Paramedian approach of the peridural space in obstetrics.

A retrospective study was carried out, in 1010 women during labour, to compare the midline and paramedian approaches to the peridural space. The success rate at the first attempt was slightly higher in the paramedian group (98%) than in the midline group (94.5%). The main reasons for failure were the inability of threading the catheter (34%) and the venous cannulation (24%); they are far more frequent via the median route. The incidence of paresthesias, while introducing the catheter, was definitely higher in the midline approach (48%) than in the paramedian one (24%).