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736 Clinical monitoring of energy expenditure for children with complex heart problems: Implications for nutrition and growth

2011; Elsevier BV; Volume: 27; Issue: 5 Linguagem: Inglês

10.1016/j.cjca.2011.07.609

1916-7075

Patricia E. Longmuir, faith Bangawan, Glenn E. Smith, Jennifer Russell, B.W. McCrindle,

Child Nutrition and Feeding Issues

BackgroundChildren with complex heart problems are at increased risk for delayed growth. Despite improvements in care, an important proportion of these children show decreased height percentile, which may be influenced by long-term caloric imbalance resulting from inadequate caloric intake, increased basal energy requirement, or both (Leitch, 2000). The gold standard for measuring energy expenditure is doubly-labelled water, an invasive procedure that exposes the child to radioisotopes. We sought to evaluate the effectiveness of two protocols for measuring resting energy expenditure in a clinical setting for identifying children at risk of growth delay related to increased energy requirements.MethodsParticipants were 85 children (42 female), 6.0 to 12.8 years, who had repaired tetralogy of Fallot (n = 10), arterial switch for transposition of the great arteries (n = 10), or the Fontan procedure for univentricular heart (n = 65). Resting energy expenditure was assessed by direct measurement of expired O2 and CO2 after the child had been resting supine in a darkened, quiet room. Thirty children were assessed at the end of a clinical echocardiogram (supine 30 minutes or more), and 55 prior to a cardiopulmonary exercise test (supine 5 to 10 minutes). All participants were instructed not to eat within 2 hours prior to the test. The equation of Maffeis et al (1993) was used to predict expected resting energy expenditure based on height, weight and age.ResultsChildren tested following echocardiogram (9.2 ± 2.0yrs) were significantly younger (-1.0 ± 0.4yrs, P = 0.01) than children tested before exercise assessment (10.2 ± 1.7yrs). Both protocols were effective for measuring postprandial resting metabolic rate, with no inter-protocol difference in O2 consumption relative to body weight (diff = 0.2 ± 0.4ml/kg/min, P = 0.61). Energy expenditure was similar at all ages, but was higher for females (diff = 0.4 ± 0.2ml/kg/min, P = 0.04) and children who were taller (diff = 0.6 ± 0.2ml/kg/min, P = 0.01) and lighter weight (diff = 0.8 ± 0.2ml/kg/min, P = 0.001). Higher energy expenditure was associated with lower BMI percentile (diff = 0.02 ± 0.3ml/kg/min per 1-centile, P = 0.04). Measured energy expenditure was significantly higher than predicted values (diff = 2.1 ± 1.9ml/kg/min, P = 0.001). The difference between measured and predicted values increased with lower BMI percentile (diff = -0.02 ± 0.1ml/kg/min per 1-centile, P = 0.01).ConclusionThe measurement of resting energy expenditure during routine clinical assessments, either at echocardiography or cardiopulmonary exercise test, is an effective, non-invasive method of identifying children who may have an increased risk of growth retardation related to elevated resting energy requirements. Measurements at the end of echocardiography assessments may be particularly effective for assessing children too young to perform cardiopulmonary exercise.Heart and Stroke Foundation of Ontario BackgroundChildren with complex heart problems are at increased risk for delayed growth. Despite improvements in care, an important proportion of these children show decreased height percentile, which may be influenced by long-term caloric imbalance resulting from inadequate caloric intake, increased basal energy requirement, or both (Leitch, 2000). The gold standard for measuring energy expenditure is doubly-labelled water, an invasive procedure that exposes the child to radioisotopes. We sought to evaluate the effectiveness of two protocols for measuring resting energy expenditure in a clinical setting for identifying children at risk of growth delay related to increased energy requirements. Children with complex heart problems are at increased risk for delayed growth. Despite improvements in care, an important proportion of these children show decreased height percentile, which may be influenced by long-term caloric imbalance resulting from inadequate caloric intake, increased basal energy requirement, or both (Leitch, 2000). The gold standard for measuring energy expenditure is doubly-labelled water, an invasive procedure that exposes the child to radioisotopes. We sought to evaluate the effectiveness of two protocols for measuring resting energy expenditure in a clinical setting for identifying children at risk of growth delay related to increased energy requirements. MethodsParticipants were 85 children (42 female), 6.0 to 12.8 years, who had repaired tetralogy of Fallot (n = 10), arterial switch for transposition of the great arteries (n = 10), or the Fontan procedure for univentricular heart (n = 65). Resting energy expenditure was assessed by direct measurement of expired O2 and CO2 after the child had been resting supine in a darkened, quiet room. Thirty children were assessed at the end of a clinical echocardiogram (supine 30 minutes or more), and 55 prior to a cardiopulmonary exercise test (supine 5 to 10 minutes). All participants were instructed not to eat within 2 hours prior to the test. The equation of Maffeis et al (1993) was used to predict expected resting energy expenditure based on height, weight and age. Participants were 85 children (42 female), 6.0 to 12.8 years, who had repaired tetralogy of Fallot (n = 10), arterial switch for transposition of the great arteries (n = 10), or the Fontan procedure for univentricular heart (n = 65). Resting energy expenditure was assessed by direct measurement of expired O2 and CO2 after the child had been resting supine in a darkened, quiet room. Thirty children were assessed at the end of a clinical echocardiogram (supine 30 minutes or more), and 55 prior to a cardiopulmonary exercise test (supine 5 to 10 minutes). All participants were instructed not to eat within 2 hours prior to the test. The equation of Maffeis et al (1993) was used to predict expected resting energy expenditure based on height, weight and age. ResultsChildren tested following echocardiogram (9.2 ± 2.0yrs) were significantly younger (-1.0 ± 0.4yrs, P = 0.01) than children tested before exercise assessment (10.2 ± 1.7yrs). Both protocols were effective for measuring postprandial resting metabolic rate, with no inter-protocol difference in O2 consumption relative to body weight (diff = 0.2 ± 0.4ml/kg/min, P = 0.61). Energy expenditure was similar at all ages, but was higher for females (diff = 0.4 ± 0.2ml/kg/min, P = 0.04) and children who were taller (diff = 0.6 ± 0.2ml/kg/min, P = 0.01) and lighter weight (diff = 0.8 ± 0.2ml/kg/min, P = 0.001). Higher energy expenditure was associated with lower BMI percentile (diff = 0.02 ± 0.3ml/kg/min per 1-centile, P = 0.04). Measured energy expenditure was significantly higher than predicted values (diff = 2.1 ± 1.9ml/kg/min, P = 0.001). The difference between measured and predicted values increased with lower BMI percentile (diff = -0.02 ± 0.1ml/kg/min per 1-centile, P = 0.01). Children tested following echocardiogram (9.2 ± 2.0yrs) were significantly younger (-1.0 ± 0.4yrs, P = 0.01) than children tested before exercise assessment (10.2 ± 1.7yrs). Both protocols were effective for measuring postprandial resting metabolic rate, with no inter-protocol difference in O2 consumption relative to body weight (diff = 0.2 ± 0.4ml/kg/min, P = 0.61). Energy expenditure was similar at all ages, but was higher for females (diff = 0.4 ± 0.2ml/kg/min, P = 0.04) and children who were taller (diff = 0.6 ± 0.2ml/kg/min, P = 0.01) and lighter weight (diff = 0.8 ± 0.2ml/kg/min, P = 0.001). Higher energy expenditure was associated with lower BMI percentile (diff = 0.02 ± 0.3ml/kg/min per 1-centile, P = 0.04). Measured energy expenditure was significantly higher than predicted values (diff = 2.1 ± 1.9ml/kg/min, P = 0.001). The difference between measured and predicted values increased with lower BMI percentile (diff = -0.02 ± 0.1ml/kg/min per 1-centile, P = 0.01). ConclusionThe measurement of resting energy expenditure during routine clinical assessments, either at echocardiography or cardiopulmonary exercise test, is an effective, non-invasive method of identifying children who may have an increased risk of growth retardation related to elevated resting energy requirements. Measurements at the end of echocardiography assessments may be particularly effective for assessing children too young to perform cardiopulmonary exercise.Heart and Stroke Foundation of Ontario The measurement of resting energy expenditure during routine clinical assessments, either at echocardiography or cardiopulmonary exercise test, is an effective, non-invasive method of identifying children who may have an increased risk of growth retardation related to elevated resting energy requirements. Measurements at the end of echocardiography assessments may be particularly effective for assessing children too young to perform cardiopulmonary exercise.