Conditions for treatment of cerebral arteriovenous malformation associated with ectasia of the vein of Galen in the newborn.

The survival rate and subsequent quality of life has improved significantly for neonates with cerebral arteriovenous malformation associated with ectasia of the vein of Galen, with recent advances in interventional neuroradiology. Transarterial endovascular occlusive techniques have emerged as the treatment of choice. However, this treatment is technically very demanding and good results are seen only in institutions with large experience in treating this rare type of congenital malformation. The conditions for granting the neonate access to this sophisticated type of treatment include appropriate clinical and neuroradiological evaluation at the highest possible level, combined with the establishment of early communication with a trained interventional neuroradiological team capable of this treatment. Not all neonates are suited to this form of treatment, but only rapid, careful and competent treatment and evaluation of the neonate can assure appropriate pre-procedural evaluation in order to give each patient, wherever born, a similar and optimized chance of survival without unnecessary sequelae.

Hypoxanthine concentration in plasma during the first two hours after birth in normal and asphyxiated infants.

The measurement of arterial plasma concentration of hypoxanthine in 16 healthy newborn infants showed a prominent increase after birth compared with the umbilical cord levels. Peak values were found 10-20 min after birth with a maximal value of 11.9 mumole/liter in the normal newborns. In five asphyxiated infants the postnatal pattern of hypoxanthine was the same as for normal infants but the increase was even more prominent. A mean peak value of 33.7 mumole/liter was noted in the asphyxiated infants. Our results indicate that the hypoxanthine concentration is influenced not only by the degree of hypoxia, but also by the peripheral circulation and the time interval between the hypoxic event and the blood sampling. It is concluded that hypoxanthine assay may be of clinical value for the detection od past hypoxia as a semiquantitative test.

Hypoxanthine as a test of perinatal hypoxia as compared to lactate, base deficit, and pH.

The possibility of detecting past hypoxia during the first 2 h after birth by means of blood analyses of hypoxanthine, lactate, base deficit, and pH was investigated in six infants with a 1 min Apgar score of less than or equal to 4. Reference values for the four biochemical variables were obtained in 16 healthy infants with a normal 1 min Apgar score of greater than or equal to 8. In the asphyxiated infants, elevated values for hypoxanthine were found in 48%, for lactate in 54%, and for base deficit in 46% while 21% of the pH values were lower than the reference. In the group of asphyxiated infants, significantly elevated hypoxanthine values were found during the first 20 min after birth, base deficit during 30 min, and lactate values during 120 min while lower pH values than the reference were found during the first 30 min. Significant correlations were found between hypoxanthine and lactate concentrations and also between hypoxanthine and base deficit but not between hypoxanthine and pH. It is concluded that the optimal time for detecting past intrauterine and 20 min after birth, but in individual cases, significantly increased hypoxanthine concentrations may be found at any time in the 10-120 min period. We propose an equation that can be used to calculate an upper normal limit for hypoxanthine concentration in any sampling time during this period.

Metabolic effects of obstetric regional analgesia and of asphyxia in the newborn infant during the first two hours after birth. I. Arterial blood glucose concentrations.

Effects of obstetric regional analgesia and of asphyxia on the arterial blood glucose concentrations were investigated in 83 newborn infants divided into a control group, an asphyxia group, a continuous epidural, and a paracervical + pudendal block group. Lidocaine was used in the analgesia groups. All infants except those of the asphyxia group had 1-minute Apgar scores greater than or equal to 7.1) In the asphyxiated infants high blood glucose values and strong correlations between blood glucose concentrations and different signs of asphyxia (Apgar score, base deficit and lactate) were found. 2) In infants whose mothers were given regional analgesia the results were: (a) high glucose values in 20% of the infants and an association between increased glucose concentrations in these infants and signs of fetal distress, (b) low blood glucose values (less than 1.67 mmol/l) in 27% of the infants. It is recommended that the blood glucose is checked in the newborns after obstetric regional analgesia.

Metabolic effects of obstetric regional analgesia and of asphyxia in the newborn infant during the first two hours after birth. II. Arterial plasma concentrations of glycerol, free fatty acids and beta-hydroxybutyrate.

Effects of obstetric regional analgesia and of asphyxia on the arterial blood concentrations of the lipid metabolites: glycerol, free fatty acids and beta-hydroxybutyrate were investigated in 85 newborn infants divided into a control group, an asphyxia group, a continuous epidural, an intermittent epidural and a paracervical + pudendal block group: lidocaine was the drug used in the analgesia groups. The postnatal changes in lipid metabolites followed three different patterns. After marked increases in glycerol and free fatty acids a steady level was reached after one hour in the control group and not before two hours in the regional analgesia groups. In the asphyxia group, however, a steady level was found already 10 min after birth. Between 30 and 120 min after birth the beta-hydroxybutyrate concentration increased in the control group, decreased in the asphyxia group and did not change in the three regional analgesia groups. The different patterns of lipid metabolites may indicate differences in sympathetic tone and/or in hormonal influences after birth.

Metabolic effects of obstetric regional analgesia and of asphyxia in the newborn infant during the first two hours after birth. III. Adjustment of arterial blood gases and acid-base balance.

Effects of obstetric regional analgesia and of asphyxia on the arterial blood gases and acid-base balance in the first two hours after birth were investigated in 85 newborn infants divided into a control group, an asphyxia group and a continuous epidural, an intermittent epidural and a paracervical + pudendal block group. Lidocaine was the drug used in the analgesia groups. In the asphyxia group the metabolic acidosis decreased and pH was normalized to the level of the control group between 10 and 30 min after birth. During this period in the asphyxia group PaO2 was higher than and PaCO2 similar to the corresponding control values. Compared with the control group, in the regional analgesia groups the metabolic acidosis tended to be less extensive and PaO2 higher, whereas PaCO2 was similar. A lower packed red cell volume in the asphyxia and in the regional analgesia groups, probably due to differences in placental transfusion, may have had influence on the results. Within the regional analgesia groups infants with hyperglycemia showed signs of an increased metabolic acidosis while infants with hypoglycemia had low base deficit and lactate values supporting the assumption that neonatal blood glucose concentration may reflect perinatal distress.

Red cell volume measurements and acute blood loss in high-risk newborn infants.

Red cell volume was measured in 259 infants admitted to a high-risk newborn unit. Red cell volume was measured using 50Cr tagging which subsequently was activated to 51Cr for counting. Total blood volume was calculated using the corrected whole body hematocrit. A low red cell volume was frequently associated with a maternal history of vaginal spotting, with placenta previa or placenta abruptio, with nonelective cesarean section, and with deliveries associated with cord compression. Asphyxiated infants without a history suggestive of blood loos often had a low red cell volume. An early central hematocrit below 45% correlated with a low red cell volume, but a normal or high hematocrit was often associated with low red cell measurements. The total blood volume depended largely on whether the tagging was done long enough after the blood loss for plasma volume equilibration to have occurred. Very low red cell volume values were associated with a high mortality rate, but birth weight played a dominant role in survival, even at low red cell volume levels.

Transcutaneous PO2 measurements in seriously ill newborn infants.

Continuous monitoring of oxygen tension using the transcutaneous electrode developed by Huch and co-workers was studied in severely ill newborn infants. Acceptable results were obtained despite the theoretical possibility that vasoconstriction might interfere with the method when used in the very ill. The reliability and clinical usefulness of the method is illustrated in 4 cases of severely ill newborn infants.