NEOnatal Central-venous Line Observational study on Thrombosis (NEOCLOT): evaluation of a national guideline on management of neonatal catheter-related venous thrombosis.

Background: In critically ill (preterm) neonates, catheter-related venous thromboembolism (CVTE) can be a life-threatening complication. Evidence on optimal management in the literature is lacking. In the Netherlands, a consensus-based national management guideline was developed to create uniform CVTE management.

Bedside placement of ventricular access devices under local anaesthesia in neonates with posthaemorrhagic hydrocephalus: preliminary experience.

Purpose: Posthaemorrhagic ventricular dilatation in preterm infants is primarily treated using temporising measures, of which the placement of a ventricular access device (VAD) is one option. Permanent shunt dependency rates are high, though vary widely. In order to improve the treatment burden and lower shunt dependency rates, we implemented several changes over the years.

NEOnatal Central-venous Line Observational study on Thrombosis (NEOCLOT): evaluation of a national guideline on management of neonatal catheter-related thrombosis.

Background: In critically ill (preterm) neonates, central venous catheters (CVCs) are increasingly used for administration of medication or parenteral nutrition. A serious complication, however, is the development of catheter-related thrombosis (CVC-thrombosis), which may resolve by itself or cause severe complications. Due to lack of evidence, management of neonatal CVC-thrombosis varies among neonatal intensive care units (NICUs).

The bilirubin albumin ratio in the management of hyperbilirubinemia in preterm infants to improve neurodevelopmental outcome: a randomized controlled trial--BARTrial.

Background And Objective: High bilirubin/albumin (B/A) ratios increase the risk of bilirubin neurotoxicity. The B/A ratio may be a valuable measure, in addition to the total serum bilirubin (TSB), in the management of hyperbilirubinemia. We aimed to assess whether the additional use of B/A ratios in the management of hyperbilirubinemia in preterm infants improved neurodevelopmental outcome.

Application of ultrasound dilution technology for cardiac output measurement: Cerebral and systemic hemodynamic consequences in a juvenile animal model.

Objective: Analysis of cerebral and systemic hemodynamic consequences of ultrasound dilution cardiac output measurements.

Design: : Prospective, experimental piglet study.

Setting: Animal laboratory.

Monitoring of cerebral haemodynamics in newborn infants.

The most important cerebrovascular injuries in newborn infants, particularly in preterm infants, are cerebral haemorrhage and ischemic injury. The typical cerebral vascular anatomy and the disturbance of cerebral haemodynamics play important roles in the pathophysiology. The term 'cerebral haemodynamics' includes cerebral blood flow (CBF), cerebral blood flow velocity, and cerebral blood volume (CBV).

Cardiac output measurement in ventilated lambs with a significant left-to-right shunt using the modified carbon dioxide fick method.

Background: It remains a great challenge to measure systemic blood flow in critically ill newborns. In a former study we validated the modified carbon dioxide Fick (mCO(2)F) method for measurement of cardiac output in a newborn lamb model. In this new study we studied the influence of a left-to-right shunt on the accuracy of the mCO(2)F method.

Surveillance study of apparent life-threatening events (ALTE) in the Netherlands.

SIDS and ALTE are different entities that somehow show some similarities. Both constitute heterogeneous conditions. The Netherlands is a low-incidence country for SIDS.

A method to calculate arterial and venous saturation from near infrared spectroscopy (NIRS).

For adequate development and functioning of the neonatal brain, sufficient oxygen (O2) should be available. With a fast sampling (f(s) > 50 Hz) continuous wave NIRS device, arterial (SaO2) and venous (SvO2) saturation can be measured using the physiological fluctuations in the oxyhemoglobin (O2Hb) and total hemoglobin (tHb) concentrations due to heart action and respiration. Before using this technique in a neonatal setting, the method was verified on adult volunteers (n=7) by decreasing inspired oxygen down to an arterial saturation of 70% using a pulse oximeter as reference.

Cardiac output measurement using a modified carbon dioxide Fick method: a validation study in ventilated lambs.

Cardiac output can be measured using a modified carbon dioxide Fick (mCO2F) method. A validation study was performed comparing mCO2F method-derived cardiac output (Q(mCO2F)) with invasively measured pulmonary blood flow. In seven randomly bred ventilated newborn lambs, cardiac output was manipulated by creating hemorrhagic hypotension.

Cerebral oxygen supply during hypotension in near-term lambs: a near-infrared spectroscopy study.

Sufficient O(2)-supply to the brain is necessary for an adequate cerebral energy metabolism, function and growth. To elucidate the relation between changes in, respectively, mean arterial blood pressure (MABP) and cerebral O(2)-supply and changes in the oxygenation state of hemoglobin during hypotension in preterm born lambs. Preterm lambs were delivered at 141 days (n=7) or 127 days (n=7) of gestation.

Influence of volume replacement with colloids versus crystalloids in neonates on venoarterial extracorporeal membrane oxygenation on fluid retention, fluid balance, and ECMO runtime.

In this retrospective study, we compared the effects of colloid versus crystalloid fluid replacement on the clinical signs of capillary leakage syndrome in 30 neonates with pulmonary hypertension due to meconium aspiration syndrome on venoarterial membrane oxygenation (VA-ECMO). Before 2000, 15 neonates received volume replacement with a pasteurized plasma protein solution (3.8% albumin); after 2000, 15 neonates received normal saline.

Effects of skin on bias and reproducibility of near-infrared spectroscopy measurement of cerebral oxygenation changes in porcine brain.

The influence of skin on the bias and reproducibility of regional cerebral oxygenation measurements is investigated using cw near-infrared spectroscopy (NIRS). Receiving optodes are placed over the left and right hemispheres of a piglet (C3, C4 EEG placement code) and one transmitting optode centrally (Cz position). Optical densities (OD) are measured during stable normo, mild, and deep hypoxemia.

Assessment of local changes of cerebral perfusion and blood concentration by near infrared spectroscopy and ultrasound contrast densitometry.

The objective of this study is to correlate regional cerebral blood concentration measurements made with near infrared spectroscopy to simultaneous local measurements of ultrasound contrast agent (CA) densitometry. Experiments were performed with piglets (7 kg) under general anesthesia. The cerebral blood flow (CBF) and volume (CBV) were changed by inducing various degrees of hypercapnia.

Brain cell function during hypoxemia in near-term lambs: a near-infrared spectroscopy study.

Background: Sufficient O2 supply to the brain is necessary for adequate cerebral energy metabolism, function and growth.

Objectives: To elucidate the relation between changes in cerebral arterial O2 content and cerebral O2 supply and changes in the oxygenation state of cerebral hemoglobin, and to determine whether concentration changes in oxyhemoglobin (DeltacO2Hb), deoxyhemoglobin (DeltacHHb), and cerebral arterial oxygenation (DeltacHbD; the difference between DeltacO2Hb and DeltacHHb), and cerebral blood volume (DeltaCBV) can be used to assess the decline in brain cell function during hypoxemia in lambs born near term.

Methods: 17 preterm lambs were delivered at a mean gestational age of 133 days.

Cerebral O2 supply thresholds for the preservation of electrocortical brain activity during hypotension in near-term-born lambs.

The fetal brain develops rapidly during the last trimester of pregnancy. Therefore, the brain of infants who are born preterm is vulnerable to changes in oxygen and nutrient supply in the neonatal period. The objective was to determine the effect of gestational age (GA) on the cerebral O2 supply threshold level for preservation of brain function during hypotension in near-term-born lambs.

Purine and pyrimidine metabolism and electrocortical brain activity during hypoxemia in near-term lambs.

Insufficient cerebral O(2) supply leads to brain cell damage and loss of brain cell function. The relationship between the severity of hypoxemic brain cell damage and the loss of electrocortical brain activity (ECBA), as measure of brain cell function, is not yet fully elucidated in near-term newborns. We hypothesized that there is a strong relationship between cerebral purine and pyrimidine metabolism, as measures of brain cell damage, and brain cell function during hypoxemia.

Oxygenation and hemodynamics in left and right cerebral hemispheres during induction of veno-arterial extracorporeal membrane oxygenation.

Objective: Oxygenation and hemodynamics in the left and right cerebral hemispheres were measured during induction of veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

Study Design: Using near infrared spectrophotometry, effects of right common carotid artery (RCCA) and right internal jugular vein (RIJV) ligation and start of VA-ECMO on concentrations of oxyhemoglobin, deoxyhemoglobin, and cerebral blood volume (CBV) were evaluated in 10 newborn infants. Mean cerebral blood flow velocity (CBFV) in the major cerebral arteries was compared before and after the start of VA-ECMO (pulsed Doppler ultrasonography).

Hemodynamic changes during opening of the bridge in venoarterial extracorporeal membrane oxygenation.

OBJECTIVE: To investigate the cause of the hemodynamic changes occurring during opening of the bridge in venoarterial (VA) extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective intervention study in animals. SETTING: Animal research laboratory of a university medical center.

Preservation of electrocortical brain activity during hypoxemia in preterm lambs.

Adequate cerebral perfusion is necessary to preserve cerebral O(2) supply in order to maintain brain cell function. Our aim was to assess the influence of gestational age on the response of cerebral hemodynamics to hypoxemia and to determine thresholds of cerebral O(2) supply for preservation of brain cell function in preterm born lambs. Lambs were delivered by hysterotomy at 141 (n=5), 134 (n=5) or 127 (n=7) days of gestation.

Ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation: effects on cerebral oxygenation and hemodynamics.

Objective: To investigate the effect on cerebral oxygenation and hemodynamics of a patent ductus arteriosus with left-to-right shunt during venoarterial extracorporeal membrane oxygenation in a lamb model.

Design: Prospective intervention study in animals.

Setting: Animal research laboratory of a university medical center.