K.D. Liem - Academia.edu (original) (raw)
Papers by K.D. Liem
Pediatric Research, 2020
BACKGROUND: Doxapram is used for the treatment of apnea of prematurity in dosing regimens only ba... more BACKGROUND: Doxapram is used for the treatment of apnea of prematurity in dosing regimens only based on bodyweight, as pharmacokinetic data are limited. This study describes the pharmacokinetics of doxapram and keto-doxapram in preterm infants. METHODS: Data (302 samples) from 75 neonates were included with a median (range) gestational age (GA) 25.9 (23.9-29.4) weeks, bodyweight 0.95 (0.48-1.61) kg, and postnatal age (PNA) 17 (1-52) days at the start of continuous treatment. A population pharmacokinetic model was developed using non-linear mixed-effects modelling (NONMEM®). RESULTS: A two-compartment model best described the pharmacokinetics of doxapram and keto-doxapram. PNA and GA affected the formation clearance of keto-doxapram (CL FORMATION KETO-DOXAPRAM) and clearance of doxapram via other routes (CL DOXAPRAM OTHER ROUTES). For a median individual of 0.95 kg, GA 25.6 weeks, and PNA 29 days, CL FORMATION KETO-DOXAPRAM was 0.115 L/h (relative standard error (RSE) 12%) and CL DOXAPRAM OTHER ROUTES was 0.645 L/h (RSE 9%). Oral bioavailability was estimated at 74% (RSE 10%). CONCLUSIONS: Dosing of doxapram only based on bodyweight results in the highest exposure in preterm infants with the lowest PNA and GA. Therefore, dosing may need to be adjusted for GA and PNA to minimize the risk of accumulation and adverse events. For switching to oral therapy, a 33% dose increase is required to maintain exposure.
Acta Paediatrica, 2007
Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. ... more Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. As earlier studies have failed to show a benefit of early intervention, it is recommended that PHVD be first treated when head circumference is rapidly increasing and/or when symptoms of raised intracranial pressure develop. Infants with PHVD, admitted to 5 of the 10 Dutch neonatal intensive care units were studied retrospectively, to investigate whether there was a difference in the time of onset of treatment of PHVD and, if so, whether this was associated with a difference in the requirement of a ventriculo-peritoneal (VP) shunt and/or neurodevelopmental outcome. The surviving infants with a gestational age <34 wk, born between 1992 and 1996, diagnosed as having a grade III haemorrhage according to Papile on cranial ultrasound and who developed PHVD were included in the study. PHVD was defined as a ventricular index (VI) exceeding the 97th percentile according to Levene (1981), and severe PHVD as a VI crossing the p 97 + 4 mm line. Ninety-five infants met the entry criteria. Intervention was not deemed necessary in 22 infants, because of lack of progression. In 31 infants lumbar punctures (LP) were done before the p 97 + 4 mm line was crossed (early intervention). In 20/31 infants, stabilization occurred. In 9 a subcutaneous reservoir was placed, with subsequent stabilization in 6. In 5/31 infants a VP shunt was eventually inserted. In 42 infants treatment was started once the p 97 + 4 mm line was crossed (late intervention). In 30 infants LPs were performed and in 17 of these a VP shunt was eventually inserted. In 11 infants a subcutaneous reservoir was immediately inserted and in 8 of these infants a VP shunt was needed. In one infant a VP shunt was immediately inserted, without any other form of treatment. Infants with late intervention crossed the p 97 + 4 mm earlier (p 0.03) and needed a shunt (26/42; 62%) more often than those with early intervention (5/31; 16%). Early LP was associated with a strongly reduced risk of VP-shunting (odds ratio = 0.22, 95% confidence interval: 0.08-0.62). The number of infants who developed a moderate or severe handicap was also higher (11/42; 26%) in the late intervention group, compared with those not requiring any intervention (3/22; 14%) or treated early (5/31; 16%). In this retrospective study, infants receiving late intervention required shunt insertion significantly more often than those treated early. A randomized prospective intervention study, comparing early and late drainage, is required to further assess the role of earlier intervention.
Neonatology, 2006
Chapman's Anomalous Cases of Dropsy. i61 MmjMtk My patient visited me to day, having come twenty-... more Chapman's Anomalous Cases of Dropsy. i61 MmjMtk My patient visited me to day, having come twenty-five miles, he was so much improved in health tliat I did not recognize him. Examined the cicatrix and found it perfectly sound-could not discover any remains of aneurismal tumour-felt the epigastric artery much enlarged and beating strongly, and a feeble, though distinct pulsation in the femoral artery immediately below-the cfural arch. X-fc'SiS ""p"*"re "d *n'1 f c' "j* «»» Much credit is d"e the patient for his firmness on the occasion; although apprised of the great danger attending so formidable an ex-C1' and *h.e1 unce^lnt-v of its re3ult; yet with a fortitude unshaken, and a full conviction that it was the only chance of proloning his lifehe cheerfully and resolutely submitted to the operation. The gratification h.s visit afforded me is not to be imagined, save by those who have been placed under similar circumstances. The perfect success of so important and novel an operation, with the entire restoration of the patient's health, was a rich reward for the anxiety I experienced in the case, and in a measure compensated for the unexpected failure of my operation on the arteria JonTnata *\eiv lork, 25 Park Place, October 15th, 1827. Art. X. Aolices of some Anomalous Cases of Dropsy. By N. Chapman, M. D. 1 ' .^'sIriesrNotIphmUrna' °f ,he MediCal and Ph-V3ic3' Vo!. IV. No. I-Nov. I82- .
ASAIO Journal, 2001
Recirculation is a limiting factor for oxygen delivery in double lumen catheter veno-venous extra... more Recirculation is a limiting factor for oxygen delivery in double lumen catheter veno-venous extracorporeal membrane oxygenation (DLVV-ECMO). This study compares three different methods for the determination of the recirculation fraction during double lumen catheter veno-venous ECMO at ECMO flow rates of 150, 125, 100, 75, and 50 ml/kg.min in nine lambs: (1) an ultrasound dilution method, in which the change in ultrasound velocity in blood after injection of a saline bolus as a marker is used for determination of recirculation; (2) an SvO 2 method using real mixed venous blood oxygen saturation, the gold standard, for determination of recirculation fraction; and (3) the CVL method, in which oxygen saturation of a blood sample of the inferior vena cava is considered to represent mixed venous oxygen saturation. In all methods, the recirculation fraction increased with increasing ECMO flow rate. The correlation coefficient between the ultrasound dilution method and the SvO 2 method was 0.68 (p < 0.01); mean difference was-2.4% (p ؍ 0.6). Correlation coefficient between the ultrasound dilution method and the CVL method was 0.48 (p < 0.01); mean difference was-18.1% (p < 0.01). The correlation coefficient between the SvO 2 method and the CVL method was 0.51 (p < 0.01); mean difference was-15.7% (p < 0.01). The ultrasound dilution method is a useful method for measurement of the recirculation fraction in DLVV-ECMO and is easier to use than the other methods.
Surveillance study of apparent life-threatening events (ALTE) in the Netherlands
Acta Neuropathologica, 1999
In two siblings (a female and a male neonate), severe microcephaly, bilateral absence of the pyra... more In two siblings (a female and a male neonate), severe microcephaly, bilateral absence of the pyramids, severe hypoplasia of the cerebral peduncles, and dysplasia of the inferior olives was found together with microphthalmia, facial malformations and multiple contractures of the extremities. In both cases, the cerebral hemispheres otherwise showed a more or less normal gyral pattern with the insula incompletely covered by the opercula, and a torn but otherwise intact corpus callosum. In case 2, congenital cataract was also observed. The present cases can be characterized as a rapidly fatal, familial syndrome, probably transmitted as an autosomal recessive trait, and have several features in common with the Neu-Laxova syndrome. They differ in having a less severe form of microcephaly, a rather normal cytoarchitecture of the cerebral cortex, an apparently normal corpus callosum, no gross cerebellar abnormalities, and no other organ malformations. The present cases belong to a group of heterogeneous syndromes which have microcephaly, ocular and facial malformations, multiple contractures, and ichthyosis-like skin in common.
Acta anaesthesiologica Scandinavica. Supplementum, 1995
To investigate the cerebrovascular response to changes in arterial CO2 tension during extracorpor... more To investigate the cerebrovascular response to changes in arterial CO2 tension during extracorporeal membrane oxygenation (ECMO) in normoxaemic and hypoxaemic piglets. Four groups of six anaesthetized, paralysed and mechanically ventilated piglets: group 1-normoxaemia without ECMO, group 2-ECMO after normoxaemia, group 3-hypoxaemia without ECMO, and group 4-ECMO after hypoxaemia, were exposed successively to hypercapnia and hypocapnia. Changes in cerebral concentrations of oxyhaemoglobin (cO2Hb), deoxyhaemoglobin (cHHb), (oxidized-reduced) cytochrome aa3 (cCyt.aa3) and blood volume (CBV) were continuously measured using near infrared spectrophotometry. Heart rate, arterial O2 saturation, arterial blood pressure, central venous pressure, intracranial pressure (ICP) and left common carotid artery blood flow (LCaBF) were measured simultaneously. Hypercapnia resulted in increased CBV, cO2Hb and ICP in all groups, while cHHb was decreased. No changes in LCaBF were found. Hypocapnia resul...
Nederlands tijdschrift voor geneeskunde, 2008
A 1-day-old premature newborn (34 weeks and 6 days) presented with respiratory insufficiency due ... more A 1-day-old premature newborn (34 weeks and 6 days) presented with respiratory insufficiency due to a group B haemolytic streptococcal (GBS) pneumonia. She recovered after temporary treatment with mechanical ventilation and antibiotics. At the time of discharge there was a slight increased fogging on the right side of the chest X-ray, interpreted as residual pleural effusion. Three days later the patient was readmitted with respiratory failure and a need for respiratory support. A chest CT scan revealed a right-sided congenital diaphragmatic hernia (CDH) with a large part of the liver and intestine in the chest. The diaphragmatic defect was closed during a surgical procedure. After an uneventful recovery the patient was discharged in good clinical condition. The combination of delayed presentation of right-sided CDH and neonatal GBS infection occurs rarely but has been described. Its pathogenesis is still unclear.
Nederlands tijdschrift voor geneeskunde, 1990
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2013
To evaluate phototherapy practices by measuring the irradiance levels of phototherapy (PT) device... more To evaluate phototherapy practices by measuring the irradiance levels of phototherapy (PT) devices. Prospective study. Tertiary neonatal intensive care units. None. Irradiance levels of PT devices used in the 10 Dutch Neonatal Intensive Care Units (NICUs) were measured according to the local PT practice patterns. The irradiance levels of all overhead and fibre-optic PT devices were measured with a radiometer using an infant silhouette model. Eight different PT devices were used in the 10 NICUs; five were overhead devices and three fibre-optic pads. The median (range) irradiance level for overhead PT devices was 9.7 (4.3-32.6) µW/cm(2)/nm and for fibre-optic pads 6.8 (0.8-15.6) µW/cm(2)/nm. Approximately 50% of PT devices failed to meet the minimal recommended irradiance level of 10 µW/cm(2)/nm. Maximal irradiance levels for overhead PT spot lights were inversely related to the distance between device and infant model (R2=0.33). The distances ranged from 37 cm to 65 cm. PT devices in the Dutch NICUs show considerable variability with often too low irradiance levels. These results indicate that suboptimal PT is frequently applied and may even be ineffective towards reducing total serum bilirubin levels. These results underline the need for greater awareness among all healthcare workers towards the requirements for effective PT including measurements of irradiance and distance.
Clinical Neurology and Neurosurgery, 1991
In maritime operational scenarios, such as smuggling, piracy, or terrorist threats, it is not onl... more In maritime operational scenarios, such as smuggling, piracy, or terrorist threats, it is not only relevant who or what an observed object is, but also where it is now and in the past in relation to other (geographical) objects. In situation and impact assessment, this information is used to determine whether an object is a threat. Single platform (ship, harbor) or single sensor information will not provide all this information. The work presented in this paper focuses on the sensor and object levels that provide a description of currently observed objects to situation assessment. For use of information of objects at higher information levels, it is necessary to have not only a good description of observed objects at this moment, but also from its past. Therefore, currently observed objects have to be linked to previous occurrences. Kinematic features, as used in tracking, are of limited use, as uncertainties over longer time intervals are so large that no unique associations can be made. Features extracted from different sensors (e.g., ESM, EO/IR) can be used for both association and classification. Features and classifications are used to associate current objects to previous object descriptions, allowing objects to be described better, and provide position history. In this paper a description of a high level architecture in which such a multi-sensor association is used is described. Results of an assessment of the usability of several features from ESM (from spectrum), EO and IR (shape, contour, keypoints) data for association and classification are shown.
Skin-to-skin contact after birth is propagated to facilitate breast-feeding and mother-child bond... more Skin-to-skin contact after birth is propagated to facilitate breast-feeding and mother-child bonding. We describe two term infants with sudden unexpected postnatal collapse (SUPC) during skin-to-skin contact. The infants were found with abnormal colour, hypotonia and apnoea, in a prone position on the chest of their mothers, both of whom were primipara with a high BMI. After stimulation, both infants recovered completely. No specific potential cause, other than the position, could be found. These cases illustrate that skin-to-skin contact after birth is not without risk. In available literature, risk factors for SUPC include primiparity and infant orientation such as prone and lateral positions. These positions are also risk factors for sudden infant death syndrome (SIDS). To improve safety, a primipara should be supervised during skin-to-skin contact and not be left alone in the first hours after delivery; the infant should be guaranteed a free airway, especially when the mother ha...
Journal of Clinical Monitoring and Computing, 2015
Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accu... more Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accurate measurement of EVLW in these patients is limited due to the lack of bedside methods. The aim of this pilot study was to investigate the reliability of the transpulmonary ultrasound dilution (TPUD) technique as a possible method for estimating EVLW in a neonatal animal model. Pulmonary edema was induced in 11 lambs by repeated surfactant lavages. In between the lavages, EVLW indexed by bodyweight was estimated by TPUD (EVLWI tpud) and transpulmonary dye dilution (EVLWI tpdd) (n = 22). Final EVLWI tpud measurements were also compared with EVLWI estimations by gold standard post mortem gravimetry (EVLWI grav) (n = 6). EVLWI was also measured in two additional lambs without pulmonary edema. Bland-Altman plots showed a mean bias between EVLWI tpud and EVLWI tpdd of-3.4 mL/kg (LOA ± 25.8 mL/kg) and between EVLWI tpud and EVLWI grav of 1.7 mL/kg (LOA ± 8.3 mL/kg). The percentage errors were 109 and 43 % respectively. The correlation between changes in EVLW measured by TPUD and TPDD was r 2 = 0.22. Agreement between EVLWI measurements by TPUD and TPDD was low. Trending ability to detect changes between these two methods in EVLWI was questionable. The accuracy of EVLWI tpud was good compared to the gold standard gravimetric method but the TPUD lacked precision in its current prototype. Based on these limited data, we believe that TPUD has potential for future use to estimate EVLW after adaptation of the algorithm. Larger studies are needed to support our findings.
Pediatric Research, 2020
BACKGROUND: Doxapram is used for the treatment of apnea of prematurity in dosing regimens only ba... more BACKGROUND: Doxapram is used for the treatment of apnea of prematurity in dosing regimens only based on bodyweight, as pharmacokinetic data are limited. This study describes the pharmacokinetics of doxapram and keto-doxapram in preterm infants. METHODS: Data (302 samples) from 75 neonates were included with a median (range) gestational age (GA) 25.9 (23.9-29.4) weeks, bodyweight 0.95 (0.48-1.61) kg, and postnatal age (PNA) 17 (1-52) days at the start of continuous treatment. A population pharmacokinetic model was developed using non-linear mixed-effects modelling (NONMEM®). RESULTS: A two-compartment model best described the pharmacokinetics of doxapram and keto-doxapram. PNA and GA affected the formation clearance of keto-doxapram (CL FORMATION KETO-DOXAPRAM) and clearance of doxapram via other routes (CL DOXAPRAM OTHER ROUTES). For a median individual of 0.95 kg, GA 25.6 weeks, and PNA 29 days, CL FORMATION KETO-DOXAPRAM was 0.115 L/h (relative standard error (RSE) 12%) and CL DOXAPRAM OTHER ROUTES was 0.645 L/h (RSE 9%). Oral bioavailability was estimated at 74% (RSE 10%). CONCLUSIONS: Dosing of doxapram only based on bodyweight results in the highest exposure in preterm infants with the lowest PNA and GA. Therefore, dosing may need to be adjusted for GA and PNA to minimize the risk of accumulation and adverse events. For switching to oral therapy, a 33% dose increase is required to maintain exposure.
Acta Paediatrica, 2007
Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. ... more Posthaemorrhagic ventricular dilatation (PHVD) in very preterm infants carries a poor prognosis. As earlier studies have failed to show a benefit of early intervention, it is recommended that PHVD be first treated when head circumference is rapidly increasing and/or when symptoms of raised intracranial pressure develop. Infants with PHVD, admitted to 5 of the 10 Dutch neonatal intensive care units were studied retrospectively, to investigate whether there was a difference in the time of onset of treatment of PHVD and, if so, whether this was associated with a difference in the requirement of a ventriculo-peritoneal (VP) shunt and/or neurodevelopmental outcome. The surviving infants with a gestational age <34 wk, born between 1992 and 1996, diagnosed as having a grade III haemorrhage according to Papile on cranial ultrasound and who developed PHVD were included in the study. PHVD was defined as a ventricular index (VI) exceeding the 97th percentile according to Levene (1981), and severe PHVD as a VI crossing the p 97 + 4 mm line. Ninety-five infants met the entry criteria. Intervention was not deemed necessary in 22 infants, because of lack of progression. In 31 infants lumbar punctures (LP) were done before the p 97 + 4 mm line was crossed (early intervention). In 20/31 infants, stabilization occurred. In 9 a subcutaneous reservoir was placed, with subsequent stabilization in 6. In 5/31 infants a VP shunt was eventually inserted. In 42 infants treatment was started once the p 97 + 4 mm line was crossed (late intervention). In 30 infants LPs were performed and in 17 of these a VP shunt was eventually inserted. In 11 infants a subcutaneous reservoir was immediately inserted and in 8 of these infants a VP shunt was needed. In one infant a VP shunt was immediately inserted, without any other form of treatment. Infants with late intervention crossed the p 97 + 4 mm earlier (p 0.03) and needed a shunt (26/42; 62%) more often than those with early intervention (5/31; 16%). Early LP was associated with a strongly reduced risk of VP-shunting (odds ratio = 0.22, 95% confidence interval: 0.08-0.62). The number of infants who developed a moderate or severe handicap was also higher (11/42; 26%) in the late intervention group, compared with those not requiring any intervention (3/22; 14%) or treated early (5/31; 16%). In this retrospective study, infants receiving late intervention required shunt insertion significantly more often than those treated early. A randomized prospective intervention study, comparing early and late drainage, is required to further assess the role of earlier intervention.
Neonatology, 2006
Chapman's Anomalous Cases of Dropsy. i61 MmjMtk My patient visited me to day, having come twenty-... more Chapman's Anomalous Cases of Dropsy. i61 MmjMtk My patient visited me to day, having come twenty-five miles, he was so much improved in health tliat I did not recognize him. Examined the cicatrix and found it perfectly sound-could not discover any remains of aneurismal tumour-felt the epigastric artery much enlarged and beating strongly, and a feeble, though distinct pulsation in the femoral artery immediately below-the cfural arch. X-fc'SiS ""p"*"re "d *n'1 f c' "j* «»» Much credit is d"e the patient for his firmness on the occasion; although apprised of the great danger attending so formidable an ex-C1' and *h.e1 unce^lnt-v of its re3ult; yet with a fortitude unshaken, and a full conviction that it was the only chance of proloning his lifehe cheerfully and resolutely submitted to the operation. The gratification h.s visit afforded me is not to be imagined, save by those who have been placed under similar circumstances. The perfect success of so important and novel an operation, with the entire restoration of the patient's health, was a rich reward for the anxiety I experienced in the case, and in a measure compensated for the unexpected failure of my operation on the arteria JonTnata *\eiv lork, 25 Park Place, October 15th, 1827. Art. X. Aolices of some Anomalous Cases of Dropsy. By N. Chapman, M. D. 1 ' .^'sIriesrNotIphmUrna' °f ,he MediCal and Ph-V3ic3' Vo!. IV. No. I-Nov. I82- .
ASAIO Journal, 2001
Recirculation is a limiting factor for oxygen delivery in double lumen catheter veno-venous extra... more Recirculation is a limiting factor for oxygen delivery in double lumen catheter veno-venous extracorporeal membrane oxygenation (DLVV-ECMO). This study compares three different methods for the determination of the recirculation fraction during double lumen catheter veno-venous ECMO at ECMO flow rates of 150, 125, 100, 75, and 50 ml/kg.min in nine lambs: (1) an ultrasound dilution method, in which the change in ultrasound velocity in blood after injection of a saline bolus as a marker is used for determination of recirculation; (2) an SvO 2 method using real mixed venous blood oxygen saturation, the gold standard, for determination of recirculation fraction; and (3) the CVL method, in which oxygen saturation of a blood sample of the inferior vena cava is considered to represent mixed venous oxygen saturation. In all methods, the recirculation fraction increased with increasing ECMO flow rate. The correlation coefficient between the ultrasound dilution method and the SvO 2 method was 0.68 (p < 0.01); mean difference was-2.4% (p ؍ 0.6). Correlation coefficient between the ultrasound dilution method and the CVL method was 0.48 (p < 0.01); mean difference was-18.1% (p < 0.01). The correlation coefficient between the SvO 2 method and the CVL method was 0.51 (p < 0.01); mean difference was-15.7% (p < 0.01). The ultrasound dilution method is a useful method for measurement of the recirculation fraction in DLVV-ECMO and is easier to use than the other methods.
Surveillance study of apparent life-threatening events (ALTE) in the Netherlands
Acta Neuropathologica, 1999
In two siblings (a female and a male neonate), severe microcephaly, bilateral absence of the pyra... more In two siblings (a female and a male neonate), severe microcephaly, bilateral absence of the pyramids, severe hypoplasia of the cerebral peduncles, and dysplasia of the inferior olives was found together with microphthalmia, facial malformations and multiple contractures of the extremities. In both cases, the cerebral hemispheres otherwise showed a more or less normal gyral pattern with the insula incompletely covered by the opercula, and a torn but otherwise intact corpus callosum. In case 2, congenital cataract was also observed. The present cases can be characterized as a rapidly fatal, familial syndrome, probably transmitted as an autosomal recessive trait, and have several features in common with the Neu-Laxova syndrome. They differ in having a less severe form of microcephaly, a rather normal cytoarchitecture of the cerebral cortex, an apparently normal corpus callosum, no gross cerebellar abnormalities, and no other organ malformations. The present cases belong to a group of heterogeneous syndromes which have microcephaly, ocular and facial malformations, multiple contractures, and ichthyosis-like skin in common.
Acta anaesthesiologica Scandinavica. Supplementum, 1995
To investigate the cerebrovascular response to changes in arterial CO2 tension during extracorpor... more To investigate the cerebrovascular response to changes in arterial CO2 tension during extracorporeal membrane oxygenation (ECMO) in normoxaemic and hypoxaemic piglets. Four groups of six anaesthetized, paralysed and mechanically ventilated piglets: group 1-normoxaemia without ECMO, group 2-ECMO after normoxaemia, group 3-hypoxaemia without ECMO, and group 4-ECMO after hypoxaemia, were exposed successively to hypercapnia and hypocapnia. Changes in cerebral concentrations of oxyhaemoglobin (cO2Hb), deoxyhaemoglobin (cHHb), (oxidized-reduced) cytochrome aa3 (cCyt.aa3) and blood volume (CBV) were continuously measured using near infrared spectrophotometry. Heart rate, arterial O2 saturation, arterial blood pressure, central venous pressure, intracranial pressure (ICP) and left common carotid artery blood flow (LCaBF) were measured simultaneously. Hypercapnia resulted in increased CBV, cO2Hb and ICP in all groups, while cHHb was decreased. No changes in LCaBF were found. Hypocapnia resul...
Nederlands tijdschrift voor geneeskunde, 2008
A 1-day-old premature newborn (34 weeks and 6 days) presented with respiratory insufficiency due ... more A 1-day-old premature newborn (34 weeks and 6 days) presented with respiratory insufficiency due to a group B haemolytic streptococcal (GBS) pneumonia. She recovered after temporary treatment with mechanical ventilation and antibiotics. At the time of discharge there was a slight increased fogging on the right side of the chest X-ray, interpreted as residual pleural effusion. Three days later the patient was readmitted with respiratory failure and a need for respiratory support. A chest CT scan revealed a right-sided congenital diaphragmatic hernia (CDH) with a large part of the liver and intestine in the chest. The diaphragmatic defect was closed during a surgical procedure. After an uneventful recovery the patient was discharged in good clinical condition. The combination of delayed presentation of right-sided CDH and neonatal GBS infection occurs rarely but has been described. Its pathogenesis is still unclear.
Nederlands tijdschrift voor geneeskunde, 1990
Archives of Disease in Childhood - Fetal and Neonatal Edition, 2013
To evaluate phototherapy practices by measuring the irradiance levels of phototherapy (PT) device... more To evaluate phototherapy practices by measuring the irradiance levels of phototherapy (PT) devices. Prospective study. Tertiary neonatal intensive care units. None. Irradiance levels of PT devices used in the 10 Dutch Neonatal Intensive Care Units (NICUs) were measured according to the local PT practice patterns. The irradiance levels of all overhead and fibre-optic PT devices were measured with a radiometer using an infant silhouette model. Eight different PT devices were used in the 10 NICUs; five were overhead devices and three fibre-optic pads. The median (range) irradiance level for overhead PT devices was 9.7 (4.3-32.6) µW/cm(2)/nm and for fibre-optic pads 6.8 (0.8-15.6) µW/cm(2)/nm. Approximately 50% of PT devices failed to meet the minimal recommended irradiance level of 10 µW/cm(2)/nm. Maximal irradiance levels for overhead PT spot lights were inversely related to the distance between device and infant model (R2=0.33). The distances ranged from 37 cm to 65 cm. PT devices in the Dutch NICUs show considerable variability with often too low irradiance levels. These results indicate that suboptimal PT is frequently applied and may even be ineffective towards reducing total serum bilirubin levels. These results underline the need for greater awareness among all healthcare workers towards the requirements for effective PT including measurements of irradiance and distance.
Clinical Neurology and Neurosurgery, 1991
In maritime operational scenarios, such as smuggling, piracy, or terrorist threats, it is not onl... more In maritime operational scenarios, such as smuggling, piracy, or terrorist threats, it is not only relevant who or what an observed object is, but also where it is now and in the past in relation to other (geographical) objects. In situation and impact assessment, this information is used to determine whether an object is a threat. Single platform (ship, harbor) or single sensor information will not provide all this information. The work presented in this paper focuses on the sensor and object levels that provide a description of currently observed objects to situation assessment. For use of information of objects at higher information levels, it is necessary to have not only a good description of observed objects at this moment, but also from its past. Therefore, currently observed objects have to be linked to previous occurrences. Kinematic features, as used in tracking, are of limited use, as uncertainties over longer time intervals are so large that no unique associations can be made. Features extracted from different sensors (e.g., ESM, EO/IR) can be used for both association and classification. Features and classifications are used to associate current objects to previous object descriptions, allowing objects to be described better, and provide position history. In this paper a description of a high level architecture in which such a multi-sensor association is used is described. Results of an assessment of the usability of several features from ESM (from spectrum), EO and IR (shape, contour, keypoints) data for association and classification are shown.
Skin-to-skin contact after birth is propagated to facilitate breast-feeding and mother-child bond... more Skin-to-skin contact after birth is propagated to facilitate breast-feeding and mother-child bonding. We describe two term infants with sudden unexpected postnatal collapse (SUPC) during skin-to-skin contact. The infants were found with abnormal colour, hypotonia and apnoea, in a prone position on the chest of their mothers, both of whom were primipara with a high BMI. After stimulation, both infants recovered completely. No specific potential cause, other than the position, could be found. These cases illustrate that skin-to-skin contact after birth is not without risk. In available literature, risk factors for SUPC include primiparity and infant orientation such as prone and lateral positions. These positions are also risk factors for sudden infant death syndrome (SIDS). To improve safety, a primipara should be supervised during skin-to-skin contact and not be left alone in the first hours after delivery; the infant should be guaranteed a free airway, especially when the mother ha...
Journal of Clinical Monitoring and Computing, 2015
Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accu... more Increased extravascular lung water (EVLW) may contribute to respiratory failure in neonates. Accurate measurement of EVLW in these patients is limited due to the lack of bedside methods. The aim of this pilot study was to investigate the reliability of the transpulmonary ultrasound dilution (TPUD) technique as a possible method for estimating EVLW in a neonatal animal model. Pulmonary edema was induced in 11 lambs by repeated surfactant lavages. In between the lavages, EVLW indexed by bodyweight was estimated by TPUD (EVLWI tpud) and transpulmonary dye dilution (EVLWI tpdd) (n = 22). Final EVLWI tpud measurements were also compared with EVLWI estimations by gold standard post mortem gravimetry (EVLWI grav) (n = 6). EVLWI was also measured in two additional lambs without pulmonary edema. Bland-Altman plots showed a mean bias between EVLWI tpud and EVLWI tpdd of-3.4 mL/kg (LOA ± 25.8 mL/kg) and between EVLWI tpud and EVLWI grav of 1.7 mL/kg (LOA ± 8.3 mL/kg). The percentage errors were 109 and 43 % respectively. The correlation between changes in EVLW measured by TPUD and TPDD was r 2 = 0.22. Agreement between EVLWI measurements by TPUD and TPDD was low. Trending ability to detect changes between these two methods in EVLWI was questionable. The accuracy of EVLWI tpud was good compared to the gold standard gravimetric method but the TPUD lacked precision in its current prototype. Based on these limited data, we believe that TPUD has potential for future use to estimate EVLW after adaptation of the algorithm. Larger studies are needed to support our findings.