Early feeding strategies in preterm and critically ill neonates

This two-part article presents feeding strategies for the NICU population over the first several weeks of life. It focuses primarily on the theory and approach to feeding extremely low birth weight (ELBW) infants, but also addresses some issues pertinent to larger, ill infants. The premise for these recommendations is that avoiding early malnutrition in ELBW and ill infants has both short- and long-term benefits. Many practitioners may consider our approach to be somewhat aggressive. In this strategy, total parenteral nutrition (TPN) is initiated in the first hours after birth and is given together with initially small, and then increasing, enteral feedings beginning on the first or second day of life. The role of the TPN is to provide rapid, maximal nutrition and that of the early enteral feedings is to "prime" the gut and stimulate normal gastrointestinal tract activity.

Skinfold caliper and ultrasound assessments of change in the distribution of subcutaneous fat during adolescent pregnancy

OBJECTIVE

This study compares skinfold caliper and sonographic measurements of the amount and distribution of subcutaneous adipose tissue teenagers gain during pregnancy to test three hypotheses: (1) skinfold caliper and sonographic measurements of subcutaneous adiposity are highly correlated in pregnancy; (2) the extent to which the skinfold caliper heads compact the tissues increases during gestation; and (3) skinfold caliper measurements yield a smaller estimate of the amount of subcutaneous adipose tissue gained during gestation than do sonographic measurements.

METHODS

We studied 28 primiparous teenagers at 10.7+/-2.8 and 29.6+/-1.8 weeks gestation. At both study visits subcutaneous adipose tissue thickness was measured at six body sites, first by skinfold caliper and then by ultrasound. Taking the nearly compression-free sonographic measurements as the standard, we quantified the extent to which the skinfold caliper heads compacted the tissues at each measurement site by computing the percentage compression: (mean adipose tissue thickness by ultrasound-(0.5xmean adipose tissue thickness by caliper)/mean adipose tissue thickness by ultrasound)x100. Pearson correlations and paired t-tests were used to compare the skinfold caliper and sonographic measurements.

RESULTS

Hypothesis 1 was supported; the skinfold caliper and sonographic measurements were highly correlated at both study visits. Hypothesis 2 was not supported; between study visits caliper-related tissue compression decreased at measurement sites on the trunk and remained the same at measurement sites on the extremities. Hypothesis 3 was also refuted; the skinfold caliper-derived estimate of the amount of subcutaneous adipose tissue gained on the trunk exceeded the corresponding sonographic determination. As anticipated, the skinfold caliper measurements indicated that adipose tissue was stored more rapidly on the trunk than the extremities, but the opposite pattern emerged when the sonographic measurement technique was used.

CONCLUSIONS

The results of this study challenge the notion that pregnant women store adipose tissue preferentially on the trunk and suggest that pregnancy-related changes in the regional distribution of maternal body fat based on skinfold caliper measurements should be interpreted cautiously.

A comparison of four techniques for measuring central adiposity in postpartum adolescents

OBJECTIVE

To develop a reliable office technique for measuring central body fat in postpartum adolescents, we compared: first, a direct sonographic measurement of visceral adiposity to measurements of visceral and subcutaneous abdominal adiposity by computed tomography (CT); and second, skinfold caliper and sonographic measurements of subcutaneous adipose tissue distribution to CT measurements of visceral and subcutaneous abdominal adiposity.

METHODS

Postpartum adipose tissue distribution was assessed in 15 teenagers by measuring the thickness of the subcutaneous fat at six body sites with skinfold calipers and ultrasound. Visceral adiposity was measured directly by ultrasound and CT. Taking the CT measurements as the standards, Pearson correlations and regression analyses were used to compare ultrasound measurement of visceral adiposity and the skinfold caliper and sonographic measurements of subcutaneous adipose tissue distribution.

RESULTS

All of the adiposity measurements correlated significantly with the two CT measurements. The correlations between the ultrasound and the two CT measurements of abdominal adiposity were weaker than the correlations between the skinfold caliper and the sonographic determinations of subcutaneous adiposity and the two CT measurements of abdominal adiposity. Multivariate analyses identified the sonographic determination of subcutaneous adiposity at the costal site as the best independent predictor of central adiposity.

CONCLUSIONS

The results of this study do not support the validity of ultrasound measurement of visceral adiposity as a measure of central adiposity in postpartum teenagers, but do suggest that sonographic determinations of subcutaneous adiposity could be useful for conducting epidemiological studies of the metabolic sequelae of gestational weight gain in this high-risk population of young women.