BACKGROUND: Paresthesia is unpleasant for patients and more importantly, is related to neurological injury in some cases. There have been few studies comparing combined spinal-epidural anesthesia (CSE) techniques such as needle-through-needle technique (NTN) and double segment technique (DST) regarding the incidence of paresthesia.

METHODS: Eighty-four parturients undergoing CSE for an elective cesarean section were divided into NTN and DST groups. A CSE was performed using 27 G Sprotte needle, 18 G Tuohy needle and 20 G multiport catheter in both groups. In the NTN group, at L3-4 or L4-5, a spinal anesthesia was performed and then an epidural catheter was inserted through the same Tuohy needle. In the DST group, an epidural catheter was inserted at L1-2 or L2-3 and then a spinal anesthesia was done two interspaces caudally. Incidences of paresthesia with each procedure were recorded with block characteristics and adverse effects.

RESULTS: Overall frequency of paresthesia was higher in the NTN group (54.8% vs. 29.3%, P = 0.033). Incidences of intrathecal paresthesia were three times higher (21.4% vs. 7.3%, not significant) and epidural paresthesia was significantly higher (45.2% vs. 22%, P = 0.044) in the NTN group. Sensory and motor block characteristics and side effects were mostly comparable between the groups.

CONCLUSIONS: Double-segment technique shows less incidence of overall paresthesia compared to needle-through-needle.