Intravenous feeding in infants

The problem of bacterial diarrhoea

The reported incidence of "pathogenic" bacteria, as judged by serotype, in the stools of children with acute diarrhoea has varied from 4 to 33% over the last twenty years. Techniques such as tissue culture provide a means for detecting enterotoxin-producing strains of bacteria, strains which often do not possess "pathogenic" serotypes. "Pathogenicity" requires redefinition, and the aetiological importance of bacteria in diarrhoea is probably considerably greater than previous reports have indicated. Colonization of the bowel by a pathogen will result in structural and/or mucosal abnormalities, and will depend on a series of complex interactions between the external environment, the pathogen, and the host and its resident bacterial flora. Enteropathogenic bacteria may be broadly classified as (i) invasive (e.g. Shigella, Salmonella and some Escherichia coli) which predominantly affect the distal bowel, or (ii) non-invasive (e.g. Vibrio cholerae and E. coli) which affect the proximal bowel. V. cholerae and E. coli elaborate heat-labile enterotoxins which activate adenylate cyclase and induce small intestinal secretion; the secretory effects of heat-stable E. coli and heat-labile Shigella dysenteriae enterotoxins are not accompanied by cyclase activation. The two major complications of acute diarrhoea are (i) hypernatraemic dehydration with its attendant neurological, renal and vascular lesions, and (ii) protracted diarrhoea which may lead to severe malnutrition. Deconjugation of bile salts and colonization of the small bowel with toxigenic strains of E. coli may be important in the pathophysiology of the protracted diarrhoea syndrome. The control of bacterial diarrhoea requires a corrdinated political, educational, social, public health and scientific attack. Bacterial diarrhoea is a major health problem throughout the world, and carries an appreciable morbidity and mortality. This is particularly the case during infancy, and in those developing parts of the world where malnutrition is common. This paper is concerned mainly with acute bacterial diarrhoea, and reviews the problem as a whole.

Rickets in a preterm infant during intravenous alimentation

A preterm baby given intravenous feeding developed severe rickets. Laboratory investigation revealed hypophosphatemia as the main cause of this picture. Recovery was achieved by giving extra phosphorus supplementation. This case demonstrates that conventional infusates do not meet the phosphorus requirement of rapidly growing infants.

Clinical and metabolic consequences of two regimens of total parenteral nutrition in the newborn

The clinical and metabolic effects of two regimens of total parenteral nutrition delivering the same amino-acid (2·8 g/kig per 24 h), fat (4·8 g/kg per 24 h), and glucose (12 g/kg per 24 h) load over 24 hours were studied. The regimens differed in the distribution of the infusate during the 24-hour period. With the continuous regimen (7 infants) all nutrients were infused together at a constant rate, whereas with the sequential regimen (9 infants) the daily doses of Vamin/glucose and Intralipid were infused together, followed by the glucose dose. The infants studied had a mean birthweight of 2·8 kg and mean gestational age of 37·9 weeks. Blood levels of glucose, lactate, pyruvate, 3-hydroxybutyrate, acetoacetate, alanine, glycerol, and insulin were measured longitudinally from day 1 to day 21 of total parenteral nutrition. The 7 infants who received the continuous regimen had blood metabolite levels comparable with those of infants fed enterally, with minor fluctuations. Insulin levels were higher than in enterally-fed infants. The 9 infants who received the sequential regimen had wide fluctuations in alanine, glycerol, insulin, 3-hydroxybutyrate, and acetoacetate levels with high peak levels of ketones at the end of the Vamin/glucose and Intralipid infusion, falling to low levels at the end of the 24-hour cycle. There was a gradual reduction in the peak ketone levels from day 6-8 to day 18-21. Clinically unsuspected hypoglycaemia occurred on 6 occasions in each group of infants. There was no significant difference in the incidence of jaundice or infection between the two groups, and the weight velocity during total parenteral nutrition was similar. Wide fluctuations in the infusion rates of individual substrates should be avoided during total parenteral nutrition in the newborn.

Parenteral nutrition in paediatric practice: a review

The special problems associated with parenteral nutrition in childhood are reviewed. A regime for administration is outlined and specific areas for further research are suggested.

Essential fatty acid deficiency in infants receiving parenteral nutrition

The clinical and biochemical features of essential fatty acid deficiency are described in an infant with gastroschisis who required long-term (6 mo) parenteral nutrition. The deficiency responded to therapy with Intralipid, topical sunflower oil, and breast milk. In a prospective study of three infants with gastroschisis, biochemical essential fatty acid deficiency developed in each during the first week of lipid-free parenteral nutrition; clinical signs of the deficiency were absent. The biochemical features were progressive in the one patient followed for 19 days, and were associated with a decrease in weight gain. Both the deficiency and weight gain were corrected by Intralipid. Biochemical essential fatty acid deficiency did not develop in three other gastroschisis infants who were given prophylactic Intralipid (two patients) or topical sunflower oil (one patient). We conclude that all infants on parenteral nutrition should receive a source of linoleic acid to prevent essential fatty acid deficiency.

Total parenteral nutrition in pediatrics

Parenteral nutrition (p.N.) is indicated whenever oral food intake is partly or completely disturbed. The objective of this type of treatments is to provide the organism with sufficient nutrients and maintain the structure and growth. The supply of an optimum mixture of water, protein, carbohydrates, fats, minerals, vitamins and trace elements is a prerequisite for this. In the following parts of this study the indications for p.N., the technique and requirements for different nutrients, minerals, trace elements and vitamins are presented. A type of amino acid mixture especially prepared for pediatric use is prevented and new results of t.p.N. are discussed. In the following parts of this study the indications for p.N., the technique and practice of the infusion programme, the clinical and laboratory investigation of t.p.N., the complications and their prophylaxis during the p.N. are discussed. The goal of better total parenteral nutrition is approached when dosage, infusion rate, contraindications and the guidelines discussed here are observed. We will, however, continue the work for a further improvement of intravenous nutrition.

Protracted diarrhoea in infancy. Analysis of 82 cases with particular reference to diagnosis and management

Eighty-two cases of protracted diarrhoea in infancy presenting over a 6-year period have been analysed, with particular reference to diagnosis and management. The patients fell into 1 of 2 categories according to whether a specific diagnosis was established or not. A diagnosis (category 1) was established in 59 (72%), the commonest diagnoses being coeliac disease (33-2%), secondary disaccharide intolerance (12-2%), and cows' milk protein intolerance (12-3%). Other diagnoses included primary sucrase-isomaltase deficiency, Shwachman's syndrome, ulcerative colitis, ganglioneuroma, defective opsonization, staphylococcal pneumonia, and Hirschsprung's disease. Despite intensive investigation in diagnosis could not be established in 23 (28%) infants (category 2). Age of onset of symptoms in this group tended to be earlier than in category 1 patients, and 6 (7%) presented with diarrhoea dating from birth. Of particular interest in these 6 patients was the high incidence of associated extraintestinal anomalies, and of sibs who had died after protracted diarrhoea dating from birth. 4 of these 6 infants died, accounting for a mortality of 5% for the whole series. The remaining 17 (21%) patients in category 2 presented at a mean age of 4-9 weeks with a range of 1-18 weeks. All these 17 patients made an excellent response after institution of a chicken-based dietary formula, the details of which are presented. The pathophysiological mechanisms which may be operating in infants with protracted diarrhoea are discussed.

Neonatal brain growth during prolonged intravenous feeding

Little is known about the affects of long-term intravenous nutrition on brain growth and development in low birthweight infants. We report the post-mortem analysis of the brain of an infant born at 32 weeks of gestation who died 10 weeks of continuous intravenous feeding. During this time there was evidence of brain growth while somatic growth was severely restricted. Compared with normal data for brain biochemistry for 42 weeks of gestational age, measurements showed that the brain was small and biochemically immature with the cerebellum and brain stem being particularly affected.

Intravenous feeding of young infants with persistent diarrhoea

42 infants with persistent diarrhoea were fed intravenously using a simplified regime based on Intralipid and an aminoacid, Fructose and ethanol solution. Peripheral veins were used for up to 56 days, and with scalp veins complications were few and minor. The use of arm and leg veins caused more frequent local problems and is not advised. Central venous lines became necessary in 5 infants, and 3 developed septicaemia. The regime was well tolerated with adequate weight gain when intake was adjusted to the infants' needs. Rates of infusion of 1 g Intralipid/kg hourly over 2 hours and up to 1 g fructose/kg hourly over 14 hours did not cause persistent lipaemia (except transiently in 2 infants) nor metabolic acidosis. Infants must be fully rehydrated with correction of acidosis and electrolyte imbalance before starting intravenous feeding, or acidosis and dehydration from osmotic diuresis may occur. Intravenous feeding should be started gradually and cautiously in severely malnourished infants, and should not be used where liver function is abnormal.

Phosphorus depletion in children on long-term total parenteral nutrition

The retention of nitrogen, calcium and phosphorus was studied in nine infants on total parenteral nutrition. The amounts of calcium, nitrogen and phosphorus were varied singly or simultaneously. The results demonstrate close interrelationships in the retention of these three elements. Not only the absolute amount of phosphorus perfused daily but also the amounts of nitrogen and/or calcium perfused simultaneously account for the phosphorus depletion that may lead to severe hypophosphatemia. The decrease in serum phosphorus concentration with a simultaneous fall of urinary phosphorus excretion to undetectable levels and a rise in urinary calcium output to 10 mg/kg/24 hours or more are warning symptoms of phosphorus depletion. Such a complication was observed in our first seven children on total parenteral nutrition. Phosphorus depletion can be prevented by using the following amounts of these elements in the perfusate: per 100 Kcal/kg/24 hours, 400 mg/kg/24 hours of nitrogen, 35 mg/kg/24 hours of calcium and 40 mg/kg/24 hours of phosphorus. With such a technique no phosphorus depletion was observed in any of the 63 subsequent patients whom we treated with total parenteral nutrition for periods varying from 20 days to 9 months.

Utilization of fat emulsion during total parenteral nutrition in children

Tolerance for Intralipid fat emulsion during total parenteral nutrition (PN) was studied in 6 children. The Intralipid dose was monitored by the daily determination of plasma Intralipid levels. Fat removal was investigated at the start of and during the PN period by the intravenous fat tolerance test (IVFTT) and by determining the plasma postheparin lipoprotein lipase (LPL) activity. When the plasma Intralipid levels exceeded a value of 100 mg/100 ml, hyper pre-beta lipoproteinaemia, hypertriglyceridaemia, hypercholesterolaemia and hyperphospholipidaemia appeared. During PN most patients showed marked increases of postheparin LPL. Return to normal values occurred after discontinuation of PN. Maximal LPL activities were found to correlate significantly with total daily caloric intake (r=0.95, 0.05 less than p less than 0.01). The Intralipid elimination constant hardly changed during PN, with the exception of patient 6, who showed a marked increase (from 7 to 22%). Conclusions of this study are as follows: First a high caloric intake during PN leads to a marked increase of postheparin LPL activity. Second, by monitoring plasma Intralipid levels at 100 mg/100 ml approximately, it is possible to adjust the Intralipid dose in order to prevent hyperlipaemia and to take maximal benefit from rising fat tolerance. Thirdly the IVFTT appeared to be of little value to estimate the child's fat elimination capacity.

Total parenteral feeding in infants using peripheral veins

Fifteen infants with life-threatening gastrointestinal anomalies received total parenteral feeding for periods ranging from 10 to 54 days; their ages ranged from one day to 5 months. The solutions were administered through peripheral veins. All patients gained weight during the period of observation and no cases of septicaemia were encountered.

Hyperlactataemia during intravenous feeding in childhood

A recently introduced synthetic amino acid preparation, Aminoplex 5, appeared suitable for use in intravenous feeding in childhood because it has a low sodium concentration and high caloric value, achieved by using sorbitol and ethanol. The effects of a 2-hour infusion of Aminoplex 5 at 5 ml or 10 ml/kg per hr on the concentrations of several blood metabolites and hormones were investigated in 8 children. All the children showed a rise in blood lactate concentration (range of increase 0·23 to 6·72 mmol/l.) and lactate/pyruvate ratio (range of increase 2·5 to 18·0) and a small consistent fall in blood acetoacetate concentration. The effects were dose related. Free blood fructose was shown in 7 children after Aminoplex 5, the only exception being a preterm infant. No significant changes were found in plasma insulin or growth hormone concentrations. We suggest that the use of this preparation should be accompanied by frequent estimations of blood lactate or acid-base status.

Comparison of an oral and an intravenous feeding regimen in the newborn

In a series of neonates undergoing comparable operations which did not affect the alimentary tract, the relative merits of similar oral and intravenous feeding regimens were compared. Metabolic balance studies were performed, together with measurement of plasma and urinary amino acids. Though the clinical response to both regimens was satisfactory, it was found that, in the group fed intravenously, certain of the plasma and urinary amino acids attained concentrations outside normal limits. This was almost certainly due to the nature of the amino acid solution infused.

Minimizing systemic infection during complete parenteral alimentation of small infants

A regimen of parenteral alimentation for infants was designed to eliminate as many factors responsible for infection as possible. The most important features of the feeding regimen were as follows. (1) Infants were fed via indwelling silastic catheters inserted into the superior vena cava or the right atrium by a cutdown operation. (2) The parenteral feeding was fat free to simplify the administration system. Y connectors and 2- or 3-way taps were avoided. (3) Extreme care was taken of junctions within the infusion system. Only certain members of the hospital staff were allowed to break such junctions, e.g. during the changing of packs of solution or of the giving sets. These junctions were sprayed with antibacterial aerosols. (4) The hypertonic solutions of nutrients were prepared in plastic packs, which do not require ventilation. The infusion system was therefore not contaminated by the entry of unsterile outside air. (5) The infused solutions were passed through 0·22 μm millipore filters before entering the patient's blood stream. There was an infection rate of 9% which was less than the 25 to 45% infection rate previously reported during parenteral feeding through indwelling venous catheters, and is also less than that associated with ventriculoatrial shunts for hydrocephalus. There was no case of systemic candidiasis, which is the most frequent and most serious infection associated with parenteral feeding.