Epidural catheter insertion: the effect of saline prior to threading in non-obstetric patients

The effects of injecting normal saline 4 ml through the epidural needle before catheter passage on ease of catheterisation and incidence of certain complications were investigated in 189 non-obstetric patients. The use of saline had no effect on ease of catheterisation, with 84.2% of Group S patients (saline, n = 95) and 88.3% of Group C patients (control, n = 94) having the difficulty of passing the catheter rated as "easy" (P = 0.31). The incidence of complications was not affected by the use of saline. Paraesthesia occurred in 27.4% of Group S patients compared with 16.0% of Group C patients (P = 0.08). Epidural venous cannulation occurred in 6.3% of Group S patients versus 11.7% of Group C patients (P = 0.30). We conclude that the use of 5 ml of normal saline prior to catheter threading provides no significant benefit in improving the ease of catheterisation or decreasing the incidence of catheter complications.