"Minitouch" treatment of very low-birth-weight infants.

In a cohort study with historical controls of non-asphyxiated very low-birth-weight infants (birth weight < or = 1500 g and gestational age < 33 completed weeks), we evaluated the use of a "minitouch" regime for stabilization after birth and treatment of respiratory distress. This combination of early (prophylactic) treatment with nasal continuous positive airway pressure and minimal handling was introduced as a routine in our Department in 1986. We compared infants born in 1987 and in 1985, when ventilator treatment was used initially in all infants with progressing respiratory distress. The frequency of mechanical ventilation was reduced significantly from 76% in 1985 to 35% in 1987 (p = 0.00001). This reduction reflected the smaller number of infants who received ventilator treatment for less than one week, whereas the frequency of long-term ventilator treatment remained unchanged. Intracranial haemorrhage grade II-IV was reduced from 49% in 1985 to 25% in 1987 (p = 0.01). Mortality rate, average duration of hospitalization, number of infants with pneumothorax, patent ductus arteriosus, need for oxygen at 28 days and number of surviving infants with handicap did not differ significantly between the two study periods. Septicaemia was diagnosed in 16% of the infants in 1987 versus 7% in 1985 (p = 0.045). This difference coincided with an increased use of total parenteral nutrition (18% in 1987 versus 3% in 1985, p = 0.007). We conclude that the minitouch regime prevents progression of respiratory distress, reduces the need for ventilator treatment and is a safe and convenient alternative to mechanical ventilation in preterm infants with mild respiratory problems.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzymuria in neonates receiving continuous intravenous infusion of gentamicin.

Urinary excretion of the tubular enzymes NAG and AAP was investigated during gentamicin treatment of 105 newborn infants. The values found for NAG and AAP show a significant positive correlation. The urinary excretion of NAG was on the average 92% higher during gentamicin treatment as compared with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP as an index of nephrotoxicity. The changes in NAg and AAP within treatment periods were studied. During gentamicin treatment an insignificant average increase in the urinary excretion of NAG occurred, whereas a significant decrease was found during non-treatment periods. A significant negative correlation was found between urinary excretion of NAG and birth weight/gestational age. The long-term effect of the higher excretion of NAG and AAP in newborn and adult patients during aminoglycoside treatment is unknown.

Vitamin K to neonates. Peroral versus intramuscular administration.

In a randomized study of 300 infants, the effect of 1 mg of peroral vitamin K given at birth was compared to the same dose given as an intramuscular injection. The combined activity of coagulation factor II + VII + X taken after 48 and before 72 hours after delivery served as the primary endpoint. Prothrombin (antigen) and PIVKA II (acarboxyprothrombin) were also measured. All infants were observed for events of bleeding until discharge from the hospital, normally on the fifth day. No significant differences between the groups in any of the biochemical markers were observed. The 95% confidence limits of the differences were very narrow for all factors. No cases of bleeding were observed. We conclude that administration of 1 mg peroral vitamin K is as efficient as intramuscular administration of the same dose in the prevention of classical hemorrhagic disease of the newborn.

[Recommendations for clinical-chemical departments: lipid-lipoprotein analysis]. / Rekommandationer for klinisk-kemiske afdelinger: lipid- og lipoproteinanalyser.

The section for preventive cardiology within the Danish Society for Cardiology has established a lipid group with representatives from The Danish Society for Clinical Chemistry, The Danish Society for Internal Medicine, The Danish Society for Cardiology, The Danish Society of Hypertension, The Danish College of General Practitioners, and The Danish Paediatric Society. The lipid group has elaborated recommendations for clinical chemical departments regarding lipid and lipoprotein analyses. The group suggests that doctors ordering lipid and lipoprotein analyses are offered the following: S-Cholesterol (total), substance conc., (fPt)S-Triglycerides, substance conc., S-HDL-cholesterol, substance conc., and (fPt)S-LDL-cholesterol, substance conc. (calculated). It is recommended that the biological variation be minimized by sampling in a sitting position after a 15 minutes' rest and by basing the clinical decision on a minimum of 2-3 determinations with an interval of about one month. The analytical variations should be reduced to below 3% (calculated as the variation coefficient), and it is recommended that laboratories participate in external quality control systems at least four times annually by reporting at least two human reference materials with different concentrations. As the use of reference intervals dependent on age and sex, based on random samplings of the background population, are less informative, it is recommended to refer to cutoff values for the clinical decision. The following cutoff values are recommended: S-Cholesterol (total), substance conc.: 6 mmol/l, (fPt)S-Triglycerides, substance conc.; 2.5 mmol/l, S-HDL-cholesterol, substance conc.: 0.9 mmol/l (fPt)-LDL-cholesterol, substance conc. (calculated): 4.5 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral blood flow reactivity in spontaneously breathing, preterm infants shortly after birth.

In 18 spontaneously breathing, preterm infants (mean gestational age 30.3 weeks) cerebral blood flow (CBF) was investigated twice, 2 and 3 hours after birth when spontaneous changes in arterial carbon dioxide tension (PaCO2) and mean arterial blood pressure (MABP) were expected. Transcutaneous oxygen tension (TcO2) was kept normal by adjusting the inspiratory oxygen fraction. In 12 infants, plasma adrenaline and noradrenaline were constant throughout the study. Changes in CBF infinity (CBF infinity) were significantly related to changes in PaCO2 (p = 0.0001) whereas neither changes in MABP nor TcO2 reached a significant association to changes in CBF infinity (p = 0.67 and p = 1.0, respectively). The calculated CBF infinity -CO2 reactivity of 28.9% per kPa PaCO2 (95% confidence interval 16.1-43.0) is comparable to findings in older newborns and healthy adults. Only one of 18 infants developed germinal layer haemorrhage (grade I) in spite of the hypercapnic state which was observed during the first hours of life. Periventricular leucomalacia was not detected. It is suggested that the cerebral blood flow is well regulated within physiological variations of PaCO2 and MABP in the healthy, preterm newborn even shortly after birth.

Auditory function after continuous infusion of gentamicin to high-risk newborns.

Audiometry was performed at four years of age in 69 of 105 surviving children who had received continuous intravenous infusion of gentamicin during neonatal intensive care. A hearing loss of 20 dB was found in 2 of them (3%), corresponding to that shown in other studies of survivors following neonatal intensive care. Free field audiometry performed in another 7 children and questionnaires returned from 13 of the remaining 29 gave no suspicion of hearing loss. Thus there is no indication that continuous 24 hours intravenous infusion of gentamicin causes more hearing impairment than intermittent intravenous or intramuscular administration.

[Parental reactions after the death of their newborn infant]. / Reaktioner hos foraeldre der har mistet et nyfødt barn.

A questionnaire was sent to the parents of 57 infants who died in 1985 while hospitalized in the Neonatal Department, Rigshospitalet. These questionnaires were sent 10-22 months after the death of the infant. 76% reacted to this contact. Information was obtained about how the parents experienced the immediate situation on the death of the infant, how the practical problems were solved, how follow-up and supportive measures were given and how this loss influenced marital relationships. Proposals are given as to how hospital staff can support parents by providing adequate practical advice, establishing contact with supportive persons outside hospital and establishing well-structured offers of talks in the hospital during the first weeks after the death of the infant and again in the case of a new pregnancy. Midwives, doctors and nurses should be particularly aware of the problems which these parents experience in subsequent pregnancies and deliveries.

Flavobacterium meningosepticum infection in a neonatal ward.

An outbreak of infections due to Flavobacterium meningosepticum type C in a neonatal intensive care unit is described. During a period of two weeks, two infants developed meningitis and a third was colonized in the respiratory tract and had transient bacteremia. The two meningitis patients were treated with clindamycin, rifampicin and cefotaxime systemically, plus rifampicin intraventricularly. Bacteriological eradication was achieved within 48 h, and both infants recovered from the meningitis without apparent neurological sequelae; however, one infant died two months later of unrelated causes. Environmental surveillance cultures failed to demonstrate a reservoir for the epidemic strain, but other Flavobacterium strains were recovered. Two clinically healthy infants were found to be colonized in the nasopharynx with strains that were extremely difficult to differentiate phenotypically from the epidemic strain. Extensive characterization of strains is necessary in order to differentiate between strains and subsequently to determine a certain source of infection.

Simultaneous quantification by double rocket immunoelectrophoresis of apolipoproteins A-I and B in blood spotted on filter paper.

We describe double rocket immunoelectrophoresis for simultaneous quantification of apolipoprotein A-I (apo A-I) and B (apo B) in blood on filter paper. The apolipoproteins from blood spots on filter paper were eluted with detergents (sodium dodecyl sulfate and Triton X-100). The eluates were subjected to electrophoresis on agarose gel containing antisera against both apolipoproteins. Within- and between-assay CVs for apo B/A-I ratios were less than 5.5% and 7.2%, respectively. The apo B/A-I ratio was influenced by length and temperature of storage. In results for 121 venous blood samples, the apo B/A-I ratios in dried blood spots correlated well with those in serum (r = 0.92) and correlated somewhat with the ratios for low-density lipoprotein/high-density lipoprotein cholesterol in serum (r = 0.87). Of these specimens, 68 were from patients with known familial hypercholesterolemia, all of whom had an apo B/A-I ratio greater than 0.90. We think this method will be of value for detecting familial hypercholesterolemia and possibly familial hyperapobeta- and hypoalphalipoproteinemia.

Stability of ampicillin, piperacillin, cefotaxime, netilmicin and amikacin in an L-amino acid solution prepared for total parenteral nutrition of newborn infants.

The stability of ampicillin, piperacillin and cefotaxime, alone or in combination with either netilmicin or amikacin, was tested by microbiological methods at 29 degrees C (ampicillin, also at 22 degrees C) in an L-amino acid solution specially prepared for newborn infants. In the case of ampicillin, the mean concentration had dropped to 84% of the initial value after 24 hours. This fall is acceptable. Piperacillin and cefotaxime were stable. Admixture of netilmicin or amikacin did not affect the activity of ampicillin, piperacillin and cefotaxime. The concentrations of netilmicin and amikacin were stable for 24 hours. Combination with ampicillin, piperacillin or cefotaxime did not affect the activity of either aminoglycoside. The antibiotics investigated could therefore be used in our TPN infusion system.

Ontogeny of glucose homeostasis in low birth weight infants.

Suppression of the endogenous glucose production rate (Ra) is the adult response to glucose infusion. Persistent Ra (greater than or equal to 1 mg.kg-1min-1 or less than 80% decrease in basal Ra) in response to glucose infusion is evidence of a transitional homeostatic state in the neonate during the first days after birth. To determine whether postnatal development produces an adultlike response, Ra was measured in 11 infants (birth weight 1716 +/- 48 g, gestational age 33 +/- 0.3 weeks) at 2 to 5 weeks of age. In these paired studies, 4 micrograms.kg-1min-1 D-(U-13C)glucose tracer was infused by prime constant infusion to determine Ra, during infusion of either saline solution or glucose, the latter at a rate of 5.3 +/- 0.2 mg.kg-1min-1 (mean +/- SEM). When the results of the saline infusion turnover period were compared with those of the glucose infusion turnover period, plasma glucose concentration increased significantly, from 88 +/- 3 mg/dL to 101 +/- 4 mg/dL (P less than 0.001). Plasma insulin concentration remained unchanged (12 +/- 5 microU/mL vs 8 +/- 3 microU/mL). Ra was heterogenous during glucose infusion, and persistent Ra was present in six of 11 infants. Of the five infants who had decreased Ra during glucose infusion, three received glucose at a rate exceeding basal Ra. Of the remaining six infants who evidenced persistent Ra during glucose infusion, three received glucose at a rate equal to or in excess of basal Ra. We conclude that glucose homeostasis in low birth weight infants is transitional throughout the neonatal period.

A new micromethod for routine measurement of serum LDL-apolipoprotein B.

A new method for low density lipoprotein (LDL) (d 1.019-1.063 g/ml)-apolipoprotein B (apoB) determination has been developed, based on the fact that very low density and intermediate density lipoproteins (VLDL and IDL) contain apolipoprotein C-I (apoC-I), whereas this apolipoprotein is apparently absent in LDL. VLDL and IDL were quantitatively precipitated with a monospecific anti-apoC-I antibody whereafter LDL-apoB in the supernatant was quantitated by Laurell rocket electrophoresis. Over a wide range of cholesterol and triglyceride values there was a linear correlation with LDL-apoB values measured after ultracentrifugation. The method would be useful for routine measurements, especially in children, since only 25 microliter of serum is required, and for making the diagnosis of hyperapobetalipoproteinemia, which at present is complicated.

Fatty acid composition of subcutaneous adipose tissue in mother-infant pairs.

The fatty acid composition of microsamples from 10 AGA term, 8 SGA term, 7 AGA preterm and 4 SGA preterm, 2-4 day old infants and their mothers were analyzed. In AGA preterm newborns the mean percent of palmitic and stearic acid was lower and the mean percent of linoleic acid was higher than in AGA term infants indicating that there is an increase in fatty acids derived by synthesis from glucose throughout gestation. SGA infants had relative amounts of palmitic and stearic acid similar to what was found in AGA term infants. This indicates that the enzymes involved in synthesis of fatty acids from glucose are intact in intrauterine growth retardation (IUGR). The absolute amount of adipose tissue and fatty acids, however, is smaller in SGA infants due to a reduced availability of glucose in IUGR gestation. No differences were found in the fatty acid composition of subcutaneous adipose tissue from the mothers in the 4 groups. All mothers had a lower mean percent of palmitic and stearic acid and a higher mean percent of oleic and linoleic acid than their infants, ensuring a transplacental gradient to the fetus of this latter essential fatty acid. The fatty acid composition of plasma free fatty acids generally reflected the composition of the subcutaneous adipose tissue in the infants.

The influence of sampling site and time upon umbilical cord blood acid-base status and PO2 in the newborn infant.

Measurement of umbilical cord blood acid-base status is routinely carried out in many obstetric centers. Umbilical cord blood pH, PO2, PCO2 and SBE (standard base excess) may change between clamping of the cord and analysis due to diffusion and metabolism. It was the aim of this study to evaluate these changes separately in artery and vein blood during storage in the clamped umbilical cord. The umbilical cords from 11 normal term deliveries were clamped immediately after delivery and kept at room temperature. Samples of artery and vein blood were drawned separately 1, 5, 10, 15 and 30 minutes post partum and pH, PO2 and PCO2 were measured and SBE calculated. As demonstrated in table I, the vein blood pH and PO2 values were higher and PCO2 values lower than in the artery blood. The changes over time are given in figure 1 with the 1 min values as points of reference. Changes within the first 15 minutes were modest. A significant fall in vein pH, vein SBE and artery PO2 and a significant rise in artery PCO2 was found. Greater variation in the changes over time was found in artery than in vein blood, being most evident for the 30 min values. Although significant changes in the umbilical cord acid-base values and PO2 do occur when the blood is stored in the clamped cord, we find these changes to be minor and we conclude that sampling can be postponed for up to 15 minutes after delivery.