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Biomedical subjects

G M Chan

Publications and source records attributed to G M Chan.

58 records · Page 4Linked to original sources
PubMedDate not supplied

Evaluation of transthyretin as a monitor of protein-energy intake in preterm and sick neonatal infants.

In the past, weight and weight gain have been the two parameters used frequently in neonatal units to monitor nutrition among high-risk infants. Our investigation sought to assess how several anthropometric measures (weight, length, head circumference, arm:head circumference ratio, and tricep skinfold) and serum albumin, transthyretin, and transferrin concentrations reflect protein and energy intake. After monitoring 42 preterm and 40 sick infants over 3 consecutive weeks, we found that transthyretin concentration proved the only serum protein which accurately measured energy and protein intakes in less than 1 week from dietary manipulation. Among preterm infants, as protein and energy intakes rose, transthyretin concentration increased significantly (p less than 0.001). Preterm infants ingested 79 +/- 39 kcal/kg/day and 2.04 +/- 1.02 g protein/kg/day at the first assessment point after birth and rose to 103 +/- 34 kcal/kg/day and 2.64 +/- 0.94 g protein/kg/day. Likewise, transthyretin measured 10.83 +/- 3.91 mg/dl at the initial measurement and rose to 14.80 +/- 4.44 at the second measurement time. Although protein intakes measured slightly lower in the sick group, their intakes correlated to transthyretin concentration (assessment time 1, r = 0.39; time 2, r = 0.33; time 3, r = 0.33). Thus, transthyretin concentration in neonatal infants offers a rapid, accurate, and moderately inexpensive way to monitor protein-energy adequacy.

Dietary Proteins↗
PubMedDate not supplied

Patterns of postnatal weight changes in infants with very low and extremely low birth weights.

OBJECTIVE: To describe (1) short-term postnatal weight loss and gain patterns in infants with very low and extremely low birth weights and (2) the variables that may affect these weight change patterns. DESIGN: Descriptive, retrospective review. SETTING: University hospital in the intermountain western United States. SUBJECTS: Sixty-two charts of infants admitted to a university neonatal intensive care unit from July 1990 through November 1992 were reviewed. Infants who weighed 1000 grams or less were categorized as extremely low birth weight (ELBW) and infants weighing 1001 to 1500 grams were categorized as very low birth weight (VLBW). Each group was comprised of 31 infants. Fifty percent of the sample were male, and 50% were female. Eighty-five percent of the sample were Anglo-American, and 15% were non-Anglo-American. MEASURES: Data were collected on a three-part data collection tool and included demographic and treatment variables. RESULTS: A significant difference was found in the maximum percent weight lost between the two groups, with the ELBW group losing a mean of 14.77% of birth weight and the VLBW group losing a mean of 11.35% of birth weight (t = 2.45, p < 0.05). The day the infants reached their nadir weight was significantly different between the two groups. The ELBW group reached their nadir on day of life 7, and the VLBW group reached their nadir on day of life 6 (t = 2.00, p < 0.05). No significant difference was noted in the time to return to birth weight between the two groups, with a mean of 15 days to return to birth weight. Factors associated with postnatal weight changes were intraventricular hemorrhage, use of diuretics and steroids, day of life when nadir weight occurred, and maximum percent of weight lost. Many of the independent variables were significantly interrelated to each other (r = -0.90 to r = 0.91, p < 0.01 to p < 0.001). However, only the variables that correlated with time to return to birth weight were entered into the regression analysis. These variables included number of days diuretics were given before return to birth weight, maximum percent of weight lost, and day of life the infants reached their nadir weight. Number of days diuretics were given before return to birth weight correlated significantly with time to return to birth weight (r = 0.77, F = 26.66, p < 0.0001) although maximum percent of weight lost and day of life the infants reached their nadir weight had a minimal effect. CONCLUSIONS: Further research into the effects of diuretic therapy on weight changes in this population of infants may lead to interventions to minimize the negative effects of diuretics on return to birth weight. In addition, the older growth charts may not be applicable to this population of infants. Generation of new growth charts that provide growth curves based on these data could be useful in developing nutritional therapies that would promote growth and possibly decrease the length of hospital stay for these infants.

Birth Weight↗
PubMedDate not supplied

Neonatal hypocalcemia mechanism of occurrence and management.

Early neonatal hypocalcemia occurs in premature infants, infants with birth asphyxia, and infants of diabetic mothers. Etiological considerations include decreased calcium (Ca) supply, increased endogenous phosphate load, hypomagnesemia, alkali therapy, functional hypoparathyroidism, defects in vitamin D metabolism, and possibly calcitonin excess. Late neonatal hypocalcemia occurs, with malabsorption of magnesium (Mg), increased exogenous phosphate loading, after alkali therapy of diarrheal acidosis, hypoparathyroidism, and vitamin D related disorders. The therapy of hypocalcemia includes oral or iv Ca salts and in the near future, possibly the newly discovered vitamin D metabolites.

Acidosis↗