically, caffeine, ibuprofen and fluconazole were studied which are drugs to treat apnea of prematurity, to close a patent ductus arteriosus and to treat or prevent infections with Candida in newborns, respectively. These drugs were introduced and used in clinical practice without sufficient knowledge, especially on appropriate dosing for this subpopulation. For caffeine and ibuprofen we found that the clearance rapidly increases with postnatal age, while for fluconazole clearance is better reflected by body weight and serum creatinine. For these drugs dosing guidelines were proposed based on identified covariates for their pharmacokinetics. Ibuprofen therapy was further investigated by examining the course of spontaneous closure of the ductus arteriosus, and evaluating the effects of ibuprofen exposure and patient characteristics simultaneously. Show less
Heuvel, J.F.M. van den; Hogeveen, M.; Holzik, M.L.; Heijst, A.F.J. van; Bekker, M.N.; Geurtzen, R. 2022
Background In case of extreme premature delivery at 24 weeks of gestation, both early intensive care and palliative comfort care for the neonate are considered treatment options. Prenatal... Show moreBackground In case of extreme premature delivery at 24 weeks of gestation, both early intensive care and palliative comfort care for the neonate are considered treatment options. Prenatal counseling, preferably using shared decision making, is needed to agree on the treatment option in case labor progresses. This article described the development of a digital decision aid (DA) to support pregnant women, partners and clinicians in prenatal counseling for imminent extreme premature labor. Methods This DA is developed following the International Patient Decision Aid Standards. The Dutch treatment guideline and the Dutch recommendations for prenatal counseling in extreme prematurity were used as basis. Development of the first prototype was done by expert clinicians and patients, further improvements were done after alpha testing with involved clinicians, patients and other experts (n = 12), and beta testing with non-involved clinicians and patients (n = 15). Results The final version includes information, probabilities and figures depending on users' preferences. Furthermore, it elicits patient values and provides guidance to aid parents and professionals in making a decision for either early intensive care or palliative comfort care in threatening extreme premature delivery. Conclusion A decision aid was developed to support prenatal counseling regarding the decision on early intensive care versus palliative comfort care in case of extreme premature delivery at 24 weeks gestation. It was well accepted by parents and healthcare professionals. Our multimedia, digital DA is openly available online to support prenatal counseling and personalized, shared decision-making in imminent extreme premature labor. Show less
Prematurely born children are at higher risk for long-term adverse motor and cognitive outcomes. The aim of this paper was to compare quantitative measures derived from electroencephalography (EEG)... Show morePrematurely born children are at higher risk for long-term adverse motor and cognitive outcomes. The aim of this paper was to compare quantitative measures derived from electroencephalography (EEG) between extremely (EP) and very prematurely (VP) born children at 9-10 years of age.Fifty-five children born < 32 weeks' of gestation underwent EEG at 9-10 years of age and were assessed for motor development and cognitive outcome. Relative frequency power and functional connectivity, as measured by the Phase Lag Index (PLI), were calculated for all frequency bands. Per subject, power spectrum and functional connectivity results were averaged over all channels and pairwise PLI values to explore differences in global frequency power and functional connectivity between EP and VP children. Brain networks were constructed for the upper alpha frequency band using the Minimum Spanning Tree method and were compared between EP and VP children. In addition, the relationships between upper alpha quantitative EEG results and cognitive and motor outcomes were investigated.Relative power and functional connectivity were significantly higher in VP than EP children in the upper alpha frequency band, and VP children had more integrated networks. A strong positive correlation was found between relative upper alpha power and motor outcome whilst controlling for gestational age, age during EEG recording, and gender (p = 0.493, p = 0.004).These results suggest that 9-10 years after birth, the effects of the degree of prematurity can be observed in terms of alterations in functional brain activity and that motor deficits are associated with decreases in relative upper alpha power. Show less
Salaets, T.; Aertgeerts, M.; Gie, A.; Vignero, J.; Winter, D. de; Regin, Y.; ... ; Toelen, J. 2020
Background Bronchopulmonary dysplasia continues to cause important respiratory morbidity throughout life, and new therapies are needed. The common denominator of all BPD cases is preterm birth,... Show moreBackground Bronchopulmonary dysplasia continues to cause important respiratory morbidity throughout life, and new therapies are needed. The common denominator of all BPD cases is preterm birth, however most preclinical research in this area focusses on the effect of hyperoxia or mechanical ventilation. In this study we investigated if and how prematurity affects lung structure and function in neonatal rabbits. Methods Pups were delivered on either day 28 or day 31. For each gestational age a group of pups was harvested immediately after birth for lung morphometry and surfactant protein B and C quantification. All other pups were hand raised and harvested on day 4 for the term pups and day 7 for the preterm pups (same corrected age) for lung morphometry, lung function testing and qPCR. A subset of pups underwent microCT and dark field imaging on day 0, 2 and 4 for terms and on day 0, 3, 5 and 7 for preterms. Results Preterm pups assessed at birth depicted a more rudimentary lung structure (larger alveoli and thicker septations) and a lower expression of surfactant proteins in comparison to term pups. MicroCT and dark field imaging revealed delayed lung aeration in preterm pups, in comparison to term pups. Preterm birth led to smaller pups, with smaller lungs with a lower alveolar surface area on day 7/day 4. Furthermore, preterm birth affected lung function with increased tissue damping, tissue elastance and resistance and decreased dynamic compliance. Expression of vascular endothelial growth factor (VEGFA) was significantly decreased in preterm pups, however in the absence of structural vascular differences. Conclusions Preterm birth affects lung structure and function at birth, but also has persistent effects on the developing lung. This supports the use of a preterm animal model, such as the preterm rabbit, for preclinical research on BPD. Future research that focuses on the identification of pathways that are involved in in-utero lung development and disrupted by pre-term birth, could lead to novel therapeutic strategies for BPD. Show less
Bij veel te vroeg geboren kinderen blijft prematurenretinopathie (ROP) een belangrijke oorzaak van blind- en slechtziendheid. Dit ondanks uitgebreid onderzoek. De oorzaak hiervan is, dat de... Show moreBij veel te vroeg geboren kinderen blijft prematurenretinopathie (ROP) een belangrijke oorzaak van blind- en slechtziendheid. Dit ondanks uitgebreid onderzoek. De oorzaak hiervan is, dat de leeftijd, waarop deze kinderen geboren en in leven gehouden kunnen worden daalt door een betere neonatologische behandeling. Het aantal kinderen, dat ernstige ROP kan oplopen neemt hierdoor toe. Een vroege opsporing en behandeling van ROP kan de kans op het ontwikkelen van een visuele beperking en de ernst daarvan verminderen. Een evidence-based richtlijn is een belangrijk hulpmiddel om de zorg voor deze hoog-risico prematuren te optimaliseren. Er is echter geen universeel screeningsprotocol op te stellen, omdat het niveau van de neonatologische zorg per land erg kan verschillen. Door middel van de NEDROP studie werden op nationaal niveau het screeningsproces, de invloed van overplaatsingen, de incidentie van ROP, de risicofactoren alsmede de behandelcriteria en de behandeling van ROP ge_nventariseerd. Dit heeft mede geresulteerd in een nieuwe richtlijn geschikt voor allen die betrokken zijn bij de screening (oogartsen, neonatologen, kinderartsen, verpleegkundigen en de ouders) en een uniforme, landelijke ouder-informatie folder. Het uiteindelijke doel van de NEDROP studie is om blind- en slechtziendheid door ROP te doen afnemen in Nederland. Show less
Teune, M.J.; Wassenaer, A.G. van; Buuren, S. van; Mol, B.J.; Opmeer, B.C.; Dutch POPS Collaborative Study Grp 2012
Red blood cells (RBCs) are probably the most frequently used drug given to very preterm infants; more than 90% of infants with a birth weight <1000 grams receive one or more RBC transfusions.... Show moreRed blood cells (RBCs) are probably the most frequently used drug given to very preterm infants; more than 90% of infants with a birth weight <1000 grams receive one or more RBC transfusions. Except for reduction of the amount of blood drawn for laboratory tests and use of a single donor program, no measures have been shown to be an irrefutable safe way to reduce donor exposure. Preventative measures for anemia should be used to reduce the number of RBC transfusions needed. Alternatives for allogenic RBC transfusions, such as autologous RBC cord blood transfusion, should be further explored and implemented. A restrictive transfusion strategy does not seem harmful for the children in short term or long term outcome. Thrombocytopenia is also a frequently encountered problem in neonatal medicine with an increased risk for hemorrhage. Thrombocytopenia, irrespective of the severity, increases the incidence of intraventricular hemorrhage. A more restrictive platelet transfusion policy significantly reduces the number of infants receiving a platelet transfusion without a difference in occurrence of (severe) hemorrhage. We state that both for red blood cell and platelet transfusions in (premature) newborn infants, safe thresholds are still not established. Transfusions may have (late) detrimental effects. Safe thresholds for both erythrocytes and platelets need to be found by large prospective randomized trials focusing not only on the direct effects but also on the long-term effects. Show less
