Low-dose combined spinal-epidural anaesthesia vs. conventional epidural anaesthesia for Caesarean section in pre-eclampsia: a retrospective analysis.

BACKGROUND AND OBJECTIVE: Epidural anaesthesia is the preferred technique of anaesthesia for Caesarean section in pre-eclampsia. Spinal anaesthesia is considered by some as a safe and effective alternative, which is especially useful in emergency situations. Combined spinal-epidural anaesthesia, using low doses of local anaesthetics with opioids, is effective and reduces the incidence of hypotension in normal pregnancy. We performed a retrospective chart analysis to evaluate the effects of combined spinal-epidural anaesthesia on maternal haemodynamics and fetal outcome compared to conventional epidural anaesthesia.

METHODS: A retrospective anaesthesia chart analysis of all pre-eclamptic patients who underwent Caesarean section over a 4 yr period was performed. Patient characteristic, obstetric, haemodynamic, fetal and neonatal data were gathered and analysed according to the anaesthetic technique used.

RESULTS: Seventy-seven pre-eclamptic parturients undergoing Caesarean section were identified (26 women were severely pre-eclamptic and 51 demonstrated mild pre-eclampsia). Epidural anaesthesia was performed in 62 patients and combined spinal-epidural anaesthesia was performed in 15. No differences in patient characteristic and obstetric data were noted. Highest mean arterial pressure prior to anaesthesia was comparable between the groups (epidural: 106 +/- 12 vs. combined spinal-epidural anaesthesia: 109 +/- 18 mmHg) as well as the lowest recorded mean arterial pressure following anaesthesia (epidural: 93 +/- 13 vs. combined spinal-epidural anaesthesia: 98 +/- 17 mmHg). In the combined spinal-epidural anaesthesia group more ephedrine was used compared to the epidural group (14.6 +/- 4.4 vs. 3.6 +/- 4.6 mg, P < 0.05). However, more lactated Ringer's was used in the epidural group. Umbilical artery pH was lower in the epidural group (7.26 +/- 0.01 vs. 7.29 +/- 0.02, P < 0.05). Similar results were noted in 26 severely pre-eclamptic patients. Seven women underwent combined spinal-epidural anaesthesia and 19 underwent epidural anaesthesia in the severely pre-eclamptic group. Also more ephedrine was used in the combined spinal-epidural anaesthesia group. A tendency towards a lower umbilical artery pH was observed in the epidural group but this difference did not reach statistical significance.

CONCLUSIONS: Combined spinal-epidural anaesthesia appears to be safe as anaesthetic technique for pre-eclampsia and severe pre-eclampsia. However, it is important to consider the retrospective design of the study and the large number of epidural anaesthetics performed.