A randomized, controlled trial of parenteral glutamine in ill, very low birth-weight neonates.

OBJECTIVE: The role of "novel substrates" in neonatal nutrition has generated much interest in recent years. Glutamine has been recognized as a "conditionally essential" amino acid in critically ill adults, particularly for gut and immune function; however, its potential role in the neonate remains unclear. The authors examined the safety and benefits of parenteral glutamine in ill, preterm neonates. DESIGN: Randomized controlled trial. METHODS: Thirty-five ill preterm neonates of <1000 g birth-weight were randomized to receive either glutamine-supplemented parenteral nutrition (PN) (n = 17) or standard PN (n = 18). RESULTS: There were no significant differences in birth-weight, gestational age, male-to-female ratio, or Clinical Risk Index for Babies (CRIB) score between the two groups. During PN there were no significant differences between the groups in white cell count, differential white cell count, blood urea nitrogen, plasma ammonia, lactate, pyruvate, plasma glutamine, or glutamate. The median time to achieving full enteral nutrition (FEN) was shorter in the study group (13 days vs. 21 days, P < 0.05). The number of episodes of culture-positive sepsis or age at discharge did not differ between groups. CONCLUSIONS: Parenteral glutamine appears to be well tolerated and safe in the ill, preterm neonate. It may reduce the time to achieving FEN.

Simultaneous monitoring of gastric and oesophageal pH reveals limitations of conventional oesophageal pH monitoring in milk fed infants.

BACKGROUND: Monitoring oesophageal pH conventionally detects "acid reflux" (pH less than 4). The pH of the gastric contents determines whether or not reflux can be detected. AIM: To monitor gastric and oesophageal pH simultaneously in order to determine the effect of milk feeds on gastric pH and how this would influence interpretation of the oesophageal pH record. METHODS: Milk fed infants for whom oesophageal pH monitoring was requested underwent simultaneous gastric and oesophageal pH monitoring using a dual channel pH probe. RESULTS: Twenty of 24 records were technically satisfactory. Mean reflux index was 1.0%, range 0.0-4.0%. Gastric pH was less than 4 for 24.5% (range 0.6-69.1%) of the total time. The average time the gastric pH was greater than 4 after feeds was 130 minutes (range 29-212 minutes). The corrected reflux index (limited to the time the gastric pH was less than 4) was 2.6% (range 0.0-11.0%). CONCLUSION: The pH of the gastric contents may be greater than 4 for prolonged intervals, during which oesophageal pH monitoring using current criteria cannot detect reflux nor correlate it with clinical events. A low reflux index may reflect prolonged buffering of gastric acidity rather than the absence of reflux.

Unusual site for oesophageal perforation in an extremely low birth weight infant.

UNLABELLED: A male infant born at 26 weeks gestation became unwell at 10 days of age with blood-stained pharyngeal aspirates. The chest radiograph revealed a feeding tube in the right pleural cavity, indicating a perforation of the thoracic oesophagus. The infant had had a chest drain inserted on the right side on two previous occasions. These had been allowed to remain across the mediastinum at the site of the subsequent perforation. The infant was successfully managed conservatively with no long-term sequelae The unusual site of the perforation led us to conclude that pressure necrosis from the drains was a contributing factor in the aetiology. CONCLUSION: Oesophageal perforations in the neonate, in contrast to the adult, can be managed conservatively.

Behavioural adjustment in school of very low birthweight children.

The school-based behavioural adjustment at 7-8 years of a cohort of 243 prematurely born, very low birthweight (< 1501 g) children and their normal birthweight controls is reported. The findings indicate that the children born preterm (both male and female) were rated by their teachers as expressing more behaviour problems than their controls, and were less well adjusted to the school environment. The deficits noted in the preterms applied across the social classes, with no amelioration noted in preterms of higher social class. It is speculated that the problem behaviours reflect a failure in self-regulatory functions.

Tolerance of mixed lipid emulsion in neonates: effect of concentration.

AIMS: To compare the effect of concentration of a mixed lipid emulsion (50:50 medium chain triglyceride/long chain triglyceride) (MCT/LCT) on lipid tolerance in neonates. METHODS: A prospective randomised controlled trial of 75 neonates requiring prolonged parenteral nutrition was conducted in the neonatal intensive care units of the Royal Maternity Hospital, Belfast, and the Waveney Hospital, Ballymena. Thirty eight infants received 10% and 37 20% lipid emulsion. Infants were randomly assigned to groups at the start of parenteral nutrition and studied if they required seven or more days of this. Lipid tolerance was assessed by twice weekly measurements of plasma triglyceride and cholesterol concentrations and weekly measurement of non-esterified fatty acids and beta hydroxy butyrate. Anthropometry was carried out weekly. RESULTS: The mean cholesterol in the 10% group was significantly higher within the first seven days of the study compared with the 20% group (3.5 vs 2.87 mmol/l), and continued to rise over the study period in contrast to the 20% group. A similar pattern was observed with the triglyceride concentrations. There was no significant difference in non-esterified fatty acids, beta hydroxy butyrate, or growth between the two groups. CONCLUSION: Sick neonates show better biochemical tolerance to 20% MCT/LCT emulsion than to 10% emulsion.

Percutaneous central venous catheter use in the very low birth weight neonate.

UNLABELLED: A retrospective study was carried out comparing 61 very low birth weight infants (VLBW) with percutaneous central venous catheters with 92 infants managed with peripheral cannulae. Eighteen infants developed one or more episodes of catheter-associated bacteraemia. In 70% of cases the infection was successfully treated with the line in situ. Logistic regression analysis was performed to examine risk factors for bacteraemia. The duration of intravenous fluids and of intermittent positive pressure ventilation were both significant risks for infection (odds ratios and 95% confidence limits 4.4, 2.7-12.0 and 2.5, 1.0-6.1 respectively), but the presence of a silastic catheter was not an independent risk factor (odds ratio 0.6, 95% confidence limits 0.1-3.0). CONCLUSION: Percutaneous central venous catheters provide a satisfactory means of delivering parenteral nutrition with minimal disturbance to ill VLBW infants.

Granulocyte and granulocyte-macrophage colony-stimulating factors in cord and maternal serum at delivery.

Impaired neutrophil responses contribute to the neonate's increased susceptibility to infection. Because granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) enhance granulocyte and macrophage number and function, their use in the management of neonatal sepsis may be beneficial. Little is known about the endogenous levels of G-CSF and GM-CSF. In adults, raised values for G-CSF, but not GM-CSF, have been demonstrated in patients with infection, and conflicting data has emerged regarding CSF levels in neonates. We have used an ELISA to measure maternal and cord serum G-CSF and GM-CSF at the time of delivery, with gestational age between 25 and 42 wk. In mothers, an inverse linear relationship between gestational age and GM-CSF levels (p = 0.049) was found, but no association with G-CSF levels was observed. In neonates, a quadratic association was found between GM-CSF levels and gestational age (p = 0.019), whereas G-CSF levels showed an inverse linear association (p = 0.015). In addition, an association was found between maternal and cord GM-CSF (p = 0.007) but not G-CSF levels in paired samples. The effect of gestational age on the cytokine levels could not be explained by the white cell count, the absolute neutrophil count, pregnancy-induced hypertension, or the presence of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Power spectral analysis of the electrocardiogram in diabetic children.

In recent years it has been shown that alteration in heart rate variability can be used for the objective assessment of autonomic function in adult diabetic patients. Using a microcomputer based system for on-line monitoring and analysis of heart rate variability by power spectral analysis, 100 children with Type 1 (insulin-dependent) diabetes mellitus were studied. A highly significant negative correlation was identified between heart rate variability and duration of diabetes (r = -0.88, p less than 0.0001). The mean heart rate variability in patients with diabetes of duration 3 years or more was significantly lower in comparison to age-matched control subjects. A highly significant negative correlation was evident between heart rate variability and mean HbA1 in patients with duration of diabetes of 5 years or more. A mean HbA1 over 10% during this period was associated with the greatest reduction in heart rate variability. Serial measurements of heart rate variability in diabetic children may be of predictive value prior to the onset of symptomatic neuropathy.

The social competence of very-low-birthweight children: teacher, peer, and self-perceptions.

Whether very-low birthweight (VLBW less than or equal to 1500 gm) children differ from normal birthweight (NBW greater than 2500 gm) children with respect to social (as opposed to intellectual) competence has been a relatively neglected issue. The social competence at school age of 183 VLBW children was therefore compared with that of 183 NBW children born at the same hospital matched for age, gender, social class, parity, and maternal age. A multi-informant, multidefinitional approach to social competence was adopted involving teacher, (same-gender) peer, and self-ratings of the 366 children's levels of social maladjustment, social skill, and peer acceptance. VLBW children from the upper, middle, and lower social classes received significantly higher mean sadness/unhappiness scores (even with IQ covaried) than their NBW counterparts. Mean scores for the VLBW group were also higher for social withdrawal, and lower for both social skill and peer acceptance. Possible antecedents and consequences of such group differences in affect and sociability are suggested.

Variation in power spectral analysis of the EEG with gestational age.

Power spectral analysis (PSA) of the EEG was studied in healthy term and preterm neonates to establish the normal range with gestational age. Sixty healthy newborn infants from 26 to 41 weeks' gestation had PSA performed at 3 days of age. Five main frequency bands were studied: delta 1 (1 Hz or less), delta 2 (2-3 Hz), theta, alpha, and beta. A significant correlation was shown between absolute power in delta 1 and delta 2 with gestational age. Relative power of each frequency band, calculated as a percentage of the total power in each channel, also correlated with gestational age. A significant quadratic relationship between absolute power in the beta range and gestational age is described for the first time.

Spectral edge frequency of the EEG in healthy neonates and variation with behavioural state.

Spectral edge frequency (SEF) of the EEG was studied in 51 healthy neonates to assess its value as a measure of cerebral maturation. SEF was calculated as the frequency below which 95% of the power in the power spectrum resides. Summated SEF (sSEF) of 4 EEG channels correlated significantly with gestational age (r = 0.83). sSEF varied with behavioural state and with EEG derivation. Intra- and interindividual variability were both greater in preterm compared to term babies. We conclude that SEF is a useful measure of cerebral maturation in the newborn and may have a role in studying stressed newborns.

Power spectral analysis of the EEG of term infants following birth asphyxia.

The aim of this pilot study was to perform power spectral analysis of the EEGs of term infants following birth asphyxia, to establish its value as a prognostic indicator. 16 term infants were studied over an 18-month period. Power spectral analysis was performed on the EEGs of babies with signs of hypoxic-ischaemic encephalopathy at regular intervals during the first five days of life. It showed distinct changes following birth asphyxia, which were related to the eventual outcome of the babies. Absolute power was significantly reduced in the babies with poor outcome compared with those with good outcome, particularly in the delta bands.

Primary medical care in a paediatric accident and emergency department.

The characteristics of a random sample of 853 children who attended the accident and emergency department of the Royal Belfast Hospital for Sick Children were studied prospectively to determine the extent to which the department was being used to provide primary medical care. Direct parent referrals accounted for 69% of all attendances with a further 21% referred by the family doctor. Parental preference and accessibility were the main reasons given for choosing to attend the department with the latter significantly higher among out-of-hours attendances. However, only 37 of the 585 parent referrals had made an attempt to contact the family doctor. Overall, 33.9% of children were felt to be inappropriate attenders, i.e. were neither accident nor emergency cases, and the proportion was highest among the parent-referred groups. The present financial restraints facing the National Health Service make it uneconomical to provide primary medical care at both hospital and community level. However, the level of demand for the accident and emergency department, together with the attitudes of those who attend, make it unlikely that a more rational use of resources will be achieved in the foreseeable future.

Acute effects of instillation of surfactant in severe respiratory distress syndrome.

Doppler ultrasound measurements of pulmonary blood flow in 20 babies with severe respiratory distress syndrome treated in a randomised controlled trial of surfactant replacement showed that the immediate improvement of oxygenation was not associated with a significant increase in pulmonary blood flow. Reduction in ventilator settings and increases in the extent of chest wall movements measured by a cardiorespiratory monitor suggested that the improvement after surfactant had been given was a result of alveolar stabilisation and increased pulmonary compliance. Further simultaneous studies of pulmonary blood flow and pulmonary compliance are needed to confirm these findings.

Do patients understand asthma? A community survey of asthma knowledge.

Four hundred and twenty-one subjects who attended metropolitan pharmacies in Melbourne that were selected at random were surveyed about the characteristics of, and their knowledge about, their asthma. An unexpectedly-high morbidity was found among 232 persons with asthma, who were aged between 16 years and 75 years. Forty per cent of subjects had been hospitalized at least once for asthma and 15% of subjects were taking maintenance corticosteroid agents by mouth. Twenty per cent of subjects currently were smoking cigarettes (15 cigarettes per day on average). When knowledge of asthma was examined by a questionnaire, the median score of questions that were answered correctly was less than 50% of the total. The best knowledge scores were associated with subjects: who had been exposed in the past to information about asthma; who had attended a private medical specialist; who were non-smokers; and who had achieved the highest levels of schooling. Among the serious misconceptions which were evident in the areas of use of medication were: that sustained-release theophylline agents acted quickly during acute attacks of asthma (62% of subjects); that antihistamine agents should be taken as soon as possible during an asthma emergency (72% of subjects); that six inhalations of beclomethasone were advisable during an asthma emergency (49% of subjects); that systemic corticosteroid agents were effective within 20 minutes of administration (87% of subjects); and that deaths of asthma usually were due to precipitous attacks without time for any intervention (73% of subjects). Only 42% of subjects considered that up to six puffs at once of a beta-agonist aerosol for an asthma emergency may be appropriate. The identification of such misconceptions is quite practical during routine consultations. The correction of such misconceptions may improve the morbidity and mortality that is due to asthma.