Eileen E. Tyrala

Serum copper concentrations in sick and well preterm infants

In order to define the range of serum copper concentrations in preterm infants and to determine the effect of growth upon these values, serial serum copper concentrations were measured in 26 preterm infants over their first six weeks of life. Fourteen healthy, growing preterm infants (Group I) had mean serum copper concentrations below 32 microgram/dl throughout the study. Clinical and hematologic signs of copper deficiency which responded promptly to the oral administration of copper sulfate were noted in five of these 14 infants. Twelve ill preterm infants (Group II-A), who received parenteral nutrition without supplemental copper and had slow rates of growth, had mean serum copper concentrations above 50 micrograms/dl after the first week of life. Seven surviving from Group II-A (Group II-B) had a decrease in mean serum copper concentrations to values similar to those in Group I after two weeks of oral feedings and resumption of normal growth. Our findings suggest that preterm infants who have normal growth while receiving oral feedings are at significant risk for developing copper deficiency.

Clinical pharmacology of hexachlorophene in newborn infants.

Bathing with soap containing hexachlorophene was instituted during two major staphylococcal epidemics in a Neonatal Intensive Care Unit. Infants who weighed less than 1,200 gm, those with a postconceptional age of less than 35 weeks, and those with large areas of abraded skin were at highest risk to achieve elevated blood HCP concentrations. T 1/2 of HCP ranged from 6.1 to 44.2 hours and appeared to follow first order kinetics. Time of peak blood concentrations of HCP following a bath ranged from 6 to 10 hours. One infant with liver disease achieved a concentration of HCP of 4,350 ng/ml after seven baths and developed clinical symptoms consistent with HCP toxicity.

Glucose metabolism in the infant weighing less than 1100 grams

We studied the rate of endogenous glucose production and disappearance in a group of 10 clinically stable < 1100 gm infants in the first week of life, using stable-isotope (6,6-2H-glucose) dilution analysis for a 2-hour study period. Plasma glucose and insulin concentrations at 2 hours were 5.4 +/- 2.5 mmol/L (97 +/- 15 mg/dl) and 71.4 +/- 2.9 pmol/L, respectively, and did not change during the study period. The rate of glucose disappearance was 37 +/- 10 mumol/kg (6.77 +/- 0.55 mg/kg) per minute. The rate of endogenous glucose production was 12.3 +/- 11 mumol/kg (2.22 +/- 0.61 mg/kg) per minute. The exogenous glucose infusion rate was 25.2 +/- 8.4 mumol/kg (4.54 +/- 0.47 mg/kg) per minute. Endogenous glucose production was correlated with plasma glucose concentration (r = 0.76; p < 0.05) and the rate of glucose disappearance (r = 0.75; p < 0.05); plasma glucose concentration was correlated with the rate of disappearance (r = 0.87; p = < 0.01) and insulin concentrations (p < 0.05). We conclude that infants who weight < 1100 gm utilize three to four times more glucose per kilogram of body weight than adults, reflecting their higher ratio of brain to body weight. Endogenous glucose production provided only approximately one third of the glucose needed--a mandate for the exogenous infusion of glucose to prevent the development of hypoglycemia.

Meconium aspiration syndrome

One years experience with MAS in a neonatal intensive-care unit is analyzed with follow-up information. Seventeen patients or 3.7% of all admissions had MAS. Four patients (23.5%) died of acute respiratory failure. Two patients with MAS and persistence of the fetal circulation required cardiac catheterization to exclude cyanotic congenital heart disease. No survivors had persistent chronic lung disease. However, two of three patients with MAS and seizures had significant psychomotor retardation at follow-up examination.

SERIAL SERUM COPPER AND CERULOPLASMIN CONCENTRATIONS IN COPPER AND NON-COPPER SUPPLEMENTED PARENTERALLY ALIMENTED INFANTS

Serial serum copper and ceruloplasmin concentrations were monitored in 2 groups of parenterally alimented premature infants. Group I (n=10, mean BW=1317gms., mean GA=30.9 weeks) did not receive copper supplementation. Group II (n=8, mean BW=1415gms., mean GA=30.5 weeks) received 100μg/kg/day of supplemental Cu as Cu chloride. Group III (n=48, mean BW=1217gms., mean GA=30 weeks) were growing premature infants receiving ≥150ml/kg of standard premature infant formula by 2 weeks of age.Serum Cu and cerulo concentrations: 1. were significantly lower in Gp. III as compared to Gps. I & II during the 3rd, 4th, and 5th weeks of study; 2. were not significantly different between Gps. I & II throughout the 5 week study period. Concl: Serum Cu and cerulo concentrations do not reflect intake and cannot be used to assess sufficiency in the parenterally alimented infant.

648 RELATIONSHIP BETWEEN SERUM CONCENTRATION AND URINARY EXCRETION OF ZN AND CU IN PREMATURE INFANTS

Serum zinc (Zn), copper (Cu), and 24 hour urine collections for Zn, Cu, and amino acid excretion were measured in 12 primarily intravenously nourished premature infants (mean GA=30.6 wks., mean birth wt=1067gms.). Five infants had two or more serial measurements. All infants were clinically stable, non post-op, and not infected at times of study. Mean age at time of first study = 3.3 wks. Serum Zn and 24 hr. urinary Zn excretion were positively correlated (r=.74 p<.0006). Infants with hypozincemia (serum Zn less than 70μg/dl) generally had urine Zn losses of <130μg/24 hr. Urine Zn concentrations of <100μg/24hr., with a serum Zn of greater than 70μg/dl was an indication of impending hypozincemia. The premature infant is capable of renal conservation of Zn under conditions of actual and impending hypozincemia.Serum Cu and 24hr. urinary Cu excretion were not related (p=.17). Urinary copper excretion, previously shown to be related to increased urinary excretion of glycine and methionine during therapy with Freamine II was markedly reduced with the use of Freamine III and the concommitant reduction in glycine and methionine excretion. Urine Cu excretion averaged <lμg/24hr. and did not contribute significantly to Cu losses.

973 Serum Zn and Cu Concentrations During Infection in the Premature Infant

Serial serum zinc (Zn) and copper (Cu) concentrations were measured in 4 intravenously fed, non-Zn, non-Cu supplemented premature infants all of whom had culture proven bacterial septicemia in the 3rd to 4th weeks of life. (Mean G.A. = 28.7 wks., mean birth wt.=1115gms.). Mean serum Zn and Cu concentrations in the infected group were compared to 9 non-Zn and non-Cu supplemented, age matched, IV nourished controls.The data suggests that the premature infant, similar to the adult, (J Infect Dis 126:77, 1977), is capable of sequesting Zn as a host response to infection from early in gestation. Serum Zn concentrations may be helpful in monitoring onset of infection and adequacy of antibiotic therapy in the newborn. No statistically significant changes in Cu in response to infection were seen.

650 SERUM COPPER AND CERULOPLASMIN IN THE PREMATURE INFANT

Serial serum copper (Cu) and ceruloplasmin (Cerlp) concentrations were followed for an average of 14 weeks in 25 well, growing AGA premature infants (mean GA=30 wks., mean B.W.=1181gms.) fed standard infant formulas.Serum Cu and Cerlp, low at birth, gradually increased over the first 5 months of life. No relationship between Cu intake (μg/kg) and serum Cu concentrations was seen as serum Cu was lowest when intake was highest. The ratio of Cerlp/Cu was constant (x=.28) except for the first 72hrs. of life when the ratio was significantly lower (p=.00007). The data suggests: 1. serum Cu is controlled by factors other than dietary intake; 2. Cerlp production relative to serum Cu increases significantly over the first week of life; 3. Changes in serum Cu are paralleled by proportional changes in Cerlp after the first 72 hrs. of life.