Influence of maternal factors on cord and neonatal plasma micronutrient levels.

The influence of gestational length, maternal prenatal supplement and maternal levels on umbilical cord and neonatal plasma selenium, alpha-tocopherol, and retinol were studied and appropriate reference intervals for ongoing studies of gestational and perinatal micronutrient requirements were derived. We measured retinol, alpha-tocopherol (total and alpha-tocopherol:cholesterol ratio), selenium, and glutathione peroxidase in 160 umbilical cord samples and 58 paired maternal and neonatal samples collected on the third postpartum day. Selenium and glutathione peroxidase were also measured in 25 paired umbilical artery and vein samples. The strongest correlation with gestational age and birthweight was found for the cord blood variables, whereas levels in maternal blood were not related to either gestation or weight. Neonatal values were significantly lower than maternal for selenium (0.96 [0.25] compared with 1.56 [0.27] mumol/liter), retinol (0.54 [0.19] and 1.26 [0.45] mumol/liter), alpha-tocopherol (11.5 [3.63] and 32.4 [9.20] mumol/liter), and glutathione peroxidase (446 [174] and 873 [176] U/liter) but not for the ratio of alpha-tocopherol:cholesterol (5.0 compared with 6.0). Maternal use of tocopherol and retinol supplements did not significantly affect blood concentrations. Maternal plasma selenium levels at term were about 60% of nonpregnant adult females. Selenium concentration and glutathione peroxidase activity did not differ between paired umbilical cord arterial and venous samples. Selenium, retinol, and glutathione peroxidase differed between infants born before or after 37 weeks' gestation.

Peak inspiratory pressure requirements in infants born weighing less than 750 g.

The possibility that peak inspiratory pressure requirements or the arterial:alveolar oxygen ratio can predict the clinical outcome in infants weighing less than 750 g at birth was explored in a consecutive series. Nine of 10 infants (90%) with a peak inspiratory pressure requirement of more than 18 cm H2O at 48 hours or more than 16 cm H2O at 72 hours from age subsequently died later of respiratory causes (defined as death after 72 hours of pulmonary interstitial emphysema, bronchopulmonary dysplasia, or cor pulmonale). Twenty of 21 remaining infants (95%) survived until discharge. Using these data a 95th centile for peak inspiratory pressure requirement during the first 72 hours of life was constructed. The potential value of this centile in predicting later death of respiratory causes was examined in a separate series. Twelve of 15 infants (80%) whose peak inspiratory pressure requirements remained below the 95th centile, or were not ventilated (n = 6), survived. In contrast, 11 of 12 (92%) infants whose requirements crossed the 95th centile died later of respiratory causes. The infants who died had more radiological changes and higher mean arterial carbon dioxide pressure than survivors suggesting that the severity of the initial lung disease rather than the way that ventilation was managed determined prognosis. Peak inspiratory pressure requirement was more useful than arterial:alveolar oxygen ratio in clearly distinguishing between survivors and infants who died later of respiratory causes.

Serial changes in selected serum constituents in low birth weight infants on peripheral parenteral nutrition with different zinc and copper supplements.

One hundred and five infants of birth weight 2000 g or less who received peripherally administered parenteral nutrition for periods of three or more weeks, were randomly assigned to groups receiving different amounts of zinc and copper supplement. The blood concentrations of zinc, copper, retinol-binding protein, prealbumin, alkaline phosphatase and aspartate transaminase were followed weekly. Mean serum zinc, retinol-binding protein and prealbumin declined significantly over time while alkaline phosphatase rose. Only the group receiving the highest zinc supplement maintained a mean serum zinc concentration within the normal range at seven weeks. No difference in the protein or enzyme concentrations was found between the different zinc supplement groups. No difference was seen in serum copper or ceruloplasmin between copper dose groups although one intravenous supplement was double that of the other.

Endotoxinemia and thrombocytopenia during neonatal necrotizing enterocolitis.

Thrombocytopenia frequently complicates neonatal necrotizing enterocolitis (NEC) and has been postulated to result from absorption of bacterial endotoxins from the injured gut. The authors tested blood obtained during 47 episodes of NEC for endotoxin-like activity (ELA), using a Limulus amoebocyte lysate assay and found 23 patients (49%) had positive results. Concentrations of ELA in plasma ranged from 0.26 to 300 ng/mL of Escherichia coli equivalent activity, with a geometric mean of 1.1 ng/mL. Serial platelet measurements were available from 40 infants, 11 (28%) of whom had nadir counts below 100,000/mm3 following NEC onset. Nine of 19 infants (47%) with ELA in plasma and only 2 of 21 without (9.5%, P less than 0.05) developed thrombocytopenia, suggesting that endotoxinemia may indeed contribute to platelet depletion during NEC.

Group support for parents of high risk neonates: an interdisciplinary approach.

Many parents are unable to develop a satisfying relationship with their sick newborn. Although data are divided over the critical nature of the attachment process, measures to assist parents and reduce socio-environmental stresses are considered desirable. Group support is one such measure which can provide parents with a commonly needed component of neonatal intensive care. In the group described, weekly sessions are informal, encouraging discussion, an understanding of neonatal care and recognition that some emotional and coping disturbance is normal. Staff involved are an interdisciplinary team (social worker, doctor and nurse). The group requires no special funding and time commitment is low considering the support provided. We have met weekly for five years with sustained attendance. No control group exists but parents appear increasingly comfortable in the nursery and able to achieve more meaningful and ongoing interaction with their infant and the staff.

Clinical and echocardiographic evidence suggesting afterload reduction as a mechanism of action of tolazoline in neonatal hypoxemia.

The effect of tolazoline was assessed in 29 hypoxic neonates. Tolazoline was given in a bolus starting at 1 mg/kg and repeated or infused for 5-134 hours. A "good clinical response," defined as a rise in PaO2 of more than 20 mm Hg, was obtained in 23 (79%), 20 of this group were weaned from the respirator, and three died. Six infants did not respond initially and four died. Failure to respond to tolazoline or to be weaned from the ventilator was usually associated with severe additional pathology. Urine output (greater than 1 ml/kg/h) was adequate in most neonates during therapy. In those with preexisting oliguria (less than 1 ml/kg/h), output improved during therapy. Blood pressure monitoring showed a fall in blood pressure in 19 patients during tolazoline administration, but true hypotension only occurred in four; in seven there was no fall and in three there was a rise in blood pressure. Echocardiography was performed prior to therapy in 19 patients and repeated in 12 patients after 24 h. Additional "tracking" was performed at 10 min, 1 h, and 4 h in seven patients. Prior to therapy, right ventricular dysfunction was demonstrated by abnormal right ventricular systolic time intervals (RVSTIs) in 17 of the patients tested. A rapid improvement was evident during therapy especially with "tracking." Left ventricular dysfunction, assessed by left ventricular systolic time intervals (LVSTIs), ejection fraction (EF), shortening fraction (SF), and velocity of circumferential fiber shortening (VCF), was also evident prior to therapy and improved, though more gradually than the RVSTIs.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of red cell and plasma transfusion on serum zinc and copper levels in the neonate.

Transfusion of packed red cells (15 to 20 ml/kg) in 11 preterm infants resulted in a slight increase in mean serum zinc levels on the 3rd post transfusion day but no effect was noted on serum copper levels. No significant difference was found between the changes in serum zinc in 141 paired specimens collected a week apart when zero, one, two or three packed cell transfusions were given in the intervening week. A slight decrease in the mean copper level was noted when one transfusion was given. Transfusion of fresh frozen plasma in six newborns with abdominal wall defects resulted in initial serum copper levels two to three times greater than the reference mean for newborns. No effect was noted on zinc levels. Serum copper results should be interpreted with caution in infants who have been transfused with plasma.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation.

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.