Spinal and epidural versus general anesthesia for elective cesarean section at term: effect on the acid-base status of the mother and newborn

Abstract

Objective: To compare general, epidural and combined spinal-epidural anesthesia with respect to short-term outcome of newborns delivered by elective Cesarean section of healthy parturients with normal pregnancies.

Study design: A total of 238 eight pregnant women admitted to our institution between January 1998 and July 2002, for whom elective Cesarean section was planned after 38 weeks' gestation, were grouped according to the kind of anesthesia used for the procedure. Maternal characteristics, birth weight, Apgar scores, and maternal and umbilical artery (UA) acid-base parameters were analyzed.

Results: Maternal pH was significantly lower and pCO2: and pO2 were significantly higher in the general anesthetic group, compared to the other two groups (7.38 +/- 0.03 vs. 7.43 +/- 0.02 and 7.43 +/- 0.05, respectively; 35.03 +/- 3.88 mmHg vs. 29.25 +/- 5.05 mmHg and 29.64 +/- 4.16 mmHg, respectively; and 224.56 +/- 86.77 mmHg vs. 151.28 +/- 38 mmHg and 157.36 +/- 53.51 mmHg, respectively, p < 0.05). The pH of the UA was higher in the general anesthetic group, compared to the spinal-epidural group (7.29 +/- 0.02 vs. 7.26 +/- 0.06, p < 0.05). The pO2 as well as O2 saturation of the UA were higher when general anesthetic was administered, compared to the two regional modalities (15.60 +/- 5.48 mmHg vs. 9.29 +/- 4.41 mmHg and 9.20 +/- 4.06 mmHg, respectively; and 17.37 +/- 9.79% vs. 7.87 +/- 4.98% and 6.90 +/- 5.22%, respectively, p < 0.05). UA O2 saturation fell to zero in some cases in the combined spinal-epidural group, without an evident effect on fetal well-being. No fetal acidemia was noted in any group. Neonatal outcomes were similar in the three groups studied.

Conclusions: Type of anesthesia does not influence short-term outcomes in infants born via elective Cesarean section, although differences in acid-base status of both the mother and especially the newborn recommend careful use of spinal anesthesia.