[Speed of intestinal passage and water content of feces in premature and full-term infants following exposure to phototherapy]. / Velocidad de tránsito intestinal y contenido de agua en las heces de recién nacidos pretérmino y a término expuestos a fototerapia

Fifty-one newborn infants were divided into five groups and were studied according to gestational age, hyperbilirubinemia and phototherapy. In each group, the speed of intestinal passage and content of water in feces was evaluated in terms of the variables mentioned. It was shown that neither hyperbilirubinemia nor phototherapy affect the content of water in feces, nor the speed of intestinal passage in pre-term infants. The same results were true for hyperbilirubinemia in full term infants in whom it was not possible to demonstrate the effect of phototherapy. Full term infants showed a greater content of water in feces and a higher speed of intestinal passage as compared with pre-term infants. This was possibly the result of different body weight due to a different gestational age.

[Renal response to intravenous administration of sodium bicarbonate in newborn infants of different gestational ages]. / Respuesta renal de recién nacidos de distinta edad gestacional, a la administración endovenosa de bicarbonato de sodio

The study comprised a series of 16 neonates made up of 5 patients of 33 weeks of gestation, 5 infants of 35 weeks and 6 more of 40 weeks of gestation. Blood pH, PaCO2 and HCO3- were measured together with bicarbonate, ammonium, titrable acidity and hydrogen ions in urine before and after intravenous infusion of sodium bicarbonate. Before infusion of bicarbonate, titrable acidity, ammonium and net acidity in urine were higher in accordance with a greater gestational age. As the administration of bicarbonate elapsed, titrable acidity, ammonium and net acidity dropped with increase in concentration of bicarbonate. A hypothesis is set forth that the differences found in the factors evaluated in urine before administration of bicarbonate depend on the physiologic characteristics set in the newborn by gestational age.

[Effect of minimal doses of phenobarbital on bilirubinemia in the newborn infant]. / Efecto de dosis mínimas de fenobarbital sobre la bilirrubinemia del neonato

To evaluate the effect of lower than usual doses of phenobarbital on prevention of hyperbilirubinemia in the neonate, a study was carried out in neonates with subnormal weight and of similar characteristics regarding gestational age, intrauterine growth, absence of pathology, type and amount of milk formula ingested and values for indirect serum bilirubin previous to the initiation of the administration of phenobarbital on their second day of life; they were separate at random into three groups according to the dose of phenobarbital given (1 mg, 3 mg and 5 mg per kilo and per day, respectively) and were numerically distributed in similar manner. In all groups, serum indirect bilirubin rate was confirmed to be practically the same; the differences did not show statistical significance from the 2nd to the 6th day of life, when the study was done. As preventive of neonatal hyperbilirubinemia, the drug is efficient at doses as low as 1 mg/kg/day. It is believed that similar responses with different low doses of phenobarbital is due to the fact that the drug enzymatic induction phenomenon is brought forward, even at minimal doses, such as has been demonstrated through experiences in animals where the effect is produced even with doses of micrograms per kilogram of weight.