Effect of uncomplicated pregnancy on body water content and distribution in baboons.

Body water content and distribution were estimated before, during, or after 32 pregnancies in baboons. Water content of the various compartments (in liters) correlated with body weight in both nonpregnant and pregnant baboons, and with length of gestation in pregnant baboons. In proportion to body weight (in ml/kg), most water compartments did not change significantly with length of gestation. Mean plasma volume and blood volume were higher during pregnancy than before or after.

Tolerance of fat emulsions in very-low-birth-weight neonates.

Fluid and energy intakes and plasma concentrations of various lipid fractions were studied in 45 newborn infants, weighing between 820 and 1550 g, randomly assigned to one of three regimens for infusion of a fat emulsion: group 1, stepwise increase in daily dosage (1 to 4 g/kg) at a steady rate over 24 hours; group 2, stepwise increase in daily dosage (1 to 4 g/kg) at a steady rate over 16 hours, followed by a rest period of eight hours; and group 3, full dosage (4 g/kg) at a steady rate over 24 hours. At a given daily rate of infusion, mean plasma concentrations of the various lipid fractions tended to be higher in group 2 than in either group 1 or group 3. Plasma lipid concentrations correlated best with the hourly rate of lipid infusion, regardless of whether the infusion was continuous over 24 hours or intermittent.

Tolerance of fat emulsions in very-low-birthweight neonates. Monitoring of plasma lipid concentrations.

Tolerance to parenterally administered fat emulsions was studied in 45 normally grown neonates ranging from 820 to 1550 gm in birthweight, from 27 to 34 weeks in gestational age, and from 2 to 10 days postnatal age. Concentrations of total lipids, free glycerol, true triglycerides, free fatty acids, and cholesterol in plasma were studied over an 8-day period. The aim was to determine whether the concentrations of any one lipid fraction could be used to predict those of other fractions. With 650 pairs of data being correlated, the best correlation coefficients were obtained between total lipids and triglycerides (r = 0.67), total lipids and cholesterol (r = 0.63), free glycerol and free fatty acids (r = 0.55), total lipids and free fatty acids (r = 0.54), and triglycerides and free fatty acids (r = 0.50). Although all correlation coefficients were highly significant statistically (P less than 0.001), the very large standard errors precluded using any of these relationships to make clinical predictions. Problems and limitations of currently available techniques are discussed in order to provide a lead for further research.