Effects of epidural analgesia on plasma catecholamines and cortisol in parturition.

To assess the effect of epidural block on plasma catecholamines and cortisol during labour and delivery, plasma epinephrine, norepinephrine and cortisol levels were determined in 26 healthy parturients, all of whom delivered vaginally (18 received an epidural block, eight had meperidine 50 mg intramuscularly). We found a significant drop of plasma epinephrine and cortisol and no significant reduction of plasma norepinephrine 1 h after administration of epidural block compared to preblock values. Observing the data during the whole course of labour in correlation with cervical dilatation, in the control group, where the parturients received meperidine, all hormones rose progressively up to the moment of delivery. One hour after delivery the catecholamines returned to normal levels; cortisol returned more slowly. In the epidural group the increase of plasma epinephrine and cortisol was significantly inhibited but not that of norepinephrine.