[Acid-base balance in the newborn infant. II. 3 technics of sample collection and the difference between amniotomy].

The study included 32 healthy newborns to evaluate the acid-base balance between two groups of newborns whose mothers underwent early or late amniotomy. The results were compared to the first study finding important differences, unquestionable due to amniotomy and age. Significant difference was found only in PO2 between arterial blood and arterialized capillary showing difference in pH, PCO2 and CO2 between the two capillaries. With the criterion pointed out in this work, the usefulness of late amniotomy and the stabilization of acid-base balance is established in newborns under 4 hours of age. Arterial blood is still being proposed to obtain an "ideal" acid-base balance and the arterialized capillary as a practical and useful method.