Bent Friis-Hansen

HYPERTENSIVE PEAKS IN THE PATHOGENESIS OF INTRAVENTRICULAR HEMORRHAGE IN THE NEWBORN. ABOLITION BY PHENOBARBITONE SEDATION

ABSTRACT. Mean arterial blood pressure (MABP) was measured continuously for 3 to 5 days after birth in 27 premature infants with a birth weight under 1500 g, and who required umbilical artery catheterisation. All had respiratory distress syndrome (RDS). Intraventricular hemorrhage (IVH) occurred in 9 infants (33%), diagnosed by computered tomography (CT). IVH was more common in infants of lower gestational age, in infants delivered vaginally and in infants with perinatal asphyxia. Variable increases in MABP over the resting value occurred in all infants associated with increases in both active and passive motor activity. In 6 infant pairs matched for birth weight, gestational age, mode of delivery and severity of perinatal asphyxia, the infants who developed IVH had higher peak MABP valued compared to matched controls. Resting and minimum MABP values were not different in the two groups. We conclude that the large increases in arterial blood pressure which occur with both spontaneous motor activity and in association with nursing procedures, are an important cause of development of IVH in very low birth weight infants. An example is given to show that pressure peaks can be abolished by phenobarbitone sedation.

LOW CEREBRAL BLOOD FLOW IN HYPOTENSIVE PERINATAL DISTRESS

Hypoxic brain injury is the most important neurological problem in the neonatal period and accounts for more neurological deficits in children than any other lesion. The neurological deficits are notably mental retardation, epilepsy and cerebral palsy. The pathogenesis has hitherto been poorly understood. Arterial hypoxia has been taken as the obvious mechanism but this does not fully explain the patho‐anatomical findings. In the present investigation we have examined the arterial blood pressure and the cerebral blood flow in eight infants a few hours after birth. The 133Xe clearance technique was used for the cerebral blood flow measurements. The study confirmed that perinatal distress may be associated with low arterial blood pressure, and it was shown that cerebral blood flow is very low, 20 ml/100 g/min or less, in hypotensive perinatal distress. It is concluded that cerebral ischaemia plays a crucial role in the development of perinatal hypoxic brain injury.

Perinatal Brain Injury and Cerebral Blood Flow in Newborn Infants

Brain injury in preterm, low birth weight infants is the most important problem in todays perinatal medicine.’ About 7% of all preterm infants develop intraventricular haemorrhage (IVH) or periventricular leucomalacia (PVL) and among infants born after less than 35 weeks of gestation or with a birth weight below 1500 g, the incidence of these lesions is as high as 50% (1). Modern techniques such as ultrasonic examination of the brain through the anterior fontanelle or CT-scan have shown that a majority of cases of IVH start within the first few days of life (2). The bleedings usually begin in the subependymal tissue of the germinal matrix (3). This richly vascular structure overlaying the caudate nucleus, is highly developed in the fetus from 6 to 8 months of age. It consists of neuroblasts which from here migrate to the surface of the brain where they form the cerebral cortex. The bleedings will often rupture through the ependymal to the parenchymal tissue. From the lateral ventricles bleedings will usually expand into the fourth ventricle and through the foraminas out into the subarachnoid space around the brain stem and cerebellum. Furthermore the premature brain is characteristic by a much thinner cortex with poorly developed convultions. PVL is an ischemic lesion with softening and necrosis of the developing white matter of the brain, usually seen in the regions surrounding the ventricles, corresponding to the “water-shed zone” i.e. the border zone between areas supplied by centrifugal and centripetal cerebral arteries. IVH and PVL are often found at the same time. In milder cases full recovery can take place, but once dilatation of the ventricle has taken place or cysts have formed in the white matter, the prognosis is more serious (4). Large bleedings may also give rise to hydrocephalus. Therefore it is easily understood that both IVH and PVL will have serious impact on later development of the infant and that cerebral blood flow (CBF) has a central role in development of these lesions.

The Extracellular Fluid Volume in Infants and Children

The extracellular volume in fifty infants and children has been studied by a micro modification of the thiosulfate method. This technique was first tried out and it was found that determinations carried out on capillary blood gave the most consistent results. Some limitations of the method are discussed.

THE BODY DENSITY OF NEWBORN INFANTS.

A method is described by which the body density of the newborn infant can be measured in vivo. The average result obtained in 29 newborn infants, all below 24 lira of age, is 1.030 with a standard deviation of ± 0.030.

Neonatal Hepatitis with Osteomalacia

A case of neonatal hepatitis with extensive osteomalacia is presented, and the relationship between bone‐metabolism and liver disease is discussed.

Body Composition During the Neonatal Period: Apparatus for Measuring the Volume and Specific Gravity of Newborns

patients of the first group were treated with ferric choline citrate 100 ml twice daily, the secoad group with ferrogluconate 66.7 mg four times daily, and the third group received no iron medication. The red blood picture was checked at 3 weeks, 3 months, and 6 months of age. Up to the third month there was not yet any difference in the red cell count, haemoglobin, or average corpuscular haemoglobin content. At 6 months of age the haemoglobin level was approximately 2 d l 0 0 ml lower in the prematures without iron medication than in the other two groups treated with iron in chelated form. At three months of age, moreover, the patients without iron medication had an incidence of infections twice that of the groups having iron medication. This proportion remained the same at the age of 6 months.

Total and extracellular body water in children during AGTH treatment

In his interesting paper Dr. Tallquist mentioned that the pyruvic acid values in the blood do not always show a correlation to the infant’s development, as judged by the birth weight. I t may be of interest to note that in a different context there is reason to assume that the true degree of fetal development at birth is better reflected in certain chemical data than in the birth weight. Dr. Berfenstam, of Uppsala, has shown that the carbonic anhydrase values in the red blood cells are strikingly correlated to the fetal development as evaluated on menstrual data.