Oxygen consumption in infants with heart disease. Relationship to severity of congestive failure, relative weight, and caloric intake

Prevalence and predictive factors of malnutrition in Thai children with congenital heart disease and short-term postoperative growth outcomes

Background: Growth restriction is still a common problem in children with congenital heart disease (CHD). Evidence demonstrates that performing cardiac surgery in appropriate timing may result in better growth outcome. Aim: To investigate prevalence and associated factors of malnutrition in pediatric patients with CHD who underwent cardiac surgery. In addition, post-operative growth outcomes at two weeks following cardiac surgery were also assessed. Methods: A retrospective cohort study was conducted in pediatric patients who underwent cardiac surgery at Chiang Mai University Hospital between January and September 2014. Results: One hundred patients with a median age of 28.5 months (range 14-62 months) were enrolled. Two-third of these patients had at least one form of malnutrition before receiving surgical treatment while wasting, stunting and combined wasting-stunting accounted for 23%, 28%, and 15% of patients, respectively. Multiple logistic regression analysis demonstrated that congestive heart failure-related symptoms were significantly associated with increasing risk of malnutrition (adjusted OR 4.4; 95% CI 1.78-11.26, p = 0.001). Two weeks after hospital discharge, wasting patients with regardless of stunting had significantly improved weight for height (WHZ) and weight for length Z-scores (WLZ) compared to growth parameters at the time of cardiac surgery, p = 0.012 and p < 0.001, respectively. Conclusion: The prevalence of acute and chronic malnutrition in pediatric patients with CHD who underwent cardiac surgery was very high in this study. Children with congestive heart failure had a four-time at risk of undernutrition. In short-term, cardiac surgery may mitigate acute malnutrition of these patients.

Energy Intake and Expenditure in Children With Heart Failure

OBJECTIVES

Up to one third of children with heart failure exhibit growth failure. Limited data exists reporting energy requirements in this population. A study was designed to characterize the energy intake and total daily energy expenditure of children with heart failure using the doubly labeled water method.

DESIGN

Prospective study using doubly labeled water to measure total daily energy expenditure in children with heart failure. Doubly labeled water was administered orally and daily urine samples collected for 10 days. Total daily energy expenditure was compared with historic data from age- and gender-matched healthy population. Anthropometrics and 3-day calorie count were also done.

SETTING

The Cardiovascular Intensive Care Unit and Cardiology ward at Texas Children's Hospital.

PATIENTS

Children with new presentation of heart failure as defined by an ejection fraction less than 35% and requiring inotrope(s) at the time of enrollment.

MEASUREMENTS AND MAIN RESULTS

A total of five children with heart failure were enrolled from 2015 to 2016. All children showed weight-for-length less than mean-for-age. All had depressed myocardial function at enrollment, and all but one demonstrated improvement in ejection fraction at follow-up. Three had energy intake that met or surpassed their total daily energy expenditure, with total daily energy expenditure that measured below historic controls. One infant, despite supplementation, had an energy intake substantially below that of measured total daily energy expenditure and required cardiac transplantation.

CONCLUSIONS

Growth failure in heart failure is likely multifactorial and may be related to suboptimal energy intake secondary to exercise intolerance, malabsorption, and/or end-organ dysfunction due to impaired cardiac output. Doubly labeled water is a feasible method to assess total daily energy expenditure in children with heart failure.

The Impact of Neonatal Illness on Nutritional Requirements-One Size Does Not Fit All

Sick neonates are at high risk for growth failure and poorer neurodevelopment than their healthy counterparts. The etiology of postnatal growth failure in sick infants is likely multi-factorial and includes undernutrition due to the difficulty of feeding them during their illness and instability. Illness also itself induces fundamental changes in cellular metabolism that appear to significantly alter nutritional demand and nutrient handling. Inflammation and physiologic stress play a large role in inducing the catabolic state characteristic of the critically ill newborn infant. Inflammatory and stress responses are critical short-term adaptations to promote survival, but are not conducive to promoting long-term growth and development. Conditions such as sepsis, surgery, necrotizing enterocolitis, chronic lung disease and intrauterine growth restriction and their treatments are characterized by altered energy, protein and micronutrient metabolism that result in nutritional requirements that are different from those of the healthy, growing term or preterm infant.

Energy metabolism in infants with congenital heart disease

Failure to thrive is common in children with congenital heart disease and influences the metabolic response to injury and outcome after corrective cardiac surgery. Energy imbalance is a major contributing factor. However, the published literature is difficult to interpret as studies generally involve small patient numbers with a diverse range of types and severity of cardiac lesions and genetic and/or prenatal factors. The age and time of corrective surgery affects the potential for nutritional recovery. Although the immediate postoperative period is characterized by a hypermetabolic state, low total and resting energy expenditure are reported within 24 h of surgery. After 5 d, resting energy expenditure returns to preoperative levels. Significant improvements in weight and growth occur within months after corrective surgery. However, limited postoperative recovery in nutritional status and growth occurs in infants with a low birth weight, intellectual deficit, or residual malformation. Further studies are needed to inform the timing of corrective cardiac surgery to maximize nutritional outcomes and to identify those infants who may benefit from aggressive preoperative nutrition support.

Primary care in children with congenital heart disease

Congenital heart defects, abnormalities in the structural development of the heart, occur in approximately 1% of live births. With improved detection, diagnosis, medical management, and surgical techniques, the number of children surviving with congenital heart disease is increasing. These children require the same comprehensive primary care as all other children; however, there are certain aspects of primary care that will be affected by the presence of a congenital heart defect. This article attempts to clarify the special considerations regarding growth and nutrition, development, physical activity, immunizations, dental care, use of over-the-counter medications, and perioperative concerns for these children. The unique needs of the cardiac transplant patient are beyond the scope of this article.

Growth, nutrition and energy expenditure in pediatric heart failure

Disturbances in growth are often a consequence of congenital heart disease during infancy and childhood. The magnitude of the growth disturbance is generally related to the anatomical lesion and is most severe in infants and children with congestive heart failure. Presently, surgical repair in this population is often delayed in order to permit increased weight gain. Surgery is preformed when a patient reaches an ideal weight and age, or failure to thrive precludes further waiting. The available data indicate that caloric intake in these infants and children may be nearly adequate for age, but is inadequate to permit normal growth rates. Energy expenditure appears to be significantly elevated in this population relative to that of age-matched infants and children. Therefore, while caloric intake may be appropriate for age, increased energy expenditure leaves the infant or child with congenital heart disease with little energy available for growth. More information is needed on energy intakes and expenditures of specific patient populations, and especially of patients with congestive heart failure, before accurate predictions of their metabolic needs are possible. This knowledge may allow us to better meet the nutritional needs of these populations and decrease the risk of malnutrition and failure to thrive, in turn decreasing surgical risk for these patients.

Somatic growth failure after the Fontan operation

Our study was designed to characterize the patterns of growth, in the medium term, of children with functionally univentricular hearts managed with a hemi-Fontan procedure in infancy, followed by a modified Fontan operation in early childhood. Failure of growth is common in patients with congenital cardiac malformations, and may be related to congestive heart failure and hypoxia. Repair of simple lesions appears to reverse the retardation in growth. Palliation of the functionally single ventricular physiology with a staged Fontan operation reduces the adverse effects of hypoxemia and prolonged ventricular volume overload. The impact of this approach on somatic growth is unknown. Retrospectively, we reviewed the parameters of growth of all children with functionally univentricular hearts followed primarily at our institution who had completed a staged construction of the Fontan circulation between January 1990 and December 1995. Measurements were available on all children prior to surgery, and annually for three years following the Fontan operation. Data was obtained on siblings and parents for comparative purposes. The criterions of eligibility for inclusion were satisfied by 65 patients. The mean Z score for weight was -1.5 +/- 1.2 at the time of the hemi-Fontan operation. Weight improved by the time of completion of the Fontan circulation (-0.91 +/- 0.99), and for the first two years following the Fontan operation, but never normalized. The mean Z scores for height at the hemi-Fontan and Fontan operations were -0.67 +/- 1.1 and -0.89 +/- 1.2 respectively. At most recent follow-up, with a mean age of 6.1 +/- 1.3 years, and a mean time from the Fontan operation of 4.4 +/- 1.4 years, the mean Z score for height was -1.15 +/- 1.2, and was significantly less than comparable Z scores for parents and siblings. In our experience, children with functionally univentricular hearts who have been palliated with a Fontan operation are significantly underweight and shorter than the general population and their siblings.

Increased energy expenditure in infants with cyanotic congenital heart disease

Infants with cyanotic congenital heart disease (CCHD) often have reduced weight gain compared with infants in control groups. Our purpose was to conduct a longitudinal study of energy intake, resting energy expenditure (REE), and total energy expenditure (TEE) of a group of infants with CCHD. We hypothesized that increased REE and TEE and decreased energy intake in these infants would lead to reduced growth. Ten infants with uncorrected CCHD and 12 infants in a control group were studied at 2 weeks of age and again at 3 months. Indirect calorimetry was used to determine REE; the doubly labeled water method was used to determine TEE and intake. At 2 weeks and 3 months of age, infants with CCHD weighed significantly less than infants in the control group. No significant difference was seen in energy intake or REE between groups during either period. TEE was slightly but not statistically increased in the CCHD group at 2 weeks (72.6 +/- 17.4 vs 59.8 +/- 10.9 kcal/kg/d) and significantly increased at 3 months (93.6 +/- 23.3 vs 72.2 +/- 13.2 kcal/kg/d, P </=.03). We conclude that increased TEE but not increased REE is a primary factor in the reduced growth in infants with CCHD.

Total but not resting energy expenditure is increased in infants with ventricular septal defects

OBJECTIVE

The purpose of this study was to determine the effect of left-to-right shunting on the resting energy expenditure (REE), total energy expenditure (TEE), and energy intake in a group of 3- to 5-month-old infants with moderate to large unrepaired ventricular septal defects (VSDs) compared with age-matched, healthy infants.

METHODS

Eight infants with VSDs and 10 healthy controls between 3 to 5 months of age participated in the study. Indirect calorimetry was used to measure REE and the doubly-labeled water method was used to measure TEE and energy intake. An echocardiogram and anthropometric measurements were performed on all study participants. Daily urine samples were collected at home for 7 days. Samples were analyzed by isotope ratio mass spectrometry. Data were compared using analysis of variance.

RESULTS

No significant differences were found in REE (VSD, 42.2 +/- 8.7 kcal/kg/d; control, 43.9 +/- 14.1 kcal/kg/d) or energy intake (VSD, 90.8 +/- 19.9 kcal/kg/d; control, 87.1 +/- 11.7 kcal/kg/d) between the groups. The percent total body water was significantly higher in the VSD infants and the percent fat mass was significantly lower. TEE was 40% higher in the VSD group (VSD, 87.6 +/- 10.8 kcal/kg/d; control, 61.9 +/- 10.3 kcal/kg/d). The difference between TEE and REE, reflecting the energy of activity, was 2.5 times greater in the VSD group.

CONCLUSIONS

REE and energy intake are virtually identical between the two groups. Despite this, infants with VSDs have substantially higher TEE than age-matched healthy infants. The large difference between TEE and REE in VSD infants suggests a substantially elevated energy cost of physical activity in these infants. These results demonstrate that, although infants with VSDs may match the energy intake of healthy infants, they are unable to meet their increased energy demands, resulting in growth retardation.

Assessing the effect of disease on nutrition of the preterm infant

OBJECTIVE

To review existing data on nutritional requirements of extremely low birth weight (ELBW) and very low birth weight (VLBW) preterm infants (those who weigh < 1000 g and 1000-1500 g at birth, respectively), and the effects of diseases on these nutritional requirements.

DATA SOURCES

A literature search was conducted on applicable articles related to nutritional requirements of preterm ELBW and VLBW infants and the effects of diseases in these infants on their nutritional and metabolic requirements.

DATA SYNTHESIS

The literature was analyzed to determine nutritional requirements of preterm ELBW and VLBW infants, to select the most common diseases that have significant and important effects on nutrition and metabolism in these infants, and to make recommendations about diagnostic and therapeutic approaches to nutritional problems as affected by diseases in ELBW and VLBW infants.

CONCLUSIONS

Many diseases unique to preterm infants, either directly or by enhancing the effects of stress on the metabolism of such infants, provide important changes in the nutrient requirements. The overriding observation from all studies, however, is that ELBW and VLBW preterm infants are underfed during the early postnatal period and that this condition, combined with additional stresses from various diseases, increases the risk of long-term neurological sequelae. The value of achieving a specific body composition and growth weight is less certain. There remains a critical need for determining the right quality as well as quantity of nutrients for these infants.

Children with congenital heart disease: a nutrition challenge

Growth in children with congenital heart disease (CHD) is often compromised. For several decades, investigators have tried to identify the factors affecting growth in children with CHD. Cardiac malformations are undoubtedly responsible for malnutrition, which may range from mild undernutrition to severe failure to thrive (FTT). Malnutrition may then significantly undermine the outcome of corrective surgical operations and postoperative recovery. Mechanisms linking CHD to malnutrition may be related either to decreased energy intake and/or to increased energy requirements. Decreased energy intake can involve deficiencies of specific nutrients, or insufficient total caloric intake. Increased respiratory rate accompanying congestive heart failure may be responsible for increased energy requirements. Different types of cardiac malformations and consequent interventions may have different effects on growth and require diverse strategies. Most treatment strategies aim to facilitate "catch-up" growth, providing extra calories and protein that exceed the Recommended Dietary Allowance for age. However, there is no generally accepted set of guidelines that define appropriate caloric intake for catch-up growth. We attempt to identify the most important causes of malnutrition and highlight the most effective nutrition strategies for children with CHD.

Energy expenditure in congenital heart disease

Growth failure is a well recognised consequence of severe congenital heart disease. Total daily energy expenditure (TDEE) was investigated in eight infants with severe congenital heart disease to determine whether an increase in this parameter is an important factor in their failure to thrive, and to estimate the energy intake that would be required to allow normal growth. The infants were studied over a seven day period before surgery using the doubly labelled water method. Growth failure was evident; their mean age standardised body mass index was 80% of the expected value. Mean TDEE was 425 kJ/kg, significantly greater than in healthy infants (mean TDEE/kg SD score = +1.4; 95% confidence interval +0.27 to +2.57). In contrast, their energy intake was only 82% of the estimated average requirements. It was estimated that in early infancy a gross energy intake of 600 kJ/kg/day is required for normal growth in patients with congenital heart disease. This is unlikely to be achieved by energy supplements alone and early recourse to nasogastric feeding should be considered.

Inhaled nitric oxide in congenital heart disease

BACKGROUND

Congenital heart lesions may be complicated by pulmonary arterial smooth muscle hyperplasia, hypertrophy, and hypertension. We assessed whether inhaling low levels of nitric oxide (NO), an endothelium-derived relaxing factor, would produce selective pulmonary vasodilation in pediatric patients with congenital heart disease and pulmonary hypertension. We also compared the pulmonary vasodilator potencies of inhaled NO and oxygen in these patients.

METHODS AND RESULTS

In 10 sequentially presenting, spontaneously breathing patients, we determined whether inhaling 20-80 ppm by volume of NO at inspired oxygen concentrations (FIO2) of 0.21-0.3 and 0.9 would reduce the pulmonary vascular resistance index (Rp). We then compared breathing oxygen with inhaling NO. Inhaling 80 ppm NO at FIO2 0.21-0.3 reduced mean pulmonary artery pressure from 48 +/- 19 to 40 +/- 14 mm Hg and Rp from 658 +/- 421 to 491 +/- 417 dyne.sec.cm-5.m-2 (mean +/- SD, both p < 0.05). Increasing the FIO2 to 0.9 without adding NO did not reduce mean pulmonary artery pressure but reduced Rp and increased the ratio of pulmonary to systemic blood flow (Qp/Qs), primarily by increasing Qp (p < 0.05). Breathing 80 ppm NO at FIO2 0.9 reduced mean pulmonary artery pressure and Rp to the lowest levels and increased Qp and Qp/Qs (all p < 0.05). While breathing at FIO2 0.9, inhalation of 40 ppm NO reduced Rp (p < 0.05); the maximum reduction of Rp occurred while breathing 80 ppm NO. Inhaling 80 ppm NO at FIO2 0.21-0.9 did not alter mean aortic pressure or systemic vascular resistance. Methemoglobin levels were unchanged by breathing up to 80 ppm NO for 30 minutes.

CONCLUSIONS

Inhaled NO is a potent and selective pulmonary vasodilator in pediatric patients with congenital heart disease complicated by pulmonary artery hypertension. Inhaling low levels of NO may provide an important and safe means for evaluating the pulmonary vasodilatory capacity of patients with congenital heart disease without producing systemic vasodilation.

The effects of high-energy feeding on energy balance and growth in infants with congenital heart disease and failure to thrive

Failure to thrive (FTT) in infants with congenital heart disease (CHD) can be attributed to their low energy intakes and high resting energy expenditures. Energy intake, energy expenditure and growth were studied in infants with CHD on normal formula feeds and then on feeds supplemented with glucose polymer to see whether supplementation improved energy retention and growth. Mean gross energy intakes increased by 31.7% on high-energy feeding and mean weight gain improved from 1.3 g/kg per d on control to 5.8 g/kg per d on high-energy feeding. Resting oxygen consumption (VO2 ml/kg per min) was not significantly different on the two feeding regimens, although respiratory quotient rose on high-energy feeding reflecting the increased carbohydrate intake. Estimated energy costs of growth on high-energy feeding fell within the previously described range for normal infants. It is recommended that infants with CHD known to be associated with FTT are fed on high-energy diets from the time of diagnosis in order to optimize growth.

Growth and nutritional intake of infants with congenital heart disease

Poor weight and length gain of infants with congenital heart disease is generally considered to be related to inadequate nutritional intake, but no longitudinal data on growth and nutritional intake of such infants are available. We compared weight, length, subscapular and triceps skinfold thickness, energy and protein intake (24-h dietary intake records) as well as serum prealbumin and albumin of infants with cyanotic heart disease (n = 8) or isolated left-to-right shunt (n = 8) with those of healthy infants aged (n = 8) 45-365 days. Weight, length, and combined (subscapular and triceps) skinfold thickness of the two groups with congenital heart disease (CHD) were significantly less from 183 through 365 days of age. However, energy and protein intake was similar to that of the control group from 45 through 365 days of age. Normal serum prealbumin and albumin in the infants with CHD ruled out protein-calorie malnutrition. It is concluded that a low level of food intake was not the main cause of inadequate growth and of small subcutaneous fat stores in these two small, but homogeneous, groups of infants with CHD.

Mechanism of decreased forward stroke volume in children and swine with ventricular septal defect and failure to thrive

Children with ventricular septal defect (VSD) often demonstrate failure to thrive (FTT). Such patients usually have reduced systemic cardiac output which has been postulated as a cause for their growth retardation. This study was conducted to ascertain the mechanism of the reduced cardiac output in children with VSD and FTT and also in a porcine model of VSD. Forward stroke volume was reduced in VSD-FTT children, 31 +/- 8 ml/m2, compared to normal children, 49 +/- 15 ml/m2 (P less than 0.05), but was not reduced in children with VSD and normal growth and development (41 +/- 16 ml/m2). Forward stroke volume was also reduced in swine with VSD compared to controls. Contractility assessed by mean velocity of circumferential shortening (Vcf) corrected for afterload was similar in normals and VSD-FTT children. Contractile performance was also similar in normal and VSD swine. Afterload assessed as systolic stress was similar in FTT-VSD children and normal subjects. Preload assessed as end-diastolic stress was increased in the VSD-FTT group. End-diastolic volume was not larger in the VSD-FTT group. We conclude that the reduced stroke volume seen in VSD-FTT children and VSD-swine was not due to reduced contractility, increased afterload or reduced preload. The reduced stroke volume may have been due to failure of end-diastolic volume to increase adequately.

Erythropoietin in cyanotic heart disease

We hypothesized that children with cyanotic congenital heart disease and moderate hypoxemia, as a result of erythrocytosis, and adequate iron stores would have low serum erythropoietin titers, low tissue oxygen delivery, and normal red cell 2,3-diphosphoglycerate (DPG) concentrations. We assessed hemoglobin levels, aortic oxygen saturation, iron stores, red cell 2,3-DPG, oxygen consumption, and systemic O2 transport in 19 hypoxemic patients, aged 3 months to 8 years. Low erythropoietin titers (less than 30 mU/dl) were found in 14 patients. Patients with high erythropoietin titers had lower Pao2 (36 +/- 7 vs 49 +/- 7 mm Hg, p less than 0.01), lower aortic saturation (68 +/- 12 vs 81 +/- 9%, p less than 0.01), and higher red cell 2,3-DPG (2.47 +/- 0.34 vs 3.23 +/- 0.73 mumol/ml, p less than 0.01). Aortic oxygen saturation higher than 80% was associated with a low erythropoietin titer and a hemoglobin level below that associated with hyperviscosity. The relationship between aortic oxygen saturation and hemoglobin concentration was strong (r = 0.77). These data suggest that for children less than 8 years of age, adequate compensation for moderate hypoxemia can occur with moderate increases in hemoglobin levels.

Food, growth and congenital heart disease

The effect of congenital heart disease on growth is reviewed. Whether being small matters is questioned, and reasons why infants with congenital heart disease are small are discussed. Methods of improving growth, and catch-up growth are described. Finally management of the child with CHD and failure to thrive is considered.

Cardiac surgery in the first year of life: the effect on weight gains of infants with congenital heart disease

Forty-seven infants with ventricular septal defect (n = 17), tetralogy of Fallot (n = 7) and transposition of the great arteries (n = 23) who had 'corrective' surgery in the first year of life were reviewed with respect to birthweight and pre- and postoperative growth. The mean birthweight for each group was below that of the standard population. There was an overall decrease in growth velocity pre-operatively which was reversed after surgery. At follow up, 12-18 months later (means), most infants had regained at least their birthweight percentile, while the group with ventricular septal defect exceeded it. Consideration is given to the pathophysiological mechanisms contributing to these observations.

Why does congenital heart disease cause failure to thrive?

Metabolisable energy intake, determined by bomb calorimetry of food, vomit, stool and urine, and resting metabolism, assessed by respiratory gas exchange, were studied in 21 infants with congenital heart disease and nine control infants. Weight for age, growth rates, and daily metabolisable energy intake per kg tended to be lower in infants with heart disease than in control infants. Resting oxygen consumption was high in those infants with pulmonary hypertension and persistent cardiac failure. Energy intake, as a percentage of that recommended for age, correlated with weight gain, and resting oxygen consumption correlated inversely with both percentage body mass index and relative fatness. Failure to thrive in infants with congenital heart disease may be due to a combination of low energy intakes and, in some cases, high energy requirements allowing insufficient energy for normal growth. Increasing the energy intakes of infants with congenital heart disease may be a way of improving their growth.

The interface between primary care and pediatric cardiology

Pediatricians and family practitioners share responsibility with pediatric cardiologists for providing these patients with comprehensive medical services. This article serves as a resource for primary care physicians when questions concerning the care of children with heart disease arise. Considered are questions on growth, development, infectious disease, psychosocial issues, pharmacology, contraception and pregnancy, genetic counseling, school, travel, minor surgery, and financial considerations.

Influence of postnatal age, energy intake, and weight gain on energy metabolism in the very low-birth-weight infant

The relative importance and interrelationship of postnatal age, energy intake, and weight gain on metabolic rate is evaluated in 28 studies in 13 formula-fed very low-birth-weight AGA infants. The relationships between metabolic rate, energy intake, weight gain, and age all follow a similar pattern, increasing in the first two weeks of life and subsequently stabilizing. Significant linear correlations are demonstrated between metabolic rate and both energy intake (r = 0.88, P less than 0.001) and weight gain (r = 0.86, P less than 0.001). For each gram of weight gain, 0.67 kcal (2.8 kj) are expended in addition to the maintenance energy requirement of 51 kcal/kg/day. The increase in metabolic rate in the early postnatal period appears to be a consequence of the energy cost of tissue synthesis. Changes in metabolic rate with postnatal age are modulated by increasing energy intake and weight gain.

Gastric emptying in infants with congenital heart disease

Gastric emptying of infant formula using a marker dilution technique was studied in 8 infants with congenital heart disease aged 1 week to 5 months. Six infants were in heart failure and 4 failed to grow. Gastric emptying followed a linear pattern in 5 and a biphasic pattern with an initial slow phase in 2 infants. The amounts of meal emptied after 1 and 2 hours, 14.7 and 31.0 ml per 0.1 m2 of body surface area, respectively, were significantly smaller than the corresponding amounts found in a group of healthy infants.

Lung biopsy in congenital heart disease: a morphometric approach to pulmonary vascular disease

Fifty patients with congenital heart disease, ages 2 days-30 years (median 12 months) at cardiac surgery, underwent lung biopsy to assess pulmonary vascular disease (PVD). Twenty-six had ventricular septal defects (VSD), 17 d-transposition of the great arteries (D-TGA), and seven, defects of the atrioventricular canal (AVC). Quantitative morphologic data was correlated with hemodynamic data. Three new grades of PVD were observed. Abnormal extension of muscle into peripheral arteries (grade A) was found in all patients; all had increased pulmonary blood flow. In addition, 38 of 50 patients had an increase in percentage arterial wall thickness (grade B); this correlated with elevation in pulmonary artery (PA) pressure (r = 0.59). Another 10 of 50 patients had, in addition to A and B, a reduction in the number of small arteries (grade C); nine of 10 were patients with elevated PA resistance greater than 3.5 mu/m2 (P less than 0.005). All three patients with Heath-Edwards changes of grade III or worse also had grade C. Reduction in peripheral arterial number probably precedes obliterative PVD and may identify those patients in whom, despite corrective surgery, PVD will progress.

Intestinal function in infants with severe congenital heart disease

We evaluated digestive tract function in 21 young infants with severe congenital heart disease. One group had congestive heart failure and ventricular septal defect or single ventricle; the other had cyanosis and transposition of the great arteries. Enteric protein loss was excessive in eight patients, and steatorrhea was found in five. These abnormalities were mild and not related to the type or severity of the cardiac lesion. Available evidence points to a need of these babies for calories in excess of normal requirements for weight. The present study suggests that in designing dietary regimens for these very sick patients, their potential for defective gastrointestinal function must be considered. Because no consistent pattern of abnormalities in apparent, each patient who fails to thrive may deserve gastroenterologic evaluation.

Growth after surgical repair of simple D-transposition of the great arteries

The effect of the Mustard procedure on growth was assesed in 45 patients with simple D-transposition of the great arteries (DTGA) surviving for at least one year after operation. Growth failure (below the third percentile for height, weight, or both) was found in 25 of the 45 patients preoperatively and in 8 patients postoperatively. The principal factors associated with poor growth before repair were advancing age, increased pulmonary and systemic flow, and subpulmonic stenosis. In those patients without postoperative growth failure, growth had returned to the normal range within two years. All patients wit retarded growth after the Mustard procedure had had preoperative growth failure as well. In addition, all 8 patients with postoperative growth failure had one or more amjor residual hemodynamic abnormalities, whereas residual lesions were present in only 10 of 37 patients with normal postoperative growth.

Nutritional management of the chronically ill child. Congenital heart disease and myelomeningocele

We have presented some of the nutritional complications encountered in two major pediatric congenital disorders. Although these conditions represent two more common major defects, it is unlikely that many health care providers will manage large numbers of these patients. Nevertheless, the nutrition principles apply to other nutritional dilemmas of chronically ill children. When an infant consumes a low volume intake, regardless of etiology, concerns such as provision of adequate nutrition, within the confines of the infant's water balance, become paramount. Methods have been discussed for increasing caloric density and for monitoring dietary safety and adequacy. When an infant has a propensity for becoming obese one needs to consider preventive measures such as providing sound nutrition information, support, and follow-up for both patient and family. Nutritional problems can become magnified unless adequate support is provided for total health and social needs of the family. The role of the dietitian must be one active participation within the the framework of an interdisciplianry team so that appropriate innovative nutrition programs can be developed and implemented.

Open-heart experience in infants using normothermia and deep hypothermia

During the 9-year period from 1967 through 1975, 124 open-heart operations were performed on infants less than 1 year of age with 35 operative deaths (28%). Ninety-seven of these procedures used continuous cardiopulmonary bypass with normothermia or mild hypothermia, and 27 were done under deep hypothermia and circulatory arrest. Mortality and morbidity were similar regardless of the operative technique, although deep hypothermia facilitated the repair of complex lesions. The highest mortality occurred in infants less than 3 months of age. Respiratory insufficiency, usually requiring prolonged ventilatory support, occurred only among infants who had pulmonary overcirculation or congestion prior to operation. Adequacy of intraoperative repair and postoperative care were the major determinants of survival.

Oxygen consumption and evaporative water loss in infants with congenital heart disease

The relation between environmental temperature, heat production, oxygen consumption, and evaporative water loss was studied in 67 infants with congenital heart disease. The majority of the cyanosed infants had a low minimum oxygen consumption, a low evaporative water loss, and a diminished metabolic response to cold stress. Minimum oxygen consumption and evaporative water loss rose in 6 of these infants after the construction of a surgical shunt. Many of the ill acyanotic infants had an abnormally high minimum oxygen consumption, and those in cardiac failure often continued to sweat in an environment below the thermoneutral temperature zone.

Metabolic rate of neonates with congenital heart disease

Seven infants under one month of age with controlled congestive heart failure showed a mean oxygen consumption of 9-4 +/- 1-6 SD ml/kg per min, a mean respiratory quotient of 0-71 +/- 0-05 SD, and a mean metabolic rate of 63 +/- 12 SD cal/kg per 24 h. This compares with a group of infants with congenital heart disease not in heart failure with Vo2 of 6-5 +/- 1-2 SD ml/min per kg, respiratory quotient of 0-80 +/- 0-11 SD, and basal metabolic rate of 45 +/- 8 SD cal/kg per 24 h. These differences are significant (P less than 0.001). The findings of a greater metabolic rate associated with congestive heart failure are thus extended to the newborn period.