MATERNAL CARDIOVASCULAR DYNAMICS III. LABOR AND DELIVERY UNDER LOCAL AND CAUDAL ANALGESIA

Maternal hemodynamic changes were evaluated in 23 normal patients who underwent induction of labor at term. Ten patients received paracervical and pudendal block analgesia during labor and delivery. Thirteen patients were given caudal analgesia. The latter modified some of the cardiovascular responses by preventing an accumulative increase in cardiac output during labor and limiting the absolute increase in cardiac output at delivery. The type of analgesia, however, did not modify the hemodynamic effects of uterine contractions or maternal posture. The magnitude of the maternal cardiovascular response was similar to changes in posture from supine to side, to uterine contractions, and to delivery, suggesting that the redistribution of blood volume was the common etiologic factor.