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Biomedical subjects

J H Ruys

Publications and source records attributed to J H Ruys.

At least 55 records · Page 3Linked to original sources
PubMed1989

Cerebral blood flow velocity changes in preterm infants after a single dose of indomethacin: duration of its effect.

Indomethacin decreases cerebral blood flow velocity and blood flow in the preterm infant. The duration of this negative effect has not been established. Cerebral blood flow velocity was evaluated in 24 preterm infants with symptomatic patent ductus arteriosus before and during the first 12 hours after a single intravenous dose of indomethacin, 0.1 mg/kg. Cerebral blood flow velocity was estimated by serial Doppler investigations of the anterior cerebral arteries. Indomethacin administration led to an instantaneous decrease of peak systolic flow velocity, temporal mean flow velocity, and end-diastolic flow velocity of the anterior cerebral arteries in all infants, which was maximal between 2 and 40 minutes after indomethacin administration and was followed by a more sustained recovery of all velocities to baseline values. Temporal mean flow velocity was not different from pre-indomethacin values at 3 hours after the administration. It is concluded that indomethacin can impact the cerebral circulation of the preterm infant for at least 2 hours. This may have consequences in preterm infants with unstable hemodynamics and pulmonary function.

Blood Flow Velocity↗
PubMed1988

The influence of abnormal blood gases on cerebral blood flow velocity in the preterm newborn.

The influence of hypercarbia, combined hypercarbia and hypoxemia, and hypocarbia on cerebral blood flow of preterm infants with a gestational age of less than 34 weeks was investigated by measuring peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and area under the velocity curve (AUVC) of the anterior cerebral artery (ACA) using transcutaneous Doppler technique. Mild and moderate hypocarbia did not change cerebral blood flow velocity. During severe hypercarbia (PaCO2 greater than or equal to 6.7 kPa) significantly lower PI-values were detected, mainly caused by an increase of EDFV, indicating a decreased cerebrovascular resistance and increased cerebral blood flow. A highly significant decrease in PI-values during combined severe hypercarbia and hypoxemia (PaO2 less than 6.0 kPa) was found suggesting that hypoxemia superimposed on hypercarbia strengthens the increase of cerebral blood flow. While the increase of EDFV is thought to be due to carbon dioxide-induced vasodilation of cerebral arterioles, we assume that the accompanied increase of PSFV during combined hypercarbia and hypoxemia is caused by an increase in cardiac output due to hypoxemia which can alter the blood flow velocity wave form of the ACA.

Blood Flow Velocity↗
PubMed1988

Outcome of periventricular-intraventricular hemorrhage at 2 years of age in 484 very preterm infants admitted to 6 neonatal intensive care units in The Netherlands.

Of 484 newborn infants with a gestational age of less than 32 weeks and admitted to 6 neonatal intensive care units in the Netherlands, 294 survived and were available for follow-up at the corrected age of two years. The total incidence of impaired neurodevelopmental outcome was 23.1%. Sixty-nine children had a periventricular-intraventricular hemorrhage (PIVH) in the neonatal period: 31 grade I, 21 grade II, 12 grade III, 5 grade IV. Children with grade I and II PIVH had significantly more handicaps than children without PIVH (36.5% vs 17.8%, p less than 0.01). This held even true after the data were adjusted for possible confounding factors (odds ratio [OR] 2.1, confidence interval [1.3, 3.3], p less than 0.01). Children with grade III and IV PIVH had also more handicaps than children without PIVH (52.9% vs 17.8%, p less than 0.001); after adjustment for confounding factors the OR was 3.0, confidence interval [1.6, 5.5], p less than 0.01. The difference between children with grade I and II PIVH and children with grade III and IV PIVH was not significant.

Cerebral Hemorrhage↗
PubMed1988

Patent ductus arteriosus in a cohort of 1338 preterm infants: a collaborative study.

As part of a prospective national survey on morbidity and mortality of all infants born at less than 32 weeks and/or weighing less than 1500 g in the Netherlands we studied the incidence of symptomatic patent ductus arteriosus (PDA) in infants surviving at least 24 hours. In 1252 of the 1338 infants the presence or absence of PDA could be established. The incidence of PDA was 10.7%. Logistic regression analyses revealed that idiopathic respiratory distress syndrome (IRDS) was the most predictive factor, followed in order of importance by septicaemia, birthweight, prolonged rupture of membranes and gestational age. None of the other maternal and perinatal factors showed any association with the occurrence of PDA. Furthermore, bronchopulmonary dysplasia (BPD) and necrotising enterocolitis (NEC) were found to be sequelae of PDA. The combination of IRDS, very pre-term birth and septicaemia should be considered as high risk for the development of PDA.

Ductus Arteriosus, Patent↗
PubMed1988

Total parenteral nutrition and sepsis.

In 1279 very premature or very low birthweight infants the use and duration of treatment with total parenteral nutrition were associated with short gestational age and low birth weight. Infants treated with total parenteral nutrition had a higher risk of sepsis usually caused by Staphylococcus epidermidis or Staphylococcus aureus.

Bacterial Infections↗
PubMed1988

Blood flow velocity pattern of the anterior cerebral arteries. Before and after drainage of posthemorrhagic hydrocephalus in the newborn.

The blood flow velocity pattern of the anterior cerebral artery (ACA) was investigated using transcutaneous Doppler technique in ten preterm infants with posthemorrhagic hydrocephalus (PHH), before and after drainage of cerebrospinal fluid. The pulsatility index of the ACA was elevated during PHH, mainly due to an increase of peak systolic flow velocity, explained by an increased compliance of the vascular wall. The end diastolic flow velocity and the area under the velocity curve were not different before and after drainage, indicating that cerebrovascular resistance was not changed and blood flow through the ACA was not affected in the studied infants during PHH.

Blood Flow Velocity↗
PubMed1988

Maternal and neonatal transport: results of a national collaborative survey of preterm and very low birth weight infants in The Netherlands.

In a Dutch national collaborative study on 1338 infants, born in 1983 after a pregnancy of less than 32 weeks and/or with a birth weight of less than 1500 g, a comparison was made between maternal transport to university hospital perinatal centers and delivery in local or regional general hospitals and between neonatal transport to university hospital neonatal centers and treatment in local or regional general hospitals. The risk of mortality was investigated by means of logistic regression analysis including 27 perinatal risk factors as confounding variables. The results showed that infants born after maternal transport to centers had a significantly lower mortality risk. Infants treated in centers after neonatal transport had a lower mortality risk as well, but this was not statistically significant at a .05 level. The results of the study confirm that referral by maternal transport to level III centers offers the best prospects for high-risk preterm infants.

Female↗
PubMed1988

Mortality in very preterm and very low birth weight infants according to place of birth and level of care: results of a national collaborative survey of preterm and very low birth weight infants in The Netherlands.

As part of a collaborative project in the Netherlands in 1983, for which data were collected on 1,338 newborn infants (less than 32 weeks' gestation and/or less than 1,500 g birth weight), all infants were assigned to one of three levels of care according to hospital of birth. Considerable centralization was achieved by antenatal and neonatal transport. Although the uncorrected mortality rates were similar, the mortality odds (adjusted for four and 22 potential confounding perinatal factors, respectively) were significantly higher in level 1 and level 2 hospitals compared with level 3 hospitals (tertiary perinatal care centers). By extending the facilities for full perinatal intensive care in level 3 centers and thus providing optimal care for all such infants, the overall mortality rate is expected to decrease further.

Female↗
PubMed1987

Cerebral blood flow velocity pattern in healthy and asphyxiated newborns: a controlled study.

In a controlled study serial determinations of cerebral blood flow velocity using Doppler ultrasound and repeated real-time ultrasonographic- or computerized axial tomographic studies of the brain were performed in 17 (nearly) full-term newborns who experienced perinatal asphyxia and in 17 healthy matched controls during the first week of life. A higher cerebral blood flow velocity was found during the first 4 days of life, indicating a lower cerebrovascular resistance in the asphyxiated infants compared to the control infants. These haemodynamic changes coincided with cerebral oedema and neurological abnormalities. It is speculated that the changes in the cerebral circulation in asphyxiated infants are at least partly caused by cerebral oedema-induced increase of intracranial pressure due to severe perinatal asphyxia. Serial Doppler ultrasound investigations of the brain may be a useful non-invasive method for early detection and follow-up of the consequences of severe perinatal asphyxia.

Asphyxia Neonatorum↗
PubMed1987

Aetiological rôle of cerebral blood-flow alterations in development and extension of peri-intraventricular haemorrhage.

The aetiology and extension of peri-intraventricular haemorrhage (PIVH) are thought to be related to cerebral blood-flow alterations, and especially to increased cerebral blood-flow and fluctuating velocity of blood-flow. Using transcutaneous Doppler technique, the authors investigated cerebral blood-flow in 60 infants with gestations of less than 34 weeks. Pulsatility index (PI) and area under the velocity curve (AUVC) of the anterior cerebral arteries (ACA) were used as qualitative measures of cerebral blood-flow, and the coefficient of variation of PI and AUVC as indicators of fluctuations in blood-flow velocity. A reasonable correlation was found between PI and AUVC and their coefficients of variation in the ACA. First onset of PIVH was related to fluctuating blood-flow velocity, and extension of PIVH with both increased velocity (indicating increased blood-flow) and fluctuating velocity. Increased cerebral blood-flow and its fluctuating pattern were positively correlated with arterial carbon dioxide tension.

Brain↗
PubMed1987

Incidence and prediction of periventricular-intraventricular hemorrhage in very preterm infants.

During a prospective national survey of mortality and morbidity in infants born before 32 weeks gestation in the Netherlands in 1983, the incidence of periventricular-intraventricular hemorrhage (PIVH) was studied with ultrasound, in 484 of those infants. Stepwise logistic regression analyses were used to examine the predictive value of several maternal, prenatal and postnatal factors for the development of neonatal PIVH. PIVH was detected in 140 infants (28.9%); of these, 36 were grade I, 39 grade II, 22 grade III and 43 grade IV. The mortality rate increased from 3 to 84% with increasing severity of PIVH. Gestational age appeared to be the strongest predictive factor for both incidence and severity of PIVH, followed by idiopathic respiratory distress syndrome (IRDS), prolonged rupture of membranes and birth weight. Of the maternal and prenatal factors studied, only prolonged rupture of membranes (greater than 24 hours) and preeclampsia appeared to influence the risk of developing PIVH. Both were associated with a 50% reduction in the incidence of PIVH. None of the intrapartum factors studied showed a significant association with subsequent development of PIVH. Development of IRDS appeared to result in a twofold increase in the incidence of PIVH.

Birth Weight↗
PubMed1986

Neonatal mortality risk in relation to gestational age and birthweight. Results of a national survey of preterm and very-low-birthweight infants in the Netherlands.

In a cohort of 1338 very preterm and/or very-low-birthweight infants, representing 94% of all infants born alive after less than 32 weeks' gestation or weighing less than 1500 g in the Netherlands in 1983, the neonatal mortality rate was 233 per 1000. In these infants, the best obstetric estimate of gestational age was a better predictor of neonatal mortality than birthweight. In such pregnancies, careful obstetric assessment of gestational age seems to be a more accurate basis for clinical decisions and management than the expected birthweight.

Birth Weight↗
PubMed1986

Perinatal factors and periventricular-intraventricular hemorrhage in preterm infants.

We studied 49 consecutively admitted infants of less than 34 weeks' gestation to analyze the role of several maternal, intrapartum, and neonatal factors associated with the occurrence of periventricular-intraventricular hemorrhage (PIVH). To detect PIVH, ultrasound studies were performed every eight hours during the first three days of life and every 12 hours during the following four days. In 20 infants (41%) PIVH was detected. Of these 20 cases, 30% were diagnosed immediately after birth and 55%, 70%, 90%, and 100% after 24, 48, 72, and 108 hours, respectively. Hypoxia, hypercapnia, and acidosis were the most important factors associated with the development of PIVH. Hypothermia was also an antecedent. Suctioning, serum osmolality, weight loss, transfusions, pneumothorax, patent ductus arteriosus, and bolus infusions with sodium bicarbonate were not associated with the onset of PIVH.

Apgar Score↗
PubMed1986

Hemostasis and periventricular-intraventricular hemorrhage of the newborn.

In a prospective study we analyzed the role of coagulopathy in the development of periventricular-intraventricular hemorrhage (PIVH) in 49 consecutively admitted preterm infants of less than 34 weeks' gestation by serial ultrasound examinations and coagulation assays. In 20 patients (41%) PIVH was detected. On the day of birth, patients with PIVH had significantly lower levels of factor V than did the patients without PIVH, but all other clotting factors gave similar results, and on the third and fifth days all results were similar, including those for factor V. Even the small subgroup of infants who subsequently developed grade IV hemorrhage did not have a more severe coagulopathy than the other infants, although they had significantly lower levels of platelets and of factor VII at birth. We conclude that coagulopathy does not play an important role in the etiology of PIVH. Standard doses of 10 mL/kg of fresh-frozen plasma, administered to increase the low levels of clotting factors, did not prevent extension of the hemorrhage.

Blood Coagulation Disorders↗