Prospective, randomized trial comparing general with spinal anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace.
BACKGROUND
There are no randomized studies on neonatal outcome after spinal versus general anesthesia for cesarean delivery in preeclamptic patients with a nonreassuring fetal heart trace. This study examined both markers of neonatal hypoxia and maternal hemodynamics.


METHODS
Seventy patients were randomized to general (n = 35) or spinal anesthesia (n = 35). The general anesthesia group received thiopentone, magnesium sulfate, and suxamethonium intravenously before intubation, followed by 50% nitrous oxide in oxygen, 0.75-1.5% isoflurane, and morphine after delivery. The target end-tidal partial pressure of carbon dioxide (Pco2) was 30-34 mmHg. The spinal anesthesia group received 1.8 ml hyperbaric bupivacaine plus 10 microg fentanyl at the L3-L4 interspace. Heart rate and blood pressure were measured at specific time points. Hypotension was treated with ephedrine. Maternal arterial and neonatal umbilical arterial blood gas samples were taken at delivery. Resuscitation requirements were recorded.


RESULTS
In both groups, hemodynamic measures remained within acceptable limits. Spinal anesthesia patients required more ephedrine (13.7 vs. 2.7 mg). Maternal Paco2 was lower in the spinal group (28.9 vs. 32.4 mmHg). One-minute Apgar scores were lower after general anesthesia. Base deficit was greater (7.13 vs. 4.68 mEq/l) and neonatal umbilical arterial pH was lower (7.20 vs. 7.23) after spinal anesthesia. Post hoc analysis showed that if maternal diastolic blood pressure on admission was greater than 110 mmHg, neonatal umbilical arterial base deficit was greater after spinal anesthesia. There was no difference in the number of patients with Apgar scores less than 7 at 1 or 5 min or umbilical arterial pH less than 7.2 or in the requirements for resuscitation.


CONCLUSIONS
In preeclamptic patients with a nonreassuring fetal heart trace, spinal anesthesia for cesarean delivery was associated with a greater mean neonatal umbilical arterial base deficit and a lower median umbilical arterial pH. The clinical significance remains to be established. Maternal hemodynamics were similar and acceptable with either anesthetic technique.
Dyer
Robert A
RA
Department of Anesthesia, University of Cape Town and New Groote Schuur Hospital, Cape Town, South Africa. dyer@cormack.uct.ac.za
Els
Ilse
I
Farbas
Josef
J
Torr
Gregory J
GJ
Schoeman
Leann K
LK
James
Michael F
MF
D000328:Adult; D000768:Anesthesia, General; D000775:Anesthesia, Spinal; D001034:Apgar Score; D001784:Blood Gas Analysis; D002585:Cesarean Section; D004569:Electroencephalography; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005318:Fetal Heart / Q000502:physiology*; D005311:Fetal Hypoxia / Q000175:diagnosis / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D011225:Pre-Eclampsia / Q000150:complications*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies