Frank Moya

INFLUENCE OF MATERNAL HYPERVENTILATION ON THE NEWBORN INFANT.

Abstract Moderate controlled hyperventilation during cesarean section can cause the fetus to have slightly less acidosis at birth. However, if maternal P CO 2 is lowered below 17 mm. Hg, the infant is likely to have severe acidosis and delayed onset of respiration. Although hyperventilation was not always accompanied by maternal alkalosis in this study, 1 of the two mothers with the most alkalosis belonged to the group in which the anesthesiologist was attempting to maintain a normal level of ventilation. There is danger not for the conscious patient hyperventilating voluntarily, but for the unconscious patient who undergoes artificial ventilation after receiving muscle relaxants. Considerable caution should be exercised, therefore, in the ventilation of pregnant women who undergo cesarean section when muscle relaxants are being used; willful overventilation should be avoided.

Effects of meperidine on the newborn infant

Abstract 1.1. In order to investigate the effect of meperidine on the condition of the newborn infant, a highly selected group of mothers was studied in which all other factors known to cause depression were eliminated. In this manner the effects of intramuscular doses of meperidine with or without barbiturates were studied and correlated with the time of administration. 2.2. In the control series of mothers who received no medication 5.7 per cent of the infants had low Apgar scores and 4.8 per cent had T.S.R. of 90 seconds or more. 3.3. In all groups of mothers who received medication when the drugs were given within 1 hour of birth, there was no statistically significant difference in the incidence of depressed babies when compared to those from the control series. However, there was a significant increase in the percentage of depressed babies born during the second hour after drug administration. This was true even if mothers had received only 50 mg. of meperidine. Increased doses tended to prolong the period in which significant neonatal depression was observed. 4.4. The addition of a barbiturate not only prolonged the period but also increased the percentage of neonatal depression. 5.5. It was concluded that even small doses of meperidine given intramuscularly to the mother can significantly depress the newborn infant, and that the time interval between administration and delivery is important for determination of the degree of neonatal depression.

Adverse effects of maternal hypocapnea on the newborn guinea pig

Abstract 1. The influence of severe maternal respiratory alkalosis upon the acid-base status of the newborn guinea pig was investigated. 2. Maternal hyperventilation produced fetal acidosis and affected adversely the clinical status of the newborn, when maternal arterial pH exceeded 7.5.