Stanley N. Graven

Incidence and treatment of the patent ductus arteriosus in the ill premature neonate

Abstract Two to 15 per cent of the patients admitted to a Neonatal Intensive-Care Unit developed signs of cardiac disease due to a PDA. In a four-year period, of 90 patients with a diagnosis of the PDA, confirmation was made in 44 (surgery, 27; autopsy, 12; and aortography, 5). Eighty per cent were 33 weeks gestation or less. Two-thirds of the patients went into congestive heart failure. Over 1 2 of these had severe respiratory distress and 44 per cent required a respirator. The diagnosis of a PDA and cardiac failure was made clinically by the presence of characteristic murmur frequently accompanied by a diastolic murmur, bounding pulses, hepatomegaly, apnea and bradycardia, roentgenographic evidence of perihilar edema and/or increased pulmonary vascularity, and an abnormal electrocardiogram. Twenty-seven patients underwent surgical ligation of the PDA. There were no deaths in the operating room. The survival rate in those over 1,000 grams was 80 per cent. Of those patients that died due to the PDA, nearly 60 per cent had bronchopulmonary dysplasia as an associated finding.

The respiratory distress syndrome

Abstract The incidence of the respiratory distress syndrome (RDS) of premature infants born to mothers delivering successive low birth weight (LBW) infants is presented. For mothers delivered of successive LBW infants, a healthy LBW infant followed a healthy LBW infant 129/134 times and a LBW infant with the RDS followed a LBW infant with the RDS 9/12 times. The incidence of the RDS among LBW infants born to female relatives of high and low risk mothers and the general population was determined. The incidence of the RDS or probable RDS for LBW infants of female relatives of low risk mothers was 7 per cent, for LBW infants of mothers of indeterminate risk was 15 per cent (general population), and for LBW infants of female relatives of high risk mothers was 42 per cent. The LBW infants born to female relatives of high risk mothers also had a higher mortality rate. On the basis of the data presented, it is proposed that there exists a genetically determined “RDS predisposition factor” which when present in a mother predisposes her low birth weight infants to the development of the respiratory distress syndrome.

Amniotic Fluid Lecithin to Sphingomyelin Ratio of 3.5 and Fetal Pulmonary Maturity

Extract: The clinical outcome of 118 pregnancies assessed by amniotic fluid lecithin to sphingomyelin concentration (L/S) ratio within 2 days of delivery is presented. It has been observed that the critical L/S ratio for pulmonary function is 3.5 in that no infant born with an L/S ratio greater than 3.5 has had respiratory distress syndrome (RDS). Below an L/S ratio of 3.5, the risk and severity of RDS is inversely related to the L/S ratio.An L/S ratio < 3.5 has the same prognostic value in infants born between 30 and 34 weeks gestation as it has in infants born between 35 and 38 weeks gestation. Under these conditions the relation between L/S ratio and RDS is independent of gestational age.Speculation: It has not been demonstrated directly to what extent the developing fetal lungs actually contribute to the amniotic fluid phospholipids. We feel that the amniotic fluid L/S ratio indeed serves as an index of pulmonary maturation, but that there are significant misconceptions about the term “L/S ratio” which have contributed to errors in performing and interpreting this test.

The Growth and Development of Low Birth Weight Infants Receiving Intensive Neonatal Care Preliminary Observations on 28 Such Infants

This study reports the growth and development of 28 survivors who had a birth weight of ≤1,000 g and were cared for at a Regional Neonatal In tensive Care Unit. Only eight (30%) had neurologic abnormalities including spastic hemiparesis, retrolental fibroplasia, hydrocephalus, motor retarda tion, and some delay in language skills. The other survivors had normal physical examinations and developmental progress judged by a variety of screening examinations up to age four years, three months. The average caloric intake during the first week was 61 kg/da, although over half never reached that level until day 4. Nearly all the infants have had standard growth patterns thus far.

Oxygen Consumption in Fetal Rabbit Ductus Arteriosus

Summary Oxygen consumption in fetal rabbit ductus arteriosus and descending aorta was studied after human umbilical artery tissue was used to standardize the technique. A steady state of oxygen consumption persisted for 90-100 min after dissection, and a tissue dry weight of greater than 15 mg was necessary to obtain reliable data, necessitating pooling of rabbit fetal tissue from an entire litter. Ductus arteriosus tissue from 25.75-26.5 day gestation had an oxygen consumption of 2.05 ± 0.22 (4)μI oxygen/10 mg dry wt/hr, and at 27.5-29.5 it was 5.69 ± 0.28 (7) (P < 0.001). There was no change with gestational age in the oxygen consumption in the descending aorta (2.15 ± 0.23 μI oxygen/10 mg dry wt/hr).

1010 A TEN YEARS EXPERIENCE WITH REGIONALIZED NEONATAL CARE

The Wisc. Perinatal Care Program including 6 regional centers has been functioning for over 10 years. Regionalization has offered educational enhancement to community health providers and allowed high risk mothers and infants more uniform exposure to intensive care and therapeutic advances. To assess the programs efficacy, we evaluated state mortality rates and compared these to national statistics. While the Wisc. birth rate of LBW infants has remained constant (6-7%), the death rate for these neonates decreased 32.7% over the survey period. Reflecting increased center utilization, 57% of neonatal deaths occurred in tertiary centers in ′74, as opposed to only 20% in ′68. Over the 10 yrs, the death rate during the first 24 hrs has decreased by 43% and during the first week by 36.1%. The decremental trend for Wisc. general and disease specific meonatal death rates has consistently surpassed national norms. Deaths/1000 live births due to HMD/RDS have continued to fall despite persistent high national trends. Further, Wisc. was unique among states with > 50,000 births/yr in showing decreasing HMD/RDS death rates between ′68-′73. Maintenance of low, declining neonatal mortality rates and consistent reduction in deaths from major causalities with a marked shift in timing and place of death, establishes the positive influence of regionalized care.

966 RELATIONSHIP OF BODY TEMPERATURE IN FIRST SIX HOURS OF LIFE TO MORTALITY IN LBW INFANTS

A relationship between body temperature and survival for LBW infants has been demonstrated by a number of centers. In reviewing the records for LBW infants for the Wisconsin Perinatal Program, the relationship between body temperature and survival was assessed.Records of 1,615 infants with birth weights between 1.0 and 2.0Kg from 72 hospitals were reviewed. All infants survived more than 6 hours. Mortality was tabulated on the basis of the lowest body temperature recorded during the first 6 hours of life. The mortality rates were as follows:The differences in mortality rate were most marked among the smaller infants (1.0-1.5Kg).Although the infants were from many different hospitals and received care under a variety of conditions, the groups were comparable in terms of birth weight and general condition at birth. Factors associated with care of infants which affect outcome other than body temperature will be discussed.